Commit f2ad3582 authored by Andy Polyakov's avatar Andy Polyakov
Browse files

s23_clnt.c: ensure interoperability by maitaining client "version capability" 

vector contiguous.
PR: 2802
parent 09e4e4b9

CHANGES

+11 −1
Original line number Diff line number Diff line
@@ -289,6 +289,16 @@ 
     whose return value is often ignored. 

     [Steve Henson]



 Changes between 1.0.1a and 1.0.1b [xx XXX xxxx]



  *) In order to ensure interoperabilty SSL_OP_NO_protocolX does not

     disable just protocol X, but all protocols above X *if* there are

     protocols *below* X still enabled. In more practical terms it means

     that if application wants to disable TLS1.0 in favor of TLS1.1 and

     above, it's not sufficient to pass SSL_OP_NO_TLSv1, one has to pass

     SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.

     [Andy Polyakov]



 Changes between 1.0.1 and 1.0.1a [19 Apr 2012]



  *) Check for potentially exploitable overflows in asn1_d2i_read_bio

ssl/s23_clnt.c

+36 −17
Original line number Diff line number Diff line
@@ -282,32 +282,51 @@ static int ssl23_client_hello(SSL *s) 
	SSL_COMP *comp;

#endif

	int ret;

	unsigned long mask, options = s->options;



	ssl2_compat = (s->options & SSL_OP_NO_SSLv2) ? 0 : 1;

	ssl2_compat = (options & SSL_OP_NO_SSLv2) ? 0 : 1;



	if (ssl2_compat && ssl23_no_ssl2_ciphers(s))

		ssl2_compat = 0;



	if (!(s->options & SSL_OP_NO_TLSv1_2))

		{

	/*

	 * SSL_OP_NO_X disables all protocols above X *if* there are

	 * some protocols below X enabled. This is required in order

	 * to maintain "version capability" vector contiguous. So

	 * that if application wants to disable TLS1.0 in favour of

	 * TLS1>=1, it would be insufficient to pass SSL_NO_TLSv1, the

	 * answer is SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.

	 */

	mask =	SSL_OP_NO_TLSv1_1|SSL_OP_NO_TLSv1

#if !defined(OPENSSL_NO_SSL3)

		|SSL_OP_NO_SSLv3

#endif

#if !defined(OPENSSL_NO_SSL2)

		|(ssl2_compat?SSL_OP_NO_SSLv2:0)

#endif

		;

#if !defined(OPENSSL_NO_TLS1_2_CLIENT)

	version = TLS1_2_VERSION;

		}

	else if (!(s->options & SSL_OP_NO_TLSv1_1))

		{



	if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)

		version = TLS1_1_VERSION;

		}

	else if (!(s->options & SSL_OP_NO_TLSv1))

		{

#else

	version = TLS1_1_VERSION;

#endif

	mask &= ~SSL_OP_NO_TLSv1_1;

	if ((options & SSL_OP_NO_TLSv1_1) && (options & mask) != mask)

		version = TLS1_VERSION;

		}

	else if (!(s->options & SSL_OP_NO_SSLv3))

		{

	mask &= ~SSL_OP_NO_TLSv1;

#if !defined(OPENSSL_NO_SSL3)

	if ((options & SSL_OP_NO_TLSv1) && (options & mask) != mask)

		version = SSL3_VERSION;

		}

	else if (!(s->options & SSL_OP_NO_SSLv2))

		{

	mask &= ~SSL_OP_NO_SSLv3;

#endif

#if !defined(OPENSSL_NO_SSL2)

	if ((options & SSL_OP_NO_SSLv3) && (options & mask) != mask)

		version = SSL2_VERSION;

		}

#endif



#ifndef OPENSSL_NO_TLSEXT

	if (version != SSL2_VERSION)

		{