s3_clnt.c

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/* ssl/s3_clnt.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson ([e-mail]).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young ([e-mail])"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson ([e-mail])"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/md5.h>
#include <openssl/sha.h>
#include <openssl/evp.h>
#include "ssl_locl.h"

static SSL_METHOD *ssl3_get_client_method(int ver);
static int ssl3_client_hello(SSL *s);
static int ssl3_get_server_hello(SSL *s);
static int ssl3_get_certificate_request(SSL *s);
static int ca_dn_cmp(const X509_NAME * const *a,const X509_NAME * const *b);
static int ssl3_get_server_done(SSL *s);
static int ssl3_send_client_verify(SSL *s);
static int ssl3_send_client_certificate(SSL *s);
static int ssl3_send_client_key_exchange(SSL *s);
static int ssl3_get_key_exchange(SSL *s);
static int ssl3_get_server_certificate(SSL *s);
static int ssl3_check_cert_and_algorithm(SSL *s);
static SSL_METHOD *ssl3_get_client_method(int ver)
	{
	if (ver == SSL3_VERSION)
		return(SSLv3_client_method());
	else
		return(NULL);
	}

SSL_METHOD *SSLv3_client_method(void)
	{
	static int init=1;
	static SSL_METHOD SSLv3_client_data;

	if (init)
		{
		init=0;
		memcpy((char *)&SSLv3_client_data,(char *)sslv3_base_method(),
			sizeof(SSL_METHOD));
		SSLv3_client_data.ssl_connect=ssl3_connect;
		SSLv3_client_data.get_ssl_method=ssl3_get_client_method;
		}
	return(&SSLv3_client_data);
	}

int ssl3_connect(SSL *s)
	{
	BUF_MEM *buf;
	unsigned long Time=time(NULL),l;
	long num1;
	void (*cb)()=NULL;
	int ret= -1;
	int new_state,state,skip=0;;

	RAND_add(&Time,sizeof(Time),0);
	ERR_clear_error();
	clear_sys_error();

	if (s->info_callback != NULL)
		cb=s->info_callback;
	else if (s->ctx->info_callback != NULL)
		cb=s->ctx->info_callback;
	
	if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 
	s->in_handshake++;

	for (;;)
		{
		state=s->state;

		switch(s->state)
			{
		case SSL_ST_RENEGOTIATE:
			s->new_session=1;
			s->state=SSL_ST_CONNECT;
			s->ctx->stats.sess_connect_renegotiate++;
			/* break */
		case SSL_ST_BEFORE:
		case SSL_ST_CONNECT:
		case SSL_ST_BEFORE|SSL_ST_CONNECT:
		case SSL_ST_OK|SSL_ST_CONNECT:

			s->server=0;
			if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);

			if ((s->version & 0xff00 ) != 0x0300)
				{
				SSLerr(SSL_F_SSL3_CONNECT, SSL_R_INTERNAL_ERROR);
				ret = -1;
				goto end;
				}
				
			/* s->version=SSL3_VERSION; */
			s->type=SSL_ST_CONNECT;

			if (s->init_buf == NULL)
				{
				if ((buf=BUF_MEM_new()) == NULL)
					{
					ret= -1;
					goto end;
					}
				if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
					{
					ret= -1;
					goto end;
					}
				s->init_buf=buf;
				}

			if (!ssl3_setup_buffers(s)) { ret= -1; goto end; }

			/* setup buffing BIO */
			if (!ssl_init_wbio_buffer(s,0)) { ret= -1; goto end; }

			/* don't push the buffering BIO quite yet */

			ssl3_init_finished_mac(s);

			s->state=SSL3_ST_CW_CLNT_HELLO_A;
			s->ctx->stats.sess_connect++;
			s->init_num=0;
			break;

		case SSL3_ST_CW_CLNT_HELLO_A:
		case SSL3_ST_CW_CLNT_HELLO_B:

			s->shutdown=0;
			ret=ssl3_client_hello(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CR_SRVR_HELLO_A;
			s->init_num=0;

			/* turn on buffering for the next lot of output */
			if (s->bbio != s->wbio)
				s->wbio=BIO_push(s->bbio,s->wbio);

			break;

		case SSL3_ST_CR_SRVR_HELLO_A:
		case SSL3_ST_CR_SRVR_HELLO_B:
			ret=ssl3_get_server_hello(s);
			if (ret <= 0) goto end;
			if (s->hit)
				s->state=SSL3_ST_CR_FINISHED_A;
			else
				s->state=SSL3_ST_CR_CERT_A;
			s->init_num=0;
			break;

		case SSL3_ST_CR_CERT_A:
		case SSL3_ST_CR_CERT_B:
			/* Check if it is anon DH */
			if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL))
				{
				ret=ssl3_get_server_certificate(s);
				if (ret <= 0) goto end;
				}
			else
				skip=1;
			s->state=SSL3_ST_CR_KEY_EXCH_A;
			s->init_num=0;
			break;

		case SSL3_ST_CR_KEY_EXCH_A:
		case SSL3_ST_CR_KEY_EXCH_B:
			ret=ssl3_get_key_exchange(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CR_CERT_REQ_A;
			s->init_num=0;

			/* at this point we check that we have the
			 * required stuff from the server */
			if (!ssl3_check_cert_and_algorithm(s))
				{
				ret= -1;
				goto end;
				}
			break;

		case SSL3_ST_CR_CERT_REQ_A:
		case SSL3_ST_CR_CERT_REQ_B:
			ret=ssl3_get_certificate_request(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CR_SRVR_DONE_A;
			s->init_num=0;
			break;

		case SSL3_ST_CR_SRVR_DONE_A:
		case SSL3_ST_CR_SRVR_DONE_B:
			ret=ssl3_get_server_done(s);
			if (ret <= 0) goto end;
			if (s->s3->tmp.cert_req)
				s->state=SSL3_ST_CW_CERT_A;
			else
				s->state=SSL3_ST_CW_KEY_EXCH_A;
			s->init_num=0;

			break;

		case SSL3_ST_CW_CERT_A:
		case SSL3_ST_CW_CERT_B:
		case SSL3_ST_CW_CERT_C:
		case SSL3_ST_CW_CERT_D:
			ret=ssl3_send_client_certificate(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CW_KEY_EXCH_A;
			s->init_num=0;
			break;

		case SSL3_ST_CW_KEY_EXCH_A:
		case SSL3_ST_CW_KEY_EXCH_B:
			ret=ssl3_send_client_key_exchange(s);
			if (ret <= 0) goto end;
			l=s->s3->tmp.new_cipher->algorithms;
			/* EAY EAY EAY need to check for DH fix cert
			 * sent back */
			/* For TLS, cert_req is set to 2, so a cert chain
			 * of nothing is sent, but no verify packet is sent */
			if (s->s3->tmp.cert_req == 1)
				{
				s->state=SSL3_ST_CW_CERT_VRFY_A;
				}
			else
				{
				s->state=SSL3_ST_CW_CHANGE_A;
				s->s3->change_cipher_spec=0;
				}

			s->init_num=0;
			break;

		case SSL3_ST_CW_CERT_VRFY_A:
		case SSL3_ST_CW_CERT_VRFY_B:
			ret=ssl3_send_client_verify(s);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CW_CHANGE_A;
			s->init_num=0;
			s->s3->change_cipher_spec=0;
			break;

		case SSL3_ST_CW_CHANGE_A:
		case SSL3_ST_CW_CHANGE_B:
			ret=ssl3_send_change_cipher_spec(s,
				SSL3_ST_CW_CHANGE_A,SSL3_ST_CW_CHANGE_B);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CW_FINISHED_A;
			s->init_num=0;

			s->session->cipher=s->s3->tmp.new_cipher;
			if (s->s3->tmp.new_compression == NULL)
				s->session->compress_meth=0;
			else
				s->session->compress_meth=
					s->s3->tmp.new_compression->id;
			if (!s->method->ssl3_enc->setup_key_block(s))
				{
				ret= -1;
				goto end;
				}

			if (!s->method->ssl3_enc->change_cipher_state(s,
				SSL3_CHANGE_CIPHER_CLIENT_WRITE))
				{
				ret= -1;
				goto end;
				}

			break;

		case SSL3_ST_CW_FINISHED_A:
		case SSL3_ST_CW_FINISHED_B:
			ret=ssl3_send_finished(s,
				SSL3_ST_CW_FINISHED_A,SSL3_ST_CW_FINISHED_B,
				s->method->ssl3_enc->client_finished_label,
				s->method->ssl3_enc->client_finished_label_len);
			if (ret <= 0) goto end;
			s->state=SSL3_ST_CW_FLUSH;

			/* clear flags */
			s->s3->flags&= ~SSL3_FLAGS_POP_BUFFER;
			if (s->hit)
				{
				s->s3->tmp.next_state=SSL_ST_OK;
				if (s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED)
					{
					s->state=SSL_ST_OK;
					s->s3->flags|=SSL3_FLAGS_POP_BUFFER;
					s->s3->delay_buf_pop_ret=0;
					}
				}
			else
				{
				s->s3->tmp.next_state=SSL3_ST_CR_FINISHED_A;
				}
			s->init_num=0;
			break;

		case SSL3_ST_CR_FINISHED_A:
		case SSL3_ST_CR_FINISHED_B:

			ret=ssl3_get_finished(s,SSL3_ST_CR_FINISHED_A,
				SSL3_ST_CR_FINISHED_B);
			if (ret <= 0) goto end;

			if (s->hit)
				s->state=SSL3_ST_CW_CHANGE_A;
			else
				s->state=SSL_ST_OK;
			s->init_num=0;
			break;

		case SSL3_ST_CW_FLUSH:
			/* number of bytes to be flushed */
			num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
			if (num1 > 0)
				{
				s->rwstate=SSL_WRITING;
				num1=BIO_flush(s->wbio);
				if (num1 <= 0) { ret= -1; goto end; }
				s->rwstate=SSL_NOTHING;
				}

			s->state=s->s3->tmp.next_state;
			break;

		case SSL_ST_OK:
			/* clean a few things up */
			ssl3_cleanup_key_block(s);

			if (s->init_buf != NULL)
				{
				BUF_MEM_free(s->init_buf);
				s->init_buf=NULL;
				}

			/* If we are not 'joining' the last two packets,
			 * remove the buffering now */
			if (!(s->s3->flags & SSL3_FLAGS_POP_BUFFER))
				ssl_free_wbio_buffer(s);
			/* else do it later in ssl3_write */

			s->init_num=0;
			s->new_session=0;

			ssl_update_cache(s,SSL_SESS_CACHE_CLIENT);
			if (s->hit) s->ctx->stats.sess_hit++;

			ret=1;
			/* s->server=0; */
			s->handshake_func=ssl3_connect;
			s->ctx->stats.sess_connect_good++;

			if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);

			goto end;
			/* break; */
			
		default:
			SSLerr(SSL_F_SSL3_CONNECT,SSL_R_UNKNOWN_STATE);
			ret= -1;
			goto end;
			/* break; */
			}

		/* did we do anything */
		if (!s->s3->tmp.reuse_message && !skip)
			{
			if (s->debug)
				{
				if ((ret=BIO_flush(s->wbio)) <= 0)
					goto end;
				}

			if ((cb != NULL) && (s->state != state))
				{
				new_state=s->state;
				s->state=state;
				cb(s,SSL_CB_CONNECT_LOOP,1);
				s->state=new_state;
				}
			}
		skip=0;
		}
end:
	if (cb != NULL)
		cb(s,SSL_CB_CONNECT_EXIT,ret);
	s->in_handshake--;
	return(ret);
	}


static int ssl3_client_hello(SSL *s)
	{
	unsigned char *buf;
	unsigned char *p,*d;
	int i,j;
	unsigned long Time,l;
	SSL_COMP *comp;

	buf=(unsigned char *)s->init_buf->data;
	if (s->state == SSL3_ST_CW_CLNT_HELLO_A)
		{
		if ((s->session == NULL) ||
			(s->session->ssl_version != s->version) ||
			(s->session->not_resumable))
			{
			if (!ssl_get_new_session(s,0))
				goto err;
			}
		/* else use the pre-loaded session */

		p=s->s3->client_random;
		Time=time(NULL);			/* Time */
		l2n(Time,p);
		RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-sizeof(Time));

		/* Do the message type and length last */
		d=p= &(buf[4]);

		*(p++)=s->version>>8;
		*(p++)=s->version&0xff;
		s->client_version=s->version;

		/* Random stuff */
		memcpy(p,s->s3->client_random,SSL3_RANDOM_SIZE);
		p+=SSL3_RANDOM_SIZE;

		/* Session ID */
		if (s->new_session)
			i=0;
		else
			i=s->session->session_id_length;
		*(p++)=i;
		if (i != 0)
			{
			memcpy(p,s->session->session_id,i);
			p+=i;
			}
		
		/* Ciphers supported */
		i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]));
		if (i == 0)
			{
			SSLerr(SSL_F_SSL3_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
			goto err;
			}
		s2n(i,p);
		p+=i;

		/* COMPRESSION */
		if (s->ctx->comp_methods == NULL)
			j=0;
		else
			j=sk_SSL_COMP_num(s->ctx->comp_methods);
		*(p++)=1+j;
		for (i=0; i<j; i++)
			{
			comp=sk_SSL_COMP_value(s->ctx->comp_methods,i);
			*(p++)=comp->id;
			}
		*(p++)=0; /* Add the NULL method */
		
		l=(p-d);
		d=buf;
		*(d++)=SSL3_MT_CLIENT_HELLO;
		l2n3(l,d);

		s->state=SSL3_ST_CW_CLNT_HELLO_B;
		/* number of bytes to write */
		s->init_num=p-buf;
		s->init_off=0;
		}

	/* SSL3_ST_CW_CLNT_HELLO_B */
	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
err:
	return(-1);
	}

static int ssl3_get_server_hello(SSL *s)
	{
	STACK_OF(SSL_CIPHER) *sk;
	SSL_CIPHER *c;
	unsigned char *p,*d;
	int i,al,ok;
	unsigned int j;
	long n;
	SSL_COMP *comp;

	n=ssl3_get_message(s,
		SSL3_ST_CR_SRVR_HELLO_A,
		SSL3_ST_CR_SRVR_HELLO_B,
		SSL3_MT_SERVER_HELLO,
		300, /* ?? */
		&ok);

	if (!ok) return((int)n);
	d=p=(unsigned char *)s->init_buf->data;

	if ((p[0] != (s->version>>8)) || (p[1] != (s->version&0xff)))
		{
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,SSL_R_WRONG_SSL_VERSION);
		s->version=(s->version&0xff00)|p[1];
		al=SSL_AD_PROTOCOL_VERSION;
		goto f_err;
		}
	p+=2;

	/* load the server hello data */
	/* load the server random */
	memcpy(s->s3->server_random,p,SSL3_RANDOM_SIZE);
	p+=SSL3_RANDOM_SIZE;

	/* get the session-id */
	j= *(p++);

	if ((j != 0) && (j != SSL3_SESSION_ID_SIZE))
		{
		/* SSLref returns 16 :-( */
		if (j < SSL2_SSL_SESSION_ID_LENGTH)
			{
			al=SSL_AD_ILLEGAL_PARAMETER;