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;
}