Commit cbb92dfa authored by Richard Levitte's avatar Richard Levitte
Browse files

Fixes for the following claims: 

  1) Certificate Message with no certs

  OpenSSL implementation sends the Certificate message during SSL
  handshake, however as per the specification, these have been omitted.

  -- RFC 2712 --
     CertificateRequest, and the ServerKeyExchange shown in Figure 1
     will be omitted since authentication and the establishment of a
     master secret will be done using the client's Kerberos credentials
     for the TLS server.  The client's certificate will be omitted for
     the same reason.
  -- RFC 2712 --

  3) Pre-master secret Protocol version

  The pre-master secret generated by OpenSSL does not have the correct
  client version.

  RFC 2712 says, if the Kerberos option is selected, the pre-master
  secret structure is the same as that used in the RSA case.

  TLS specification defines pre-master secret as:
         struct {
             ProtocolVersion client_version;
             opaque random[46];
         } PreMasterSecret;

  where client_version is the latest protocol version supported by the
  client

  The pre-master secret generated by OpenSSL does not have the correct
  client version. The implementation does not update the first 2 bytes
  of random secret for Kerberos Cipher suites. At the server-end, the
  client version from the pre-master secret is not validated.

PR: 1336
parent 019bfef8

ssl/s3_clnt.c

+4 −2
Original line number Diff line number Diff line
@@ -1902,7 +1902,9 @@ int ssl3_send_client_key_exchange(SSL *s) 
				n+=2;

				}

 

			if (RAND_bytes(tmp_buf,sizeof tmp_buf) <= 0)

			    tmp_buf[0]=s->client_version>>8;

			    tmp_buf[1]=s->client_version&0xff;

			    if (RAND_bytes(&(tmp_buf[2]),sizeof tmp_buf-2) <= 0)

				goto err;



			/*  20010420 VRS.  Tried it this way; failed.

ssl/s3_srvr.c

+24 −4
Original line number Diff line number Diff line 
/* ssl/s3_srvr.c */

/* ssl/s3_srvr.c -*- mode:C; c-file-style: "eay" -*- */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *
@@ -323,10 +323,11 @@ int ssl3_accept(SSL *s) 


		case SSL3_ST_SW_CERT_A:

		case SSL3_ST_SW_CERT_B:

			/* Check if it is anon DH or anon ECDH */

			/* or normal PSK */

			/* Check if it is anon DH or anon ECDH, */

			/* normal PSK or KRB5 */

			if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL)

				&& !(s->s3->tmp.new_cipher->algorithms & SSL_kPSK))

				&& !(s->s3->tmp.new_cipher->algorithms & SSL_kPSK)

				&& !(s->s3->tmp.new_cipher->algorithms & SSL_aKRB5))

				{

				ret=ssl3_send_server_certificate(s);

				if (ret <= 0) goto end;
@@ -2061,6 +2062,25 @@ int ssl3_get_client_key_exchange(SSL *s) 
				SSL_R_DATA_LENGTH_TOO_LONG);

			goto err;

			}

		if (!((p[0] == (s->client_version>>8)) && (p[1] == (s->client_version & 0xff))))

		    {

		    /* The premaster secret must contain the same version number as the

		     * ClientHello to detect version rollback attacks (strangely, the

		     * protocol does not offer such protection for DH ciphersuites).

		     * However, buggy clients exist that send random bytes instead of

		     * the protocol version.

		     * If SSL_OP_TLS_ROLLBACK_BUG is set, tolerate such clients. 

		     * (Perhaps we should have a separate BUG value for the Kerberos cipher)

		     */

		    if (!((s->options & SSL_OP_TLS_ROLLBACK_BUG) &&

			   (p[0] == (s->version>>8)) && (p[1] == (s->version & 0xff))))

		        {

			SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,

			       SSL_AD_DECODE_ERROR);

			goto err;

			}

		    }



		EVP_CIPHER_CTX_cleanup(&ciph_ctx);



                s->session->master_key_length=