Revision 4f2112351b4ac964b0249bdd883f7b79601f39d8 authored by Linus Torvalds on 22 April 2015, 18:27:36 UTC, committed by Linus Torvalds on 22 April 2015, 18:27:36 UTC
Pull tracing fixes from Steven Rostedt: "This adds three fixes for the tracing code. The first is a bug when ftrace_dump_on_oops is triggered in atomic context and function graph tracer is the tracer that is being reported. The second fix is bad parsing of the trace_events from the kernel command line, where it would ignore specific events if the system name is used with defining the event(it enables all events within the system). The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was missing to see if the ptr was incremented to the end of the string, but the loop increments it again and can miss the nul delimiter to stop processing" * tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix possible out of bounds memory access when parsing enums tracing: Fix incorrect enabling of trace events by boot cmdline tracing: Handle ftrace_dump() atomic context in graph_trace_open()
digsig.c
/*
* Copyright (C) 2011 Nokia Corporation
* Copyright (C) 2011 Intel Corporation
*
* Author:
* Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
* <dmitry.kasatkin@intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2 of the License.
*
* File: sign.c
* implements signature (RSA) verification
* pkcs decoding is based on LibTomCrypt code
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/err.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/key.h>
#include <linux/crypto.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <keys/user-type.h>
#include <linux/mpi.h>
#include <linux/digsig.h>
static struct crypto_shash *shash;
static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
unsigned long msglen,
unsigned long modulus_bitlen,
unsigned long *outlen)
{
unsigned long modulus_len, ps_len, i;
modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0);
/* test message size */
if ((msglen > modulus_len) || (modulus_len < 11))
return NULL;
/* separate encoded message */
if (msg[0] != 0x00 || msg[1] != 0x01)
return NULL;
for (i = 2; i < modulus_len - 1; i++)
if (msg[i] != 0xFF)
break;
/* separator check */
if (msg[i] != 0)
/* There was no octet with hexadecimal value 0x00
to separate ps from m. */
return NULL;
ps_len = i - 2;
*outlen = (msglen - (2 + ps_len + 1));
return msg + 2 + ps_len + 1;
}
/*
* RSA Signature verification with public key
*/
static int digsig_verify_rsa(struct key *key,
const char *sig, int siglen,
const char *h, int hlen)
{
int err = -EINVAL;
unsigned long len;
unsigned long mlen, mblen;
unsigned nret, l;
int head, i;
unsigned char *out1 = NULL;
const char *m;
MPI in = NULL, res = NULL, pkey[2];
uint8_t *p, *datap, *endp;
struct user_key_payload *ukp;
struct pubkey_hdr *pkh;
down_read(&key->sem);
ukp = key->payload.data;
if (ukp->datalen < sizeof(*pkh))
goto err1;
pkh = (struct pubkey_hdr *)ukp->data;
if (pkh->version != 1)
goto err1;
if (pkh->algo != PUBKEY_ALGO_RSA)
goto err1;
if (pkh->nmpi != 2)
goto err1;
datap = pkh->mpi;
endp = ukp->data + ukp->datalen;
err = -ENOMEM;
for (i = 0; i < pkh->nmpi; i++) {
unsigned int remaining = endp - datap;
pkey[i] = mpi_read_from_buffer(datap, &remaining);
if (!pkey[i])
goto err;
datap += remaining;
}
mblen = mpi_get_nbits(pkey[0]);
mlen = DIV_ROUND_UP(mblen, 8);
if (mlen == 0)
goto err;
out1 = kzalloc(mlen, GFP_KERNEL);
if (!out1)
goto err;
nret = siglen;
in = mpi_read_from_buffer(sig, &nret);
if (!in)
goto err;
res = mpi_alloc(mpi_get_nlimbs(in) * 2);
if (!res)
goto err;
err = mpi_powm(res, in, pkey[1], pkey[0]);
if (err)
goto err;
if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) {
err = -EINVAL;
goto err;
}
p = mpi_get_buffer(res, &l, NULL);
if (!p) {
err = -EINVAL;
goto err;
}
len = mlen;
head = len - l;
memset(out1, 0, head);
memcpy(out1 + head, p, l);
kfree(p);
m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
if (!m || len != hlen || memcmp(m, h, hlen))
err = -EINVAL;
err:
mpi_free(in);
mpi_free(res);
kfree(out1);
while (--i >= 0)
mpi_free(pkey[i]);
err1:
up_read(&key->sem);
return err;
}
/**
* digsig_verify() - digital signature verification with public key
* @keyring: keyring to search key in
* @sig: digital signature
* @siglen: length of the signature
* @data: data
* @datalen: length of the data
*
* Returns 0 on success, -EINVAL otherwise
*
* Verifies data integrity against digital signature.
* Currently only RSA is supported.
* Normally hash of the content is used as a data for this function.
*
*/
int digsig_verify(struct key *keyring, const char *sig, int siglen,
const char *data, int datalen)
{
int err = -ENOMEM;
struct signature_hdr *sh = (struct signature_hdr *)sig;
struct shash_desc *desc = NULL;
unsigned char hash[SHA1_DIGEST_SIZE];
struct key *key;
char name[20];
if (siglen < sizeof(*sh) + 2)
return -EINVAL;
if (sh->algo != PUBKEY_ALGO_RSA)
return -ENOTSUPP;
sprintf(name, "%llX", __be64_to_cpup((uint64_t *)sh->keyid));
if (keyring) {
/* search in specific keyring */
key_ref_t kref;
kref = keyring_search(make_key_ref(keyring, 1UL),
&key_type_user, name);
if (IS_ERR(kref))
key = ERR_CAST(kref);
else
key = key_ref_to_ptr(kref);
} else {
key = request_key(&key_type_user, name, NULL);
}
if (IS_ERR(key)) {
pr_err("key not found, id: %s\n", name);
return PTR_ERR(key);
}
desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash),
GFP_KERNEL);
if (!desc)
goto err;
desc->tfm = shash;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
crypto_shash_init(desc);
crypto_shash_update(desc, data, datalen);
crypto_shash_update(desc, sig, sizeof(*sh));
crypto_shash_final(desc, hash);
kfree(desc);
/* pass signature mpis address */
err = digsig_verify_rsa(key, sig + sizeof(*sh), siglen - sizeof(*sh),
hash, sizeof(hash));
err:
key_put(key);
return err ? -EINVAL : 0;
}
EXPORT_SYMBOL_GPL(digsig_verify);
static int __init digsig_init(void)
{
shash = crypto_alloc_shash("sha1", 0, 0);
if (IS_ERR(shash)) {
pr_err("shash allocation failed\n");
return PTR_ERR(shash);
}
return 0;
}
static void __exit digsig_cleanup(void)
{
crypto_free_shash(shash);
}
module_init(digsig_init);
module_exit(digsig_cleanup);
MODULE_LICENSE("GPL");
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