Commit b362ccab authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Security framework. 

Security callback: selects which parameters are permitted including
sensible defaults based on bits of security.

The "parameters" which can be selected include: ciphersuites,
curves, key sizes, certificate signature algorithms, supported
signature algorithms, DH parameters, SSL/TLS version, session tickets
and compression.

In some cases prohibiting the use of a parameters will mean they are
not advertised to the peer: for example cipher suites and ECC curves.
In other cases it will abort the handshake: e.g DH parameters or the
peer key size.

Documentation to follow...
parent 66f96fe2

ssl/s23_clnt.c

+12 −2
Original line number Diff line number Diff line
@@ -259,10 +259,13 @@ static int ssl23_no_ssl2_ciphers(SSL *s) 
	SSL_CIPHER *cipher;

	STACK_OF(SSL_CIPHER) *ciphers;

	int i;

	ssl_set_client_disabled(s);

	ciphers = SSL_get_ciphers(s);

	for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++)

		{

		cipher = sk_SSL_CIPHER_value(ciphers, i);

		if (ssl_cipher_disabled(s, cipher, SSL_SECOP_CIPHER_SUPPORTED))

			continue;

		if (cipher->algorithm_ssl == SSL_SSLV2)

			return 0;

		}
@@ -309,6 +312,8 @@ static int ssl23_client_hello(SSL *s) 


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



	if (ssl2_compat && !ssl_security(s, SSL_SECOP_SSL2_COMPAT, 0, 0, NULL))

		ssl2_compat = 0;

	if (ssl2_compat && ssl23_no_ssl2_ciphers(s))

		ssl2_compat = 0;
@@ -533,8 +538,7 @@ static int ssl23_client_hello(SSL *s) 
#ifdef OPENSSL_NO_COMP

			*(p++)=1;

#else

			if ((s->options & SSL_OP_NO_COMPRESSION)

						|| !s->ctx->comp_methods)

			if (!ssl_allow_compression(s) || !s->ctx->comp_methods)

				j=0;

			else

				j=sk_SSL_COMP_num(s->ctx->comp_methods);
@@ -750,6 +754,12 @@ static int ssl23_get_server_hello(SSL *s) 
			goto err;

			}



		if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL))

			{

			SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_VERSION_TOO_LOW);

			goto err;

			}



		if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING)

			{

			/* fatal alert */

ssl/s23_srvr.c

+6 −0
Original line number Diff line number Diff line
@@ -441,6 +441,12 @@ int ssl23_get_client_hello(SSL *s) 
		}

#endif



	if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL))

		{

		SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_VERSION_TOO_LOW);

		goto err;

		}



	if (s->state == SSL23_ST_SR_CLNT_HELLO_B)

		{

		/* we have SSLv3/TLSv1 in an SSLv2 header

ssl/s2_clnt.c

+6 −0
Original line number Diff line number Diff line
@@ -1056,6 +1056,12 @@ int ssl2_set_certificate(SSL *s, int type, int len, const unsigned char *data) 
	ERR_clear_error(); /* but we keep s->verify_result */

	s->session->verify_result = s->verify_result;



	if (i > 1)

		{

		SSLerr(SSL_F_SSL2_SET_CERTIFICATE, i);

		goto err;

		}



	/* server's cert for this session */

	sc=ssl_sess_cert_new();

	if (sc == NULL)

ssl/s2_srvr.c

+6 −0
Original line number Diff line number Diff line
@@ -1053,6 +1053,12 @@ static int request_certificate(SSL *s) 


	i=ssl_verify_cert_chain(s,sk);



	if (i > 1)

		{

		SSLerr(SSL_F_REQUEST_CERTIFICATE, i);

		goto msg_end;

		}



	if (i > 0)	/* we like the packet, now check the chksum */

		{

		EVP_MD_CTX ctx;

ssl/s3_both.c

+9 −2
Original line number Diff line number Diff line
@@ -695,7 +695,7 @@ int ssl3_setup_read_buffer(SSL *s) 
			len += SSL3_RT_MAX_EXTRA;

			}

#ifndef OPENSSL_NO_COMP

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

		if (ssl_allow_compression(s))

			len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;

#endif

		if ((p=freelist_extract(s->ctx, 1, len)) == NULL)
@@ -732,7 +732,7 @@ int ssl3_setup_write_buffer(SSL *s) 
			+ SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD

			+ headerlen + align;

#ifndef OPENSSL_NO_COMP

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

		if (ssl_allow_compression(s))

			len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;

#endif

		if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
@@ -782,3 +782,10 @@ int ssl3_release_read_buffer(SSL *s) 
	return 1;

	}



int ssl_allow_compression(SSL *s)

	{

	if (s->options & SSL_OP_NO_COMPRESSION)

		return 0;

	return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);

	}