net: add NSS support for RFC 5705

net/third_party/nss/ssl/sslinfo.c

Index: net/third_party/nss/ssl/sslinfo.c
diff --git a/net/third_party/nss/ssl/sslinfo.c b/net/third_party/nss/ssl/sslinfo.c
index 96377b0d1e816e9385e3e7e1247b5bb8162adc30..9a58b4d3b9174443c01b2845c49b2ddfbb54e43d 100644
--- a/net/third_party/nss/ssl/sslinfo.c
+++ b/net/third_party/nss/ssl/sslinfo.c
@@ -20,6 +20,7 @@
  *
  * Contributor(s):
  *   Dr Vipul Gupta <vipul.gupta@sun.com>, Sun Microsystems Laboratories
+ *   Douglas Stebila <douglas@stebila.ca>
  *
  * 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
@@ -38,6 +39,7 @@
 #include "ssl.h"
 #include "sslimpl.h"
 #include "sslproto.h"
+#include "pk11func.h"

[wtc, 2011/07/21 19:56:16]

I don't see anything in the new code that requires
"pk11func.h".  Can this header be removed?

[agl, 2011/07/22 14:05:40]

Done.

 
 static const char *
 ssl_GetCompressionMethodName(SSLCompressionMethod compression)
@@ -316,6 +318,67 @@ SSL_IsExportCipherSuite(PRUint16 cipherSuite)
     return PR_FALSE;
 }
 
+/* Export keying material according to draft-ietf-tls-extractor-06.

[wtc, 2011/07/21 19:56:16]

Change draft-ietf-tls-extractor-06 to RFC 5705.

[agl, 2011/07/22 14:05:40]

Done.

+** fd must correspond to a TLS 1.0 or higher socket, out must
+** be already allocated.
+*/
+SECStatus
+SSL_ExportKeyingMaterial(PRFileDesc *fd, const char *label,
+			 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);

[wtc, 2011/07/21 19:56:16]

This is a new meaning for the SSL_ERROR_UNSUPPORTED_VERSION
error code.  It's fine for now.  (It'll be confusing if someone
prints the error message for this error code:
"Peer using unsupported version of security protocol.")

+	return SECFailure;
+    }
+
+    if (ss->ssl3.hs.ws != idle_handshake) {
+	PORT_SetError(SSL_ERROR_HANDSHAKE_NOT_COMPLETED);

[wtc, 2011/07/21 19:56:16]

In the other place where NSS sets this error code, the
test is much more complicated:
http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/security/nss/lib/ssl/ssl3...

Should we do the same here?  We can omit the
(ss->version >= SSL_LIBRARY_VERSION_3_0) test because it is
ensured by the test on line 344 above.

[agl, 2011/07/22 14:05:40]

I've copied the referenced test for completeness (omitting the version clause.)

+	return SECFailure;
+    }
+
+    valLen = SSL3_RANDOM_LENGTH * 2;
+    if (contextLen > 0)
+	valLen += 2 /* uint16 length */ + contextLen;
+    val = PORT_Alloc(valLen);
+    if (val == NULL)
+	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) {
+	val[i++] = contextLen >> 8;
+	val[i++] = contextLen;
+	PORT_Memcpy(val + i, context, contextLen);
+	i += contextLen;
+    }
+    PORT_Assert(i == valLen);
+
+    ssl_GetSpecReadLock(ss);
+    rv = ssl3_TLSPRFWithMasterSecret(ss->ssl3.crSpec, label, strlen(label), val, valLen, out, outLen);

[wtc, 2011/07/21 19:56:16]

Please fold this long line.

[agl, 2011/07/22 14:05:40]

Done.

+    ssl_ReleaseSpecReadLock(ss);
+
+    if (val != NULL)
+	PORT_ZFree(val, valLen);
+    return rv;
+}
+
 SECItem*
 SSL_GetNegotiatedHostInfo(PRFileDesc *fd)
 {