https://github.com/obgm/libcoap
Tip revision: 4cab59dbbf3048e44220ff2e7d6b36284b3ef131 authored by Olaf Bergmann on 18 March 2021, 13:51:57 UTC
configure.ac: bounce version number to v4.3.0rc1
configure.ac: bounce version number to v4.3.0rc1
Tip revision: 4cab59d
coap_openssl.c
/*
* coap_openssl.c -- Datagram Transport Layer Support for libcoap with openssl
*
* Copyright (C) 2017 Jean-Claude Michelou <jcm@spinetix.com>
* Copyright (C) 2018 Jon Shallow <supjps-libcoap@jpshallow.com>
*
* This file is part of the CoAP library libcoap. Please see README for terms
* of use.
*/
#include "coap2/coap_internal.h"
#ifdef HAVE_OPENSSL
/*
* OpenSSL 1.1.0 has support for making decisions during receipt of
* the Client Hello - the call back function is set up using
* SSL_CTX_set_tlsext_servername_callback() which is called later in the
* Client Hello processing - but called every Client Hello.
* Certificates and Preshared Keys have to be set up in the SSL CTX before
* SSL_accept() is called, making the code messy to decide whether this is a
* PKI or PSK incoming request to handle things accordingly if both are
* defined. SNI has to create a new SSL CTX to handle different server names
* with different crtificates.
*
* OpenSSL 1.1.1 introduces a new function SSL_CTX_set_client_hello_cb().
* The call back is invoked early on in the Client Hello processing giving
* the ability to easily use different Preshared Keys, Certificates etc.
* Certificates do not have to be set up in the SSL CTX before SSL_Accept is
* called.
* Later in the Client Hello code, the callback for
* SSL_CTX_set_tlsext_servername_callback() is still called, but only if SNI
* is being used by the client, so cannot be used for doing things the
* OpenSSL 1.1.0 way.
*
* OpenSSL 1.1.1 supports TLS1.3.
*
* Consequently, this code has to have compile time options to include /
* exclude code based on whether compiled against 1.1.0 or 1.1.1, as well as
* have additional run time checks.
*
* It is possible to override the Ciphers, define the Algorithms or Groups
* to use for the SSL negotiations at compile time. This is done by the adding
* of the appropriate -D option to the CPPFLAGS parameter that is used on the
* ./configure command line.
* E.g. ./configure CPPFLAGS="-DXX=\"YY\" -DUU=\"VV\""
* The parameter value is case-sensitive.
*
* The ciphers can be overridden with (example)
* -DCOAP_OPENSSL_CIPHERS=\"ECDHE-ECDSA-AES256-GCM-SHA384\"
*
* The Algorithms can be defined by (example)
* -DCOAP_OPENSSL_SIGALGS=\"ed25519\"
*
* The Groups (OpenSSL 1.1.1 or later) can be defined by (example)
* -DCOAP_OPENSSL_GROUPS=\"X25519\"
*
*/
#include <openssl/ssl.h>
#include <openssl/engine.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/hmac.h>
#include <openssl/x509v3.h>
#ifdef COAP_EPOLL_SUPPORT
# include <sys/epoll.h>
#endif /* COAP_EPOLL_SUPPORT */
#if OPENSSL_VERSION_NUMBER < 0x10100000L
#error Must be compiled against OpenSSL 1.1.0 or later
#endif
#ifdef _WIN32
#define strcasecmp _stricmp
#define strncasecmp _strnicmp
#endif
/* RFC6091/RFC7250 */
#ifndef TLSEXT_TYPE_client_certificate_type
#define TLSEXT_TYPE_client_certificate_type 19
#endif
#ifndef TLSEXT_TYPE_server_certificate_type
#define TLSEXT_TYPE_server_certificate_type 20
#endif
#ifndef COAP_OPENSSL_CIPHERS
#if OPENSSL_VERSION_NUMBER >= 0x10101000L
#define COAP_OPENSSL_CIPHERS "TLSv1.3:TLSv1.2:!NULL"
#else /* OPENSSL_VERSION_NUMBER < 0x10101000L */
#define COAP_OPENSSL_CIPHERS "TLSv1.2:!NULL"
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
#endif /*COAP_OPENSSL_CIPHERS */
#ifndef COAP_OPENSSL_PSK_CIPHERS
#define COAP_OPENSSL_PSK_CIPHERS "PSK:!NULL"
#endif /*COAP_OPENSSL_PSK_CIPHERS */
/* This structure encapsulates the OpenSSL context object. */
typedef struct coap_dtls_context_t {
SSL_CTX *ctx;
SSL *ssl; /* OpenSSL object for listening to connection requests */
HMAC_CTX *cookie_hmac;
BIO_METHOD *meth;
BIO_ADDR *bio_addr;
} coap_dtls_context_t;
typedef struct coap_tls_context_t {
SSL_CTX *ctx;
BIO_METHOD *meth;
} coap_tls_context_t;
#define IS_PSK 0x1
#define IS_PKI 0x2
typedef struct sni_entry {
char *sni;
#if OPENSSL_VERSION_NUMBER < 0x10101000L
SSL_CTX *ctx;
#else /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
coap_dtls_key_t pki_key;
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
} sni_entry;
typedef struct psk_sni_entry {
char *sni;
#if OPENSSL_VERSION_NUMBER < 0x10101000L
SSL_CTX *ctx;
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
coap_dtls_spsk_info_t psk_info;
} psk_sni_entry;
typedef struct coap_openssl_context_t {
coap_dtls_context_t dtls;
#if !COAP_DISABLE_TCP
coap_tls_context_t tls;
#endif /* !COAP_DISABLE_TCP */
coap_dtls_pki_t setup_data;
int psk_pki_enabled;
size_t sni_count;
sni_entry *sni_entry_list;
size_t psk_sni_count;
psk_sni_entry *psk_sni_entry_list;
} coap_openssl_context_t;
#if OPENSSL_VERSION_NUMBER < 0x10101000L
static int psk_tls_server_name_call_back(SSL *ssl, int *sd, void *arg);
#else /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
static int psk_tls_client_hello_call_back(SSL *ssl, int *al, void *arg);
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
int coap_dtls_is_supported(void) {
if (SSLeay() < 0x10100000L) {
coap_log(LOG_WARNING, "OpenSSL version 1.1.0 or later is required\n");
return 0;
}
#if OPENSSL_VERSION_NUMBER >= 0x10101000L
/*
* For 1.1.1, we need to use SSL_CTX_set_client_hello_cb()
* which is not in 1.1.0 instead of SSL_CTX_set_tlsext_servername_callback()
*
* However, there could be a runtime undefined external reference error
* as SSL_CTX_set_client_hello_cb() is not there in 1.1.0.
*/
if (SSLeay() < 0x10101000L) {
coap_log(LOG_WARNING, "OpenSSL version 1.1.1 or later is required\n");
return 0;
}
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
return 1;
}
int coap_tls_is_supported(void) {
#if !COAP_DISABLE_TCP
if (SSLeay() < 0x10100000L) {
coap_log(LOG_WARNING, "OpenSSL version 1.1.0 or later is required\n");
return 0;
}
#if OPENSSL_VERSION_NUMBER >= 0x10101000L
if (SSLeay() < 0x10101000L) {
coap_log(LOG_WARNING, "OpenSSL version 1.1.1 or later is required\n");
return 0;
}
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
return 1;
#else /* COAP_DISABLE_TCP */
return 0;
#endif /* COAP_DISABLE_TCP */
}
coap_tls_version_t *
coap_get_tls_library_version(void) {
static coap_tls_version_t version;
version.version = SSLeay();
version.built_version = OPENSSL_VERSION_NUMBER;
version.type = COAP_TLS_LIBRARY_OPENSSL;
return &version;
}
static ENGINE* ssl_engine = NULL;
void coap_dtls_startup(void) {
SSL_load_error_strings();
SSL_library_init();
ENGINE_load_dynamic();
}
void coap_dtls_shutdown(void) {
if (ssl_engine) {
/* Release the functional reference from ENGINE_init() */
ENGINE_finish(ssl_engine);
/* Release the structural reference from ENGINE_by_id() */
ENGINE_free(ssl_engine);
ssl_engine = NULL;
}
}
static int dtls_log_level = 0;
void coap_dtls_set_log_level(int level) {
dtls_log_level = level;
}
int coap_dtls_get_log_level(void) {
return dtls_log_level;
}
typedef struct coap_ssl_st {
coap_session_t *session;
const void *pdu;
unsigned pdu_len;
unsigned peekmode;
coap_tick_t timeout;
} coap_ssl_data;
static int coap_dgram_create(BIO *a) {
coap_ssl_data *data = NULL;
data = malloc(sizeof(coap_ssl_data));
if (data == NULL)
return 0;
BIO_set_init(a, 1);
BIO_set_data(a, data);
memset(data, 0x00, sizeof(coap_ssl_data));
return 1;
}
static int coap_dgram_destroy(BIO *a) {
coap_ssl_data *data;
if (a == NULL)
return 0;
data = (coap_ssl_data *)BIO_get_data(a);
if (data != NULL)
free(data);
return 1;
}
static int coap_dgram_read(BIO *a, char *out, int outl) {
int ret = 0;
coap_ssl_data *data = (coap_ssl_data *)BIO_get_data(a);
if (out != NULL) {
if (data != NULL && data->pdu_len > 0) {
if (outl < (int)data->pdu_len) {
memcpy(out, data->pdu, outl);
ret = outl;
} else {
memcpy(out, data->pdu, data->pdu_len);
ret = (int)data->pdu_len;
}
if (!data->peekmode) {
data->pdu_len = 0;
data->pdu = NULL;
}
} else {
ret = -1;
}
BIO_clear_retry_flags(a);
if (ret < 0)
BIO_set_retry_read(a);
}
return ret;
}
static int coap_dgram_write(BIO *a, const char *in, int inl) {
int ret = 0;
coap_ssl_data *data = (coap_ssl_data *)BIO_get_data(a);
if (data->session) {
if (data->session->sock.flags == COAP_SOCKET_EMPTY && data->session->endpoint == NULL) {
/* socket was closed on client due to error */
BIO_clear_retry_flags(a);
return -1;
}
ret = (int)coap_session_send(data->session, (const uint8_t *)in, (size_t)inl);
BIO_clear_retry_flags(a);
if (ret <= 0)
BIO_set_retry_write(a);
} else {
BIO_clear_retry_flags(a);
ret = -1;
}
return ret;
}
static int coap_dgram_puts(BIO *a, const char *pstr) {
return coap_dgram_write(a, pstr, (int)strlen(pstr));
}
static long coap_dgram_ctrl(BIO *a, int cmd, long num, void *ptr) {
long ret = 1;
coap_ssl_data *data = BIO_get_data(a);
(void)ptr;
switch (cmd) {
case BIO_CTRL_GET_CLOSE:
ret = BIO_get_shutdown(a);
break;
case BIO_CTRL_SET_CLOSE:
BIO_set_shutdown(a, (int)num);
ret = 1;
break;
case BIO_CTRL_DGRAM_SET_PEEK_MODE:
data->peekmode = (unsigned)num;
break;
case BIO_CTRL_DGRAM_CONNECT:
case BIO_C_SET_FD:
case BIO_C_GET_FD:
case BIO_CTRL_DGRAM_SET_DONT_FRAG:
case BIO_CTRL_DGRAM_GET_MTU:
case BIO_CTRL_DGRAM_SET_MTU:
case BIO_CTRL_DGRAM_QUERY_MTU:
case BIO_CTRL_DGRAM_GET_FALLBACK_MTU:
ret = -1;
break;
case BIO_CTRL_DUP:
case BIO_CTRL_FLUSH:
case BIO_CTRL_DGRAM_MTU_DISCOVER:
case BIO_CTRL_DGRAM_SET_CONNECTED:
ret = 1;
break;
case BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT:
data->timeout = coap_ticks_from_rt_us((uint64_t)((struct timeval*)ptr)->tv_sec * 1000000 + ((struct timeval*)ptr)->tv_usec);
ret = 1;
break;
case BIO_CTRL_RESET:
case BIO_C_FILE_SEEK:
case BIO_C_FILE_TELL:
case BIO_CTRL_INFO:
case BIO_CTRL_PENDING:
case BIO_CTRL_WPENDING:
case BIO_CTRL_DGRAM_GET_PEER:
case BIO_CTRL_DGRAM_SET_PEER:
case BIO_CTRL_DGRAM_SET_RECV_TIMEOUT:
case BIO_CTRL_DGRAM_GET_RECV_TIMEOUT:
case BIO_CTRL_DGRAM_SET_SEND_TIMEOUT:
case BIO_CTRL_DGRAM_GET_SEND_TIMEOUT:
case BIO_CTRL_DGRAM_GET_SEND_TIMER_EXP:
case BIO_CTRL_DGRAM_GET_RECV_TIMER_EXP:
case BIO_CTRL_DGRAM_MTU_EXCEEDED:
case BIO_CTRL_DGRAM_GET_MTU_OVERHEAD:
default:
ret = 0;
break;
}
return ret;
}
static int
coap_dtls_generate_cookie(SSL *ssl,
unsigned char *cookie,
unsigned int *cookie_len) {
coap_dtls_context_t *dtls =
(coap_dtls_context_t *)SSL_CTX_get_app_data(SSL_get_SSL_CTX(ssl));
coap_ssl_data *data = (coap_ssl_data*)BIO_get_data(SSL_get_rbio(ssl));
int r = HMAC_Init_ex(dtls->cookie_hmac, NULL, 0, NULL, NULL);
r &= HMAC_Update(dtls->cookie_hmac,
(const uint8_t*)&data->session->addr_info.local.addr,
(size_t)data->session->addr_info.local.size);
r &= HMAC_Update(dtls->cookie_hmac,
(const uint8_t*)&data->session->addr_info.remote.addr,
(size_t)data->session->addr_info.remote.size);
r &= HMAC_Final(dtls->cookie_hmac, cookie, cookie_len);
return r;
}
static int
coap_dtls_verify_cookie(SSL *ssl,
const uint8_t *cookie,
unsigned int cookie_len) {
uint8_t hmac[32];
unsigned len = 32;
if (coap_dtls_generate_cookie(ssl, hmac, &len) &&
cookie_len == len && memcmp(cookie, hmac, len) == 0)
return 1;
else
return 0;
}
static unsigned int
coap_dtls_psk_client_callback(
SSL *ssl,
const char *hint,
char *identity,
unsigned int max_identity_len,
unsigned char *psk,
unsigned int max_psk_len
) {
size_t hint_len = 0, identity_len = 0, psk_len;
coap_session_t *c_session;
coap_openssl_context_t *o_context;
coap_dtls_cpsk_t *setup_data;
c_session = (coap_session_t*)SSL_get_app_data(ssl);
if (c_session == NULL || c_session->context == NULL ||
c_session->context->get_client_psk == NULL)
return 0;
o_context = (coap_openssl_context_t *)c_session->context->dtls_context;
if (o_context == NULL)
return 0;
setup_data = &c_session->cpsk_setup_data;
if (c_session->psk_hint) {
coap_delete_bin_const(c_session->psk_hint);
c_session->psk_hint = NULL;
}
if (hint) {
hint_len = strlen(hint);
c_session->psk_hint = coap_new_bin_const((const uint8_t *)hint, hint_len);
}
else
hint = "";
coap_log(LOG_DEBUG, "got psk_identity_hint: '%.*s'\n", (int)hint_len, hint);
if (setup_data->validate_ih_call_back) {
coap_str_const_t lhint;
lhint.length = hint_len;
lhint.s = (const uint8_t*)hint;
const coap_dtls_cpsk_info_t *psk_info =
setup_data->validate_ih_call_back(&lhint,
c_session,
setup_data->ih_call_back_arg);
if (psk_info == NULL)
return 0;
if (psk_info->identity.length >= max_identity_len)
return 0;
if (psk_info->key.length > max_psk_len)
return 0;
if (c_session->psk_identity) {
coap_delete_bin_const(c_session->psk_identity);
}
identity_len = psk_info->identity.length;
c_session->psk_identity = coap_new_bin_const(psk_info->identity.s, identity_len);
memcpy(identity, psk_info->identity.s, identity_len);
identity[identity_len] = '\000';
if (c_session->psk_key) {
coap_delete_bin_const(c_session->psk_key);
}
psk_len = psk_info->key.length;
c_session->psk_key = coap_new_bin_const(psk_info->key.s, psk_len);
memcpy(psk, psk_info->key.s, psk_len);
return (unsigned int)psk_len;
}
psk_len = c_session->context->get_client_psk(c_session,
(const uint8_t*)hint,
hint_len,
(uint8_t*)identity,
&identity_len,
max_identity_len - 1,
(uint8_t*)psk, max_psk_len);
if (identity_len < max_identity_len)
identity[identity_len] = 0;
return (unsigned)psk_len;
}
static unsigned int
coap_dtls_psk_server_callback(
SSL *ssl,
const char *identity,
unsigned char *psk,
unsigned int max_psk_len
) {
size_t identity_len = 0;
coap_session_t *c_session;
coap_dtls_spsk_t *setup_data;
c_session = (coap_session_t*)SSL_get_app_data(ssl);
if (c_session == NULL || c_session->context == NULL ||
c_session->context->get_server_psk == NULL)
return 0;
setup_data = &c_session->context->spsk_setup_data;
if (identity)
identity_len = strlen(identity);
else
identity = "";
/* Track the Identity being used */
if (c_session->psk_identity)
coap_delete_bin_const(c_session->psk_identity);
c_session->psk_identity = coap_new_bin_const((const uint8_t *)identity,
identity_len);
coap_log(LOG_DEBUG, "got psk_identity: '%.*s'\n",
(int)identity_len, identity);
if (setup_data->validate_id_call_back) {
coap_bin_const_t lidentity;
lidentity.length = identity_len;
lidentity.s = (const uint8_t*)identity;
const coap_bin_const_t *psk_key =
setup_data->validate_id_call_back(&lidentity,
c_session,
setup_data->id_call_back_arg);
if (psk_key == NULL)
return 0;
if (psk_key->length > max_psk_len)
return 0;
memcpy(psk, psk_key->s, psk_key->length);
coap_session_refresh_psk_key(c_session, psk_key);
return (unsigned int)psk_key->length;
}
return (unsigned)c_session->context->get_server_psk(c_session,
(const uint8_t*)identity,
identity_len,
(uint8_t*)psk,
max_psk_len);
}
static void coap_dtls_info_callback(const SSL *ssl, int where, int ret) {
coap_session_t *session = (coap_session_t*)SSL_get_app_data(ssl);
const char *pstr;
int w = where &~SSL_ST_MASK;
if (w & SSL_ST_CONNECT)
pstr = "SSL_connect";
else if (w & SSL_ST_ACCEPT)
pstr = "SSL_accept";
else
pstr = "undefined";
if (where & SSL_CB_LOOP) {
if (dtls_log_level >= LOG_DEBUG)
coap_log(LOG_DEBUG, "* %s: %s:%s\n",
coap_session_str(session), pstr, SSL_state_string_long(ssl));
} else if (where & SSL_CB_ALERT) {
int log_level = LOG_INFO;
pstr = (where & SSL_CB_READ) ? "read" : "write";
if ((where & (SSL_CB_WRITE|SSL_CB_READ)) && (ret >> 8) == SSL3_AL_FATAL) {
session->dtls_event = COAP_EVENT_DTLS_ERROR;
if ((ret & 0xff) != SSL3_AD_CLOSE_NOTIFY)
log_level = LOG_WARNING;
}
if (dtls_log_level >= log_level)
coap_log(log_level, "* %s: SSL3 alert %s:%s:%s\n",
coap_session_str(session),
pstr,
SSL_alert_type_string_long(ret),
SSL_alert_desc_string_long(ret));
} else if (where & SSL_CB_EXIT) {
if (ret == 0) {
if (dtls_log_level >= LOG_WARNING) {
unsigned long e;
coap_log(LOG_WARNING, "* %s: %s:failed in %s\n",
coap_session_str(session), pstr, SSL_state_string_long(ssl));
while ((e = ERR_get_error()))
coap_log(LOG_WARNING, "* %s: %s at %s:%s\n",
coap_session_str(session), ERR_reason_error_string(e),
ERR_lib_error_string(e), ERR_func_error_string(e));
}
} else if (ret < 0) {
if (dtls_log_level >= LOG_WARNING) {
int err = SSL_get_error(ssl, ret);
if (err != SSL_ERROR_WANT_READ && err != SSL_ERROR_WANT_WRITE && err != SSL_ERROR_WANT_CONNECT && err != SSL_ERROR_WANT_ACCEPT && err != SSL_ERROR_WANT_X509_LOOKUP) {
long e;
coap_log(LOG_WARNING, "* %s: %s:error in %s\n",
coap_session_str(session), pstr, SSL_state_string_long(ssl));
while ((e = ERR_get_error()))
coap_log(LOG_WARNING, "* %s: %s at %s:%s\n",
coap_session_str(session), ERR_reason_error_string(e),
ERR_lib_error_string(e), ERR_func_error_string(e));
}
}
}
}
if (where == SSL_CB_HANDSHAKE_START && SSL_get_state(ssl) == TLS_ST_OK)
session->dtls_event = COAP_EVENT_DTLS_RENEGOTIATE;
}
#if !COAP_DISABLE_TCP
static int coap_sock_create(BIO *a) {
BIO_set_init(a, 1);
return 1;
}
static int coap_sock_destroy(BIO *a) {
(void)a;
return 1;
}
static int coap_sock_read(BIO *a, char *out, int outl) {
int ret = 0;
coap_session_t *session = (coap_session_t *)BIO_get_data(a);
if (out != NULL) {
ret = (int)coap_socket_read(&session->sock, (uint8_t*)out, (size_t)outl);
if (ret == 0) {
BIO_set_retry_read(a);
ret = -1;
} else {
BIO_clear_retry_flags(a);
}
}
return ret;
}
static int coap_sock_write(BIO *a, const char *in, int inl) {
int ret = 0;
coap_session_t *session = (coap_session_t *)BIO_get_data(a);
ret = (int)coap_socket_write(&session->sock, (const uint8_t*)in, (size_t)inl);
BIO_clear_retry_flags(a);
if (ret == 0) {
BIO_set_retry_read(a);
ret = -1;
} else {
BIO_clear_retry_flags(a);
if (ret == -1) {
if ((session->state == COAP_SESSION_STATE_CSM ||
session->state == COAP_SESSION_STATE_HANDSHAKE) &&
(errno == EPIPE || errno == ECONNRESET)) {
/*
* Need to handle a TCP timing window where an agent continues with
* the sending of the next handshake or a CSM.
* However, the peer does not like a certificate and so sends a
* fatal alert and closes the TCP session.
* The sending of the next handshake or CSM may get terminated because
* of the closed TCP session, but there is still an outstanding alert
* to be read in and reported on.
* In this case, pretend that sending the info was fine so that the
* alert can be read (which effectively is what happens with DTLS).
*/
ret = inl;
}
else {
coap_log(LOG_DEBUG, "* %s: failed to send %d bytes (%s) state %d\n",
coap_session_str(session), inl, coap_socket_strerror(),
session->state);
}
}
}
return ret;
}
static int coap_sock_puts(BIO *a, const char *pstr) {
return coap_sock_write(a, pstr, (int)strlen(pstr));
}
static long coap_sock_ctrl(BIO *a, int cmd, long num, void *ptr) {
int r = 1;
(void)a;
(void)ptr;
(void)num;
switch (cmd) {
case BIO_C_SET_FD:
case BIO_C_GET_FD:
r = -1;
break;
case BIO_CTRL_SET_CLOSE:
case BIO_CTRL_DUP:
case BIO_CTRL_FLUSH:
r = 1;
break;
default:
case BIO_CTRL_GET_CLOSE:
r = 0;
break;
}
return r;
}
#endif /* !COAP_DISABLE_TCP */
static void coap_set_user_prefs(SSL_CTX *ctx) {
SSL_CTX_set_cipher_list(ctx, COAP_OPENSSL_CIPHERS);
#ifdef COAP_OPENSSL_SIGALGS
SSL_CTX_set1_sigalgs_list(ctx, COAP_OPENSSL_SIGALGS);
SSL_CTX_set1_client_sigalgs_list(ctx, COAP_OPENSSL_SIGALGS);
#endif
#if OPENSSL_VERSION_NUMBER >= 0x10101000L && defined(COAP_OPENSSL_GROUPS)
SSL_CTX_set1_groups_list(ctx, COAP_OPENSSL_GROUPS);
#endif
}
void *coap_dtls_new_context(struct coap_context_t *coap_context) {
coap_openssl_context_t *context;
(void)coap_context;
context = (coap_openssl_context_t *)coap_malloc(sizeof(coap_openssl_context_t));
if (context) {
uint8_t cookie_secret[32];
memset(context, 0, sizeof(coap_openssl_context_t));
/* Set up DTLS context */
context->dtls.ctx = SSL_CTX_new(DTLS_method());
if (!context->dtls.ctx)
goto error;
SSL_CTX_set_min_proto_version(context->dtls.ctx, DTLS1_2_VERSION);
SSL_CTX_set_app_data(context->dtls.ctx, &context->dtls);
SSL_CTX_set_read_ahead(context->dtls.ctx, 1);
coap_set_user_prefs(context->dtls.ctx);
memset(cookie_secret, 0, sizeof(cookie_secret));
if (!RAND_bytes(cookie_secret, (int)sizeof(cookie_secret))) {
if (dtls_log_level >= LOG_WARNING)
coap_log(LOG_WARNING,
"Insufficient entropy for random cookie generation");
coap_prng(cookie_secret, sizeof(cookie_secret));
}
context->dtls.cookie_hmac = HMAC_CTX_new();
if (!HMAC_Init_ex(context->dtls.cookie_hmac, cookie_secret, (int)sizeof(cookie_secret), EVP_sha256(), NULL))
goto error;
SSL_CTX_set_cookie_generate_cb(context->dtls.ctx, coap_dtls_generate_cookie);
SSL_CTX_set_cookie_verify_cb(context->dtls.ctx, coap_dtls_verify_cookie);
SSL_CTX_set_info_callback(context->dtls.ctx, coap_dtls_info_callback);
SSL_CTX_set_options(context->dtls.ctx, SSL_OP_NO_QUERY_MTU);
context->dtls.meth = BIO_meth_new(BIO_TYPE_DGRAM, "coapdgram");
if (!context->dtls.meth)
goto error;
context->dtls.bio_addr = BIO_ADDR_new();
if (!context->dtls.bio_addr)
goto error;
BIO_meth_set_write(context->dtls.meth, coap_dgram_write);
BIO_meth_set_read(context->dtls.meth, coap_dgram_read);
BIO_meth_set_puts(context->dtls.meth, coap_dgram_puts);
BIO_meth_set_ctrl(context->dtls.meth, coap_dgram_ctrl);
BIO_meth_set_create(context->dtls.meth, coap_dgram_create);
BIO_meth_set_destroy(context->dtls.meth, coap_dgram_destroy);
#if !COAP_DISABLE_TCP
/* Set up TLS context */
context->tls.ctx = SSL_CTX_new(TLS_method());
if (!context->tls.ctx)
goto error;
SSL_CTX_set_app_data(context->tls.ctx, &context->tls);
SSL_CTX_set_min_proto_version(context->tls.ctx, TLS1_VERSION);
coap_set_user_prefs(context->tls.ctx);
SSL_CTX_set_info_callback(context->tls.ctx, coap_dtls_info_callback);
context->tls.meth = BIO_meth_new(BIO_TYPE_SOCKET, "coapsock");
if (!context->tls.meth)
goto error;
BIO_meth_set_write(context->tls.meth, coap_sock_write);
BIO_meth_set_read(context->tls.meth, coap_sock_read);
BIO_meth_set_puts(context->tls.meth, coap_sock_puts);
BIO_meth_set_ctrl(context->tls.meth, coap_sock_ctrl);
BIO_meth_set_create(context->tls.meth, coap_sock_create);
BIO_meth_set_destroy(context->tls.meth, coap_sock_destroy);
#endif /* !COAP_DISABLE_TCP */
}
return context;
error:
coap_dtls_free_context(context);
return NULL;
}
int
coap_dtls_context_set_spsk(coap_context_t *c_context,
coap_dtls_spsk_t *setup_data
) {
coap_openssl_context_t *o_context =
((coap_openssl_context_t *)c_context->dtls_context);
BIO *bio;
if (!setup_data || !o_context)
return 0;
SSL_CTX_set_psk_server_callback(o_context->dtls.ctx,
coap_dtls_psk_server_callback);
#if !COAP_DISABLE_TCP
SSL_CTX_set_psk_server_callback(o_context->tls.ctx,
coap_dtls_psk_server_callback);
#endif /* !COAP_DISABLE_TCP */
if (setup_data->psk_info.hint.s) {
char hint[COAP_DTLS_HINT_LENGTH];
snprintf(hint, sizeof(hint), "%.*s", (int)setup_data->psk_info.hint.length,
setup_data->psk_info.hint.s);
SSL_CTX_use_psk_identity_hint(o_context->dtls.ctx, hint);
#if !COAP_DISABLE_TCP
SSL_CTX_use_psk_identity_hint(o_context->tls.ctx, hint);
#endif /* !COAP_DISABLE_TCP */
}
if (setup_data->validate_sni_call_back) {
#if OPENSSL_VERSION_NUMBER < 0x10101000L
SSL_CTX_set_tlsext_servername_arg(o_context->dtls.ctx,
&c_context->spsk_setup_data);
SSL_CTX_set_tlsext_servername_callback(o_context->dtls.ctx,
psk_tls_server_name_call_back);
#if !COAP_DISABLE_TCP
SSL_CTX_set_tlsext_servername_arg(o_context->tls.ctx,
&c_context->spsk_setup_data);
SSL_CTX_set_tlsext_servername_callback(o_context->tls.ctx,
psk_tls_server_name_call_back);
#endif /* !COAP_DISABLE_TCP */
#else /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
SSL_CTX_set_client_hello_cb(o_context->dtls.ctx,
psk_tls_client_hello_call_back,
NULL);
#if !COAP_DISABLE_TCP
SSL_CTX_set_client_hello_cb(o_context->tls.ctx,
psk_tls_client_hello_call_back,
NULL);
#endif /* !COAP_DISABLE_TCP */
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
}
if (!o_context->dtls.ssl) {
/* This is set up to handle new incoming sessions to a server */
o_context->dtls.ssl = SSL_new(o_context->dtls.ctx);
if (!o_context->dtls.ssl)
return 0;
bio = BIO_new(o_context->dtls.meth);
if (!bio) {
SSL_free (o_context->dtls.ssl);
o_context->dtls.ssl = NULL;
return 0;
}
SSL_set_bio(o_context->dtls.ssl, bio, bio);
SSL_set_app_data(o_context->dtls.ssl, NULL);
SSL_set_options(o_context->dtls.ssl, SSL_OP_COOKIE_EXCHANGE);
SSL_set_mtu(o_context->dtls.ssl, COAP_DEFAULT_MTU);
}
o_context->psk_pki_enabled |= IS_PSK;
return 1;
}
int
coap_dtls_context_set_cpsk(coap_context_t *c_context,
coap_dtls_cpsk_t *setup_data
) {
coap_openssl_context_t *o_context =
((coap_openssl_context_t *)c_context->dtls_context);
BIO *bio;
if (!setup_data || !o_context)
return 0;
if (!o_context->dtls.ssl) {
/* This is set up to handle new incoming sessions to a server */
o_context->dtls.ssl = SSL_new(o_context->dtls.ctx);
if (!o_context->dtls.ssl)
return 0;
bio = BIO_new(o_context->dtls.meth);
if (!bio) {
SSL_free (o_context->dtls.ssl);
o_context->dtls.ssl = NULL;
return 0;
}
SSL_set_bio(o_context->dtls.ssl, bio, bio);
SSL_set_app_data(o_context->dtls.ssl, NULL);
SSL_set_options(o_context->dtls.ssl, SSL_OP_COOKIE_EXCHANGE);
SSL_set_mtu(o_context->dtls.ssl, COAP_DEFAULT_MTU);
}
o_context->psk_pki_enabled |= IS_PSK;
return 1;
}
static int
map_key_type(int asn1_private_key_type
) {
switch (asn1_private_key_type) {
case COAP_ASN1_PKEY_NONE: return EVP_PKEY_NONE;
case COAP_ASN1_PKEY_RSA: return EVP_PKEY_RSA;
case COAP_ASN1_PKEY_RSA2: return EVP_PKEY_RSA2;
case COAP_ASN1_PKEY_DSA: return EVP_PKEY_DSA;
case COAP_ASN1_PKEY_DSA1: return EVP_PKEY_DSA1;
case COAP_ASN1_PKEY_DSA2: return EVP_PKEY_DSA2;
case COAP_ASN1_PKEY_DSA3: return EVP_PKEY_DSA3;
case COAP_ASN1_PKEY_DSA4: return EVP_PKEY_DSA4;
case COAP_ASN1_PKEY_DH: return EVP_PKEY_DH;
case COAP_ASN1_PKEY_DHX: return EVP_PKEY_DHX;
case COAP_ASN1_PKEY_EC: return EVP_PKEY_EC;
case COAP_ASN1_PKEY_HMAC: return EVP_PKEY_HMAC;
case COAP_ASN1_PKEY_CMAC: return EVP_PKEY_CMAC;
case COAP_ASN1_PKEY_TLS1_PRF: return EVP_PKEY_TLS1_PRF;
case COAP_ASN1_PKEY_HKDF: return EVP_PKEY_HKDF;
default:
coap_log(LOG_WARNING,
"*** setup_pki: DTLS: Unknown Private Key type %d for ASN1\n",
asn1_private_key_type);
break;
}
return 0;
}
#if !COAP_DISABLE_TCP
static uint8_t coap_alpn[] = { 4, 'c', 'o', 'a', 'p' };
static int
server_alpn_callback (SSL *ssl COAP_UNUSED,
const unsigned char **out,
unsigned char *outlen,
const unsigned char *in,
unsigned int inlen,
void *arg COAP_UNUSED
) {
unsigned char *tout = NULL;
int ret;
if (inlen == 0)
return SSL_TLSEXT_ERR_NOACK;
ret = SSL_select_next_proto(&tout,
outlen,
coap_alpn,
sizeof(coap_alpn),
in,
inlen);
*out = tout;
return (ret != OPENSSL_NPN_NEGOTIATED) ? SSL_TLSEXT_ERR_NOACK : SSL_TLSEXT_ERR_OK;
}
#endif /* !COAP_DISABLE_TCP */
static void
add_ca_to_cert_store(X509_STORE *st, X509 *x509)
{
long e;
/* Flush out existing errors */
while ((e = ERR_get_error()) != 0) {
}
if (!X509_STORE_add_cert(st, x509)) {
while ((e = ERR_get_error()) != 0) {
int r = ERR_GET_REASON(e);
if (r != X509_R_CERT_ALREADY_IN_HASH_TABLE) {
/* Not already added */
coap_log(LOG_WARNING, "***setup_pki: (D)TLS: %s at %s:%s\n",
ERR_reason_error_string(e),
ERR_lib_error_string(e),
ERR_func_error_string(e));
}
}
}
}
static X509 *
missing_ENGINE_load_cert (const char *cert_id)
{
struct {
const char *cert_id;
X509 *cert;
} params;
params.cert_id = cert_id;
params.cert = NULL;
/* There is no ENGINE_load_cert() */
if (!ENGINE_ctrl_cmd(ssl_engine, "LOAD_CERT_CTRL", 0, ¶ms, NULL, 1)) {
params.cert = NULL;
}
return params.cert;
}
#if OPENSSL_VERSION_NUMBER < 0x10101000L
static int
setup_pki_server(SSL_CTX *ctx,
const coap_dtls_pki_t* setup_data
) {
switch (setup_data->pki_key.key_type) {
case COAP_PKI_KEY_PEM:
if (setup_data->pki_key.key.pem.public_cert &&
setup_data->pki_key.key.pem.public_cert[0]) {
if (!(SSL_CTX_use_certificate_file(ctx,
setup_data->pki_key.key.pem.public_cert,
SSL_FILETYPE_PEM))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Certificate\n",
setup_data->pki_key.key.pem.public_cert);
return 0;
}
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Certificate defined\n");
return 0;
}
if (setup_data->pki_key.key.pem.private_key &&
setup_data->pki_key.key.pem.private_key[0]) {
if (!(SSL_CTX_use_PrivateKey_file(ctx,
setup_data->pki_key.key.pem.private_key,
SSL_FILETYPE_PEM))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Private Key\n",
setup_data->pki_key.key.pem.private_key);
return 0;
}
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Private Key defined\n");
return 0;
}
if (setup_data->check_common_ca && setup_data->pki_key.key.pem.ca_file &&
setup_data->pki_key.key.pem.ca_file[0]) {
STACK_OF(X509_NAME) *cert_names;
X509_STORE *st;
BIO *in;
X509 *x = NULL;
char *rw_var = NULL;
cert_names = SSL_load_client_CA_file(setup_data->pki_key.key.pem.ca_file);
if (cert_names != NULL)
SSL_CTX_set_client_CA_list(ctx, cert_names);
else {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"client CA File\n",
setup_data->pki_key.key.pem.ca_file);
return 0;
}
/* Add CA to the trusted root CA store */
st = SSL_CTX_get_cert_store(ctx);
in = BIO_new(BIO_s_file());
/* Need to do this to not get a compiler warning about const parameters */
memcpy(&rw_var, &setup_data->pki_key.key.pem.ca_file, sizeof (rw_var));
if (!BIO_read_filename(in, rw_var)) {
BIO_free(in);
X509_free(x);
break;
}
for (;;) {
if (PEM_read_bio_X509(in, &x, NULL, NULL) == NULL)
break;
add_ca_to_cert_store(st, x);
}
BIO_free(in);
X509_free(x);
}
break;
case COAP_PKI_KEY_PEM_BUF:
if (setup_data->pki_key.key.pem_buf.public_cert &&
setup_data->pki_key.key.pem_buf.public_cert_len) {
BIO *bp = BIO_new_mem_buf(setup_data->pki_key.key.pem_buf.public_cert,
setup_data->pki_key.key.pem_buf.public_cert_len);
X509 *cert = bp ? PEM_read_bio_X509(bp, NULL, 0, NULL) : NULL;
if (!cert || !SSL_CTX_use_certificate(ctx, cert)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: Unable to configure "
"Server PEM Certificate\n");
if (bp) BIO_free(bp);
if (cert) X509_free(cert);
return 0;
}
if (bp) BIO_free(bp);
if (cert) X509_free(cert);
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Certificate defined\n");
return 0;
}
if (setup_data->pki_key.key.pem_buf.private_key &&
setup_data->pki_key.key.pem_buf.private_key_len) {
BIO *bp = BIO_new_mem_buf(setup_data->pki_key.key.pem_buf.private_key,
setup_data->pki_key.key.pem_buf.private_key_len);
EVP_PKEY *pkey = bp ? PEM_read_bio_PrivateKey(bp, NULL, 0, NULL) : NULL;
if (!pkey || !SSL_CTX_use_PrivateKey(ctx, pkey)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: Unable to configure "
"Server PEM Private Key\n");
if (bp) BIO_free(bp);
if (pkey) EVP_PKEY_free(pkey);
return 0;
}
if (bp) BIO_free(bp);
if (pkey) EVP_PKEY_free(pkey);
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Private Key defined\n");
return 0;
}
if (setup_data->pki_key.key.pem_buf.ca_cert &&
setup_data->pki_key.key.pem_buf.ca_cert_len) {
BIO *bp = BIO_new_mem_buf(setup_data->pki_key.key.pem_buf.ca_cert,
setup_data->pki_key.key.pem_buf.ca_cert_len);
X509_STORE *st;
X509 *x;
st = SSL_CTX_get_cert_store(ctx);
if (bp) {
for (;;) {
if ((x = PEM_read_bio_X509(bp, NULL, NULL, NULL)) == NULL)
break;
add_ca_to_cert_store(st, x);
SSL_CTX_add_client_CA(ctx, x);
X509_free(x);
}
BIO_free(bp);
}
}
break;
case COAP_PKI_KEY_ASN1:
if (setup_data->pki_key.key.asn1.public_cert &&
setup_data->pki_key.key.asn1.public_cert_len > 0) {
if (!(SSL_CTX_use_certificate_ASN1(ctx,
setup_data->pki_key.key.asn1.public_cert_len,
setup_data->pki_key.key.asn1.public_cert))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Certificate\n",
"ASN1");
return 0;
}
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Certificate defined\n");
return 0;
}
if (setup_data->pki_key.key.asn1.private_key &&
setup_data->pki_key.key.asn1.private_key_len > 0) {
int pkey_type = map_key_type(setup_data->pki_key.key.asn1.private_key_type);
if (!(SSL_CTX_use_PrivateKey_ASN1(pkey_type, ctx,
setup_data->pki_key.key.asn1.private_key,
setup_data->pki_key.key.asn1.private_key_len))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Private Key\n",
"ASN1");
return 0;
}
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Private Key defined\n");
return 0;
}
if (setup_data->pki_key.key.asn1.ca_cert &&
setup_data->pki_key.key.asn1.ca_cert_len > 0) {
/* Need to use a temp variable as it gets incremented*/
const uint8_t *p = setup_data->pki_key.key.asn1.ca_cert;
X509* x509 = d2i_X509(NULL, &p, setup_data->pki_key.key.asn1.ca_cert_len);
X509_STORE *st;
if (!x509 || !SSL_CTX_add_client_CA(ctx, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"client CA File\n",
"ASN1");
if (x509) X509_free(x509);
return 0;
}
st = SSL_CTX_get_cert_store(ctx);
add_ca_to_cert_store(st, x509);
X509_free(x509);
}
break;
case COAP_PKI_KEY_PKCS11:
if (!ssl_engine) {
ssl_engine = ENGINE_by_id("pkcs11");
if (!ssl_engine) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No PKCS11 support\nn");
return 0;
}
if (!ENGINE_init(ssl_engine)) {
/* the engine couldn't initialise, release 'ssl_engine' */
ENGINE_free(ssl_engine);
ssl_engine = NULL;
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: PKCS11 engine initialize failed\n");
return 0;
}
}
if (setup_data->pki_key.key.pkcs11.user_pin) {
/* If not set, pin may be held in pkcs11: URI */
if (ENGINE_ctrl_cmd_string(ssl_engine, "PIN",
setup_data->pki_key.key.pkcs11.user_pin, 0) == 0) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: PKCS11: %s: Unable to set pin\n",
setup_data->pki_key.key.pkcs11.user_pin);
return 0;
}
}
if (setup_data->pki_key.key.pkcs11.private_key &&
setup_data->pki_key.key.pkcs11.private_key[0]) {
if (strncasecmp (setup_data->pki_key.key.pkcs11.private_key,
"pkcs11:", 7) == 0) {
EVP_PKEY* pkey = ENGINE_load_private_key(ssl_engine,
setup_data->pki_key.key.pkcs11.private_key,
NULL, NULL);
if (!pkey) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to load "
"Server Private Key\n",
setup_data->pki_key.key.pkcs11.private_key);
return 0;
}
if (!SSL_CTX_use_PrivateKey(ctx, pkey)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Private Key\n",
setup_data->pki_key.key.pkcs11.private_key);
EVP_PKEY_free(pkey);
return 0;
}
EVP_PKEY_free(pkey);
}
else {
if (!(SSL_CTX_use_PrivateKey_file(ctx,
setup_data->pki_key.key.pkcs11.private_key,
SSL_FILETYPE_ASN1))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Private Key\n",
setup_data->pki_key.key.pkcs11.private_key);
return 0;
}
}
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Private Key defined\n");
return 0;
}
if (setup_data->pki_key.key.pkcs11.public_cert &&
setup_data->pki_key.key.pkcs11.public_cert[0]) {
if (strncasecmp (setup_data->pki_key.key.pkcs11.public_cert,
"pkcs11:", 7) == 0) {
X509 *x509;
x509 = missing_ENGINE_load_cert(
setup_data->pki_key.key.pkcs11.public_cert);
if (!x509) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to load "
"Server Certificate\n",
setup_data->pki_key.key.pkcs11.public_cert);
return 0;
}
if (!SSL_CTX_use_certificate(ctx, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Certificate\n",
setup_data->pki_key.key.pkcs11.public_cert);
X509_free (x509);
return 0;
}
X509_free (x509);
}
else {
if (!(SSL_CTX_use_certificate_file(ctx,
setup_data->pki_key.key.pkcs11.public_cert,
SSL_FILETYPE_ASN1))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server Certificate\n",
setup_data->pki_key.key.pkcs11.public_cert);
return 0;
}
}
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Certificate defined\n");
return 0;
}
if (setup_data->pki_key.key.pkcs11.ca &&
setup_data->pki_key.key.pkcs11.ca[0]) {
X509_STORE *st;
if (strncasecmp (setup_data->pki_key.key.pkcs11.ca, "pkcs11:", 7) == 0) {
X509 *x509;
x509 = missing_ENGINE_load_cert (
setup_data->pki_key.key.pkcs11.ca);
if (!x509) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to load "
"Server CA Certificate\n",
setup_data->pki_key.key.pkcs11.ca);
return 0;
}
if (!SSL_CTX_add_client_CA(ctx, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Server CA File\n",
setup_data->pki_key.key.pkcs11.ca);
X509_free(x509);
return 0;
}
st = SSL_CTX_get_cert_store(ctx);
add_ca_to_cert_store(st, x509);
X509_free(x509);
}
else {
FILE *fp = fopen(setup_data->pki_key.key.pkcs11.ca, "r");
X509 *x509 = fp ? d2i_X509_fp(fp, NULL) : NULL;
if (!x509 || !SSL_CTX_add_client_CA(ctx, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"client CA File\n",
setup_data->pki_key.key.pkcs11.ca);
if (x509) X509_free(x509);
return 0;
}
st = SSL_CTX_get_cert_store(ctx);
add_ca_to_cert_store(st, x509);
X509_free(x509);
}
}
break;
default:
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: Unknown key type %d\n",
setup_data->pki_key.key_type);
return 0;
}
return 1;
}
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
static int
setup_pki_ssl(SSL *ssl,
coap_dtls_pki_t* setup_data, coap_dtls_role_t role
) {
if (setup_data->is_rpk_not_cert) {
coap_log(LOG_ERR,
"RPK Support not available in OpenSSL\n");
return 0;
}
switch (setup_data->pki_key.key_type) {
case COAP_PKI_KEY_PEM:
if (setup_data->pki_key.key.pem.public_cert &&
setup_data->pki_key.key.pem.public_cert[0]) {
if (!(SSL_use_certificate_file(ssl,
setup_data->pki_key.key.pem.public_cert,
SSL_FILETYPE_PEM))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Certificate\n",
setup_data->pki_key.key.pem.public_cert,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
}
else if (role == COAP_DTLS_ROLE_SERVER ||
(setup_data->pki_key.key.pem.private_key &&
setup_data->pki_key.key.pem.private_key[0])) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No %s Certificate defined\n",
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (setup_data->pki_key.key.pem.private_key &&
setup_data->pki_key.key.pem.private_key[0]) {
if (!(SSL_use_PrivateKey_file(ssl,
setup_data->pki_key.key.pem.private_key,
SSL_FILETYPE_PEM))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"Client Private Key\n",
setup_data->pki_key.key.pem.private_key);
return 0;
}
}
else if (role == COAP_DTLS_ROLE_SERVER ||
(setup_data->pki_key.key.pem.public_cert &&
setup_data->pki_key.key.pem.public_cert[0])) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No %s Private Key defined\n",
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (setup_data->check_common_ca && setup_data->pki_key.key.pem.ca_file &&
setup_data->pki_key.key.pem.ca_file[0]) {
X509_STORE *st;
BIO *in;
X509 *x = NULL;
char *rw_var = NULL;
SSL_CTX *ctx = SSL_get_SSL_CTX(ssl);
if (role == COAP_DTLS_ROLE_SERVER) {
STACK_OF(X509_NAME) *cert_names = SSL_load_client_CA_file(setup_data->pki_key.key.pem.ca_file);
if (cert_names != NULL)
SSL_set_client_CA_list(ssl, cert_names);
else {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s CA File\n",
setup_data->pki_key.key.pem.ca_file,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
}
/* Add CA to the trusted root CA store */
in = BIO_new(BIO_s_file());
/* Need to do this to not get a compiler warning about const parameters */
memcpy(&rw_var, &setup_data->pki_key.key.pem.ca_file, sizeof (rw_var));
if (!BIO_read_filename(in, rw_var)) {
BIO_free(in);
X509_free(x);
break;
}
st = SSL_CTX_get_cert_store(ctx);
for (;;) {
if (PEM_read_bio_X509(in, &x, NULL, NULL) == NULL)
break;
add_ca_to_cert_store(st, x);
}
BIO_free(in);
X509_free(x);
}
break;
case COAP_PKI_KEY_PEM_BUF:
if (setup_data->pki_key.key.pem_buf.public_cert &&
setup_data->pki_key.key.pem_buf.public_cert_len) {
BIO *bp = BIO_new_mem_buf(setup_data->pki_key.key.pem_buf.public_cert,
(int)setup_data->pki_key.key.pem_buf.public_cert_len);
X509 *cert = bp ? PEM_read_bio_X509(bp, NULL, 0, NULL) : NULL;
if (!cert || !SSL_use_certificate(ssl, cert)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: Unable to configure "
"Server PEM Certificate\n");
if (bp) BIO_free(bp);
if (cert) X509_free(cert);
return 0;
}
if (bp) BIO_free(bp);
if (cert) X509_free(cert);
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Certificate defined\n");
return 0;
}
if (setup_data->pki_key.key.pem_buf.private_key &&
setup_data->pki_key.key.pem_buf.private_key_len) {
BIO *bp = BIO_new_mem_buf(setup_data->pki_key.key.pem_buf.private_key,
(int)setup_data->pki_key.key.pem_buf.private_key_len);
EVP_PKEY *pkey = bp ? PEM_read_bio_PrivateKey(bp, NULL, 0, NULL) : NULL;
if (!pkey || !SSL_use_PrivateKey(ssl, pkey)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: Unable to configure "
"Server PEM Private Key\n");
if (bp) BIO_free(bp);
if (pkey) EVP_PKEY_free(pkey);
return 0;
}
if (bp) BIO_free(bp);
if (pkey) EVP_PKEY_free(pkey);
}
else {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Private Key defined\n");
return 0;
}
if (setup_data->pki_key.key.pem_buf.ca_cert &&
setup_data->pki_key.key.pem_buf.ca_cert_len) {
BIO *bp = BIO_new_mem_buf(setup_data->pki_key.key.pem_buf.ca_cert,
(int)setup_data->pki_key.key.pem_buf.ca_cert_len);
SSL_CTX *ctx = SSL_get_SSL_CTX(ssl);
X509 *x;
X509_STORE *st = SSL_CTX_get_cert_store(ctx);
if (bp) {
for (;;) {
if ((x = PEM_read_bio_X509(bp, NULL, 0, NULL)) == NULL)
break;
add_ca_to_cert_store(st, x);
SSL_add_client_CA(ssl, x);
X509_free(x);
}
BIO_free(bp);
}
}
break;
case COAP_PKI_KEY_ASN1:
if (setup_data->pki_key.key.asn1.public_cert &&
setup_data->pki_key.key.asn1.public_cert_len > 0) {
if (!(SSL_use_certificate_ASN1(ssl,
setup_data->pki_key.key.asn1.public_cert,
(int)setup_data->pki_key.key.asn1.public_cert_len))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Certificate\n",
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client",
"ASN1");
return 0;
}
}
else if (role == COAP_DTLS_ROLE_SERVER ||
(setup_data->pki_key.key.asn1.private_key &&
setup_data->pki_key.key.asn1.private_key[0])) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No %s Certificate defined\n",
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (setup_data->pki_key.key.asn1.private_key &&
setup_data->pki_key.key.asn1.private_key_len > 0) {
int pkey_type = map_key_type(setup_data->pki_key.key.asn1.private_key_type);
if (!(SSL_use_PrivateKey_ASN1(pkey_type, ssl,
setup_data->pki_key.key.asn1.private_key,
(long)setup_data->pki_key.key.asn1.private_key_len))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Private Key\n",
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client",
"ASN1");
return 0;
}
}
else if (role == COAP_DTLS_ROLE_SERVER ||
(setup_data->pki_key.key.asn1.public_cert &&
setup_data->pki_key.key.asn1.public_cert_len > 0)) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No %s Private Key defined",
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (setup_data->pki_key.key.asn1.ca_cert &&
setup_data->pki_key.key.asn1.ca_cert_len > 0) {
/* Need to use a temp variable as it gets incremented*/
const uint8_t *p = setup_data->pki_key.key.asn1.ca_cert;
X509* x509 = d2i_X509(NULL, &p, (long)setup_data->pki_key.key.asn1.ca_cert_len);
X509_STORE *st;
SSL_CTX *ctx = SSL_get_SSL_CTX(ssl);
if (role == COAP_DTLS_ROLE_SERVER) {
if (!x509 || !SSL_add_client_CA(ssl, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"client CA File\n",
"ASN1");
X509_free(x509);
return 0;
}
}
/* Add CA to the trusted root CA store */
st = SSL_CTX_get_cert_store(ctx);
add_ca_to_cert_store(st, x509);
X509_free(x509);
}
break;
case COAP_PKI_KEY_PKCS11:
if (!ssl_engine) {
ssl_engine = ENGINE_by_id("pkcs11");
if (!ssl_engine) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No PKCS11 support\nn");
return 0;
}
if (!ENGINE_init(ssl_engine)) {
/* the engine couldn't initialise, release 'ssl_engine' */
ENGINE_free(ssl_engine);
ssl_engine = NULL;
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: PKCS11 engine initialize failed\nn");
return 0;
}
}
if (setup_data->pki_key.key.pkcs11.user_pin) {
/* If not set, pin may be held in pkcs11: URI */
if (ENGINE_ctrl_cmd_string(ssl_engine,
"PIN",
setup_data->pki_key.key.pkcs11.user_pin, 0) == 0) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: PKCS11: %s: Unable to set pin\n",
setup_data->pki_key.key.pkcs11.user_pin);
return 0;
}
}
if (setup_data->pki_key.key.pkcs11.private_key &&
setup_data->pki_key.key.pkcs11.private_key[0]) {
if (strncasecmp (setup_data->pki_key.key.pkcs11.private_key,
"pkcs11:", 7) == 0) {
EVP_PKEY* pkey = ENGINE_load_private_key(ssl_engine,
setup_data->pki_key.key.pkcs11.private_key,
NULL, NULL);
if (!pkey) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to load "
"%s Private Key\n",
setup_data->pki_key.key.pkcs11.private_key,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (!SSL_use_PrivateKey(ssl, pkey)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Private Key\n",
setup_data->pki_key.key.pkcs11.private_key,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
EVP_PKEY_free(pkey);
return 0;
}
EVP_PKEY_free(pkey);
}
else {
if (!(SSL_use_PrivateKey_file(ssl,
setup_data->pki_key.key.pkcs11.private_key,
SSL_FILETYPE_ASN1))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Private Key\n",
setup_data->pki_key.key.pkcs11.private_key,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
}
}
else if (role == COAP_DTLS_ROLE_SERVER) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Private Key defined\n");
return 0;
}
if (setup_data->pki_key.key.pkcs11.public_cert &&
setup_data->pki_key.key.pkcs11.public_cert[0]) {
if (strncasecmp (setup_data->pki_key.key.pkcs11.public_cert,
"pkcs11:", 7) == 0) {
X509 *x509;
x509 = missing_ENGINE_load_cert(
setup_data->pki_key.key.pkcs11.public_cert);
if (!x509) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to load "
"%s Certificate\n",
setup_data->pki_key.key.pkcs11.public_cert,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (!SSL_use_certificate(ssl, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Certificate\n",
setup_data->pki_key.key.pkcs11.public_cert,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
X509_free (x509);
return 0;
}
X509_free (x509);
}
else {
if (!(SSL_use_certificate_file(ssl,
setup_data->pki_key.key.pkcs11.public_cert,
SSL_FILETYPE_ASN1))) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s Certificate\n",
setup_data->pki_key.key.pkcs11.public_cert,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
}
}
else if (role == COAP_DTLS_ROLE_SERVER) {
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: No Server Certificate defined\n");
return 0;
}
if (setup_data->pki_key.key.pkcs11.ca &&
setup_data->pki_key.key.pkcs11.ca[0]) {
X509_STORE *st;
if (strncasecmp (setup_data->pki_key.key.pkcs11.ca, "pkcs11:", 7) == 0) {
X509 *x509;
SSL_CTX *ctx = SSL_get_SSL_CTX(ssl);
x509 = missing_ENGINE_load_cert(
setup_data->pki_key.key.pkcs11.public_cert);
if (!x509) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to load "
"%s CA Certificate\n",
setup_data->pki_key.key.pkcs11.ca,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
return 0;
}
if (!SSL_add_client_CA(ssl, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s CA Certificate\n",
setup_data->pki_key.key.pkcs11.ca,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
X509_free(x509);
return 0;
}
st = SSL_CTX_get_cert_store(ctx);
add_ca_to_cert_store(st, x509);
X509_free(x509);
}
else {
FILE *fp = fopen(setup_data->pki_key.key.pkcs11.ca, "r");
X509 *x509 = fp ? d2i_X509_fp(fp, NULL) : NULL;
SSL_CTX *ctx = SSL_get_SSL_CTX(ssl);
if (!x509 || !SSL_add_client_CA(ssl, x509)) {
coap_log(LOG_WARNING,
"*** setup_pki: (D)TLS: %s: Unable to configure "
"%s CA File\n",
setup_data->pki_key.key.pkcs11.ca,
role == COAP_DTLS_ROLE_SERVER ? "Server" : "Client");
if (x509) X509_free(x509);
return 0;
}
st = SSL_CTX_get_cert_store(ctx);
add_ca_to_cert_store(st, x509);
X509_free(x509);
}
}
break;
default:
coap_log(LOG_ERR,
"*** setup_pki: (D)TLS: Unknown key type %d\n",
setup_data->pki_key.key_type);
return 0;
}
return 1;
}
static char*
get_san_or_cn_from_cert(X509* x509) {
if (x509) {
char *cn;
int n;
STACK_OF(GENERAL_NAME) *san_list;
char buffer[256];
san_list = X509_get_ext_d2i(x509, NID_subject_alt_name, NULL, NULL);
if (san_list) {
int san_count = sk_GENERAL_NAME_num(san_list);
for (n = 0; n < san_count; n++) {
const GENERAL_NAME * name = sk_GENERAL_NAME_value (san_list, n);
if (name->type == GEN_DNS) {
const char *dns_name = (const char *)ASN1_STRING_get0_data(name->d.dNSName);
/* Make sure that there is not an embedded NUL in the dns_name */
if (ASN1_STRING_length(name->d.dNSName) != (int)strlen (dns_name))
continue;
cn = OPENSSL_strdup(dns_name);
sk_GENERAL_NAME_pop_free(san_list, GENERAL_NAME_free);
return cn;
}
}
sk_GENERAL_NAME_pop_free(san_list, GENERAL_NAME_free);
}
/* Otherwise look for the CN= field */
X509_NAME_oneline(X509_get_subject_name(x509), buffer, sizeof(buffer));
/* Need to emulate strcasestr() here. Looking for CN= */
n = (int)strlen(buffer) - 3;
cn = buffer;
while (n > 0) {
if (((cn[0] == 'C') || (cn[0] == 'c')) &&
((cn[1] == 'N') || (cn[1] == 'n')) &&
(cn[2] == '=')) {
cn += 3;
break;
}
cn++;
n--;
}
if (n > 0) {
char * ecn = strchr(cn, '/');
if (ecn) {
return OPENSSL_strndup(cn, ecn-cn);
}
else {
return OPENSSL_strdup(cn);
}
}
}
return NULL;
}
static int
tls_verify_call_back(int preverify_ok, X509_STORE_CTX *ctx) {
SSL *ssl = X509_STORE_CTX_get_ex_data(ctx,
SSL_get_ex_data_X509_STORE_CTX_idx());
coap_session_t *session = SSL_get_app_data(ssl);
coap_openssl_context_t *context =
((coap_openssl_context_t *)session->context->dtls_context);
coap_dtls_pki_t *setup_data = &context->setup_data;
int depth = X509_STORE_CTX_get_error_depth(ctx);
int err = X509_STORE_CTX_get_error(ctx);
X509 *x509 = X509_STORE_CTX_get_current_cert(ctx);
char *cn = get_san_or_cn_from_cert(x509);
int keep_preverify_ok = preverify_ok;
if (!preverify_ok) {
switch (err) {
case X509_V_ERR_CERT_NOT_YET_VALID:
case X509_V_ERR_CERT_HAS_EXPIRED:
if (setup_data->allow_expired_certs)
preverify_ok = 1;
break;
case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
if (setup_data->allow_self_signed && !setup_data->check_common_ca)
preverify_ok = 1;
break;
case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: /* Set if the CA is not known */
if (!setup_data->verify_peer_cert)
preverify_ok = 1;
break;
case X509_V_ERR_UNABLE_TO_GET_CRL:
if (setup_data->allow_no_crl)
preverify_ok = 1;
break;
case X509_V_ERR_CRL_NOT_YET_VALID:
case X509_V_ERR_CRL_HAS_EXPIRED:
if (setup_data->allow_expired_crl)
preverify_ok = 1;
break;
case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
if (!setup_data->verify_peer_cert)
preverify_ok = 1;
break;
default:
break;
}
if (setup_data->cert_chain_validation &&
depth > (setup_data->cert_chain_verify_depth + 1)) {
preverify_ok = 0;
err = X509_V_ERR_CERT_CHAIN_TOO_LONG;
X509_STORE_CTX_set_error(ctx, err);
}
if (!preverify_ok) {
if (err == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) {
coap_log(LOG_WARNING,
" %s: %s: '%s' depth=%d\n",
coap_session_str(session),
"Unknown CA", cn ? cn : "?", depth);
}
else {
coap_log(LOG_WARNING,
" %s: %s: '%s' depth=%d\n",
coap_session_str(session),
X509_verify_cert_error_string(err), cn ? cn : "?", depth);
}
}
else {
coap_log(LOG_INFO,
" %s: %s: overridden: '%s' depth=%d\n",
coap_session_str(session),
X509_verify_cert_error_string(err), cn ? cn : "?", depth);
}
}
/* Certificate - depth == 0 is the Client Cert */
if (setup_data->validate_cn_call_back && keep_preverify_ok) {
int length = i2d_X509(x509, NULL);
uint8_t *base_buf;
uint8_t *base_buf2 = base_buf = OPENSSL_malloc(length);
/* base_buf2 gets moved to the end */
i2d_X509(x509, &base_buf2);
if (!setup_data->validate_cn_call_back(cn, base_buf, length, session,
depth, preverify_ok,
setup_data->cn_call_back_arg)) {
if (depth == 0) {
X509_STORE_CTX_set_error(ctx, X509_V_ERR_CERT_REJECTED);
}
else {
X509_STORE_CTX_set_error(ctx, X509_V_ERR_INVALID_CA);
}
preverify_ok = 0;
}
OPENSSL_free(base_buf);
}
OPENSSL_free(cn);
return preverify_ok;
}
#if OPENSSL_VERSION_NUMBER < 0x10101000L
/*
* During the SSL/TLS initial negotiations, tls_secret_call_back() is called so
* it is possible to determine whether this is a PKI or PSK incoming
* request and adjust the ciphers if necessary
*
* Set up by SSL_set_session_secret_cb() in tls_server_name_call_back()
*/
static int
tls_secret_call_back(SSL *ssl,
void *secret,
int *secretlen,
STACK_OF(SSL_CIPHER) *peer_ciphers,
const SSL_CIPHER **cipher COAP_UNUSED,
void *arg
) {
int ii;
int psk_requested = 0;
coap_session_t *session;
coap_dtls_pki_t *setup_data = (coap_dtls_pki_t*)arg;
session = (coap_session_t *)SSL_get_app_data(ssl);
assert(session != NULL);
assert(session->context != NULL);
if (session == NULL ||
session->context == NULL)
return 0;
if ((session->psk_key) ||
(session->context->spsk_setup_data.psk_info.key.s &&
session->context->spsk_setup_data.psk_info.key.length)) {
/* Is PSK being requested - if so, we need to change algorithms */
for (ii = 0; ii < sk_SSL_CIPHER_num (peer_ciphers); ii++) {
const SSL_CIPHER *peer_cipher = sk_SSL_CIPHER_value(peer_ciphers, ii);
coap_log(COAP_LOG_CIPHERS, "Client cipher: %s\n",
SSL_CIPHER_get_name(peer_cipher));
if (strstr (SSL_CIPHER_get_name (peer_cipher), "PSK")) {
psk_requested = 1;
break;
}
}
}
if (!psk_requested) {
coap_log(LOG_DEBUG, " %s: Using PKI ciphers\n",
coap_session_str(session));
if (setup_data->verify_peer_cert) {
SSL_set_verify(ssl,
SSL_VERIFY_PEER |
SSL_VERIFY_CLIENT_ONCE |
SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
tls_verify_call_back);
}
else {
SSL_set_verify(ssl, SSL_VERIFY_NONE, tls_verify_call_back);
}
/* Check CA Chain */
if (setup_data->cert_chain_validation)
SSL_set_verify_depth(ssl, setup_data->cert_chain_verify_depth + 2);
/* Certificate Revocation */
if (setup_data->check_cert_revocation) {
X509_VERIFY_PARAM *param;
param = X509_VERIFY_PARAM_new();
X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
SSL_set1_param(ssl, param);
X509_VERIFY_PARAM_free(param);
}
if (setup_data->additional_tls_setup_call_back) {
/* Additional application setup wanted */
if (!setup_data->additional_tls_setup_call_back(ssl, setup_data))
return 0;
}
}
else {
if (session->psk_key) {
memcpy(secret, session->psk_key->s, session->psk_key->length);
*secretlen = session->psk_key->length;
}
else if (session->context->spsk_setup_data.psk_info.key.s &&
session->context->spsk_setup_data.psk_info.key.length) {
memcpy(secret, session->context->spsk_setup_data.psk_info.key.s,
session->context->spsk_setup_data.psk_info.key.length);
*secretlen = session->context->spsk_setup_data.psk_info.key.length;
}
coap_log(LOG_DEBUG, " %s: Setting PSK ciphers\n",
coap_session_str(session));
/*
* Force a PSK algorithm to be used, so we do PSK
*/
SSL_set_cipher_list (ssl, COAP_OPENSSL_PSK_CIPHERS);
SSL_set_psk_server_callback(ssl, coap_dtls_psk_server_callback);
}
return 0;
}
/*
* During the SSL/TLS initial negotiations, tls_server_name_call_back() is
* called so it is possible to set up an extra callback to determine whether
* this is a PKI or PSK incoming request and adjust the ciphers if necessary
*
* Set up by SSL_CTX_set_tlsext_servername_callback() in
* coap_dtls_context_set_pki()
*/
static int
tls_server_name_call_back(SSL *ssl,
int *sd COAP_UNUSED,
void *arg
) {
coap_dtls_pki_t *setup_data = (coap_dtls_pki_t*)arg;
if (!ssl) {
return SSL_TLSEXT_ERR_NOACK;
}
if (setup_data->validate_sni_call_back) {
/* SNI checking requested */
coap_session_t *session = (coap_session_t*)SSL_get_app_data(ssl);
coap_openssl_context_t *context =
((coap_openssl_context_t *)session->context->dtls_context);
const char *sni = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
size_t i;
if (!sni || !sni[0]) {
sni = "";
}
for (i = 0; i < context->sni_count; i++) {
if (!strcasecmp(sni, context->sni_entry_list[i].sni)) {
break;
}
}
if (i == context->sni_count) {
SSL_CTX *ctx;
coap_dtls_pki_t sni_setup_data;
coap_dtls_key_t *new_entry = setup_data->validate_sni_call_back(sni,
setup_data->sni_call_back_arg);
if (!new_entry) {
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
/* Need to set up a new SSL_CTX to switch to */
if (session->proto == COAP_PROTO_DTLS) {
/* Set up DTLS context */
ctx = SSL_CTX_new(DTLS_method());
if (!ctx)
goto error;
SSL_CTX_set_min_proto_version(ctx, DTLS1_2_VERSION);
SSL_CTX_set_app_data(ctx, &context->dtls);
SSL_CTX_set_read_ahead(ctx, 1);
coap_set_user_prefs(ctx);
SSL_CTX_set_cookie_generate_cb(ctx, coap_dtls_generate_cookie);
SSL_CTX_set_cookie_verify_cb(ctx, coap_dtls_verify_cookie);
SSL_CTX_set_info_callback(ctx, coap_dtls_info_callback);
SSL_CTX_set_options(ctx, SSL_OP_NO_QUERY_MTU);
}
#if !COAP_DISABLE_TCP
else {
/* Set up TLS context */
ctx = SSL_CTX_new(TLS_method());
if (!ctx)
goto error;
SSL_CTX_set_app_data(ctx, &context->tls);
SSL_CTX_set_min_proto_version(ctx, TLS1_VERSION);
coap_set_user_prefs(ctx);
SSL_CTX_set_info_callback(ctx, coap_dtls_info_callback);
SSL_CTX_set_alpn_select_cb(ctx, server_alpn_callback, NULL);
}
#endif /* !COAP_DISABLE_TCP */
sni_setup_data = *setup_data;
sni_setup_data.pki_key = *new_entry;
setup_pki_server(ctx, &sni_setup_data);
context->sni_entry_list = OPENSSL_realloc(context->sni_entry_list,
(context->sni_count+1)*sizeof(sni_entry));
context->sni_entry_list[context->sni_count].sni = OPENSSL_strdup(sni);
context->sni_entry_list[context->sni_count].ctx = ctx;
context->sni_count++;
}
SSL_set_SSL_CTX (ssl, context->sni_entry_list[i].ctx);
SSL_clear_options (ssl, 0xFFFFFFFFL);
SSL_set_options (ssl, SSL_CTX_get_options (context->sni_entry_list[i].ctx));
}
/*
* Have to do extra call back next to get client algorithms
* SSL_get_client_ciphers() does not work this early on
*/
SSL_set_session_secret_cb(ssl, tls_secret_call_back, arg);
return SSL_TLSEXT_ERR_OK;
error:
return SSL_TLSEXT_ERR_ALERT_WARNING;
}
/*
* During the SSL/TLS initial negotiations, psk_tls_server_name_call_back() is
* called to see if SNI is being used.
*
* Set up by SSL_CTX_set_tlsext_servername_callback()
* in coap_dtls_context_set_spsk()
*/
static int
psk_tls_server_name_call_back(SSL *ssl,
int *sd COAP_UNUSED,
void *arg
) {
coap_dtls_spsk_t *setup_data = (coap_dtls_spsk_t*)arg;
if (!ssl) {
return SSL_TLSEXT_ERR_NOACK;
}
if (setup_data->validate_sni_call_back) {
/* SNI checking requested */
coap_session_t *c_session = (coap_session_t*)SSL_get_app_data(ssl);
coap_openssl_context_t *o_context =
((coap_openssl_context_t *)c_session->context->dtls_context);
const char *sni = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
size_t i;
char lhint[COAP_DTLS_HINT_LENGTH];
if (!sni || !sni[0]) {
sni = "";
}
for (i = 0; i < o_context->psk_sni_count; i++) {
if (!strcasecmp(sni, (char*)o_context->psk_sni_entry_list[i].sni)) {
break;
}
}
if (i == o_context->psk_sni_count) {
SSL_CTX *ctx;
const coap_dtls_spsk_info_t *new_entry =
setup_data->validate_sni_call_back(sni,
c_session,
setup_data->sni_call_back_arg);
if (!new_entry) {
return SSL_TLSEXT_ERR_ALERT_FATAL;
}
/* Need to set up a new SSL_CTX to switch to */
if (c_session->proto == COAP_PROTO_DTLS) {
/* Set up DTLS context */
ctx = SSL_CTX_new(DTLS_method());
if (!ctx)
goto error;
SSL_CTX_set_min_proto_version(ctx, DTLS1_2_VERSION);
SSL_CTX_set_app_data(ctx, &o_context->dtls);
SSL_CTX_set_read_ahead(ctx, 1);
SSL_CTX_set_cipher_list(ctx, COAP_OPENSSL_CIPHERS);
SSL_CTX_set_cookie_generate_cb(ctx, coap_dtls_generate_cookie);
SSL_CTX_set_cookie_verify_cb(ctx, coap_dtls_verify_cookie);
SSL_CTX_set_info_callback(ctx, coap_dtls_info_callback);
SSL_CTX_set_options(ctx, SSL_OP_NO_QUERY_MTU);
}
#if !COAP_DISABLE_TCP
else {
/* Set up TLS context */
ctx = SSL_CTX_new(TLS_method());
if (!ctx)
goto error;
SSL_CTX_set_app_data(ctx, &o_context->tls);
SSL_CTX_set_min_proto_version(ctx, TLS1_VERSION);
SSL_CTX_set_cipher_list(ctx, COAP_OPENSSL_CIPHERS);
SSL_CTX_set_info_callback(ctx, coap_dtls_info_callback);
SSL_CTX_set_alpn_select_cb(ctx, server_alpn_callback, NULL);
}
#endif /* !COAP_DISABLE_TCP */
o_context->psk_sni_entry_list =
OPENSSL_realloc(o_context->psk_sni_entry_list,
(o_context->psk_sni_count+1)*sizeof(psk_sni_entry));
o_context->psk_sni_entry_list[o_context->psk_sni_count].sni =
OPENSSL_strdup(sni);
o_context->psk_sni_entry_list[o_context->psk_sni_count].psk_info =
*new_entry;
o_context->psk_sni_entry_list[o_context->psk_sni_count].ctx =
ctx;
o_context->psk_sni_count++;
}
SSL_set_SSL_CTX (ssl, o_context->psk_sni_entry_list[i].ctx);
SSL_clear_options (ssl, 0xFFFFFFFFL);
SSL_set_options (ssl,
SSL_CTX_get_options (o_context->psk_sni_entry_list[i].ctx));
coap_session_refresh_psk_key(c_session,
&o_context->psk_sni_entry_list[i].psk_info.key);
snprintf(lhint, sizeof(lhint), "%.*s",
(int)o_context->psk_sni_entry_list[i].psk_info.hint.length,
o_context->psk_sni_entry_list[i].psk_info.hint.s);
SSL_use_psk_identity_hint(ssl, lhint);
}
/*
* Have to do extra call back next to get client algorithms
* SSL_get_client_ciphers() does not work this early on
*/
SSL_set_session_secret_cb(ssl, tls_secret_call_back, arg);
return SSL_TLSEXT_ERR_OK;
error:
return SSL_TLSEXT_ERR_ALERT_WARNING;
}
#else /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
/*
* During the SSL/TLS initial negotiations, tls_client_hello_call_back() is
* called early in the Client Hello processing so it is possible to determine
* whether this is a PKI or PSK incoming request and adjust the ciphers if
* necessary.
*
* Set up by SSL_CTX_set_client_hello_cb().
*/
static int
tls_client_hello_call_back(SSL *ssl,
int *al,
void *arg COAP_UNUSED
) {
coap_session_t *session;
coap_openssl_context_t *dtls_context;
coap_dtls_pki_t *setup_data;
int psk_requested = 0;
const unsigned char *out;
size_t outlen;
if (!ssl) {
*al = SSL_AD_INTERNAL_ERROR;
return SSL_CLIENT_HELLO_ERROR;
}
session = (coap_session_t *)SSL_get_app_data(ssl);
assert(session != NULL);
assert(session->context != NULL);
assert(session->context->dtls_context != NULL);
if (session == NULL ||
session->context == NULL ||
session->context->dtls_context == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return SSL_CLIENT_HELLO_ERROR;
}
dtls_context = (coap_openssl_context_t *)session->context->dtls_context;
setup_data = &dtls_context->setup_data;
/*
* See if PSK being requested
*/
if ((session->psk_key) ||
(session->context->spsk_setup_data.psk_info.key.s &&
session->context->spsk_setup_data.psk_info.key.length)) {
size_t len = SSL_client_hello_get0_ciphers(ssl, &out);
STACK_OF(SSL_CIPHER) *peer_ciphers = NULL;
STACK_OF(SSL_CIPHER) *scsvc = NULL;
if (len && SSL_bytes_to_cipher_list(ssl, out, len,
SSL_client_hello_isv2(ssl),
&peer_ciphers, &scsvc)) {
int ii;
for (ii = 0; ii < sk_SSL_CIPHER_num (peer_ciphers); ii++) {
const SSL_CIPHER *peer_cipher = sk_SSL_CIPHER_value(peer_ciphers, ii);
coap_log(COAP_LOG_CIPHERS, "Client cipher: %s (%04x)\n",
SSL_CIPHER_get_name(peer_cipher),
SSL_CIPHER_get_protocol_id(peer_cipher));
if (strstr (SSL_CIPHER_get_name (peer_cipher), "PSK")) {
psk_requested = 1;
break;
}
}
}
sk_SSL_CIPHER_free(peer_ciphers);
sk_SSL_CIPHER_free(scsvc);
}
if (psk_requested) {
/*
* Client has requested PSK and it is supported
*/
coap_log(LOG_DEBUG, " %s: PSK request\n",
coap_session_str(session));
SSL_set_psk_server_callback(ssl, coap_dtls_psk_server_callback);
if (setup_data->additional_tls_setup_call_back) {
/* Additional application setup wanted */
if (!setup_data->additional_tls_setup_call_back(ssl, setup_data))
return 0;
}
return SSL_CLIENT_HELLO_SUCCESS;
}
/*
* Handle Certificate requests
*/
/*
* Determine what type of certificate is being requested
*/
if (SSL_client_hello_get0_ext(ssl, TLSEXT_TYPE_client_certificate_type,
&out, &outlen)) {
size_t ii;
for (ii = 0; ii < outlen; ii++) {
switch (out[ii]) {
case 0:
/* RFC6091 X.509 */
if (outlen >= 2) {
/* X.509 cannot be the singular entry. RFC6091 3.1. Client Hello */
goto is_x509;
}
break;
case 2:
/* RFC7250 RPK - not yet supported */
break;
default:
break;
}
}
*al = SSL_AD_UNSUPPORTED_EXTENSION;
return SSL_CLIENT_HELLO_ERROR;
}
is_x509:
if (setup_data->validate_sni_call_back) {
/*
* SNI checking requested
*/
coap_dtls_pki_t sni_setup_data;
coap_openssl_context_t *context =
((coap_openssl_context_t *)session->context->dtls_context);
const char *sni = "";
char *sni_tmp = NULL;
size_t i;
if (SSL_client_hello_get0_ext (ssl, TLSEXT_TYPE_server_name, &out, &outlen) &&
outlen > 5 &&
(((out[0]<<8) + out[1] +2) == (int)outlen) &&
out[2] == TLSEXT_NAMETYPE_host_name &&
(((out[3]<<8) + out[4] +2 +3) == (int)outlen)) {
/* Skip over length, type and length */
out += 5;
outlen -= 5;
sni_tmp = OPENSSL_malloc(outlen+1);
sni_tmp[outlen] = '\000';
memcpy(sni_tmp, out, outlen);
sni = sni_tmp;
}
/* Is this a cached entry? */
for (i = 0; i < context->sni_count; i++) {
if (!strcasecmp(sni, context->sni_entry_list[i].sni)) {
break;
}
}
if (i == context->sni_count) {
/*
* New SNI request
*/
coap_dtls_key_t *new_entry = setup_data->validate_sni_call_back(sni,
setup_data->sni_call_back_arg);
if (!new_entry) {
*al = SSL_AD_UNRECOGNIZED_NAME;
return SSL_CLIENT_HELLO_ERROR;
}
context->sni_entry_list = OPENSSL_realloc(context->sni_entry_list,
(context->sni_count+1)*sizeof(sni_entry));
context->sni_entry_list[context->sni_count].sni = OPENSSL_strdup(sni);
context->sni_entry_list[context->sni_count].pki_key = *new_entry;
context->sni_count++;
}
if (sni_tmp) {
OPENSSL_free(sni_tmp);
}
sni_setup_data = *setup_data;
sni_setup_data.pki_key = context->sni_entry_list[i].pki_key;
setup_pki_ssl(ssl, &sni_setup_data, 1);
}
else {
setup_pki_ssl(ssl, setup_data, 1);
}
coap_log(LOG_DEBUG, " %s: Using PKI ciphers\n",
coap_session_str(session));
if (setup_data->verify_peer_cert) {
SSL_set_verify(ssl,
SSL_VERIFY_PEER |
SSL_VERIFY_CLIENT_ONCE |
SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
tls_verify_call_back);
}
else {
SSL_set_verify(ssl, SSL_VERIFY_NONE, tls_verify_call_back);
}
/* Check CA Chain */
if (setup_data->cert_chain_validation)
SSL_set_verify_depth(ssl, setup_data->cert_chain_verify_depth + 2);
/* Certificate Revocation */
if (setup_data->check_cert_revocation) {
X509_VERIFY_PARAM *param;
param = X509_VERIFY_PARAM_new();
X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
SSL_set1_param(ssl, param);
X509_VERIFY_PARAM_free(param);
}
if (setup_data->additional_tls_setup_call_back) {
/* Additional application setup wanted */
if (!setup_data->additional_tls_setup_call_back(ssl, setup_data))
return 0;
}
return SSL_CLIENT_HELLO_SUCCESS;
}
/*
* During the SSL/TLS initial negotiations, psk_tls_client_hello_call_back() is
* called early in the Client Hello processing so it is possible to determine
* whether SNI needs to be handled
*
* Set up by SSL_CTX_set_client_hello_cb().
*/
static int
psk_tls_client_hello_call_back(SSL *ssl,
int *al,
void *arg COAP_UNUSED
) {
coap_session_t *c_session;
coap_openssl_context_t *o_context;
coap_dtls_spsk_t *setup_data;
const unsigned char *out;
size_t outlen;
if (!ssl)
goto int_err;
c_session = (coap_session_t *)SSL_get_app_data(ssl);
if (!c_session || !c_session->context) {
goto int_err;
}
o_context = (coap_openssl_context_t *)c_session->context->dtls_context;
if (!o_context) {
goto int_err;
}
setup_data = &c_session->context->spsk_setup_data;
if (setup_data->validate_sni_call_back) {
/*
* SNI checking requested
*/
const char *sni = "";
char *sni_tmp = NULL;
size_t i;
char lhint[COAP_DTLS_HINT_LENGTH];
if (SSL_client_hello_get0_ext (ssl, TLSEXT_TYPE_server_name, &out, &outlen) &&
outlen > 5 &&
(((out[0]<<8) + out[1] +2) == (int)outlen) &&
out[2] == TLSEXT_NAMETYPE_host_name &&
(((out[3]<<8) + out[4] +2 +3) == (int)outlen)) {
/* Skip over length, type and length */
out += 5;
outlen -= 5;
sni_tmp = OPENSSL_malloc(outlen+1);
if (sni_tmp) {
sni_tmp[outlen] = '\000';
memcpy(sni_tmp, out, outlen);
sni = sni_tmp;
}
}
/* Is this a cached entry? */
for (i = 0; i < o_context->psk_sni_count; i++) {
if (strcasecmp(sni, o_context->psk_sni_entry_list[i].sni) == 0) {
break;
}
}
if (i == o_context->psk_sni_count) {
/*
* New SNI request
*/
psk_sni_entry *tmp_entry;
const coap_dtls_spsk_info_t *new_entry = setup_data->validate_sni_call_back(
sni,
c_session,
setup_data->sni_call_back_arg);
if (!new_entry) {
*al = SSL_AD_UNRECOGNIZED_NAME;
return SSL_CLIENT_HELLO_ERROR;
}
tmp_entry =
OPENSSL_realloc(o_context->psk_sni_entry_list,
(o_context->psk_sni_count+1)*sizeof(sni_entry));
if (tmp_entry) {
o_context->psk_sni_entry_list = tmp_entry;
o_context->psk_sni_entry_list[o_context->psk_sni_count].sni =
OPENSSL_strdup(sni);
if (o_context->psk_sni_entry_list[o_context->psk_sni_count].sni) {
o_context->psk_sni_entry_list[o_context->psk_sni_count].psk_info =
*new_entry;
o_context->psk_sni_count++;
}
}
}
if (sni_tmp) {
OPENSSL_free(sni_tmp);
}
if (coap_session_refresh_psk_hint(c_session,
&o_context->psk_sni_entry_list[i].psk_info.hint)
== 0) {
goto int_err;
}
if (coap_session_refresh_psk_key(c_session,
&o_context->psk_sni_entry_list[i].psk_info.key)
== 0) {
goto int_err;
}
if (o_context->psk_sni_entry_list[i].psk_info.hint.s) {
snprintf(lhint, sizeof(lhint), "%.*s",
(int)o_context->psk_sni_entry_list[i].psk_info.hint.length,
o_context->psk_sni_entry_list[i].psk_info.hint.s);
SSL_use_psk_identity_hint(ssl, lhint);
}
}
return SSL_CLIENT_HELLO_SUCCESS;
int_err:
*al = SSL_AD_INTERNAL_ERROR;
return SSL_CLIENT_HELLO_ERROR;
}
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
int
coap_dtls_context_set_pki(coap_context_t *ctx,
const coap_dtls_pki_t *setup_data,
const coap_dtls_role_t role
) {
coap_openssl_context_t *context =
((coap_openssl_context_t *)ctx->dtls_context);
BIO *bio;
if (!setup_data)
return 0;
context->setup_data = *setup_data;
if (!context->setup_data.verify_peer_cert) {
/* Needs to be clear so that no CA DNs are transmitted */
context->setup_data.check_common_ca = 0;
/* Allow all of these but warn if issue */
context->setup_data.allow_self_signed = 1;
context->setup_data.allow_expired_certs = 1;
context->setup_data.cert_chain_validation = 1;
context->setup_data.cert_chain_verify_depth = 10;
context->setup_data.check_cert_revocation = 1;
context->setup_data.allow_no_crl = 1;
context->setup_data.allow_expired_crl = 1;
context->setup_data.allow_bad_md_hash = 1;
context->setup_data.allow_short_rsa_length = 1;
}
if (role == COAP_DTLS_ROLE_SERVER) {
if (context->dtls.ctx) {
/* SERVER DTLS */
#if OPENSSL_VERSION_NUMBER < 0x10101000L
if (!setup_pki_server(context->dtls.ctx, setup_data))
return 0;
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
/* libcoap is managing TLS connection based on setup_data options */
/* Need to set up logic to differentiate between a PSK or PKI session */
/*
* For OpenSSL 1.1.1, we need to use SSL_CTX_set_client_hello_cb()
* which is not in 1.1.0
*/
#if OPENSSL_VERSION_NUMBER < 0x10101000L
if (SSLeay() >= 0x10101000L) {
coap_log(LOG_WARNING,
"OpenSSL compiled with %lux, linked with %lux, so "
"no certificate checking\n",
OPENSSL_VERSION_NUMBER, SSLeay());
}
SSL_CTX_set_tlsext_servername_arg(context->dtls.ctx, &context->setup_data);
SSL_CTX_set_tlsext_servername_callback(context->dtls.ctx,
tls_server_name_call_back);
#else /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
SSL_CTX_set_client_hello_cb(context->dtls.ctx,
tls_client_hello_call_back,
NULL);
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
}
#if !COAP_DISABLE_TCP
if (context->tls.ctx) {
/* SERVER TLS */
#if OPENSSL_VERSION_NUMBER < 0x10101000L
if (!setup_pki_server(context->tls.ctx, setup_data))
return 0;
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
/* libcoap is managing TLS connection based on setup_data options */
/* Need to set up logic to differentiate between a PSK or PKI session */
/*
* For OpenSSL 1.1.1, we need to use SSL_CTX_set_client_hello_cb()
* which is not in 1.1.0
*/
#if OPENSSL_VERSION_NUMBER < 0x10101000L
if (SSLeay() >= 0x10101000L) {
coap_log(LOG_WARNING,
"OpenSSL compiled with %lux, linked with %lux, so "
"no certificate checking\n",
OPENSSL_VERSION_NUMBER, SSLeay());
}
SSL_CTX_set_tlsext_servername_arg(context->tls.ctx, &context->setup_data);
SSL_CTX_set_tlsext_servername_callback(context->tls.ctx,
tls_server_name_call_back);
#else /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
SSL_CTX_set_client_hello_cb(context->tls.ctx,
tls_client_hello_call_back,
NULL);
#endif /* OPENSSL_VERSION_NUMBER >= 0x10101000L */
/* TLS Only */
SSL_CTX_set_alpn_select_cb(context->tls.ctx, server_alpn_callback, NULL);
}
#endif /* !COAP_DISABLE_TCP */
}
if (!context->dtls.ssl) {
/* This is set up to handle new incoming sessions to a server */
context->dtls.ssl = SSL_new(context->dtls.ctx);
if (!context->dtls.ssl)
return 0;
bio = BIO_new(context->dtls.meth);
if (!bio) {
SSL_free (context->dtls.ssl);
context->dtls.ssl = NULL;
return 0;
}
SSL_set_bio(context->dtls.ssl, bio, bio);
SSL_set_app_data(context->dtls.ssl, NULL);
SSL_set_options(context->dtls.ssl, SSL_OP_COOKIE_EXCHANGE);
SSL_set_mtu(context->dtls.ssl, COAP_DEFAULT_MTU);
}
context->psk_pki_enabled |= IS_PKI;
return 1;
}
int
coap_dtls_context_set_pki_root_cas(struct coap_context_t *ctx,
const char *ca_file,
const char *ca_dir
) {
coap_openssl_context_t *context =
((coap_openssl_context_t *)ctx->dtls_context);
if (context->dtls.ctx) {
if (!SSL_CTX_load_verify_locations(context->dtls.ctx, ca_file, ca_dir)) {
coap_log(LOG_WARNING, "Unable to install root CAs (%s/%s)\n",
ca_file ? ca_file : "NULL", ca_dir ? ca_dir : "NULL");
return 0;
}
}
#if !COAP_DISABLE_TCP
if (context->tls.ctx) {
if (!SSL_CTX_load_verify_locations(context->tls.ctx, ca_file, ca_dir)) {
coap_log(LOG_WARNING, "Unable to install root CAs (%s/%s)\n",
ca_file ? ca_file : "NULL", ca_dir ? ca_dir : "NULL");
return 0;
}
}
#endif /* !COAP_DISABLE_TCP */
return 1;
}
int
coap_dtls_context_check_keys_enabled(coap_context_t *ctx)
{
coap_openssl_context_t *context =
((coap_openssl_context_t *)ctx->dtls_context);
return context->psk_pki_enabled ? 1 : 0;
}
void coap_dtls_free_context(void *handle) {
size_t i;
coap_openssl_context_t *context = (coap_openssl_context_t *)handle;
if (context->dtls.ssl)
SSL_free(context->dtls.ssl);
if (context->dtls.ctx)
SSL_CTX_free(context->dtls.ctx);
if (context->dtls.cookie_hmac)
HMAC_CTX_free(context->dtls.cookie_hmac);
if (context->dtls.meth)
BIO_meth_free(context->dtls.meth);
if (context->dtls.bio_addr)
BIO_ADDR_free(context->dtls.bio_addr);
#if !COAP_DISABLE_TCP
if ( context->tls.ctx )
SSL_CTX_free( context->tls.ctx );
if ( context->tls.meth )
BIO_meth_free( context->tls.meth );
#endif /* !COAP_DISABLE_TCP */
for (i = 0; i < context->sni_count; i++) {
OPENSSL_free(context->sni_entry_list[i].sni);
#if OPENSSL_VERSION_NUMBER < 0x10101000L
SSL_CTX_free(context->sni_entry_list[i].ctx);
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
}
if (context->sni_count)
OPENSSL_free(context->sni_entry_list);
for (i = 0; i < context->psk_sni_count; i++) {
OPENSSL_free((char*)context->psk_sni_entry_list[i].sni);
#if OPENSSL_VERSION_NUMBER < 0x10101000L
SSL_CTX_free(context->psk_sni_entry_list[i].ctx);
#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
}
if (context->psk_sni_count)
OPENSSL_free(context->psk_sni_entry_list);
coap_free(context);
}
void * coap_dtls_new_server_session(coap_session_t *session) {
BIO *nbio = NULL;
SSL *nssl = NULL, *ssl = NULL;
coap_ssl_data *data;
coap_dtls_context_t *dtls = &((coap_openssl_context_t *)session->context->dtls_context)->dtls;
int r;
nssl = SSL_new(dtls->ctx);
if (!nssl)
goto error;
nbio = BIO_new(dtls->meth);
if (!nbio)
goto error;
SSL_set_bio(nssl, nbio, nbio);
SSL_set_app_data(nssl, NULL);
SSL_set_options(nssl, SSL_OP_COOKIE_EXCHANGE);
SSL_set_mtu(nssl, (long)session->mtu);
ssl = dtls->ssl;
dtls->ssl = nssl;
nssl = NULL;
SSL_set_app_data(ssl, session);
data = (coap_ssl_data*)BIO_get_data(SSL_get_rbio(ssl));
data->session = session;
if (session->context->get_server_hint) {
/* hint may get updated if/when handling SNI callback */
char hint[COAP_DTLS_HINT_LENGTH] = "";
size_t hint_len = session->context->get_server_hint(session,
(uint8_t*)hint, sizeof(hint) - 1);
if (hint_len > 0 && hint_len < sizeof(hint)) {
hint[hint_len] = 0;
SSL_use_psk_identity_hint(ssl, hint);
}
}
r = SSL_accept(ssl);
if (r == -1) {
int err = SSL_get_error(ssl, r);
if (err != SSL_ERROR_WANT_READ && err != SSL_ERROR_WANT_WRITE)
r = 0;
}
if (r == 0) {
SSL_free(ssl);
return NULL;
}
return ssl;
error:
if (nssl)
SSL_free(nssl);
return NULL;
}
static int
setup_client_ssl_session(coap_session_t *session, SSL *ssl
) {
coap_openssl_context_t *context =
((coap_openssl_context_t *)session->context->dtls_context);
if (context->psk_pki_enabled & IS_PSK) {
coap_dtls_cpsk_t *setup_data = &session->cpsk_setup_data;
/* Issue SNI if requested */
if (setup_data->client_sni &&
SSL_set_tlsext_host_name (ssl, setup_data->client_sni) != 1) {
coap_log(LOG_WARNING, "SSL_set_tlsext_host_name: set '%s' failed",
setup_data->client_sni);
}
SSL_set_psk_client_callback(ssl, coap_dtls_psk_client_callback);
SSL_set_psk_server_callback(ssl, coap_dtls_psk_server_callback);
SSL_set_cipher_list(ssl, COAP_OPENSSL_PSK_CIPHERS);
if (setup_data->validate_ih_call_back) {
if (session->proto == COAP_PROTO_DTLS) {
SSL_set_max_proto_version(ssl, DTLS1_2_VERSION);
}
#if !COAP_DISABLE_TCP
else {
SSL_set_max_proto_version(ssl, TLS1_2_VERSION);
}
#endif /* !COAP_DISABLE_TCP */
coap_log(LOG_DEBUG,
"CoAP Client restricted to (D)TLS1.2 with Identity Hint callback\n");
}
}
if (context->psk_pki_enabled & IS_PKI) {
coap_dtls_pki_t *setup_data = &context->setup_data;
if (!setup_pki_ssl(ssl, setup_data, 0))
return 0;
/* libcoap is managing (D)TLS connection based on setup_data options */
#if !COAP_DISABLE_TCP
if (session->proto == COAP_PROTO_TLS)
SSL_set_alpn_protos(ssl, coap_alpn, sizeof(coap_alpn));
#endif /* !COAP_DISABLE_TCP */
/* Issue SNI if requested */
if (setup_data->client_sni &&
SSL_set_tlsext_host_name (ssl, setup_data->client_sni) != 1) {
coap_log(LOG_WARNING, "SSL_set_tlsext_host_name: set '%s' failed",
setup_data->client_sni);
}
/* Certificate Revocation */
if (setup_data->check_cert_revocation) {
X509_VERIFY_PARAM *param;
param = X509_VERIFY_PARAM_new();
X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
SSL_set1_param(ssl, param);
X509_VERIFY_PARAM_free(param);
}
/* Verify Peer */
if (setup_data->verify_peer_cert)
SSL_set_verify(ssl,
SSL_VERIFY_PEER |
SSL_VERIFY_CLIENT_ONCE |
SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
tls_verify_call_back);
else
SSL_set_verify(ssl, SSL_VERIFY_NONE, tls_verify_call_back);
/* Check CA Chain */
if (setup_data->cert_chain_validation)
SSL_set_verify_depth(ssl, setup_data->cert_chain_verify_depth + 1);
}
return 1;
}
void *coap_dtls_new_client_session(coap_session_t *session) {
BIO *bio = NULL;
SSL *ssl = NULL;
coap_ssl_data *data;
int r;
coap_openssl_context_t *context = ((coap_openssl_context_t *)session->context->dtls_context);
coap_dtls_context_t *dtls = &context->dtls;
ssl = SSL_new(dtls->ctx);
if (!ssl)
goto error;
bio = BIO_new(dtls->meth);
if (!bio)
goto error;
data = (coap_ssl_data *)BIO_get_data(bio);
data->session = session;
SSL_set_bio(ssl, bio, bio);
SSL_set_app_data(ssl, session);
SSL_set_options(ssl, SSL_OP_COOKIE_EXCHANGE);
SSL_set_mtu(ssl, (long)session->mtu);
if (!setup_client_ssl_session(session, ssl))
goto error;
session->dtls_timeout_count = 0;
r = SSL_connect(ssl);
if (r == -1) {
int ret = SSL_get_error(ssl, r);
if (ret != SSL_ERROR_WANT_READ && ret != SSL_ERROR_WANT_WRITE)
r = 0;
}
if (r == 0)
goto error;
return ssl;
error:
if (ssl)
SSL_free(ssl);
return NULL;
}
void coap_dtls_session_update_mtu(coap_session_t *session) {
SSL *ssl = (SSL *)session->tls;
if (ssl)
SSL_set_mtu(ssl, (long)session->mtu);
}
void coap_dtls_free_session(coap_session_t *session) {
SSL *ssl = (SSL *)session->tls;
if (ssl) {
if (!SSL_in_init(ssl) && !(SSL_get_shutdown(ssl) & SSL_SENT_SHUTDOWN)) {
int r = SSL_shutdown(ssl);
if (r == 0) r = SSL_shutdown(ssl);
}
SSL_free(ssl);
session->tls = NULL;
if (session->context)
coap_handle_event(session->context, COAP_EVENT_DTLS_CLOSED, session);
}
}
int coap_dtls_send(coap_session_t *session,
const uint8_t *data, size_t data_len) {
int r;
SSL *ssl = (SSL *)session->tls;
assert(ssl != NULL);
session->dtls_event = -1;
r = SSL_write(ssl, data, (int)data_len);
if (r <= 0) {
int err = SSL_get_error(ssl, r);
if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
r = 0;
} else {
coap_log(LOG_WARNING, "coap_dtls_send: cannot send PDU\n");
if (err == SSL_ERROR_ZERO_RETURN)
session->dtls_event = COAP_EVENT_DTLS_CLOSED;
else if (err == SSL_ERROR_SSL)
session->dtls_event = COAP_EVENT_DTLS_ERROR;
r = -1;
}
}
if (session->dtls_event >= 0) {
/* COAP_EVENT_DTLS_CLOSED event reported in coap_session_disconnected() */
if (session->dtls_event != COAP_EVENT_DTLS_CLOSED)
coap_handle_event(session->context, session->dtls_event, session);
if (session->dtls_event == COAP_EVENT_DTLS_ERROR ||
session->dtls_event == COAP_EVENT_DTLS_CLOSED) {
coap_session_disconnected(session, COAP_NACK_TLS_FAILED);
r = -1;
}
}
return r;
}
int coap_dtls_is_context_timeout(void) {
return 0;
}
coap_tick_t coap_dtls_get_context_timeout(void *dtls_context) {
(void)dtls_context;
return 0;
}
coap_tick_t coap_dtls_get_timeout(coap_session_t *session, coap_tick_t now COAP_UNUSED) {
SSL *ssl = (SSL *)session->tls;
coap_ssl_data *ssl_data;
assert(ssl != NULL && session->state == COAP_SESSION_STATE_HANDSHAKE);
ssl_data = (coap_ssl_data*)BIO_get_data(SSL_get_rbio(ssl));
return ssl_data->timeout;
}
void coap_dtls_handle_timeout(coap_session_t *session) {
SSL *ssl = (SSL *)session->tls;
assert(ssl != NULL && session->state == COAP_SESSION_STATE_HANDSHAKE);
if ((++session->dtls_timeout_count > session->max_retransmit) ||
(DTLSv1_handle_timeout(ssl) < 0)) {
/* Too many retries */
coap_session_disconnected(session, COAP_NACK_TLS_FAILED);
}
}
int coap_dtls_hello(coap_session_t *session,
const uint8_t *data, size_t data_len) {
coap_dtls_context_t *dtls = &((coap_openssl_context_t *)session->context->dtls_context)->dtls;
coap_ssl_data *ssl_data;
int r;
SSL_set_mtu(dtls->ssl, (long)session->mtu);
ssl_data = (coap_ssl_data*)BIO_get_data(SSL_get_rbio(dtls->ssl));
assert(ssl_data != NULL);
if (ssl_data->pdu_len) {
coap_log(LOG_ERR, "** %s: Previous data not read %u bytes\n",
coap_session_str(session), ssl_data->pdu_len);
}
ssl_data->session = session;
ssl_data->pdu = data;
ssl_data->pdu_len = (unsigned)data_len;
r = DTLSv1_listen(dtls->ssl, dtls->bio_addr);
if (r <= 0) {
int err = SSL_get_error(dtls->ssl, r);
if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
/* Got a ClientHello, sent-out a VerifyRequest */
r = 0;
}
} else {
/* Got a valid answer to a VerifyRequest */
r = 1;
}
/*
* Cannot check if data is left on the stack in error as DTLSv1_listen()
* only does a 'peek' read of the incoming data.
*
*/
return r;
}
int coap_dtls_receive(coap_session_t *session,
const uint8_t *data, size_t data_len) {
coap_ssl_data *ssl_data;
SSL *ssl = (SSL *)session->tls;
int r;
assert(ssl != NULL);
int in_init = SSL_in_init(ssl);
uint8_t pdu[COAP_RXBUFFER_SIZE];
ssl_data = (coap_ssl_data*)BIO_get_data(SSL_get_rbio(ssl));
assert(ssl_data != NULL);
if (ssl_data->pdu_len) {
coap_log(LOG_ERR, "** %s: Previous data not read %u bytes\n",
coap_session_str(session), ssl_data->pdu_len);
}
ssl_data->pdu = data;
ssl_data->pdu_len = (unsigned)data_len;
session->dtls_event = -1;
r = SSL_read(ssl, pdu, (int)sizeof(pdu));
if (r > 0) {
r = coap_handle_dgram(session->context, session, pdu, (size_t)r);
goto finished;
} else {
int err = SSL_get_error(ssl, r);
if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
if (in_init && SSL_is_init_finished(ssl)) {
coap_log(COAP_LOG_CIPHERS, "* %s: Using cipher: %s\n",
coap_session_str(session), SSL_get_cipher_name(ssl));
coap_handle_event(session->context, COAP_EVENT_DTLS_CONNECTED, session);
coap_session_connected(session);
}
r = 0;
} else {
if (err == SSL_ERROR_ZERO_RETURN) /* Got a close notify alert from the remote side */
session->dtls_event = COAP_EVENT_DTLS_CLOSED;
else if (err == SSL_ERROR_SSL)
session->dtls_event = COAP_EVENT_DTLS_ERROR;
r = -1;
}
if (session->dtls_event >= 0) {
/* COAP_EVENT_DTLS_CLOSED event reported in coap_session_disconnected() */
if (session->dtls_event != COAP_EVENT_DTLS_CLOSED)
coap_handle_event(session->context, session->dtls_event, session);
if (session->dtls_event == COAP_EVENT_DTLS_ERROR ||
session->dtls_event == COAP_EVENT_DTLS_CLOSED) {
coap_session_disconnected(session, COAP_NACK_TLS_FAILED);
ssl_data = NULL;
r = -1;
}
}
}
finished:
if (ssl_data && ssl_data->pdu_len) {
/* pdu data is held on stack which will not stay there */
coap_log(LOG_DEBUG, "coap_dtls_receive: ret %d: remaining data %u\n", r, ssl_data->pdu_len);
ssl_data->pdu_len = 0;
ssl_data->pdu = NULL;
}
return r;
}
unsigned int coap_dtls_get_overhead(coap_session_t *session) {
unsigned int overhead = 37;
const SSL_CIPHER *s_ciph = NULL;
if (session->tls != NULL)
s_ciph = SSL_get_current_cipher(session->tls);
if ( s_ciph ) {
unsigned int ivlen, maclen, blocksize = 1, pad = 0;
const EVP_CIPHER *e_ciph;
const EVP_MD *e_md;
char cipher[128];
e_ciph = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(s_ciph));
switch (EVP_CIPHER_mode(e_ciph)) {
case EVP_CIPH_GCM_MODE:
ivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
maclen = EVP_GCM_TLS_TAG_LEN;
break;
case EVP_CIPH_CCM_MODE:
ivlen = EVP_CCM_TLS_EXPLICIT_IV_LEN;
SSL_CIPHER_description(s_ciph, cipher, sizeof(cipher));
if (strstr(cipher, "CCM8"))
maclen = 8;
else
maclen = 16;
break;
case EVP_CIPH_CBC_MODE:
e_md = EVP_get_digestbynid(SSL_CIPHER_get_digest_nid(s_ciph));
blocksize = EVP_CIPHER_block_size(e_ciph);
ivlen = EVP_CIPHER_iv_length(e_ciph);
pad = 1;
maclen = EVP_MD_size(e_md);
break;
case EVP_CIPH_STREAM_CIPHER:
/* Seen with PSK-CHACHA20-POLY1305 */
ivlen = 8;
maclen = 8;
break;
default:
SSL_CIPHER_description(s_ciph, cipher, sizeof(cipher));
coap_log(LOG_WARNING, "Unknown overhead for DTLS with cipher %s\n",
cipher);
ivlen = 8;
maclen = 16;
break;
}
overhead = DTLS1_RT_HEADER_LENGTH + ivlen + maclen + blocksize - 1 + pad;
}
return overhead;
}
#if !COAP_DISABLE_TCP
void *coap_tls_new_client_session(coap_session_t *session, int *connected) {
BIO *bio = NULL;
SSL *ssl = NULL;
int r;
coap_openssl_context_t *context = ((coap_openssl_context_t *)session->context->dtls_context);
coap_tls_context_t *tls = &context->tls;
*connected = 0;
ssl = SSL_new(tls->ctx);
if (!ssl)
goto error;
bio = BIO_new(tls->meth);
if (!bio)
goto error;
BIO_set_data(bio, session);
SSL_set_bio(ssl, bio, bio);
SSL_set_app_data(ssl, session);
if (!setup_client_ssl_session(session, ssl))
return 0;
r = SSL_connect(ssl);
if (r == -1) {
int ret = SSL_get_error(ssl, r);
if (ret != SSL_ERROR_WANT_READ && ret != SSL_ERROR_WANT_WRITE)
r = 0;
if (ret == SSL_ERROR_WANT_READ)
session->sock.flags |= COAP_SOCKET_WANT_READ;
if (ret == SSL_ERROR_WANT_WRITE) {
session->sock.flags |= COAP_SOCKET_WANT_WRITE;
#ifdef COAP_EPOLL_SUPPORT
coap_epoll_ctl_mod(&session->sock,
EPOLLOUT |
((session->sock.flags & COAP_SOCKET_WANT_READ) ?
EPOLLIN : 0),
__func__);
#endif /* COAP_EPOLL_SUPPORT */
}
}
if (r == 0)
goto error;
*connected = SSL_is_init_finished(ssl);
return ssl;
error:
if (ssl)
SSL_free(ssl);
return NULL;
}
void *coap_tls_new_server_session(coap_session_t *session, int *connected) {
BIO *bio = NULL;
SSL *ssl = NULL;
coap_tls_context_t *tls = &((coap_openssl_context_t *)session->context->dtls_context)->tls;
int r;
*connected = 0;
ssl = SSL_new(tls->ctx);
if (!ssl)
goto error;
bio = BIO_new(tls->meth);
if (!bio)
goto error;
BIO_set_data(bio, session);
SSL_set_bio(ssl, bio, bio);
SSL_set_app_data(ssl, session);
if (session->context->get_server_hint) {
char hint[COAP_DTLS_HINT_LENGTH] = "";
size_t hint_len = session->context->get_server_hint(session, (uint8_t*)hint, sizeof(hint) - 1);
if (hint_len > 0 && hint_len < sizeof(hint)) {
hint[hint_len] = 0;
SSL_use_psk_identity_hint(ssl, hint);
}
}
r = SSL_accept(ssl);
if (r == -1) {
int err = SSL_get_error(ssl, r);
if (err != SSL_ERROR_WANT_READ && err != SSL_ERROR_WANT_WRITE)
r = 0;
if (err == SSL_ERROR_WANT_READ)
session->sock.flags |= COAP_SOCKET_WANT_READ;
if (err == SSL_ERROR_WANT_WRITE) {
session->sock.flags |= COAP_SOCKET_WANT_WRITE;
#ifdef COAP_EPOLL_SUPPORT
coap_epoll_ctl_mod(&session->sock,
EPOLLOUT |
((session->sock.flags & COAP_SOCKET_WANT_READ) ?
EPOLLIN : 0),
__func__);
#endif /* COAP_EPOLL_SUPPORT */
}
}
if (r == 0)
goto error;
*connected = SSL_is_init_finished(ssl);
return ssl;
error:
if (ssl)
SSL_free(ssl);
return NULL;
}
void coap_tls_free_session(coap_session_t *session) {
SSL *ssl = (SSL *)session->tls;
if (ssl) {
if (!SSL_in_init(ssl) && !(SSL_get_shutdown(ssl) & SSL_SENT_SHUTDOWN)) {
int r = SSL_shutdown(ssl);
if (r == 0) r = SSL_shutdown(ssl);
}
SSL_free(ssl);
session->tls = NULL;
if (session->context)
coap_handle_event(session->context, COAP_EVENT_DTLS_CLOSED, session);
}
}
ssize_t coap_tls_write(coap_session_t *session,
const uint8_t *data,
size_t data_len
) {
SSL *ssl = (SSL *)session->tls;
int r, in_init;
if (ssl == NULL)
return -1;
in_init = !SSL_is_init_finished(ssl);
session->dtls_event = -1;
r = SSL_write(ssl, data, (int)data_len);
if (r <= 0) {
int err = SSL_get_error(ssl, r);
if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
if (in_init && SSL_is_init_finished(ssl)) {
coap_log(COAP_LOG_CIPHERS, "* %s: Using cipher: %s\n",
coap_session_str(session), SSL_get_cipher_name(ssl));
coap_handle_event(session->context, COAP_EVENT_DTLS_CONNECTED, session);
coap_session_send_csm(session);
}
if (err == SSL_ERROR_WANT_READ)
session->sock.flags |= COAP_SOCKET_WANT_READ;
if (err == SSL_ERROR_WANT_WRITE) {
session->sock.flags |= COAP_SOCKET_WANT_WRITE;
#ifdef COAP_EPOLL_SUPPORT
coap_epoll_ctl_mod(&session->sock,
EPOLLOUT |
((session->sock.flags & COAP_SOCKET_WANT_READ) ?
EPOLLIN : 0),
__func__);
#endif /* COAP_EPOLL_SUPPORT */
}
r = 0;
} else {
coap_log(LOG_INFO, "***%s: coap_tls_write: cannot send PDU\n",
coap_session_str(session));
if (err == SSL_ERROR_ZERO_RETURN)
session->dtls_event = COAP_EVENT_DTLS_CLOSED;
else if (err == SSL_ERROR_SSL)
session->dtls_event = COAP_EVENT_DTLS_ERROR;
r = -1;
}
} else if (in_init && SSL_is_init_finished(ssl)) {
coap_log(COAP_LOG_CIPHERS, "* %s: Using cipher: %s\n",
coap_session_str(session), SSL_get_cipher_name(ssl));
coap_handle_event(session->context, COAP_EVENT_DTLS_CONNECTED, session);
coap_session_send_csm(session);
}
if (session->dtls_event >= 0) {
/* COAP_EVENT_DTLS_CLOSED event reported in coap_session_disconnected() */
if (session->dtls_event != COAP_EVENT_DTLS_CLOSED)
coap_handle_event(session->context, session->dtls_event, session);
if (session->dtls_event == COAP_EVENT_DTLS_ERROR ||
session->dtls_event == COAP_EVENT_DTLS_CLOSED) {
coap_session_disconnected(session, COAP_NACK_TLS_FAILED);
r = -1;
}
}
return r;
}
ssize_t coap_tls_read(coap_session_t *session,
uint8_t *data,
size_t data_len
) {
SSL *ssl = (SSL *)session->tls;
int r, in_init;
if (ssl == NULL)
return -1;
in_init = !SSL_is_init_finished(ssl);
session->dtls_event = -1;
r = SSL_read(ssl, data, (int)data_len);
if (r <= 0) {
int err = SSL_get_error(ssl, r);
if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) {
if (in_init && SSL_is_init_finished(ssl)) {
coap_log(COAP_LOG_CIPHERS, "* %s: Using cipher: %s\n",
coap_session_str(session), SSL_get_cipher_name(ssl));
coap_handle_event(session->context, COAP_EVENT_DTLS_CONNECTED, session);
coap_session_send_csm(session);
}
if (err == SSL_ERROR_WANT_READ)
session->sock.flags |= COAP_SOCKET_WANT_READ;
if (err == SSL_ERROR_WANT_WRITE) {
session->sock.flags |= COAP_SOCKET_WANT_WRITE;
#ifdef COAP_EPOLL_SUPPORT
coap_epoll_ctl_mod(&session->sock,
EPOLLOUT |
((session->sock.flags & COAP_SOCKET_WANT_READ) ?
EPOLLIN : 0),
__func__);
#endif /* COAP_EPOLL_SUPPORT */
}
r = 0;
} else {
if (err == SSL_ERROR_ZERO_RETURN) /* Got a close notify alert from the remote side */
session->dtls_event = COAP_EVENT_DTLS_CLOSED;
else if (err == SSL_ERROR_SSL)
session->dtls_event = COAP_EVENT_DTLS_ERROR;
r = -1;
}
} else if (in_init && SSL_is_init_finished(ssl)) {
coap_log(COAP_LOG_CIPHERS, "* %s: Using cipher: %s\n",
coap_session_str(session), SSL_get_cipher_name(ssl));
coap_handle_event(session->context, COAP_EVENT_DTLS_CONNECTED, session);
coap_session_send_csm(session);
}
if (session->dtls_event >= 0) {
/* COAP_EVENT_DTLS_CLOSED event reported in coap_session_disconnected() */
if (session->dtls_event != COAP_EVENT_DTLS_CLOSED)
coap_handle_event(session->context, session->dtls_event, session);
if (session->dtls_event == COAP_EVENT_DTLS_ERROR ||
session->dtls_event == COAP_EVENT_DTLS_CLOSED) {
coap_session_disconnected(session, COAP_NACK_TLS_FAILED);
r = -1;
}
}
return r;
}
#endif /* !COAP_DISABLE_TCP */
coap_digest_ctx_t *
coap_digest_setup(void) {
SHA256_CTX *digest_ctx = OPENSSL_malloc(sizeof(SHA256_CTX));
if (digest_ctx) {
SHA256_Init(digest_ctx);
}
return digest_ctx;
}
void
coap_digest_free(coap_digest_ctx_t *digest_ctx) {
OPENSSL_free(digest_ctx);
}
int
coap_digest_update(coap_digest_ctx_t *digest_ctx,
const uint8_t *data,
size_t data_len) {
return SHA256_Update(digest_ctx, data, data_len);
}
int
coap_digest_final(coap_digest_ctx_t *digest_ctx,
coap_digest_t *digest_buffer) {
int ret = SHA256_Final((uint8_t*)digest_buffer, digest_ctx);
coap_digest_free(digest_ctx);
return ret;
}
#else /* !HAVE_OPENSSL */
#ifdef __clang__
/* Make compilers happy that do not like empty modules. As this function is
* never used, we ignore -Wunused-function at the end of compiling this file
*/
#pragma GCC diagnostic ignored "-Wunused-function"
#endif
static inline void dummy(void) {
}
#endif /* HAVE_OPENSSL */
