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- static int ssl23_client_hello(SSL *s)
- {
- unsigned char *buf;
- unsigned char *p,*d;
- int i,ch_len;
- unsigned long l;
- int ssl2_compat;
- int version = 0, version_major, version_minor;
- int al = 0;
- #ifndef OPENSSL_NO_COMP
- int j;
- SSL_COMP *comp;
- #endif
- int ret;
- unsigned long mask, options = s->options;
- 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;
- /*
- * 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;
- if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)
- version = TLS1_1_VERSION;
- #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;
- mask &= ~SSL_OP_NO_TLSv1;
- #if !defined(OPENSSL_NO_SSL3)
- if ((options & SSL_OP_NO_TLSv1) && (options & mask) != mask)
- version = SSL3_VERSION;
- 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)
- {
- /* have to disable SSL 2.0 compatibility if we need TLS extensions */
- if (s->tlsext_hostname != NULL)
- ssl2_compat = 0;
- if (s->tlsext_status_type != -1)
- ssl2_compat = 0;
- #ifdef TLSEXT_TYPE_opaque_prf_input
- if (s->ctx->tlsext_opaque_prf_input_callback != 0 || s->tlsext_opaque_prf_input != NULL)
- ssl2_compat = 0;
- #endif
- if (s->ctx->custom_cli_ext_records_count != 0)
- ssl2_compat = 0;
- if (s->ctx->cli_supp_data_records_count != 0)
- ssl2_compat = 0;
- }
- #endif
- buf=(unsigned char *)s->init_buf->data;
- if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
- {
- #if 0
- /* don't reuse session-id's */
- if (!ssl_get_new_session(s,0))
- {
- return(-1);
- }
- #endif
- p=s->s3->client_random;
- if (ssl_fill_hello_random(s, 0, p, SSL3_RANDOM_SIZE) <= 0)
- return -1;
- if (version == TLS1_2_VERSION)
- {
- version_major = TLS1_2_VERSION_MAJOR;
- version_minor = TLS1_2_VERSION_MINOR;
- }
- else if (tls1_suiteb(s))
- {
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,
- SSL_R_ONLY_TLS_1_2_ALLOWED_IN_SUITEB_MODE);
- return -1;
- }
- else if (version == TLS1_1_VERSION)
- {
- version_major = TLS1_1_VERSION_MAJOR;
- version_minor = TLS1_1_VERSION_MINOR;
- }
- else if (version == TLS1_VERSION)
- {
- version_major = TLS1_VERSION_MAJOR;
- version_minor = TLS1_VERSION_MINOR;
- }
- #ifdef OPENSSL_FIPS
- else if(FIPS_mode())
- {
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,
- SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
- return -1;
- }
- #endif
- else if (version == SSL3_VERSION)
- {
- version_major = SSL3_VERSION_MAJOR;
- version_minor = SSL3_VERSION_MINOR;
- }
- else if (version == SSL2_VERSION)
- {
- version_major = SSL2_VERSION_MAJOR;
- version_minor = SSL2_VERSION_MINOR;
- }
- else
- {
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_PROTOCOLS_AVAILABLE);
- return(-1);
- }
- s->client_version = version;
- if (ssl2_compat)
- {
- /* create SSL 2.0 compatible Client Hello */
- /* two byte record header will be written last */
- d = &(buf[2]);
- p = d + 9; /* leave space for message type, version, individual length fields */
- *(d++) = SSL2_MT_CLIENT_HELLO;
- *(d++) = version_major;
- *(d++) = version_minor;
- /* Ciphers supported */
- i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),p,0);
- if (i == 0)
- {
- /* no ciphers */
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
- return -1;
- }
- s2n(i,d);
- p+=i;
- /* put in the session-id length (zero since there is no reuse) */
- #if 0
- s->session->session_id_length=0;
- #endif
- s2n(0,d);
- if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
- ch_len=SSL2_CHALLENGE_LENGTH;
- else
- ch_len=SSL2_MAX_CHALLENGE_LENGTH;
- /* write out sslv2 challenge */
- /* Note that ch_len must be <= SSL3_RANDOM_SIZE (32),
- because it is one of SSL2_MAX_CHALLENGE_LENGTH (32)
- or SSL2_MAX_CHALLENGE_LENGTH (16), but leave the
- check in for futurproofing */
- if (SSL3_RANDOM_SIZE < ch_len)
- i=SSL3_RANDOM_SIZE;
- else
- i=ch_len;
- s2n(i,d);
- memset(&(s->s3->client_random[0]),0,SSL3_RANDOM_SIZE);
- if (RAND_pseudo_bytes(&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i) <= 0)
- return -1;
- memcpy(p,&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
- p+=i;
- i= p- &(buf[2]);
- buf[0]=((i>>8)&0xff)|0x80;
- buf[1]=(i&0xff);
- /* number of bytes to write */
- s->init_num=i+2;
- s->init_off=0;
- ssl3_finish_mac(s,&(buf[2]),i);
- }
- else
- {
- /* create Client Hello in SSL 3.0/TLS 1.0 format */
- /* do the record header (5 bytes) and handshake message header (4 bytes) last */
- d = p = &(buf[9]);
- *(p++) = version_major;
- *(p++) = version_minor;
- /* Random stuff */
- memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
- p += SSL3_RANDOM_SIZE;
- /* Session ID (zero since there is no reuse) */
- *(p++) = 0;
- /* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
- i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]),ssl3_put_cipher_by_char);
- if (i == 0)
- {
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
- return -1;
- }
- #ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
- /* Some servers hang if client hello > 256 bytes
- * as hack workaround chop number of supported ciphers
- * to keep it well below this if we use TLS v1.2
- */
- if (TLS1_get_version(s) >= TLS1_2_VERSION
- && i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
- i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
- #endif
- s2n(i,p);
- p+=i;
- /* COMPRESSION */
- #ifdef OPENSSL_NO_COMP
- *(p++)=1;
- #else
- if (!ssl_allow_compression(s) || !s->ctx->comp_methods)
- 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;
- }
- #endif
- *(p++)=0; /* Add the NULL method */
- #ifndef OPENSSL_NO_TLSEXT
- /* TLS extensions*/
- if (ssl_prepare_clienthello_tlsext(s) <= 0)
- {
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
- return -1;
- }
- if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH, &al)) == NULL)
- {
- ssl3_send_alert(s,SSL3_AL_FATAL,al);
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
- return -1;
- }
- #endif
- l = p-d;
- /* fill in 4-byte handshake header */
- d=&(buf[5]);
- *(d++)=SSL3_MT_CLIENT_HELLO;
- l2n3(l,d);
- l += 4;
- if (l > SSL3_RT_MAX_PLAIN_LENGTH)
- {
- SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
- return -1;
- }
- /* fill in 5-byte record header */
- d=buf;
- *(d++) = SSL3_RT_HANDSHAKE;
- *(d++) = version_major;
- /* Some servers hang if we use long client hellos
- * and a record number > TLS 1.0.
- */
- if (TLS1_get_client_version(s) > TLS1_VERSION)
- *(d++) = 1;
- else
- *(d++) = version_minor;
- s2n((int)l,d);
- /* number of bytes to write */
- s->init_num=p-buf;
- s->init_off=0;
- ssl3_finish_mac(s,&(buf[5]), s->init_num - 5);
- }
- s->state=SSL23_ST_CW_CLNT_HELLO_B;
- s->init_off=0;
- }
- /* SSL3_ST_CW_CLNT_HELLO_B */
- ret = ssl23_write_bytes(s);
- if ((ret >= 2) && s->msg_callback)
- {
- /* Client Hello has been sent; tell msg_callback */
- if (ssl2_compat)
- s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg);
- else
- {
- s->msg_callback(1, version, SSL3_RT_HEADER, s->init_buf->data, 5, s, s->msg_callback_arg);
- s->msg_callback(1, version, SSL3_RT_HANDSHAKE, s->init_buf->data+5, ret-5, s, s->msg_callback_arg);
- }
- }
- return ret;
- }
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