diff -puN -r a/net/third_party/nss/ssl/ssl3con.c b/net/third_party/nss/ssl/ssl3con.c
--- a/net/third_party/nss/ssl/ssl3con.c	2012-11-09 15:34:12.258133766 -0800
+++ b/net/third_party/nss/ssl/ssl3con.c	2012-11-09 15:35:08.488958561 -0800
@@ -2033,6 +2033,9 @@ ssl3_ClientAuthTokenPresent(sslSessionID
     PRBool isPresent = PR_TRUE;
 
     /* we only care if we are doing client auth */
+    /* If NSS_PLATFORM_CLIENT_AUTH is defined and a platformClientKey is being
+     * used, u.ssl3.clAuthValid will be false and this function will always
+     * return PR_TRUE. */
     if (!sid || !sid->u.ssl3.clAuthValid) {
 	return PR_TRUE;
     }
@@ -5226,24 +5229,33 @@ ssl3_SendCertificateVerify(sslSocket *ss
     }
 
     isTLS = (PRBool)(ss->ssl3.pwSpec->version > SSL_LIBRARY_VERSION_3_0);
-    rv = ssl3_SignHashes(&hashes, ss->ssl3.clientPrivateKey, &buf, isTLS);
-    if (rv == SECSuccess) {
-	PK11SlotInfo * slot;
-	sslSessionID * sid   = ss->sec.ci.sid;
+    if (ss->ssl3.platformClientKey) {
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+	rv = ssl3_PlatformSignHashes(&hashes, ss->ssl3.platformClientKey,
+				     &buf, isTLS);
+	ssl_FreePlatformKey(ss->ssl3.platformClientKey);
+	ss->ssl3.platformClientKey = (PlatformKey)NULL;
+#endif /* NSS_PLATFORM_CLIENT_AUTH */
+    } else {
+	rv = ssl3_SignHashes(&hashes, ss->ssl3.clientPrivateKey, &buf, isTLS);
+	if (rv == SECSuccess) {
+	    PK11SlotInfo * slot;
+	    sslSessionID * sid   = ss->sec.ci.sid;
 
-    	/* Remember the info about the slot that did the signing.
-	** Later, when doing an SSL restart handshake, verify this.
-	** These calls are mere accessors, and can't fail.
-	*/
-	slot = PK11_GetSlotFromPrivateKey(ss->ssl3.clientPrivateKey);
-	sid->u.ssl3.clAuthSeries     = PK11_GetSlotSeries(slot);
-	sid->u.ssl3.clAuthSlotID     = PK11_GetSlotID(slot);
-	sid->u.ssl3.clAuthModuleID   = PK11_GetModuleID(slot);
-	sid->u.ssl3.clAuthValid      = PR_TRUE;
-	PK11_FreeSlot(slot);
+	    /* Remember the info about the slot that did the signing.
+	    ** Later, when doing an SSL restart handshake, verify this.
+	    ** These calls are mere accessors, and can't fail.
+	    */
+	    slot = PK11_GetSlotFromPrivateKey(ss->ssl3.clientPrivateKey);
+	    sid->u.ssl3.clAuthSeries     = PK11_GetSlotSeries(slot);
+	    sid->u.ssl3.clAuthSlotID     = PK11_GetSlotID(slot);
+	    sid->u.ssl3.clAuthModuleID   = PK11_GetModuleID(slot);
+	    sid->u.ssl3.clAuthValid      = PR_TRUE;
+	    PK11_FreeSlot(slot);
+	}
+	SECKEY_DestroyPrivateKey(ss->ssl3.clientPrivateKey);
+	ss->ssl3.clientPrivateKey = NULL;
     }
-    SECKEY_DestroyPrivateKey(ss->ssl3.clientPrivateKey);
-    ss->ssl3.clientPrivateKey = NULL;
     if (rv != SECSuccess) {
 	goto done;	/* err code was set by ssl3_SignHashes */
     }
@@ -5311,6 +5323,12 @@ ssl3_HandleServerHello(sslSocket *ss, SS
        SECKEY_DestroyPrivateKey(ss->ssl3.clientPrivateKey);
        ss->ssl3.clientPrivateKey = NULL;
     }
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    if (ss->ssl3.platformClientKey) {
+       ssl_FreePlatformKey(ss->ssl3.platformClientKey);
+       ss->ssl3.platformClientKey = (PlatformKey)NULL;
+    }
+#endif  /* NSS_PLATFORM_CLIENT_AUTH */
 
     temp = ssl3_ConsumeHandshakeNumber(ss, 2, &b, &length);
     if (temp < 0) {
@@ -5901,6 +5919,10 @@ ssl3_HandleCertificateRequest(sslSocket 
     SSL3AlertDescription desc        = illegal_parameter;
     SECItem              cert_types  = {siBuffer, NULL, 0};
     CERTDistNames        ca_list;
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    CERTCertList *       platform_cert_list = NULL;
+    CERTCertListNode *   certNode = NULL;
+#endif  /* NSS_PLATFORM_CLIENT_AUTH */
 
     SSL_TRC(3, ("%d: SSL3[%d]: handle certificate_request handshake",
 		SSL_GETPID(), ss->fd));
@@ -5917,6 +5939,7 @@ ssl3_HandleCertificateRequest(sslSocket 
     PORT_Assert(ss->ssl3.clientCertChain == NULL);
     PORT_Assert(ss->ssl3.clientCertificate == NULL);
     PORT_Assert(ss->ssl3.clientPrivateKey == NULL);
+    PORT_Assert(ss->ssl3.platformClientKey == (PlatformKey)NULL);
 
     isTLS = (PRBool)(ss->ssl3.prSpec->version > SSL_LIBRARY_VERSION_3_0);
     rv = ssl3_ConsumeHandshakeVariable(ss, &cert_types, 1, &b, &length);
@@ -5983,6 +6006,18 @@ ssl3_HandleCertificateRequest(sslSocket 
     desc = no_certificate;
     ss->ssl3.hs.ws = wait_hello_done;
 
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    if (ss->getPlatformClientAuthData != NULL) {
+	/* XXX Should pass cert_types in this call!! */
+        rv = (SECStatus)(*ss->getPlatformClientAuthData)(
+                                        ss->getPlatformClientAuthDataArg,
+                                        ss->fd, &ca_list,
+                                        &platform_cert_list,
+                                        (void**)&ss->ssl3.platformClientKey,
+                                        &ss->ssl3.clientCertificate,
+                                        &ss->ssl3.clientPrivateKey);
+    } else
+#endif
     if (ss->getClientAuthData == NULL) {
 	rv = SECFailure; /* force it to send a no_certificate alert */
     } else {
@@ -5992,12 +6029,52 @@ ssl3_HandleCertificateRequest(sslSocket 
 						 &ss->ssl3.clientCertificate,
 						 &ss->ssl3.clientPrivateKey);
     }
+
     switch (rv) {
     case SECWouldBlock:	/* getClientAuthData has put up a dialog box. */
 	ssl3_SetAlwaysBlock(ss);
 	break;	/* not an error */
 
     case SECSuccess:
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+        if (!platform_cert_list || CERT_LIST_EMPTY(platform_cert_list) ||
+            !ss->ssl3.platformClientKey) {
+            if (platform_cert_list) {
+                CERT_DestroyCertList(platform_cert_list);
+                platform_cert_list = NULL;
+            }
+            if (ss->ssl3.platformClientKey) {
+                ssl_FreePlatformKey(ss->ssl3.platformClientKey);
+                ss->ssl3.platformClientKey = (PlatformKey)NULL;
+            }
+	    /* Fall through to NSS client auth check */
+        } else {
+	    certNode = CERT_LIST_HEAD(platform_cert_list);
+	    ss->ssl3.clientCertificate = CERT_DupCertificate(certNode->cert);
+
+	    /* Setting ssl3.clientCertChain non-NULL will cause
+	     * ssl3_HandleServerHelloDone to call SendCertificate.
+	     * Note: clientCertChain should include the EE cert as
+	     * clientCertificate is ignored during the actual sending
+	     */
+	    ss->ssl3.clientCertChain =
+		    hack_NewCertificateListFromCertList(platform_cert_list);
+	    CERT_DestroyCertList(platform_cert_list);
+	    platform_cert_list = NULL;
+	    if (ss->ssl3.clientCertChain == NULL) {
+		if (ss->ssl3.clientCertificate != NULL) {
+		    CERT_DestroyCertificate(ss->ssl3.clientCertificate);
+		    ss->ssl3.clientCertificate = NULL;
+		}
+		if (ss->ssl3.platformClientKey) {
+		    ssl_FreePlatformKey(ss->ssl3.platformClientKey);
+		    ss->ssl3.platformClientKey = (PlatformKey)NULL;
+		}
+		goto send_no_certificate;
+	    }
+	    break;  /* not an error */
+	}
+#endif   /* NSS_PLATFORM_CLIENT_AUTH */
         /* check what the callback function returned */
         if ((!ss->ssl3.clientCertificate) || (!ss->ssl3.clientPrivateKey)) {
             /* we are missing either the key or cert */
@@ -6060,6 +6137,10 @@ loser:
 done:
     if (arena != NULL)
     	PORT_FreeArena(arena, PR_FALSE);
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    if (platform_cert_list)
+        CERT_DestroyCertList(platform_cert_list);
+#endif
     return rv;
 }
 
@@ -6134,7 +6215,8 @@ ssl3_SendClientSecondRound(sslSocket *ss
 
     sendClientCert = !ss->ssl3.sendEmptyCert &&
 		     ss->ssl3.clientCertChain  != NULL &&
-		     ss->ssl3.clientPrivateKey != NULL;
+		     (ss->ssl3.platformClientKey ||
+		     ss->ssl3.clientPrivateKey != NULL);
 
     /* We must wait for the server's certificate to be authenticated before
      * sending the client certificate in order to disclosing the client
@@ -10446,6 +10528,10 @@ ssl3_DestroySSL3Info(sslSocket *ss)
 
     if (ss->ssl3.clientPrivateKey != NULL)
 	SECKEY_DestroyPrivateKey(ss->ssl3.clientPrivateKey);
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    if (ss->ssl3.platformClientKey)
+	ssl_FreePlatformKey(ss->ssl3.platformClientKey);
+#endif /* NSS_PLATFORM_CLIENT_AUTH */
 
     if (ss->ssl3.peerCertArena != NULL)
 	ssl3_CleanupPeerCerts(ss);
diff -puN -r a/net/third_party/nss/ssl/ssl3ext.c b/net/third_party/nss/ssl/ssl3ext.c
--- a/net/third_party/nss/ssl/ssl3ext.c	2012-11-09 15:34:12.258133766 -0800
+++ b/net/third_party/nss/ssl/ssl3ext.c	2012-11-09 15:35:08.488958561 -0800
@@ -11,8 +11,8 @@
 #include "nssrenam.h"
 #include "nss.h"
 #include "ssl.h"
-#include "sslproto.h"
 #include "sslimpl.h"
+#include "sslproto.h"
 #include "pk11pub.h"
 #ifdef NO_PKCS11_BYPASS
 #include "blapit.h"
diff -puN -r a/net/third_party/nss/ssl/sslauth.c b/net/third_party/nss/ssl/sslauth.c
--- a/net/third_party/nss/ssl/sslauth.c	2012-11-09 15:27:15.952019947 -0800
+++ b/net/third_party/nss/ssl/sslauth.c	2012-11-09 15:35:08.488958561 -0800
@@ -219,6 +219,28 @@ SSL_GetClientAuthDataHook(PRFileDesc *s,
     return SECSuccess;
 }
 
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+/* NEED LOCKS IN HERE.  */
+SECStatus 
+SSL_GetPlatformClientAuthDataHook(PRFileDesc *s,
+                                  SSLGetPlatformClientAuthData func,
+                                  void *arg)
+{
+    sslSocket *ss;
+
+    ss = ssl_FindSocket(s);
+    if (!ss) {
+	SSL_DBG(("%d: SSL[%d]: bad socket in GetPlatformClientAuthDataHook",
+		 SSL_GETPID(), s));
+	return SECFailure;
+    }
+
+    ss->getPlatformClientAuthData = func;
+    ss->getPlatformClientAuthDataArg = arg;
+    return SECSuccess;
+}
+#endif   /* NSS_PLATFORM_CLIENT_AUTH */
+
 /* NEED LOCKS IN HERE.  */
 SECStatus 
 SSL_SetPKCS11PinArg(PRFileDesc *s, void *arg)
diff -puN -r a/net/third_party/nss/ssl/ssl.h b/net/third_party/nss/ssl/ssl.h
--- a/net/third_party/nss/ssl/ssl.h	2012-11-09 15:34:12.258133766 -0800
+++ b/net/third_party/nss/ssl/ssl.h	2012-11-09 15:35:08.488958561 -0800
@@ -483,6 +483,48 @@ typedef SECStatus (PR_CALLBACK *SSLGetCl
 SSL_IMPORT SECStatus SSL_GetClientAuthDataHook(PRFileDesc *fd, 
 			                       SSLGetClientAuthData f, void *a);
 
+/*
+ * Prototype for SSL callback to get client auth data from the application,
+ * optionally using the underlying platform's cryptographic primitives.
+ * To use the platform cryptographic primitives, caNames and pRetCerts
+ * should be set.  To use NSS, pRetNSSCert and pRetNSSKey should be set.
+ * Returning SECFailure will cause the socket to send no client certificate.
+ *	arg - application passed argument
+ *	caNames - pointer to distinguished names of CAs that the server likes
+ *	pRetCerts - pointer to pointer to list of certs, with the first being
+ *		    the client cert, and any following being used for chain
+ *		    building
+ *	pRetKey - pointer to native key pointer, for return of key
+ *          - Windows: A pointer to a PCERT_KEY_CONTEXT that was allocated
+ *                     via PORT_Alloc(). Ownership of the PCERT_KEY_CONTEXT
+ *                     is transferred to NSS, which will free via
+ *                     PORT_Free().
+ *          - Mac OS X: A pointer to a SecKeyRef. Ownership is
+ *                      transferred to NSS, which will free via CFRelease().
+ *	pRetNSSCert - pointer to pointer to NSS cert, for return of cert.
+ *	pRetNSSKey - pointer to NSS key pointer, for return of key.
+ */
+typedef SECStatus (PR_CALLBACK *SSLGetPlatformClientAuthData)(void *arg,
+                                PRFileDesc *fd,
+                                CERTDistNames *caNames,
+                                CERTCertList **pRetCerts,/*return */
+                                void **pRetKey,/* return */
+                                CERTCertificate **pRetNSSCert,/*return */
+                                SECKEYPrivateKey **pRetNSSKey);/* return */
+
+/*
+ * Set the client side callback for SSL to retrieve user's private key
+ * and certificate.
+ * Note: If a platform client auth callback is set, the callback configured by
+ * SSL_GetClientAuthDataHook, if any, will not be called.
+ *
+ *	fd - the file descriptor for the connection in question
+ *	f - the application's callback that delivers the key and cert
+ *	a - application specific data
+ */
+SSL_IMPORT SECStatus
+SSL_GetPlatformClientAuthDataHook(PRFileDesc *fd,
+                                  SSLGetPlatformClientAuthData f, void *a);
 
 /*
 ** SNI extension processing callback function.
diff -puN -r a/net/third_party/nss/ssl/sslimpl.h b/net/third_party/nss/ssl/sslimpl.h
--- a/net/third_party/nss/ssl/sslimpl.h	2012-11-09 15:34:12.258133766 -0800
+++ b/net/third_party/nss/ssl/sslimpl.h	2012-11-09 15:36:42.600338478 -0800
@@ -32,6 +32,15 @@
 
 #include "sslt.h" /* for some formerly private types, now public */
 
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+#if defined(XP_WIN32)
+#include <windows.h>
+#include <wincrypt.h>
+#elif defined(XP_MACOSX)
+#include <Security/Security.h>
+#endif
+#endif
+
 /* to make some of these old enums public without namespace pollution,
 ** it was necessary to prepend ssl_ to the names.
 ** These #defines preserve compatibility with the old code here in libssl.
@@ -446,6 +455,14 @@ typedef SECStatus (*SSLCompressor)(void 
                                    int                  inlen);
 typedef SECStatus (*SSLDestroy)(void *context, PRBool freeit);
 
+#if defined(NSS_PLATFORM_CLIENT_AUTH) && defined(XP_WIN32)
+typedef PCERT_KEY_CONTEXT PlatformKey;
+#elif defined(NSS_PLATFORM_CLIENT_AUTH) && defined(XP_MACOSX)
+typedef SecKeyRef PlatformKey;
+#else
+typedef void *PlatformKey;
+#endif
+
 
 
 /*
@@ -870,6 +887,10 @@ struct ssl3StateStr {
 
     CERTCertificate *    clientCertificate;  /* used by client */
     SECKEYPrivateKey *   clientPrivateKey;   /* used by client */
+    /* platformClientKey is present even when NSS_PLATFORM_CLIENT_AUTH is not
+     * defined in order to allow cleaner conditional code.
+     * At most one of clientPrivateKey and platformClientKey may be set. */
+    PlatformKey          platformClientKey;  /* used by client */
     CERTCertificateList *clientCertChain;    /* used by client */
     PRBool               sendEmptyCert;      /* used by client */
 
@@ -1127,6 +1148,10 @@ const unsigned char *  preferredCipher;
     void                     *authCertificateArg;
     SSLGetClientAuthData      getClientAuthData;
     void                     *getClientAuthDataArg;
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    SSLGetPlatformClientAuthData getPlatformClientAuthData;
+    void                        *getPlatformClientAuthDataArg;
+#endif  /* NSS_PLATFORM_CLIENT_AUTH */
     SSLSNISocketConfig        sniSocketConfig;
     void                     *sniSocketConfigArg;
     SSLBadCertHandler         handleBadCert;
@@ -1700,7 +1725,6 @@ extern void ssl_FreePRSocket(PRFileDesc 
  * various ciphers */
 extern int ssl3_config_match_init(sslSocket *);
 
-
 /* Create a new ref counted key pair object from two keys. */
 extern ssl3KeyPair * ssl3_NewKeyPair( SECKEYPrivateKey * privKey, 
                                       SECKEYPublicKey * pubKey);
@@ -1740,6 +1764,26 @@ extern SECStatus ssl_InitSessionCacheLoc
 
 extern SECStatus ssl_FreeSessionCacheLocks(void);
 
+/***************** platform client auth ****************/
+
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+// Releases the platform key.
+extern void ssl_FreePlatformKey(PlatformKey key);
+
+// Implement the client CertificateVerify message for SSL3/TLS1.0
+extern SECStatus ssl3_PlatformSignHashes(SSL3Hashes *hash,
+                                         PlatformKey key, SECItem *buf,
+                                         PRBool isTLS);
+
+// Converts a CERTCertList* (A collection of CERTCertificates) into a
+// CERTCertificateList* (A collection of SECItems), or returns NULL if
+// it cannot be converted.
+// This is to allow the platform-supplied chain to be created with purely
+// public API functions, using the preferred CERTCertList mutators, rather
+// pushing this hack to clients.
+extern CERTCertificateList* hack_NewCertificateListFromCertList(
+        CERTCertList* list);
+#endif  /* NSS_PLATFORM_CLIENT_AUTH */
 
 /**************** DTLS-specific functions **************/
 extern void dtls_FreeQueuedMessage(DTLSQueuedMessage *msg);
diff -puN -r a/net/third_party/nss/ssl/sslplatf.c b/net/third_party/nss/ssl/sslplatf.c
--- a/net/third_party/nss/ssl/sslplatf.c	1969-12-31 16:00:00.000000000 -0800
+++ b/net/third_party/nss/ssl/sslplatf.c	2012-11-09 15:35:08.498958708 -0800
@@ -0,0 +1,399 @@
+/*
+ * Platform specific crypto wrappers
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the Netscape security libraries.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1994-2000
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Ryan Sleevi <ryan.sleevi@gmail.com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+/* $Id$ */
+#include "ssl.h"
+#include "certt.h"
+#include "keythi.h"
+#include "sslimpl.h"
+#include "cryptohi.h"
+#include "secitem.h"
+
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+CERTCertificateList*
+hack_NewCertificateListFromCertList(CERTCertList* list)
+{
+    CERTCertificateList * chain = NULL;
+    PRArenaPool * arena = NULL;
+    CERTCertListNode * node;
+    int len;
+
+    if (CERT_LIST_EMPTY(list))
+        goto loser;
+
+    arena = PORT_NewArena(4096);
+    if (arena == NULL)
+        goto loser;
+
+    for (len = 0, node = CERT_LIST_HEAD(list); !CERT_LIST_END(node, list);
+        len++, node = CERT_LIST_NEXT(node)) {
+    }
+
+    chain = PORT_ArenaNew(arena, CERTCertificateList);
+    if (chain == NULL)
+        goto loser;
+
+    chain->certs = PORT_ArenaNewArray(arena, SECItem, len);
+    if (!chain->certs)
+        goto loser;
+    chain->len = len;
+
+    for (len = 0, node = CERT_LIST_HEAD(list); !CERT_LIST_END(node, list);
+        len++, node = CERT_LIST_NEXT(node)) {
+        // Check to see if the last cert to be sent is a self-signed cert,
+        // and if so, omit it from the list of certificates. However, if
+        // there is only one cert (len == 0), include the cert, as it means
+        // the EE cert is self-signed.
+        if (len > 0 && (len == chain->len - 1) && node->cert->isRoot) {
+            chain->len = len;
+            break;
+        }
+        SECITEM_CopyItem(arena, &chain->certs[len], &node->cert->derCert);
+    }
+
+    chain->arena = arena;
+    return chain;
+
+loser:
+    if (arena) {
+        PORT_FreeArena(arena, PR_FALSE);
+    }
+    return NULL;
+}
+
+#if defined(XP_WIN32)
+void
+ssl_FreePlatformKey(PlatformKey key)
+{
+    if (key) {
+        if (key->dwKeySpec != CERT_NCRYPT_KEY_SPEC)
+            CryptReleaseContext(key->hCryptProv, 0);
+        /* FIXME(rsleevi): Close CNG keys. */
+        PORT_Free(key);
+    }
+}
+
+SECStatus
+ssl3_PlatformSignHashes(SSL3Hashes *hash, PlatformKey key, SECItem *buf, 
+                        PRBool isTLS)
+{
+    SECStatus    rv             = SECFailure;
+    PRBool       doDerEncode    = PR_FALSE;
+    SECItem      hashItem;
+    HCRYPTKEY    hKey           = 0;
+    DWORD        argLen         = 0;
+    ALG_ID       keyAlg         = 0;
+    DWORD        signatureLen   = 0;
+    ALG_ID       hashAlg        = 0;
+    HCRYPTHASH   hHash          = 0;
+    DWORD        hashLen        = 0;
+    unsigned int i              = 0;
+
+    buf->data = NULL;
+    if (!CryptGetUserKey(key->hCryptProv, key->dwKeySpec, &hKey)) {
+        if (GetLastError() == NTE_NO_KEY) {
+            PORT_SetError(SEC_ERROR_NO_KEY);
+        } else {
+            PORT_SetError(SEC_ERROR_INVALID_KEY);
+        }
+        goto done;
+    }
+
+    argLen = sizeof(keyAlg);
+    if (!CryptGetKeyParam(hKey, KP_ALGID, (BYTE*)&keyAlg, &argLen, 0)) {
+        PORT_SetError(SEC_ERROR_INVALID_KEY);
+        goto done;
+    }
+
+    switch (keyAlg) {
+        case CALG_RSA_KEYX:
+        case CALG_RSA_SIGN:
+            hashAlg       = CALG_SSL3_SHAMD5;
+            hashItem.data = hash->md5;
+            hashItem.len  = sizeof(SSL3Hashes);
+            break;
+        case CALG_DSS_SIGN:
+        case CALG_ECDSA:
+            if (keyAlg == CALG_ECDSA) {
+                doDerEncode = PR_TRUE;
+            } else {
+                doDerEncode = isTLS;
+            }
+            hashAlg       = CALG_SHA1;
+            hashItem.data = hash->sha;
+            hashItem.len  = sizeof(hash->sha);
+            break;
+        default:
+            PORT_SetError(SEC_ERROR_INVALID_KEY);
+            goto done;
+    }
+    PRINT_BUF(60, (NULL, "hash(es) to be signed", hashItem.data, hashItem.len));
+
+    if (!CryptCreateHash(key->hCryptProv, hashAlg, 0, 0, &hHash)) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;    
+    }
+    argLen = sizeof(hashLen);
+    if (!CryptGetHashParam(hHash, HP_HASHSIZE, (BYTE*)&hashLen, &argLen, 0)) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+    if (hashLen != hashItem.len) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+    if (!CryptSetHashParam(hHash, HP_HASHVAL, (BYTE*)hashItem.data, 0)) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+    if (!CryptSignHash(hHash, key->dwKeySpec, NULL, 0,
+                       NULL, &signatureLen) || signatureLen == 0) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+    buf->data = (unsigned char *)PORT_Alloc(signatureLen);
+    if (!buf->data)
+        goto done;    /* error code was set. */
+
+    if (!CryptSignHash(hHash, key->dwKeySpec, NULL, 0,
+                       (BYTE*)buf->data, &signatureLen)) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+    buf->len = signatureLen;
+
+    /* CryptoAPI signs in little-endian, so reverse */
+    for (i = 0; i < buf->len / 2; ++i) {
+        unsigned char tmp = buf->data[i];
+        buf->data[i] = buf->data[buf->len - 1 - i];
+        buf->data[buf->len - 1 - i] = tmp;
+    }
+    if (doDerEncode) {
+        SECItem   derSig = {siBuffer, NULL, 0};
+
+        /* This also works for an ECDSA signature */
+        rv = DSAU_EncodeDerSigWithLen(&derSig, buf, buf->len);
+        if (rv == SECSuccess) {
+            PORT_Free(buf->data);     /* discard unencoded signature. */
+            *buf = derSig;            /* give caller encoded signature. */
+        } else if (derSig.data) {
+            PORT_Free(derSig.data);
+        }
+    } else {
+        rv = SECSuccess;
+    }
+
+    PRINT_BUF(60, (NULL, "signed hashes", buf->data, buf->len));
+done:
+    if (hHash)
+        CryptDestroyHash(hHash);
+    if (hKey)
+        CryptDestroyKey(hKey);
+    if (rv != SECSuccess && buf->data) {
+        PORT_Free(buf->data);
+        buf->data = NULL;
+    }
+    return rv;
+}
+
+#elif defined(XP_MACOSX)
+#include <Security/cssm.h>
+
+void
+ssl_FreePlatformKey(PlatformKey key)
+{
+    CFRelease(key);
+}
+
+SECStatus
+ssl3_PlatformSignHashes(SSL3Hashes *hash, PlatformKey key, SECItem *buf, 
+                        PRBool isTLS)
+{
+    SECStatus       rv                  = SECFailure;
+    PRBool          doDerEncode         = PR_FALSE;
+    unsigned int    signatureLen;
+    OSStatus        status              = noErr;
+    CSSM_CSP_HANDLE cspHandle           = 0;
+    const CSSM_KEY *cssmKey             = NULL;
+    CSSM_ALGORITHMS sigAlg;
+    const CSSM_ACCESS_CREDENTIALS * cssmCreds = NULL;
+    CSSM_RETURN     cssmRv;
+    CSSM_DATA       hashData;
+    CSSM_DATA       signatureData;
+    CSSM_CC_HANDLE  cssmSignature       = 0;
+
+    buf->data = NULL;
+
+    status = SecKeyGetCSPHandle(key, &cspHandle);
+    if (status != noErr) {
+        PORT_SetError(SEC_ERROR_INVALID_KEY);
+        goto done;
+    }
+
+    status = SecKeyGetCSSMKey(key, &cssmKey);
+    if (status != noErr || !cssmKey) {
+        PORT_SetError(SEC_ERROR_NO_KEY);
+        goto done;
+    }
+
+    /* SecKeyGetBlockSize wasn't addeded until OS X 10.6 - but the
+     * needed information is readily available on the key itself.
+     */
+    signatureLen = (cssmKey->KeyHeader.LogicalKeySizeInBits + 7) / 8;
+    
+    if (signatureLen == 0) {
+        PORT_SetError(SEC_ERROR_INVALID_KEY);
+        goto done;
+    }
+
+    buf->data = (unsigned char *)PORT_Alloc(signatureLen);
+    if (!buf->data)
+        goto done;    /* error code was set. */
+
+    sigAlg = cssmKey->KeyHeader.AlgorithmId;
+    switch (sigAlg) {
+        case CSSM_ALGID_RSA:
+            hashData.Data   = hash->md5;
+            hashData.Length = sizeof(SSL3Hashes);
+            break;
+        case CSSM_ALGID_ECDSA:
+        case CSSM_ALGID_DSA:
+            if (sigAlg == CSSM_ALGID_ECDSA) {
+                doDerEncode = PR_TRUE;
+            } else {
+                doDerEncode = isTLS;
+            }
+            hashData.Data   = hash->sha;
+            hashData.Length = sizeof(hash->sha);
+            break;
+        default:
+            PORT_SetError(SEC_ERROR_INVALID_KEY);
+            goto done;
+    }
+    PRINT_BUF(60, (NULL, "hash(es) to be signed", hashData.Data, hashData.Length));
+
+    /* TODO(rsleevi): Should it be kSecCredentialTypeNoUI? In Win32, at least,
+     * you can prevent the UI by setting the provider handle on the
+     * certificate to be opened with CRYPT_SILENT, but is there an equivalent?
+     */
+    status = SecKeyGetCredentials(key, CSSM_ACL_AUTHORIZATION_SIGN,
+                                  kSecCredentialTypeDefault, &cssmCreds);
+    if (status != noErr) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+
+    signatureData.Length = signatureLen;
+    signatureData.Data   = (uint8*)buf->data;
+    
+    cssmRv = CSSM_CSP_CreateSignatureContext(cspHandle, sigAlg, cssmCreds,
+                                             cssmKey, &cssmSignature);
+    if (cssmRv) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+
+    /* See "Apple Cryptographic Service Provider Functional Specification" */
+    if (cssmKey->KeyHeader.AlgorithmId == CSSM_ALGID_RSA) {
+        /* To set RSA blinding for RSA keys */
+        CSSM_CONTEXT_ATTRIBUTE blindingAttr;
+        blindingAttr.AttributeType   = CSSM_ATTRIBUTE_RSA_BLINDING;
+        blindingAttr.AttributeLength = sizeof(uint32);
+        blindingAttr.Attribute.Uint32 = 1;
+        cssmRv = CSSM_UpdateContextAttributes(cssmSignature, 1, &blindingAttr);
+        if (cssmRv) {
+            PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+            goto done;
+        }
+    }
+
+    cssmRv = CSSM_SignData(cssmSignature, &hashData, 1, CSSM_ALGID_NONE,
+                           &signatureData);
+    if (cssmRv) {
+        PORT_SetError(SSL_ERROR_SIGN_HASHES_FAILURE);
+        goto done;
+    }
+    buf->len = signatureData.Length;
+
+    if (doDerEncode) {
+        SECItem derSig = {siBuffer, NULL, 0};
+
+        /* This also works for an ECDSA signature */
+        rv = DSAU_EncodeDerSigWithLen(&derSig, buf, buf->len);
+        if (rv == SECSuccess) {
+            PORT_Free(buf->data);     /* discard unencoded signature. */
+            *buf = derSig;            /* give caller encoded signature. */
+        } else if (derSig.data) {
+            PORT_Free(derSig.data);
+        }
+    } else {
+        rv = SECSuccess;
+    }
+
+    PRINT_BUF(60, (NULL, "signed hashes", buf->data, buf->len));
+done:
+    /* cspHandle, cssmKey, and cssmCreds are owned by the SecKeyRef and
+     * should not be freed. When the PlatformKey is freed, they will be
+     * released.
+     */
+    if (cssmSignature)
+        CSSM_DeleteContext(cssmSignature);
+
+    if (rv != SECSuccess && buf->data) {
+        PORT_Free(buf->data);
+        buf->data = NULL;
+    }
+    return rv;
+}
+#else
+void
+ssl_FreePlatformKey(PlatformKey key)
+{
+}
+
+SECStatus
+ssl3_PlatformSignHashes(SSL3Hashes *hash, PlatformKey key, SECItem *buf,
+                        PRBool isTLS)
+{
+    PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
+    return SECFailure;
+}
+#endif
+
+#endif /* NSS_PLATFORM_CLIENT_AUTH */
diff -puN -r a/net/third_party/nss/ssl/sslsock.c b/net/third_party/nss/ssl/sslsock.c
--- a/net/third_party/nss/ssl/sslsock.c	2012-11-09 15:34:12.268133912 -0800
+++ b/net/third_party/nss/ssl/sslsock.c	2012-11-09 15:35:08.498958708 -0800
@@ -335,6 +335,10 @@ ssl_DupSocket(sslSocket *os)
 	    ss->authCertificateArg    = os->authCertificateArg;
 	    ss->getClientAuthData     = os->getClientAuthData;
 	    ss->getClientAuthDataArg  = os->getClientAuthDataArg;
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+	    ss->getPlatformClientAuthData    = os->getPlatformClientAuthData;
+	    ss->getPlatformClientAuthDataArg = os->getPlatformClientAuthDataArg;
+#endif
             ss->sniSocketConfig       = os->sniSocketConfig;
             ss->sniSocketConfigArg    = os->sniSocketConfigArg;
 	    ss->handleBadCert         = os->handleBadCert;
@@ -1712,6 +1716,12 @@ SSL_ReconfigFD(PRFileDesc *model, PRFile
         ss->getClientAuthData     = sm->getClientAuthData;
     if (sm->getClientAuthDataArg)
         ss->getClientAuthDataArg  = sm->getClientAuthDataArg;
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+    if (sm->getPlatformClientAuthData)
+        ss->getPlatformClientAuthData    = sm->getPlatformClientAuthData;
+    if (sm->getPlatformClientAuthDataArg)
+        ss->getPlatformClientAuthDataArg = sm->getPlatformClientAuthDataArg;
+#endif
     if (sm->sniSocketConfig)
         ss->sniSocketConfig       = sm->sniSocketConfig;
     if (sm->sniSocketConfigArg)
@@ -2942,6 +2952,10 @@ ssl_NewSocket(PRBool makeLocks, SSLProto
         ss->sniSocketConfig    = NULL;
         ss->sniSocketConfigArg = NULL;
 	ss->getClientAuthData  = NULL;
+#ifdef NSS_PLATFORM_CLIENT_AUTH
+	ss->getPlatformClientAuthData = NULL;
+	ss->getPlatformClientAuthDataArg = NULL;
+#endif   /* NSS_PLATFORM_CLIENT_AUTH */
 	ss->handleBadCert      = NULL;
 	ss->badCertArg         = NULL;
 	ss->pkcs11PinArg       = NULL;