nsHttpNegotiateAuth.cpp
/* vim:set ts=4 sw=4 sts=4 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//
// HTTP Negotiate Authentication Support Module
//
// Described by IETF Internet draft: draft-brezak-kerberos-http-00.txt
// (formerly draft-brezak-spnego-http-04.txt)
//
// Also described here:
// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsecure/html/http-sso-1.asp
//
#include <string.h>
#include <stdlib.h>
#include "nsAuth.h"
#include "nsHttpNegotiateAuth.h"
#include "nsIHttpAuthenticableChannel.h"
#include "nsIProxiedChannel.h"
#include "nsIAuthModule.h"
#include "nsIServiceManager.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIProxyInfo.h"
#include "nsIURI.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsNetCID.h"
#include "plbase64.h"
#include "plstr.h"
#include "prprf.h"
#include "prlog.h"
#include "prmem.h"
#include "prnetdb.h"
#include "mozilla/Likely.h"
//-----------------------------------------------------------------------------
static const char kNegotiate[] = "Negotiate";
static const char kNegotiateAuthTrustedURIs[] = "network.negotiate-auth.trusted-uris";
static const char kNegotiateAuthDelegationURIs[] = "network.negotiate-auth.delegation-uris";
static const char kNegotiateAuthAllowProxies[] = "network.negotiate-auth.allow-proxies";
static const char kNegotiateAuthAllowNonFqdn[] = "network.negotiate-auth.allow-non-fqdn";
static const char kNegotiateAuthSSPI[] = "network.auth.use-sspi";
#define kNegotiateLen (sizeof(kNegotiate)-1)
//-----------------------------------------------------------------------------
NS_IMETHODIMP
nsHttpNegotiateAuth::GetAuthFlags(uint32_t *flags)
{
//
// Negotiate Auth creds should not be reused across multiple requests.
// Only perform the negotiation when it is explicitly requested by the
// server. Thus, do *NOT* use the "REUSABLE_CREDENTIALS" flag here.
//
// CONNECTION_BASED is specified instead of REQUEST_BASED since we need
// to complete a sequence of transactions with the server over the same
// connection.
//
*flags = CONNECTION_BASED | IDENTITY_IGNORED;
return NS_OK;
}
//
// Always set *identityInvalid == FALSE here. This
// will prevent the browser from popping up the authentication
// prompt window. Because GSSAPI does not have an API
// for fetching initial credentials (ex: A Kerberos TGT),
// there is no correct way to get the users credentials.
//
NS_IMETHODIMP
nsHttpNegotiateAuth::ChallengeReceived(nsIHttpAuthenticableChannel *authChannel,
const char *challenge,
bool isProxyAuth,
nsISupports **sessionState,
nsISupports **continuationState,
bool *identityInvalid)
{
nsIAuthModule *module = (nsIAuthModule *) *continuationState;
*identityInvalid = false;
if (module)
return NS_OK;
nsresult rv;
nsCOMPtr<nsIURI> uri;
rv = authChannel->GetURI(getter_AddRefs(uri));
if (NS_FAILED(rv))
return rv;
uint32_t req_flags = nsIAuthModule::REQ_DEFAULT;
nsAutoCString service;
if (isProxyAuth) {
if (!TestBoolPref(kNegotiateAuthAllowProxies)) {
LOG(("nsHttpNegotiateAuth::ChallengeReceived proxy auth blocked\n"));
return NS_ERROR_ABORT;
}
nsCOMPtr<nsIProxyInfo> proxyInfo;
authChannel->GetProxyInfo(getter_AddRefs(proxyInfo));
NS_ENSURE_STATE(proxyInfo);
proxyInfo->GetHost(service);
}
else {
bool allowed = TestNonFqdn(uri) ||
TestPref(uri, kNegotiateAuthTrustedURIs);
if (!allowed) {
LOG(("nsHttpNegotiateAuth::ChallengeReceived URI blocked\n"));
return NS_ERROR_ABORT;
}
bool delegation = TestPref(uri, kNegotiateAuthDelegationURIs);
if (delegation) {
LOG((" using REQ_DELEGATE\n"));
req_flags |= nsIAuthModule::REQ_DELEGATE;
}
rv = uri->GetAsciiHost(service);
if (NS_FAILED(rv))
return rv;
}
LOG((" service = %s\n", service.get()));
//
// The correct service name for IIS servers is "HTTP/f.q.d.n", so
// construct the proper service name for passing to "gss_import_name".
//
// TODO: Possibly make this a configurable service name for use
// with non-standard servers that use stuff like "khttp/f.q.d.n"
// instead.
//
service.Insert("HTTP@", 0);
const char *contractID;
if (TestBoolPref(kNegotiateAuthSSPI)) {
LOG((" using negotiate-sspi\n"));
contractID = NS_AUTH_MODULE_CONTRACTID_PREFIX "negotiate-sspi";
}
else {
LOG((" using negotiate-gss\n"));
contractID = NS_AUTH_MODULE_CONTRACTID_PREFIX "negotiate-gss";
}
rv = CallCreateInstance(contractID, &module);
if (NS_FAILED(rv)) {
LOG((" Failed to load Negotiate Module \n"));
return rv;
}
rv = module->Init(service.get(), req_flags, nullptr, nullptr, nullptr);
if (NS_FAILED(rv)) {
NS_RELEASE(module);
return rv;
}
*continuationState = module;
return NS_OK;
}
NS_IMPL_ISUPPORTS1(nsHttpNegotiateAuth, nsIHttpAuthenticator)
//
// GenerateCredentials
//
// This routine is responsible for creating the correct authentication
// blob to pass to the server that requested "Negotiate" authentication.
//
NS_IMETHODIMP
nsHttpNegotiateAuth::GenerateCredentials(nsIHttpAuthenticableChannel *authChannel,
const char *challenge,
bool isProxyAuth,
const PRUnichar *domain,
const PRUnichar *username,
const PRUnichar *password,
nsISupports **sessionState,
nsISupports **continuationState,
uint32_t *flags,
char **creds)
{
// ChallengeReceived must have been called previously.
nsIAuthModule *module = (nsIAuthModule *) *continuationState;
NS_ENSURE_TRUE(module, NS_ERROR_NOT_INITIALIZED);
*flags = USING_INTERNAL_IDENTITY;
LOG(("nsHttpNegotiateAuth::GenerateCredentials() [challenge=%s]\n", challenge));
NS_ASSERTION(creds, "null param");
#ifdef DEBUG
bool isGssapiAuth =
!PL_strncasecmp(challenge, kNegotiate, kNegotiateLen);
NS_ASSERTION(isGssapiAuth, "Unexpected challenge");
#endif
//
// If the "Negotiate:" header had some data associated with it,
// that data should be used as the input to this call. This may
// be a continuation of an earlier call because GSSAPI authentication
// often takes multiple round-trips to complete depending on the
// context flags given. We want to use MUTUAL_AUTHENTICATION which
// generally *does* require multiple round-trips. Don't assume
// auth can be completed in just 1 call.
//
unsigned int len = strlen(challenge);
void *inToken, *outToken;
uint32_t inTokenLen, outTokenLen;
if (len > kNegotiateLen) {
challenge += kNegotiateLen;
while (*challenge == ' ')
challenge++;
len = strlen(challenge);
// strip off any padding (see bug 230351)
while (challenge[len - 1] == '=')
len--;
inTokenLen = (len * 3)/4;
inToken = malloc(inTokenLen);
if (!inToken)
return (NS_ERROR_OUT_OF_MEMORY);
//
// Decode the response that followed the "Negotiate" token
//
if (PL_Base64Decode(challenge, len, (char *) inToken) == NULL) {
free(inToken);
return(NS_ERROR_UNEXPECTED);
}
}
else {
//
// Initializing, don't use an input token.
//
inToken = nullptr;
inTokenLen = 0;
}
nsresult rv = module->GetNextToken(inToken, inTokenLen, &outToken, &outTokenLen);
free(inToken);
if (NS_FAILED(rv))
return rv;
if (outTokenLen == 0) {
LOG((" No output token to send, exiting"));
return NS_ERROR_FAILURE;
}
//
// base64 encode the output token.
//
char *encoded_token = PL_Base64Encode((char *)outToken, outTokenLen, nullptr);
nsMemory::Free(outToken);
if (!encoded_token)
return NS_ERROR_OUT_OF_MEMORY;
LOG((" Sending a token of length %d\n", outTokenLen));
// allocate a buffer sizeof("Negotiate" + " " + b64output_token + "\0")
*creds = (char *) nsMemory::Alloc(kNegotiateLen + 1 + strlen(encoded_token) + 1);
if (MOZ_UNLIKELY(!*creds))
rv = NS_ERROR_OUT_OF_MEMORY;
else
sprintf(*creds, "%s %s", kNegotiate, encoded_token);
PR_Free(encoded_token);
return rv;
}
bool
nsHttpNegotiateAuth::TestBoolPref(const char *pref)
{
nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
if (!prefs)
return false;
bool val;
nsresult rv = prefs->GetBoolPref(pref, &val);
if (NS_FAILED(rv))
return false;
return val;
}
bool
nsHttpNegotiateAuth::TestNonFqdn(nsIURI *uri)
{
nsAutoCString host;
PRNetAddr addr;
if (!TestBoolPref(kNegotiateAuthAllowNonFqdn))
return false;
if (NS_FAILED(uri->GetAsciiHost(host)))
return false;
// return true if host does not contain a dot and is not an ip address
return !host.IsEmpty() && host.FindChar('.') == kNotFound &&
PR_StringToNetAddr(host.BeginReading(), &addr) != PR_SUCCESS;
}
bool
nsHttpNegotiateAuth::TestPref(nsIURI *uri, const char *pref)
{
nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
if (!prefs)
return false;
nsAutoCString scheme, host;
int32_t port;
if (NS_FAILED(uri->GetScheme(scheme)))
return false;
if (NS_FAILED(uri->GetAsciiHost(host)))
return false;
if (NS_FAILED(uri->GetPort(&port)))
return false;
char *hostList;
if (NS_FAILED(prefs->GetCharPref(pref, &hostList)) || !hostList)
return false;
// pseudo-BNF
// ----------
//
// url-list base-url ( base-url "," LWS )*
// base-url ( scheme-part | host-part | scheme-part host-part )
// scheme-part scheme "://"
// host-part host [":" port]
//
// for example:
// "https://, http://office.foo.com"
//
char *start = hostList, *end;
for (;;) {
// skip past any whitespace
while (*start == ' ' || *start == '\t')
++start;
end = strchr(start, ',');
if (!end)
end = start + strlen(start);
if (start == end)
break;
if (MatchesBaseURI(scheme, host, port, start, end))
return true;
if (*end == '\0')
break;
start = end + 1;
}
nsMemory::Free(hostList);
return false;
}
bool
nsHttpNegotiateAuth::MatchesBaseURI(const nsCSubstring &matchScheme,
const nsCSubstring &matchHost,
int32_t matchPort,
const char *baseStart,
const char *baseEnd)
{
// check if scheme://host:port matches baseURI
// parse the base URI
const char *hostStart, *schemeEnd = strstr(baseStart, "://");
if (schemeEnd) {
// the given scheme must match the parsed scheme exactly
if (!matchScheme.Equals(Substring(baseStart, schemeEnd)))
return false;
hostStart = schemeEnd + 3;
}
else
hostStart = baseStart;
// XXX this does not work for IPv6-literals
const char *hostEnd = strchr(hostStart, ':');
if (hostEnd && hostEnd < baseEnd) {
// the given port must match the parsed port exactly
int port = atoi(hostEnd + 1);
if (matchPort != (int32_t) port)
return false;
}
else
hostEnd = baseEnd;
// if we didn't parse out a host, then assume we got a match.
if (hostStart == hostEnd)
return true;
uint32_t hostLen = hostEnd - hostStart;
// matchHost must either equal host or be a subdomain of host
if (matchHost.Length() < hostLen)
return false;
const char *end = matchHost.EndReading();
if (PL_strncasecmp(end - hostLen, hostStart, hostLen) == 0) {
// if matchHost ends with host from the base URI, then make sure it is
// either an exact match, or prefixed with a dot. we don't want
// "foobar.com" to match "bar.com"
if (matchHost.Length() == hostLen ||
*(end - hostLen) == '.' ||
*(end - hostLen - 1) == '.')
return true;
}
return false;
}
