diff --git a/ssl/ssl.h b/ssl/ssl.h
index 80717db..e9f5fb0 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -191,6 +191,9 @@ SSL_IMPORT PRFileDesc *DTLS_ImportFD(PRFileDesc *model, PRFileDesc *fd);
 #define SSL_ENABLE_FALLBACK_SCSV       28 /* Send fallback SCSV in
                                            * handshakes. */
 
+/* Request Signed Certificate Timestamps via TLS extension (client) */
+#define SSL_ENABLE_SIGNED_CERT_TIMESTAMPS 29
+
 #ifdef SSL_DEPRECATED_FUNCTION 
 /* Old deprecated function names */
 SSL_IMPORT SECStatus SSL_Enable(PRFileDesc *fd, int option, PRBool on);
@@ -493,6 +496,23 @@ SSL_IMPORT CERTCertList *SSL_PeerCertificateChain(PRFileDesc *fd);
  */
 SSL_IMPORT const SECItemArray * SSL_PeerStapledOCSPResponses(PRFileDesc *fd);
 
+/* SSL_PeerSignedCertTimestamps returns the signed_certificate_timestamp
+ * extension data provided by the TLS server. The return value is a pointer
+ * to an internal SECItem that contains the returned response (as a serialized
+ * SignedCertificateTimestampList, see RFC 6962). The returned pointer is only
+ * valid until the callback function that calls SSL_PeerSignedCertTimestamps
+ * (e.g. the authenticate certificate hook, or the handshake callback) returns.
+ *
+ * If no Signed Certificate Timestamps were given by the server then the result
+ * will be empty. If there was an error, then the result will be NULL.
+ *
+ * You must set the SSL_ENABLE_SIGNED_CERT_TIMESTAMPS option to indicate support
+ * for Signed Certificate Timestamps to a server.
+ *
+ * libssl does not do any parsing or validation of the response itself.
+ */
+SSL_IMPORT const SECItem * SSL_PeerSignedCertTimestamps(PRFileDesc *fd);
+
 /* SSL_SetStapledOCSPResponses stores an array of one or multiple OCSP responses
  * in the fd's data, which may be sent as part of a server side cert_status
  * handshake message. Parameter |responses| is for the server certificate of
diff --git a/ssl/ssl3con.c b/ssl/ssl3con.c
index 708a4c7..3421e0b 100644
--- a/ssl/ssl3con.c
+++ b/ssl/ssl3con.c
@@ -6737,10 +6737,22 @@ ssl3_HandleServerHello(sslSocket *ss, SSL3Opaque *b, PRUint32 length)
     sid->u.ssl3.sessionIDLength = sidBytes.len;
     PORT_Memcpy(sid->u.ssl3.sessionID, sidBytes.data, sidBytes.len);
 
+    /* Copy Signed Certificate Timestamps, if any. */
+    if (ss->xtnData.signedCertTimestamps.data) {
+	rv = SECITEM_CopyItem(NULL, &sid->u.ssl3.signedCertTimestamps,
+			      &ss->xtnData.signedCertTimestamps);
+	if (rv != SECSuccess)
+	    goto loser;
+    }
+
     ss->ssl3.hs.isResuming = PR_FALSE;
     ss->ssl3.hs.ws         = wait_server_cert;
 
 winner:
+    /* Clean up the temporary pointer to the handshake buffer. */
+    ss->xtnData.signedCertTimestamps.data = NULL;
+    ss->xtnData.signedCertTimestamps.len = 0;
+
     /* If we will need a ChannelID key then we make the callback now. This
      * allows the handshake to be restarted cleanly if the callback returns
      * SECWouldBlock. */
@@ -6766,6 +6778,9 @@ alert_loser:
     (void)SSL3_SendAlert(ss, alert_fatal, desc);
 
 loser:
+    /* Clean up the temporary pointer to the handshake buffer. */
+    ss->xtnData.signedCertTimestamps.data = NULL;
+    ss->xtnData.signedCertTimestamps.len = 0;
     errCode = ssl_MapLowLevelError(errCode);
     return SECFailure;
 }
diff --git a/ssl/ssl3ext.c b/ssl/ssl3ext.c
index b6ed17d..6c120ff 100644
--- a/ssl/ssl3ext.c
+++ b/ssl/ssl3ext.c
@@ -85,6 +85,12 @@ static PRInt32 ssl3_ClientSendSigAlgsXtn(sslSocket *ss, PRBool append,
                                          PRUint32 maxBytes);
 static SECStatus ssl3_ServerHandleSigAlgsXtn(sslSocket *ss, PRUint16 ex_type,
                                              SECItem *data);
+static PRInt32 ssl3_ClientSendSignedCertTimestampXtn(sslSocket *ss,
+                                                     PRBool append,
+                                                     PRUint32 maxBytes);
+static SECStatus ssl3_ClientHandleSignedCertTimestampXtn(sslSocket *ss,
+                                                         PRUint16 ex_type,
+                                                         SECItem *data);
 
 static PRInt32 ssl3_ClientSendDraftVersionXtn(sslSocket *ss, PRBool append,
                                               PRUint32 maxBytes);
@@ -270,6 +276,8 @@ static const ssl3HelloExtensionHandler serverHelloHandlersTLS[] = {
     { ssl_use_srtp_xtn,           &ssl3_HandleUseSRTPXtn },
     { ssl_channel_id_xtn,         &ssl3_ClientHandleChannelIDXtn },
     { ssl_cert_status_xtn,        &ssl3_ClientHandleStatusRequestXtn },
+    { ssl_signed_certificate_timestamp_xtn,
+      &ssl3_ClientHandleSignedCertTimestampXtn },
     { -1, NULL }
 };
 
@@ -298,6 +306,8 @@ ssl3HelloExtensionSender clientHelloSendersTLS[SSL_MAX_EXTENSIONS] = {
     { ssl_use_srtp_xtn,           &ssl3_SendUseSRTPXtn },
     { ssl_channel_id_xtn,         &ssl3_ClientSendChannelIDXtn },
     { ssl_cert_status_xtn,        &ssl3_ClientSendStatusRequestXtn },
+    { ssl_signed_certificate_timestamp_xtn,
+      &ssl3_ClientSendSignedCertTimestampXtn },
     { ssl_signature_algorithms_xtn, &ssl3_ClientSendSigAlgsXtn },
     { ssl_tls13_draft_version_xtn, &ssl3_ClientSendDraftVersionXtn },
     /* any extra entries will appear as { 0, NULL }    */
@@ -2582,3 +2592,64 @@ loser:
     return SECSuccess;
 }
 
+/* ssl3_ClientSendSignedCertTimestampXtn sends the signed_certificate_timestamp
+ * extension for TLS ClientHellos. */
+static PRInt32
+ssl3_ClientSendSignedCertTimestampXtn(sslSocket *ss, PRBool append,
+                                      PRUint32 maxBytes)
+{
+    PRInt32 extension_length = 2 /* extension_type */ +
+                               2 /* length(extension_data) */;
+
+    /* Only send the extension if processing is enabled. */
+    if (!ss->opt.enableSignedCertTimestamps)
+        return 0;
+
+    if (append && maxBytes >= extension_length) {
+        SECStatus rv;
+        /* extension_type */
+        rv = ssl3_AppendHandshakeNumber(ss,
+                                        ssl_signed_certificate_timestamp_xtn,
+                                        2);
+        if (rv != SECSuccess)
+            goto loser;
+        /* zero length */
+        rv = ssl3_AppendHandshakeNumber(ss, 0, 2);
+        if (rv != SECSuccess)
+            goto loser;
+        ss->xtnData.advertised[ss->xtnData.numAdvertised++] =
+            ssl_signed_certificate_timestamp_xtn;
+    } else if (maxBytes < extension_length) {
+        PORT_Assert(0);
+        return 0;
+    }
+
+    return extension_length;
+loser:
+    return -1;
+}
+
+static SECStatus
+ssl3_ClientHandleSignedCertTimestampXtn(sslSocket *ss, PRUint16 ex_type,
+                                        SECItem *data)
+{
+    /* We do not yet know whether we'll be resuming a session or creating
+     * a new one, so we keep a pointer to the data in the TLSExtensionData
+     * structure. This pointer is only valid in the scope of
+     * ssl3_HandleServerHello, and, if not resuming a session, the data is
+     * copied once a new session structure has been set up.
+     * All parsing is currently left to the application and we accept
+     * everything, including empty data.
+     */
+    SECItem *scts = &ss->xtnData.signedCertTimestamps;
+    PORT_Assert(!scts->data && !scts->len);
+
+    if (!data->len) {
+        /* Empty extension data: RFC 6962 mandates non-empty contents. */
+        return SECFailure;
+    }
+    *scts = *data;
+    /* Keep track of negotiated extensions. */
+    ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
+    return SECSuccess;
+}
diff --git a/ssl/sslimpl.h b/ssl/sslimpl.h
index 62f822a..2f61a46 100644
--- a/ssl/sslimpl.h
+++ b/ssl/sslimpl.h
@@ -339,6 +339,7 @@ typedef struct sslOptionsStr {
     unsigned int enableALPN             : 1;  /* 27 */
     unsigned int reuseServerECDHEKey    : 1;  /* 28 */
     unsigned int enableFallbackSCSV     : 1;  /* 29 */
+    unsigned int enableSignedCertTimestamps : 1;  /* 30 */
 } sslOptions;
 
 typedef enum { sslHandshakingUndetermined = 0,
@@ -721,6 +722,11 @@ struct sslSessionIDStr {
              * resumption handshake to the original handshake. */
 	    SECItem           originalHandshakeHash;
 
+	    /* Signed certificate timestamps received in a TLS extension.
+	    ** (used only in client).
+	    */
+	    SECItem	      signedCertTimestamps;
+
 	    /* This lock is lazily initialized by CacheSID when a sid is first
 	     * cached. Before then, there is no need to lock anything because
 	     * the sid isn't being shared by anything.
@@ -829,6 +835,18 @@ struct TLSExtensionDataStr {
      * is beyond ssl3_HandleClientHello function. */
     SECItem *sniNameArr;
     PRUint32 sniNameArrSize;
+
+    /* Signed Certificate Timestamps extracted from the TLS extension.
+     * (client only).
+     * This container holds a temporary pointer to the extension data,
+     * until a session structure (the sec.ci.sid of an sslSocket) is setup
+     * that can hold a permanent copy of the data
+     * (in sec.ci.sid.u.ssl3.signedCertTimestamps).
+     * The data pointed to by this structure is neither explicitly allocated
+     * nor copied: the pointer points to the handshake message buffer and is
+     * only valid in the scope of ssl3_HandleServerHello.
+     */
+    SECItem signedCertTimestamps;
 };
 
 typedef SECStatus (*sslRestartTarget)(sslSocket *);
diff --git a/ssl/sslnonce.c b/ssl/sslnonce.c
index c45849d..cefdda6 100644
--- a/ssl/sslnonce.c
+++ b/ssl/sslnonce.c
@@ -131,6 +131,9 @@ ssl_DestroySID(sslSessionID *sid)
         if (sid->u.ssl3.originalHandshakeHash.data) {
             SECITEM_FreeItem(&sid->u.ssl3.originalHandshakeHash, PR_FALSE);
         }
+        if (sid->u.ssl3.signedCertTimestamps.data) {
+            SECITEM_FreeItem(&sid->u.ssl3.signedCertTimestamps, PR_FALSE);
+        }
 
         if (sid->u.ssl3.lock) {
             PR_DestroyRWLock(sid->u.ssl3.lock);
diff --git a/ssl/sslsock.c b/ssl/sslsock.c
index 0d12273..80f4e67 100644
--- a/ssl/sslsock.c
+++ b/ssl/sslsock.c
@@ -89,7 +89,8 @@ static sslOptions ssl_defaults = {
     PR_TRUE,    /* enableNPN          */
     PR_FALSE,   /* enableALPN         */
     PR_TRUE,    /* reuseServerECDHEKey */
-    PR_FALSE    /* enableFallbackSCSV */
+    PR_FALSE,   /* enableFallbackSCSV */
+    PR_FALSE,   /* enableSignedCertTimestamps */
 };
 
 /*
@@ -807,6 +808,10 @@ SSL_OptionSet(PRFileDesc *fd, PRInt32 which, PRBool on)
         ss->opt.enableFallbackSCSV = on;
         break;
 
+      case SSL_ENABLE_SIGNED_CERT_TIMESTAMPS:
+        ss->opt.enableSignedCertTimestamps = on;
+        break;
+
       default:
         PORT_SetError(SEC_ERROR_INVALID_ARGS);
         rv = SECFailure;
@@ -882,6 +887,9 @@ SSL_OptionGet(PRFileDesc *fd, PRInt32 which, PRBool *pOn)
     case SSL_REUSE_SERVER_ECDHE_KEY:
                                   on = ss->opt.reuseServerECDHEKey; break;
     case SSL_ENABLE_FALLBACK_SCSV: on = ss->opt.enableFallbackSCSV; break;
+    case SSL_ENABLE_SIGNED_CERT_TIMESTAMPS:
+        on = ss->opt.enableSignedCertTimestamps;
+        break;
 
     default:
         PORT_SetError(SEC_ERROR_INVALID_ARGS);
@@ -951,6 +959,9 @@ SSL_OptionGetDefault(PRInt32 which, PRBool *pOn)
     case SSL_ENABLE_FALLBACK_SCSV:
        on = ssl_defaults.enableFallbackSCSV;
        break;
+    case SSL_ENABLE_SIGNED_CERT_TIMESTAMPS:
+       on = ssl_defaults.enableSignedCertTimestamps;
+       break;
 
     default:
         PORT_SetError(SEC_ERROR_INVALID_ARGS);
@@ -1134,6 +1145,10 @@ SSL_OptionSetDefault(PRInt32 which, PRBool on)
         ssl_defaults.enableFallbackSCSV = on;
         break;
 
+      case SSL_ENABLE_SIGNED_CERT_TIMESTAMPS:
+        ssl_defaults.enableSignedCertTimestamps = on;
+        break;
+
       default:
         PORT_SetError(SEC_ERROR_INVALID_ARGS);
         return SECFailure;
@@ -1963,6 +1978,29 @@ SSL_PeerStapledOCSPResponses(PRFileDesc *fd)
     return &ss->sec.ci.sid->peerCertStatus;
 }
 
+const SECItem *
+SSL_PeerSignedCertTimestamps(PRFileDesc *fd)
+{
+    sslSocket *ss = ssl_FindSocket(fd);
+
+    if (!ss) {
+       SSL_DBG(("%d: SSL[%d]: bad socket in SSL_PeerSignedCertTimestamps",
+		SSL_GETPID(), fd));
+       return NULL;
+    }
+
+    if (!ss->sec.ci.sid) {
+       PORT_SetError(SEC_ERROR_NOT_INITIALIZED);
+       return NULL;
+    }
+
+    if (ss->sec.ci.sid->version < SSL_LIBRARY_VERSION_3_0) {
+	PORT_SetError(SSL_ERROR_FEATURE_NOT_SUPPORTED_FOR_SSL2);
+	return NULL;
+    }
+    return &ss->sec.ci.sid->u.ssl3.signedCertTimestamps;
+}
+
 SECStatus
 SSL_HandshakeResumedSession(PRFileDesc *fd, PRBool *handshake_resumed) {
     sslSocket *ss = ssl_FindSocket(fd);
diff --git a/ssl/sslt.h b/ssl/sslt.h
index fe0ad07..c36b8c7 100644
--- a/ssl/sslt.h
+++ b/ssl/sslt.h
@@ -202,6 +202,7 @@ typedef enum {
     ssl_signature_algorithms_xtn     = 13,
     ssl_use_srtp_xtn                 = 14,
     ssl_app_layer_protocol_xtn       = 16,
+    ssl_signed_certificate_timestamp_xtn = 18,   /* RFC 6962 */
     ssl_padding_xtn                  = 21,
     ssl_session_ticket_xtn           = 35,
     ssl_next_proto_nego_xtn          = 13172,
@@ -210,6 +211,6 @@ typedef enum {
     ssl_tls13_draft_version_xtn      = 0xff02   /* experimental number */
 } SSLExtensionType;
 
-#define SSL_MAX_EXTENSIONS             12 /* doesn't include ssl_padding_xtn. */
+#define SSL_MAX_EXTENSIONS             13 /* doesn't include ssl_padding_xtn. */
 
 #endif /* __sslt_h_ */