Added client-side support for the TLS cached info extension. This feature is disabled by default ...

net/third_party/nss/ssl/ssl3ext.c

 /*
  * SSL3 Protocol
  *
  * ***** 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/
@@ skipping 229 matching lines @@
 };
 
 /* These two tables are used by the client, to handle server hello
  * extensions. */
 static const ssl3HelloExtensionHandler serverHelloHandlersTLS[] = {
     { ssl_server_name_xtn,        &ssl3_HandleServerNameXtn },
     /* TODO: add a handler for ssl_ec_point_formats_xtn */
     { ssl_session_ticket_xtn,     &ssl3_ClientHandleSessionTicketXtn },
     { ssl_renegotiation_info_xtn, &ssl3_HandleRenegotiationInfoXtn },
     { ssl_next_proto_neg_xtn,     &ssl3_ClientHandleNextProtoNegoXtn },
+    { ssl_cached_info_xtn,        &ssl3_ClientHandleCachedInfoXtn },
     { ssl_cert_status_xtn,        &ssl3_ClientHandleStatusRequestXtn },
     { -1, NULL }
 };
 
 static const ssl3HelloExtensionHandler serverHelloHandlersSSL3[] = {
     { ssl_renegotiation_info_xtn, &ssl3_HandleRenegotiationInfoXtn },
     { -1, NULL }
 };
 
 /* Tables of functions to format TLS hello extensions, one function per
  * extension.
  * These static tables are for the formatting of client hello extensions.
  * The server's table of hello senders is dynamic, in the socket struct,
  * and sender functions are registered there.
  */
 static const 
 ssl3HelloExtensionSender clientHelloSendersTLS[SSL_MAX_EXTENSIONS] = {
     { ssl_server_name_xtn,        &ssl3_SendServerNameXtn        },
     { ssl_renegotiation_info_xtn, &ssl3_SendRenegotiationInfoXtn },
 #ifdef NSS_ENABLE_ECC
     { ssl_elliptic_curves_xtn,    &ssl3_SendSupportedCurvesXtn },
     { ssl_ec_point_formats_xtn,   &ssl3_SendSupportedPointFormatsXtn },
 #endif
     { ssl_session_ticket_xtn,     &ssl3_SendSessionTicketXtn },
     { ssl_next_proto_neg_xtn,     &ssl3_ClientSendNextProtoNegoXtn },
+    { ssl_cached_info_xtn,        &ssl3_ClientSendCachedInfoXtn },
     { ssl_cert_status_xtn,        &ssl3_ClientSendStatusRequestXtn }
     /* any extra entries will appear as { 0, NULL }    */
 };
 
 static const 
 ssl3HelloExtensionSender clientHelloSendersSSL3[SSL_MAX_EXTENSIONS] = {
     { ssl_renegotiation_info_xtn, &ssl3_SendRenegotiationInfoXtn }
     /* any extra entries will appear as { 0, NULL }    */
 };
 
@@ skipping 384 matching lines @@
         return SECFailure;
 
     ss->ssl3.hs.may_get_cert_status = PR_TRUE;
 
     /* Keep track of negotiated extensions. */
     ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
 
     return SECSuccess;
 }
 
+/* ssl3_ClientSendCachedInfoXtn builds the cached_info extension on the
+ * client side. */
+PRInt32
+ssl3_ClientSendCachedInfoXtn(sslSocket * ss, PRBool append,
+                                PRUint32 maxBytes)
+{
+    PRInt32 extension_length;
+    PRBool send_empty;
+
+    if (!ss->opt.enableCachedInfo)
+        return 0;
+
+    CERTCertificate ** predictedCertChain = ss->ssl3.predictedCertChain;
+    //send_empty = (predictedCertChain == NULL || predictedCertChain[0] == NULL)
+    //    ? PR_TRUE : PR_FALSE;

[wtc, 2011/06/17 22:57:09]

Declare predictedCertChain at the beginning of the block.
Please go through the file to fix all occurrences of this
problem.

Remove the commented-out code.

[rkn, 2011/06/20 21:21:09]

Done.

+    send_empty = (predictedCertChain == NULL) ? PR_TRUE : PR_FALSE;

[wtc, 2011/06/17 22:57:09]

This can be written simply as:
    send_empty = (predictedCertChain == NULL);

[rkn, 2011/06/20 21:21:09]

Done.

+    
+    /* minimum extension:
+     * extension_type (2-bytes) +
+     * length(extension_data) (2-bytes) +
+     * length(cached_info) (2-bytes) +
+     */
+    extension_length = send_empty ? 6 : 16;
+
+    if (append && maxBytes >= extension_length) {
+        SECStatus rv;
+
+        /* ExtensionType */
+        rv = ssl3_AppendHandshakeNumber(ss, ssl_cached_info_xtn, 2);
+        if (rv != SECSuccess)
+            return -1;
+        /* Extension Length */
+        rv = ssl3_AppendHandshakeNumber(ss, extension_length - 4, 2);
+        if (rv != SECSuccess)
+            return -1;
+        if (send_empty) {
+            /* Cached Information Length */
+            rv = ssl3_AppendHandshakeNumber(ss, 0, 2);
+            if (rv != SECSuccess)
+              return -1;
+        } else {
+            /* Cached Information Length */
+            rv = ssl3_AppendHandshakeNumber(ss, 10, 2);
+            if (rv != SECSuccess)
+                return -1;
+            /* Cached Information Type */
+            rv = ssl3_AppendHandshakeNumber(ss, 1 /* certificate_chain */, 1);
+            if (rv != SECSuccess)
+                return -1;
+            /* hash length */
+            rv = ssl3_AppendHandshakeNumber(ss, 8, 1);
+            if (rv != SECSuccess)
+                return -1;
+            /* hash */
+            PRUint64 certChainHash;
+            FNV1A64_Init(&certChainHash);
+            int i;
+            for (i = 0; predictedCertChain[i] != NULL; i++) {
+                unsigned int certLen = predictedCertChain[i]->derCert.len;
+                unsigned char certLenArray[3] =
+                    {(certLen & 0xff0000) >> 16, (certLen & 0xff00) >> 8,
+                     certLen & 0xff};

[wtc, 2011/06/17 22:57:09]

Nit: format this as:
    unsigned char certLenArray[3] = {
        (certLen & 0xff0000) >> 16,
        (certLen & 0xff00) >> 8,
        certLen & 0xff
    };

[rkn, 2011/06/20 21:21:09]

Done.

+                FNV1A64_Update(&certChainHash, certLenArray, 3);
+                FNV1A64_Update(&certChainHash,
+                               predictedCertChain[i]->derCert.data, certLen);
+            }
+            FNV1A64_Final(&certChainHash);
+            rv = ssl3_AppendHandshake(ss, &certChainHash, 8);
+            if (rv != SECSuccess)
+                return -1;
+            PRUint8* digestPtr = (PRUint8*) &certChainHash;
+            for (i = 0; i < 8; i++) {
+                ss->ssl3.certChainDigest[i] = digestPtr[i];
+            }
+        }
+
+    } else if (maxBytes < extension_length) {
+        PORT_Assert(0);
+        return 0;
+    }
+    ss->xtnData.advertised[ss->xtnData.numAdvertised++] =
+        ssl_cached_info_xtn;
+    return extension_length;
+}
+
+SECStatus
+ssl3_ClientHandleCachedInfoXtn(sslSocket *ss, PRUint16 ex_type,
+                               SECItem *data)
+{
+    /* If we didn't request this extension, then the server may not echo it. */
+    if (!ss->opt.enableCachedInfo)
+        return SECFailure;
+
+    if (data->len == 0) {
+        /* The server supports information caching, but provides no information
+         * about what information types it supports */
+        ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
+        return SECSuccess;
+    }
+
+    if (data->len < 2)
+        return SECFailure;
+    unsigned char * cached_info = data->data;
+    unsigned int remaining_cached_info_length =
+        (cached_info[0] << 8) | cached_info[1];
+    if (remaining_cached_info_length != data->len - 2)
+        return SECFailure;
+    cached_info += 2;
+    PRBool has_correct_cert_chain = PR_FALSE;
+    while (remaining_cached_info_length >= 2) {
+        /* The server supports only those CachedInformationType types that are
+         * identified by a present CachedObject */
+        unsigned char cached_object_type;
+        unsigned int cached_object_length;
+        unsigned char cached_object_digest[8];
+        cached_object_type = *cached_info++;
+        cached_object_length = *cached_info++;
+        remaining_cached_info_length -= 2;
+        if (remaining_cached_info_length < cached_object_length)
+            return SECFailure;
+        if (cached_object_length != 0 && cached_object_length != 8)
+            return SECFailure;
+        remaining_cached_info_length -= cached_object_length;
+        if (cached_object_type == cached_info_certificate_chain) {
+            if (cached_object_length == 0)
+                has_correct_cert_chain = PR_TRUE;
+            else { /* Hashes must match */
+                int i;
+                for (i = 0; i < 8; i++)
+                    cached_object_digest[i] = *cached_info++;
+                if (!memcmp(cached_object_digest, ss->ssl3.certChainDigest, 8))
+                    has_correct_cert_chain = PR_TRUE;
+            }
+        }
+    }
+
+    if (remaining_cached_info_length != 0)
+        return SECFailure;
+
+    if (has_correct_cert_chain) {
+        ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
+        return SECSuccess;
+    }
+
+    return SECFailure;
+}
+
 /* ssl3_ClientSendStatusRequestXtn builds the status_request extension on the
  * client side. See RFC 4366 section 3.6. */
 PRInt32
 ssl3_ClientSendStatusRequestXtn(sslSocket * ss, PRBool append,
                                 PRUint32 maxBytes)
 {
     PRInt32 extension_length;
 
     if (!ss->opt.enableOCSPStapling)
         return 0;
@@ skipping 1019 matching lines @@
     ss->peerRequestedProtection = 1;
     ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
     if (ss->sec.isServer) {
         /* prepare to send back the appropriate response */
         rv = ssl3_RegisterServerHelloExtensionSender(ss, ex_type,
                                              ssl3_SendRenegotiationInfoXtn);
     }
     return rv;
 }