Implement RFC 5764 (DTLS-SRTP).

net/third_party/nss/ssl/sslsock.c

Index: net/third_party/nss/ssl/sslsock.c
===================================================================
--- net/third_party/nss/ssl/sslsock.c	(revision 130750)
+++ net/third_party/nss/ssl/sslsock.c	(working copy)
@@ -225,6 +225,13 @@
 char lockStatus[] = "Locks are ENABLED.  ";
 #define LOCKSTATUS_OFFSET 10 /* offset of ENABLED */
 
+static PRUint16 srtpCiphers[] = {
+    SRTP_AES128_CM_SHA1_80,
+    SRTP_AES128_CM_SHA1_32,
+    /* XXX what about SRTP_NULL_SHA1_80 and SRTP_NULL_SHA1_32? */

[wtc, 2012/04/04 23:32:49]

Should SRTP_NULL_SHA1_80 and SRTP_NULL_SHA1_32 be added to
this array?  You allow tstclnt.c to set these null encryption
cipher suites using the letters C and D.

[ekr, 2012/04/19 14:29:36]

I think my preference is to simply not implement them, and remove them from
tstclnt.c as well.

+    0
+};
+
 /* forward declarations. */
 static sslSocket *ssl_NewSocket(PRBool makeLocks, SSLProtocolVariant variant);
 static SECStatus  ssl_MakeLocks(sslSocket *ss);
@@ -1596,6 +1603,66 @@
     return SECSuccess;
 }
 
+SSL_IMPORT SECStatus SSL_SetSRTPCiphers(PRFileDesc *socket,
+					const PRUint16 *ciphers,
+					unsigned int numCiphers)
+{
+    sslSocket * ss;
+    int i;
+
+    ss = ssl_FindSocket(socket);
+    if (!ss || !IS_DTLS(ss)) {
+	SSL_DBG(("%d: SSL[%d]: bad socket in SSL_SetSRTPCiphers"));
+	PORT_SetError(SEC_ERROR_INVALID_ARGS);
+	return SECFailure;
+    }
+
+    for (i = 0; i < numCiphers; i++) {
+	PRUint16 *srtpCipher = srtpCiphers;
+
+	while (*srtpCipher) {
+	    if (ciphers[i] == *srtpCipher)
+		break;
+	    srtpCipher++;
+	}
+	if (!*srtpCipher) {
+	    SSL_DBG(("%d: SSL[%d]: invalid SRTP cipher suite specified"));
+	    PORT_SetError(SEC_ERROR_INVALID_ARGS);
+	    return SECFailure;
+	}
+    }
+
+    if (numCiphers > MAX_DTLS_SRTP_CIPHER_SUITES) {
+	PORT_SetError(SEC_ERROR_INVALID_ARGS);
+	return SECFailure;
+    }
+    memcpy(ss->ssl3.dtlsSRTPCiphers, ciphers, sizeof(PRUint16) * numCiphers);
+    ss->ssl3.dtlsSRTPCipherCount = numCiphers;
+
+    return SECSuccess;
+}
+
+SECStatus
+SSL_GetSRTPCipher(PRFileDesc *socket, PRUint16 *cipher)
+{
+    sslSocket * ss;
+
+    ss = ssl_FindSocket(socket);
+    if (!ss) {
+	SSL_DBG(("%d: SSL[%d]: bad socket in SSL_GetSRTPCipher"));
+	PORT_SetError(SEC_ERROR_INVALID_ARGS);
+	return SECFailure;
+    }
+
+    if (!ss->ssl3.dtlsSRTPCipherSuite) {
+	PORT_SetError(SEC_ERROR_INVALID_ARGS);
+	return SECFailure;
+    }
+
+    *cipher = ss->ssl3.dtlsSRTPCipherSuite;
+    return SECSuccess;
+}
+
 PRFileDesc *
 SSL_ReconfigFD(PRFileDesc *model, PRFileDesc *fd)
 {