diff --git a/lib/ssl/ssl.h b/lib/ssl/ssl.h
index 0983b5f..cf9f6db 100644
--- a/lib/ssl/ssl.h
+++ b/lib/ssl/ssl.h
@@ -896,6 +896,16 @@ SSL_IMPORT SECStatus SSL_ReHandshakeWithTimeout(PRFileDesc *fd,
                                                 PRBool flushCache,
                                                 PRIntervalTime timeout);
 
+/* Returns a SECItem containing the certificate_types field of the
+** CertificateRequest message.  Each byte of the data is a TLS
+** ClientCertificateType value, and they are ordered from most preferred to
+** least.  This function should only be called from the
+** SSL_GetClientAuthDataHook callback, and will return NULL if called at any
+** other time.  The returned value is valid only until the callback returns, and
+** should not be freed.
+*/
+SSL_IMPORT const SECItem *
+SSL_GetRequestedClientCertificateTypes(PRFileDesc *fd);
 
 #ifdef SSL_DEPRECATED_FUNCTION 
 /* deprecated!
diff --git a/lib/ssl/ssl3con.c b/lib/ssl/ssl3con.c
index cc193cd..27038f3 100644
--- a/lib/ssl/ssl3con.c
+++ b/lib/ssl/ssl3con.c
@@ -7266,6 +7266,9 @@ ssl3_HandleCertificateRequest(sslSocket *ss, SSL3Opaque *b, PRUint32 length)
     if (rv != SECSuccess)
     	goto loser;		/* malformed, alert has been sent */
 
+    PORT_Assert(!ss->requestedCertTypes);
+    ss->requestedCertTypes = &cert_types;
+
     if (isTLS12) {
 	rv = ssl3_ConsumeHandshakeVariable(ss, &algorithms, 2, &b, &length);
 	if (rv != SECSuccess)
@@ -7469,6 +7472,7 @@ loser:
     PORT_SetError(errCode);
     rv = SECFailure;
 done:
+    ss->requestedCertTypes = NULL;
     if (arena != NULL)
     	PORT_FreeArena(arena, PR_FALSE);
 #ifdef NSS_PLATFORM_CLIENT_AUTH
diff --git a/lib/ssl/sslimpl.h b/lib/ssl/sslimpl.h
index 94bb9f4..c7231a7 100644
--- a/lib/ssl/sslimpl.h
+++ b/lib/ssl/sslimpl.h
@@ -1265,6 +1265,10 @@ struct sslSocketStr {
     unsigned int     sizeCipherSpecs;
 const unsigned char *  preferredCipher;
 
+    /* TLS ClientCertificateTypes requested during HandleCertificateRequest. */
+    /* Will be NULL at all other times. */
+    const SECItem      *requestedCertTypes;
+
     ssl3KeyPair *         stepDownKeyPair;	/* RSA step down keys */
 
     const ssl3DHParams *dheParams;          /* DHE param */
diff --git a/lib/ssl/sslsock.c b/lib/ssl/sslsock.c
index b73f8f6..11e66f2 100644
--- a/lib/ssl/sslsock.c
+++ b/lib/ssl/sslsock.c
@@ -2165,6 +2165,20 @@ SSL_HandshakeResumedSession(PRFileDesc *fd, PRBool *handshake_resumed) {
     return SECSuccess;
 }
 
+const SECItem *
+SSL_GetRequestedClientCertificateTypes(PRFileDesc *fd)
+{
+  sslSocket *ss = ssl_FindSocket(fd);
+
+  if (!ss) {
+      SSL_DBG(("%d: SSL[%d]: bad socket in "
+               "SSL_GetRequestedClientCertificateTypes", SSL_GETPID(), fd));
+      return NULL;
+  }
+
+  return ss->requestedCertTypes;
+}
+
 /************************************************************************/
 /* The following functions are the TOP LEVEL SSL functions.
 ** They all get called through the NSPRIOMethods table below.
@@ -3243,6 +3257,7 @@ ssl_NewSocket(PRBool makeLocks, SSLProtocolVariant protocolVariant)
             sc->serverKeyBits   = 0;
             ss->certStatusArray[i] = NULL;
         }
+        ss->requestedCertTypes = NULL;
         ss->stepDownKeyPair    = NULL;
 
         ss->dheParams = NULL;