NSS: move the first protocol to the end of the ALPN extension.

net/third_party/nss/patches/alpn.patch

 diff -pu a/nss/lib/ssl/ssl3con.c b/nss/lib/ssl/ssl3con.c
 --- a/nss/lib/ssl/ssl3con.c     2013-07-31 14:17:20.669282120 -0700
 +++ b/nss/lib/ssl/ssl3con.c     2013-07-31 14:28:56.549496061 -0700
 @@ -9912,8 +9912,10 @@ ssl3_SendNextProto(sslSocket *ss)
      int padding_len;
      static const unsigned char padding[32] = {0};
  
 -    if (ss->ssl3.nextProto.len == 0)
 +    if (ss->ssl3.nextProto.len == 0 ||
 +        ss->ssl3.nextProtoState == SSL_NEXT_PROTO_SELECTED) {
         return SECSuccess;
 +    }
  
      PORT_Assert( ss->opt.noLocks || ssl_HaveXmitBufLock(ss));
      PORT_Assert( ss->opt.noLocks || ssl_HaveSSL3HandshakeLock(ss));
 diff -pu a/nss/lib/ssl/ssl3ext.c b/nss/lib/ssl/ssl3ext.c
 --- a/nss/lib/ssl/ssl3ext.c     2013-07-31 14:10:00.342814862 -0700
 +++ b/nss/lib/ssl/ssl3ext.c     2013-07-31 14:28:56.549496061 -0700
-@@ -52,8 +52,12 @@ static SECStatus ssl3_HandleRenegotiatio
+@@ -53,8 +53,12 @@ static SECStatus ssl3_HandleRenegotiationInfoXtn(sslSocket *ss,
      PRUint16 ex_type, SECItem *data);
  static SECStatus ssl3_ClientHandleNextProtoNegoXtn(sslSocket *ss,
                         PRUint16 ex_type, SECItem *data);
 +static SECStatus ssl3_ClientHandleAppProtoXtn(sslSocket *ss,
 +                       PRUint16 ex_type, SECItem *data);
  static SECStatus ssl3_ServerHandleNextProtoNegoXtn(sslSocket *ss,
                         PRUint16 ex_type, SECItem *data);
 +static PRInt32 ssl3_ClientSendAppProtoXtn(sslSocket *ss, PRBool append,
 +                                              PRUint32 maxBytes);
  static PRInt32 ssl3_ClientSendNextProtoNegoXtn(sslSocket *ss, PRBool append,
                                                PRUint32 maxBytes);
  static PRInt32 ssl3_SendUseSRTPXtn(sslSocket *ss, PRBool append,
-@@ -246,14 +250,15 @@ static const ssl3HelloExtensionHandler c
- /* These two tables are used by the client, to handle server hello
-  * extensions. */
- static const ssl3HelloExtensionHandler serverHelloHandlersTLS[] = {
--    { ssl_server_name_xtn,        &ssl3_HandleServerNameXtn },
-+    { 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_nego_xtn,    &ssl3_ClientHandleNextProtoNegoXtn },
--    { ssl_use_srtp_xtn,           &ssl3_HandleUseSRTPXtn },
--    { ssl_channel_id_xtn,         &ssl3_ClientHandleChannelIDXtn },
--    { ssl_cert_status_xtn,        &ssl3_ClientHandleStatusRequestXtn },
-+    { ssl_session_ticket_xtn,         &ssl3_ClientHandleSessionTicketXtn },
-+    { ssl_renegotiation_info_xtn,     &ssl3_HandleRenegotiationInfoXtn },
-+    { ssl_next_proto_nego_xtn,        &ssl3_ClientHandleNextProtoNegoXtn },
-+    { ssl_app_layer_protocol_xtn,     &ssl3_ClientHandleAppProtoXtn },
-+    { ssl_use_srtp_xtn,               &ssl3_HandleUseSRTPXtn },
-+    { ssl_channel_id_xtn,             &ssl3_ClientHandleChannelIDXtn },
-+    { ssl_cert_status_xtn,            &ssl3_ClientHandleStatusRequestXtn },
-     { -1, NULL }
- };
- 
-@@ -270,17 +275,18 @@ static const ssl3HelloExtensionHandler s
+@@ -252,6 +256,7 @@ static const ssl3HelloExtensionHandler serverHelloHandlersTLS[] = {
+     { ssl_session_ticket_xtn,     &ssl3_ClientHandleSessionTicketXtn },
+     { ssl_renegotiation_info_xtn, &ssl3_HandleRenegotiationInfoXtn },
+     { ssl_next_proto_nego_xtn,    &ssl3_ClientHandleNextProtoNegoXtn },
++    { ssl_app_layer_protocol_xtn, &ssl3_ClientHandleAppProtoXtn },
+     { ssl_use_srtp_xtn,           &ssl3_HandleUseSRTPXtn },
+     { ssl_channel_id_xtn,         &ssl3_ClientHandleChannelIDXtn },
+     { ssl_cert_status_xtn,        &ssl3_ClientHandleStatusRequestXtn },
+@@ -271,18 +276,19 @@ static const ssl3HelloExtensionHandler serverHelloHandlersSSL3[] = {
   */
  static const 
  ssl3HelloExtensionSender clientHelloSendersTLS[SSL_MAX_EXTENSIONS] = {
 -    { ssl_server_name_xtn,        &ssl3_SendServerNameXtn        },
 -    { ssl_renegotiation_info_xtn, &ssl3_SendRenegotiationInfoXtn },
 +    { 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 },
 +    { ssl_elliptic_curves_xtn,        &ssl3_SendSupportedCurvesXtn },
 +    { ssl_ec_point_formats_xtn,       &ssl3_SendSupportedPointFormatsXtn },
  #endif
 -    { ssl_session_ticket_xtn,     &ssl3_SendSessionTicketXtn },
 -    { ssl_next_proto_nego_xtn,    &ssl3_ClientSendNextProtoNegoXtn },
 -    { ssl_use_srtp_xtn,           &ssl3_SendUseSRTPXtn },
 -    { ssl_channel_id_xtn,         &ssl3_ClientSendChannelIDXtn },
 -    { ssl_cert_status_xtn,        &ssl3_ClientSendStatusRequestXtn },
+-    { ssl_signature_algorithms_xtn, &ssl3_ClientSendSigAlgsXtn }
 +    { ssl_session_ticket_xtn,         &ssl3_SendSessionTicketXtn },
 +    { ssl_next_proto_nego_xtn,        &ssl3_ClientSendNextProtoNegoXtn },
 +    { ssl_app_layer_protocol_xtn,     &ssl3_ClientSendAppProtoXtn },
 +    { ssl_use_srtp_xtn,               &ssl3_SendUseSRTPXtn },
 +    { ssl_channel_id_xtn,             &ssl3_ClientSendChannelIDXtn },
 +    { ssl_cert_status_xtn,            &ssl3_ClientSendStatusRequestXtn },
-     { ssl_signature_algorithms_xtn, &ssl3_ClientSendSigAlgsXtn }
++    { ssl_signature_algorithms_xtn,   &ssl3_ClientSendSigAlgsXtn }
      /* any extra entries will appear as { 0, NULL }    */
  };
-@@ -605,6 +611,11 @@ ssl3_ClientHandleNextProtoNegoXtn(sslSoc
+ 
+@@ -606,6 +612,11 @@ ssl3_ClientHandleNextProtoNegoXtn(sslSocket *ss, PRUint16 ex_type,
  
      PORT_Assert(!ss->firstHsDone);
  
 +    if (ssl3_ExtensionNegotiated(ss, ssl_app_layer_protocol_xtn)) {
 +       PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
 +       return SECFailure;
 +    }
 +
      rv = ssl3_ValidateNextProtoNego(data->data, data->len);
      if (rv != SECSuccess)
         return rv;
-@@ -638,6 +649,44 @@ ssl3_ClientHandleNextProtoNegoXtn(sslSoc
+@@ -639,6 +650,44 @@ ssl3_ClientHandleNextProtoNegoXtn(sslSocket *ss, PRUint16 ex_type,
      return SECITEM_CopyItem(NULL, &ss->ssl3.nextProto, &result);
  }
  
 +static SECStatus
 +ssl3_ClientHandleAppProtoXtn(sslSocket *ss, PRUint16 ex_type, SECItem *data)
 +{
 +    const unsigned char* d = data->data;
 +    PRUint16 name_list_len;
 +    SECItem protocol_name;
 +
@@ skipping 24 matching lines @@
 +
 +    SECITEM_FreeItem(&ss->ssl3.nextProto, PR_FALSE);
 +    ss->ssl3.nextProtoState = SSL_NEXT_PROTO_SELECTED;
 +    ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
 +    return SECITEM_CopyItem(NULL, &ss->ssl3.nextProto, &protocol_name);
 +}
 +
  static PRInt32
  ssl3_ClientSendNextProtoNegoXtn(sslSocket * ss, PRBool append,
                                 PRUint32 maxBytes)
-@@ -664,6 +713,44 @@ ssl3_ClientSendNextProtoNegoXtn(sslSocke
-     } else if (maxBytes < extension_length) {
-        return 0;
-     }
-+
-+    return extension_length;
-+
-+loser:
-+    return -1;
-+}
-+
+@@ -672,6 +721,70 @@ loser:
+     return -1;
+ }
+ 
 +static PRInt32
 +ssl3_ClientSendAppProtoXtn(sslSocket * ss, PRBool append, PRUint32 maxBytes)
 +{
 +    PRInt32 extension_length;
++    unsigned char *alpn_protos = NULL;
 +
 +    /* Renegotiations do not send this extension. */
 +    if (!ss->opt.nextProtoNego.data || ss->firstHsDone) {
 +       return 0;
 +    }
 +
 +    extension_length = 2 /* extension type */ + 2 /* extension length */ +
 +                       2 /* protocol name list length */ +
 +                       ss->opt.nextProtoNego.len;
 +
 +    if (append && maxBytes >= extension_length) {
++       /* NPN requires that the client's fallback protocol is first in the
++        * list. However, ALPN sends protocols in preference order. So we
++        * allocate a buffer and move the first protocol to the end of the
++        * list. */
 +       SECStatus rv;
++       const unsigned int len = ss->opt.nextProtoNego.len;
++
++       alpn_protos = PORT_Alloc(len);
++       if (alpn_protos == NULL) {
++           return SECFailure;
++       }
++       if (len > 0) {
++           /* Each protocol string is prefixed with a single byte length. */
++           unsigned int i = ss->opt.nextProtoNego.data[0] + 1;
++           if (i <= len) {
++               memcpy(alpn_protos, &ss->opt.nextProtoNego.data[i], len - i);
++               memcpy(alpn_protos + len - i, ss->opt.nextProtoNego.data, i);
++           } else {
++               /* This seems to be invalid data so we'll send as-is. */
++               memcpy(alpn_protos, ss->opt.nextProtoNego.data, len);
++           }
++       }
++
 +       rv = ssl3_AppendHandshakeNumber(ss, ssl_app_layer_protocol_xtn, 2);
 +       if (rv != SECSuccess)
 +           goto loser;
 +       rv = ssl3_AppendHandshakeNumber(ss, extension_length - 4, 2);
 +       if (rv != SECSuccess)
 +           goto loser;
-+       rv = ssl3_AppendHandshakeVariable(ss, ss->opt.nextProtoNego.data,
-+                                         ss->opt.nextProtoNego.len, 2);
++       rv = ssl3_AppendHandshakeVariable(ss, alpn_protos, len, 2);
++       PORT_Free(alpn_protos);
++       alpn_protos = NULL;
 +       if (rv != SECSuccess)
 +           goto loser;
 +       ss->xtnData.advertised[ss->xtnData.numAdvertised++] =
 +               ssl_app_layer_protocol_xtn;
 +    } else if (maxBytes < extension_length) {
 +       return 0;
 +    }
- 
-     return extension_length;
- 
++
++    return extension_length;
++
++loser:
++    if (alpn_protos)
++       PORT_Free(alpn_protos);
++    return -1;
++}
++
+ static SECStatus
+ ssl3_ClientHandleChannelIDXtn(sslSocket *ss, PRUint16 ex_type,
+                             SECItem *data)
 diff -pu a/nss/lib/ssl/ssl.h b/nss/lib/ssl/ssl.h
 --- a/nss/lib/ssl/ssl.h 2013-07-31 14:10:35.113325316 -0700
 +++ b/nss/lib/ssl/ssl.h 2013-07-31 14:28:56.589496647 -0700
-@@ -203,6 +203,11 @@ SSL_IMPORT SECStatus SSL_SetNextProtoCal
+@@ -203,6 +203,15 @@ SSL_IMPORT SECStatus SSL_SetNextProtoCal
   * protocol in server-preference order. If no matching protocol is found it
   * selects the first supported protocol.
   *
 + * Using this function also allows the client to transparently support ALPN.
 + * The same set of protocols will be advertised via ALPN and, if the server
 + * uses ALPN to select a protocol, SSL_GetNextProto will return
 + * SSL_NEXT_PROTO_SELECTED as the state.
 + *
++ * Since NPN uses the first protocol as the fallback protocol, when sending an
++ * ALPN extension, the first protocol is moved to the end of the list. This
++ * indicates that the protocol is the least preferred.
++ *
   * The supported protocols are specified in |data| in wire-format (8-bit
   * length-prefixed). For example: "\010http/1.1\006spdy/2". */
  SSL_IMPORT SECStatus SSL_SetNextProtoNego(PRFileDesc *fd,
 @@ -212,7 +217,8 @@ SSL_IMPORT SECStatus SSL_SetNextProtoNeg
  typedef enum SSLNextProtoState { 
    SSL_NEXT_PROTO_NO_SUPPORT = 0, /* No peer support                */
    SSL_NEXT_PROTO_NEGOTIATED = 1, /* Mutual agreement               */
 -  SSL_NEXT_PROTO_NO_OVERLAP = 2  /* No protocol overlap found      */
 +  SSL_NEXT_PROTO_NO_OVERLAP = 2, /* No protocol overlap found      */
 +  SSL_NEXT_PROTO_SELECTED   = 3  /* Server selected proto (ALPN)   */
@@ skipping 11 matching lines @@
      ssl_session_ticket_xtn           = 35,
      ssl_next_proto_nego_xtn          = 13172,
      ssl_channel_id_xtn               = 30031,
      ssl_renegotiation_info_xtn       = 0xff01  /* experimental number */
  } SSLExtensionType;
  
 -#define SSL_MAX_EXTENSIONS             10
 +#define SSL_MAX_EXTENSIONS             11
  
  #endif /* __sslt_h_ */