Add a boolean |had_context| argument to the TLS ExportKeyingMaterial

net/third_party/nss/ssl/sslinfo.c

 /* ***** 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
@@ skipping 299 matching lines @@
 {
     unsigned int i;
     for (i = 0; i < NUM_SUITEINFOS; i++) {
         if (suiteInfo[i].cipherSuite == cipherSuite) {
             return (PRBool)(suiteInfo[i].isExportable);
         }
     }
     return PR_FALSE;
 }
 
-/* Export keying material according to RFC 5705.
-** fd must correspond to a TLS 1.0 or higher socket, out must
-** be already allocated.
-*/
 SECStatus
 SSL_ExportKeyingMaterial(PRFileDesc *fd,
-                         const char *label,
-                         unsigned int labelLen,
-                         const unsigned char *context,
-                         unsigned int contextLen,
-                         unsigned char *out,
-                         unsigned int outLen)
+                         const char *label, unsigned int labelLen,
+                         PRBool hasContext,
+                         const unsigned char *context, unsigned int contextLen,
+                         unsigned char *out, unsigned int outLen)
 {
     sslSocket *ss;
     unsigned char *val = NULL;
     unsigned int valLen, i;
     SECStatus rv = SECFailure;
 
     ss = ssl_FindSocket(fd);
     if (!ss) {
         SSL_DBG(("%d: SSL[%d]: bad socket in ExportKeyingMaterial",
                  SSL_GETPID(), fd));
         return SECFailure;
     }
 
     if (ss->version < SSL_LIBRARY_VERSION_3_1_TLS) {
         PORT_SetError(SSL_ERROR_UNSUPPORTED_VERSION);
         return SECFailure;
     }
 
+    /* construct PRF arguments */
     valLen = SSL3_RANDOM_LENGTH * 2;
-    if (contextLen > 0)
+    if (hasContext) {
         valLen += 2 /* uint16 length */ + contextLen;
+    }
     val = PORT_Alloc(valLen);
-    if (val == NULL)
+    if (!val) {
         return SECFailure;
+    }
     i = 0;
     PORT_Memcpy(val + i, &ss->ssl3.hs.client_random.rand, SSL3_RANDOM_LENGTH);
     i += SSL3_RANDOM_LENGTH;
     PORT_Memcpy(val + i, &ss->ssl3.hs.server_random.rand, SSL3_RANDOM_LENGTH);
     i += SSL3_RANDOM_LENGTH;
-    if (contextLen > 0) {
+    if (hasContext) {
         val[i++] = contextLen >> 8;
         val[i++] = contextLen;
-        PORT_Memcpy(val + i, context, contextLen);
-        i += contextLen;
+        if (contextLen > 0) {

[agl, 2012/03/12 15:22:21]

(very minor): I think that this if is superfluous, but you might feel that it
aids readability.

+            PORT_Memcpy(val + i, context, contextLen);
+            i += contextLen;
+        }
     }
     PORT_Assert(i == valLen);
 
+    /* Allow TLS keying material to be exported sooner, when the master
+     * secret is available and we have sent ChangeCipherSpec.
+     */
     ssl_GetSpecReadLock(ss);
     if (!ss->ssl3.cwSpec->master_secret && !ss->ssl3.cwSpec->msItem.len) {
         PORT_SetError(SSL_ERROR_HANDSHAKE_NOT_COMPLETED);
         rv = SECFailure;
     } else {
         rv = ssl3_TLSPRFWithMasterSecret(ss->ssl3.cwSpec, label, labelLen, val,
                                          valLen, out, outLen);
     }
     ssl_ReleaseSpecReadLock(ss);
 
@@ skipping 33 matching lines @@
         sniName = PORT_ZNew(SECItem);
         if (!sniName) {
             PORT_Free(name);
             return NULL;
         }
         sniName->data = (void*)name;
         sniName->len  = PORT_Strlen(name);
     }
     return sniName;
 }