s3_srvr.c

来自「一个用于点对点传输加密的工具包源码」· C语言 代码 · 共 1,755 行 · 第 1/3 页

		SSL3_MT_CLIENT_HELLO,
		SSL3_RT_MAX_PLAIN_LENGTH,
		&ok);

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

	/* use version from inside client hello, not from record header
	 * (may differ: see RFC 2246, Appendix E, second paragraph) */
	s->client_version=(((int)p[0])<<8)|(int)p[1];
	p+=2;

	/* load the client random */
	memcpy(s->s3->client_random,p,SSL3_RANDOM_SIZE);
	p+=SSL3_RANDOM_SIZE;

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

	s->hit=0;
	if (j == 0)
		{
		if (!ssl_get_new_session(s,1))
			goto err;
		}
	else
		{
		i=ssl_get_prev_session(s,p,j);
		if (i == 1)
			{ /* previous session */
			s->hit=1;
			}
		else if (i == -1)
			goto err;
		else /* i == 0 */
			{
			if (!ssl_get_new_session(s,1))
				goto err;
			}
		}

	p+=j;
	n2s(p,i);
	if ((i == 0) && (j != 0))
		{
		/* we need a cipher if we are not resuming a session */
		al=SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_CIPHERS_SPECIFIED);
		goto f_err;
		}
	if ((i+p) > (d+n))
		{
		/* not enough data */
		al=SSL_AD_DECODE_ERROR;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_LENGTH_MISMATCH);
		goto f_err;
		}
	if ((i > 0) && (ssl_bytes_to_cipher_list(s,p,i,&(ciphers))
		== NULL))
		{
		goto err;
		}
	p+=i;

	/* If it is a hit, check that the cipher is in the list */
	if ((s->hit) && (i > 0))
		{
		j=0;
		id=s->session->cipher->id;

#ifdef CIPHER_DEBUG
		printf("client sent %d ciphers\n",sk_num(ciphers));
#endif
		for (i=0; i<sk_SSL_CIPHER_num(ciphers); i++)
			{
			c=sk_SSL_CIPHER_value(ciphers,i);
#ifdef CIPHER_DEBUG
			printf("client [%2d of %2d]:%s\n",
				i,sk_num(ciphers),SSL_CIPHER_get_name(c));
#endif
			if (c->id == id)
				{
				j=1;
				break;
				}
			}
		if (j == 0)
			{
			if ((s->options & SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG) && (sk_SSL_CIPHER_num(ciphers) == 1))
				{
				/* Very bad for multi-threading.... */
				s->session->cipher=sk_SSL_CIPHER_value(ciphers,
								       0);
				}
			else
				{
				/* we need to have the cipher in the cipher
				 * list if we are asked to reuse it */
				al=SSL_AD_ILLEGAL_PARAMETER;
				SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_REQUIRED_CIPHER_MISSING);
				goto f_err;
				}
			}
		}

	/* compression */
	i= *(p++);
	q=p;
	for (j=0; j<i; j++)
		{
		if (p[j] == 0) break;
		}

	p+=i;
	if (j >= i)
		{
		/* no compress */
		al=SSL_AD_DECODE_ERROR;
		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_COMPRESSION_SPECIFIED);
		goto f_err;
		}

	/* Worst case, we will use the NULL compression, but if we have other
	 * options, we will now look for them.  We have i-1 compression
	 * algorithms from the client, starting at q. */
	s->s3->tmp.new_compression=NULL;
	if (s->ctx->comp_methods != NULL)
		{ /* See if we have a match */
		int m,nn,o,v,done=0;

		nn=sk_SSL_COMP_num(s->ctx->comp_methods);
		for (m=0; m<nn; m++)
			{
			comp=sk_SSL_COMP_value(s->ctx->comp_methods,m);
			v=comp->id;
			for (o=0; o<i; o++)
				{
				if (v == q[o])
					{
					done=1;
					break;
					}
				}
			if (done) break;
			}
		if (done)
			s->s3->tmp.new_compression=comp;
		else
			comp=NULL;
		}

	/* TLS does not mind if there is extra stuff */
	if (s->version == SSL3_VERSION)
		{
		if (p > (d+n))
			{
			/* wrong number of bytes,
			 * there could be more to follow */
			al=SSL_AD_DECODE_ERROR;
			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_LENGTH_MISMATCH);
			goto f_err;
			}
		}

	/* Given s->session->ciphers and ssl_get_ciphers_by_id(s), we must
	 * pick a cipher */

	if (!s->hit)
		{
		s->session->compress_meth=(comp == NULL)?0:comp->id;
		if (s->session->ciphers != NULL)
			sk_SSL_CIPHER_free(s->session->ciphers);
		s->session->ciphers=ciphers;
		if (ciphers == NULL)
			{
			al=SSL_AD_ILLEGAL_PARAMETER;
			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_CIPHERS_PASSED);
			goto f_err;
			}
		ciphers=NULL;
		c=ssl3_choose_cipher(s,s->session->ciphers,
				     ssl_get_ciphers_by_id(s));

		if (c == NULL)
			{
			al=SSL_AD_HANDSHAKE_FAILURE;
			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_SHARED_CIPHER);
			goto f_err;
			}
		s->s3->tmp.new_cipher=c;
		}
	else
		{
		/* Session-id reuse */
#ifdef REUSE_CIPHER_BUG
		STACK_OF(SSL_CIPHER) *sk;
		SSL_CIPHER *nc=NULL;
		SSL_CIPHER *ec=NULL;

		if (s->options & SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG)
			{
			sk=s->session->ciphers;
			for (i=0; i<sk_SSL_CIPHER_num(sk); i++)
				{
				c=sk_SSL_CIPHER_value(sk,i);
				if (c->algorithms & SSL_eNULL)
					nc=c;
				if (SSL_C_IS_EXPORT(c))
					ec=c;
				}
			if (nc != NULL)
				s->s3->tmp.new_cipher=nc;
			else if (ec != NULL)
				s->s3->tmp.new_cipher=ec;
			else
				s->s3->tmp.new_cipher=s->session->cipher;
			}
		else
#endif
		s->s3->tmp.new_cipher=s->session->cipher;
		}
	
	/* we now have the following setup. 
	 * client_random
	 * cipher_list 		- our prefered list of ciphers
	 * ciphers 		- the clients prefered list of ciphers
	 * compression		- basically ignored right now
	 * ssl version is set	- sslv3
	 * s->session		- The ssl session has been setup.
	 * s->hit		- session reuse flag
	 * s->tmp.new_cipher	- the new cipher to use.
	 */

	ret=1;
	if (0)
		{
f_err:
		ssl3_send_alert(s,SSL3_AL_FATAL,al);
		}
err:
	if (ciphers != NULL) sk_SSL_CIPHER_free(ciphers);
	return(ret);
	}

static int ssl3_send_server_hello(SSL *s)
	{
	unsigned char *buf;
	unsigned char *p,*d;
	int i,sl;
	unsigned long l,Time;

	if (s->state == SSL3_ST_SW_SRVR_HELLO_A)
		{
		buf=(unsigned char *)s->init_buf->data;
		p=s->s3->server_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;

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

		/* now in theory we have 3 options to sending back the
		 * session id.  If it is a re-use, we send back the
		 * old session-id, if it is a new session, we send
		 * back the new session-id or we send back a 0 length
		 * session-id if we want it to be single use.
		 * Currently I will not implement the '0' length session-id
		 * 12-Jan-98 - I'll now support the '0' length stuff.
		 */
		if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER))
			s->session->session_id_length=0;

		sl=s->session->session_id_length;
		*(p++)=sl;
		memcpy(p,s->session->session_id,sl);
		p+=sl;

		/* put the cipher */
		i=ssl3_put_cipher_by_char(s->s3->tmp.new_cipher,p);
		p+=i;

		/* put the compression method */
		if (s->s3->tmp.new_compression == NULL)
			*(p++)=0;
		else
			*(p++)=s->s3->tmp.new_compression->id;

		/* do the header */
		l=(p-d);
		d=buf;
		*(d++)=SSL3_MT_SERVER_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));
	}

static int ssl3_send_server_done(SSL *s)
	{
	unsigned char *p;

	if (s->state == SSL3_ST_SW_SRVR_DONE_A)
		{
		p=(unsigned char *)s->init_buf->data;

		/* do the header */
		*(p++)=SSL3_MT_SERVER_DONE;
		*(p++)=0;
		*(p++)=0;
		*(p++)=0;

		s->state=SSL3_ST_SW_SRVR_DONE_B;
		/* number of bytes to write */
		s->init_num=4;
		s->init_off=0;
		}

	/* SSL3_ST_CW_CLNT_HELLO_B */
	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
	}

static int ssl3_send_server_key_exchange(SSL *s)
	{
#ifndef NO_RSA
	unsigned char *q;
	int j,num;
	RSA *rsa;
	unsigned char md_buf[MD5_DIGEST_LENGTH+SHA_DIGEST_LENGTH];
	unsigned int u;
#endif
#ifndef NO_DH
	DH *dh=NULL,*dhp;
#endif
	EVP_PKEY *pkey;
	unsigned char *p,*d;
	int al,i;
	unsigned long type;
	int n;
	CERT *cert;
	BIGNUM *r[4];
	int nr[4],kn;
	BUF_MEM *buf;
	EVP_MD_CTX md_ctx;

	if (s->state == SSL3_ST_SW_KEY_EXCH_A)
		{
		type=s->s3->tmp.new_cipher->algorithms & SSL_MKEY_MASK;
		cert=s->cert;

		buf=s->init_buf;

		r[0]=r[1]=r[2]=r[3]=NULL;
		n=0;
#ifndef NO_RSA
		if (type & SSL_kRSA)
			{
			rsa=cert->rsa_tmp;
			if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL))
				{
				rsa=s->cert->rsa_tmp_cb(s,
				      SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
				      SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
				if(rsa == NULL)
				{
					al=SSL_AD_HANDSHAKE_FAILURE;
					SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
					goto f_err;
				}
				CRYPTO_add(&rsa->references,1,CRYPTO_LOCK_RSA);
				cert->rsa_tmp=rsa;
				}
			if (rsa == NULL)
				{
				al=SSL_AD_HANDSHAKE_FAILURE;
				SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_RSA_KEY);
				goto f_err;
				}
			r[0]=rsa->n;
			r[1]=rsa->e;
			s->s3->tmp.use_rsa_tmp=1;
			}
		else
#endif
#ifndef NO_DH
			if (type & SSL_kEDH)
			{
			dhp=cert->dh_tmp;
			if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
				dhp=s->cert->dh_tmp_cb(s,
				      SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
				      SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
			if (dhp == NULL)
				{
				al=SSL_AD_HANDSHAKE_FAILURE;
				SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_DH_KEY);
				goto f_err;
				}

			if (s->s3->tmp.dh != NULL)
				{
				DH_free(dh);
				SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE, SSL_R_INTERNAL_ERROR);
				goto err;
				}

			if ((dh=DHparams_dup(dhp)) == NULL)
				{
				SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
				goto err;
				}

			s->s3->tmp.dh=dh;
			if ((dhp->pub_key == NULL ||
			     dhp->priv_key == NULL ||
			     (s->options & SSL_OP_SINGLE_DH_USE)))
				{
				if(!DH_generate_key(dh))
				    {
				    SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
					   ERR_R_DH_LIB);
				    goto err;
				    }
				}
			else
				{
				dh->pub_key=BN_dup(dhp->pub_key);
				dh->priv_key=BN_dup(dhp->priv_key);
				if ((dh->pub_key == NULL) ||
					(dh->priv_key == NULL))
					{
					SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
					goto err;
					}
				}
			r[0]=dh->p;
			r[1]=dh->g;
			r[2]=dh->pub_key;
			}
		else 
#endif
			{
			al=SSL_AD_HANDSHAKE_FAILURE;
			SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
			goto f_err;
			}
		for (i=0; r[i] != NULL; i++)
			{
			nr[i]=BN_num_bytes(r[i]);
			n+=2+nr[i];
			}

		if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL))
			{
			if ((pkey=ssl_get_sign_pkey(s,s->s3->tmp.new_cipher))
				== NULL)
				{
				al=SSL_AD_DECODE_ERROR;
				goto f_err;
				}
			kn=EVP_PKEY_size(pkey);
			}
		else
			{
			pkey=NULL;
			kn=0;
			}

		if (!BUF_MEM_grow(buf,n+4+kn))
			{
			SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_BUF);
			goto err;
			}
		d=(unsigned char *)s->init_buf->data;
		p= &(d[4]);

		for (i=0; r[i] != NULL; i++)
			{
			s2n(nr[i],p);
			BN_bn2bin(r[i],p);
			p+=nr[i];
			}

		/* not anonymous */
		if (pkey != NULL)
			{
			/* n is the length of the params, they start at &(d[4])
			 * and p points to the space at the end. */
#ifndef NO_RSA
			if (pkey->type == EVP_PKEY_RSA)
				{
				q=md_buf;
				j=0;
				for (num=2; num > 0; num--)
					{
					EVP_DigestInit(&md_ctx,(num == 2)
						?s->ctx->md5:s->ctx->sha1);
					EVP_DigestUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
					EVP_DigestUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
					EVP_DigestUpdate(&md_ctx,&(d[4]),n);
					EVP_DigestFinal(&md_ctx,q,
						(unsigned int *)&i);
					q+=i;
					j+=i;
					}
				if (RSA_sign(NID_md5_sha1, md_buf, j,
					&(p[2]), &u, pkey->pkey.rsa) <= 0)
					{
					SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_RSA);
					goto err;
					}
				s2n(u,p);
				n+=u+2;
				}
			else
#endif
#if !defined(NO_DSA)
				if (pkey->type == EVP_PKEY_DSA)
				{
				/* lets do DSS */
				EVP_SignInit(&md_ctx,EVP_dss1());
				EVP_SignUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
				EVP_SignUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
				EVP_SignUpdate(&md_ctx,&(d[4]),n);
				if (!EVP_SignFinal(&md_ctx,&(p[2]),
					(unsigned int *)&i,pkey))
					{
					SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_DSA);
					goto err;
					}
				s2n(i,p);
				n+=i+2;
				}
			else
#endif
				{
				/* Is this error check actually needed? */
				al=SSL_AD_HANDSHAKE_FAILURE;
				SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_PKEY_TYPE);
				goto f_err;
				}
			}

		*(d++)=SSL3_MT_SERVER_KEY_EXCHANGE;
		l2n3(n,d);

		/* we should now have things packed up, so lets send
		 * it off */
		s->init_num=n+4;
		s->init_off=0;
		}

	s->state = SSL3_ST_SW_KEY_EXCH_B;
	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
f_err:
	ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
	return(-1);
	}

static int ssl3_send_certificate_request(SSL *s)
	{
	unsigned char *p,*d;
	int i,j,nl,off,n;
	STACK_OF(X509_NAME) *sk=NULL;
	X509_NAME *name;
	BUF_MEM *buf;

	if (s->state == SSL3_ST_SW_CERT_REQ_A)
		{
		buf=s->init_buf;

		d=p=(unsigned char *)&(buf->data[4]);