int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
{
unsigned short length;
unsigned short type;
unsigned short size;
unsigned char *data = *p;
int tlsext_servername = 0;
int renegotiate_seen = 0;
if (data >= (d+n-2))
goto ri_check;
n2s(data,length);
if (data+length != d+n)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while(data <= (d+n-4))
{
n2s(data,type);
n2s(data,size);
if (data+size > (d+n))
goto ri_check;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size,
s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_server_name)
{
if (s->tlsext_hostname == NULL || size > 0)
{
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
tlsext_servername = 1;
}
else if (type == TLSEXT_TYPE_session_ticket)
{
if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
|| (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
s->tlsext_ticket_expected = 1;
}
else if (type == TLSEXT_TYPE_status_request &&
s->version != DTLS1_VERSION)
{
/* MUST be empty and only sent if we've requested
* a status request message.
*/
if ((s->tlsext_status_type == -1) || (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* Set flag to expect CertificateStatus message */
s->tlsext_status_expected = 1;
}
else if (type == TLSEXT_TYPE_renegotiate)
{
if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
return 0;
renegotiate_seen = 1;
}
data+=size;
}
if (data != d+n)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && tlsext_servername == 1)
{
if (s->tlsext_hostname)
{
if (s->session->tlsext_hostname == NULL)
{
s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
if (!s->session->tlsext_hostname)
{
*al = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
}
else
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
*p = data;
ri_check:
/* Determine if we need to see RI. Strictly speaking if we want to
* avoid an attack we should *always* see RI even on initial server
* hello because the client doesn't see any renegotiation during an
* attack. However this would mean we could not connect to any server
* which doesn't support RI so for the immediate future tolerate RI
* absence on initial connect only.
*/
if (!renegotiate_seen
&& !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
&& !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
{
unsigned short length;
unsigned short type;
unsigned short size;
unsigned char *data = *p;
int tlsext_servername = 0;
int renegotiate_seen = 0;
if (data >= (d+n-2))
goto ri_check;
n2s(data,length);
if (data+length != d+n)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while(data <= (d+n-4))
{
n2s(data,type);
n2s(data,size);
if (data+size > (d+n))
goto ri_check;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size,
s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_server_name)
{
if (s->tlsext_hostname == NULL || size > 0)
{
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
tlsext_servername = 1;
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats &&
s->version != DTLS1_VERSION)
{
unsigned char *sdata = data;
int ecpointformatlist_length = *(sdata++);
if (ecpointformatlist_length != size - 1)
{
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length = 0;
if (s->session->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->session->tlsext_ecpointformatlist);
if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
#if 0
fprintf(stderr,"ssl_parse_serverhello_tlsext s->session->tlsext_ecpointformatlist ");
sdata = s->session->tlsext_ecpointformatlist;
for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
fprintf(stderr,"%i ",*(sdata++));
fprintf(stderr,"\n");
#endif
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket)
{
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
|| (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
s->tlsext_ticket_expected = 1;
}
#ifdef TLSEXT_TYPE_opaque_prf_input
else if (type == TLSEXT_TYPE_opaque_prf_input &&
s->version != DTLS1_VERSION)
{
unsigned char *sdata = data;
if (size < 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
n2s(sdata, s->s3->server_opaque_prf_input_len);
if (s->s3->server_opaque_prf_input_len != size - 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
OPENSSL_free(s->s3->server_opaque_prf_input);
if (s->s3->server_opaque_prf_input_len == 0)
s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
else
s->s3->server_opaque_prf_input = BUF_memdup(sdata, s->s3->server_opaque_prf_input_len);
if (s->s3->server_opaque_prf_input == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
#endif
else if (type == TLSEXT_TYPE_status_request &&
s->version != DTLS1_VERSION)
{
/* MUST be empty and only sent if we've requested
* a status request message.
*/
if ((s->tlsext_status_type == -1) || (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* Set flag to expect CertificateStatus message */
s->tlsext_status_expected = 1;
}
else if (type == TLSEXT_TYPE_renegotiate)
{
if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
return 0;
renegotiate_seen = 1;
}
data+=size;
}
if (data != d+n)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && tlsext_servername == 1)
{
if (s->tlsext_hostname)
{
if (s->session->tlsext_hostname == NULL)
{
s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
if (!s->session->tlsext_hostname)
{
*al = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
}
else
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
*p = data;
ri_check:
/* Determine if we need to see RI. Strictly speaking if we want to
* avoid an attack we should *always* see RI even on initial server
* hello because the client doesn't see any renegotiation during an
* attack. However this would mean we could not connect to any server
* which doesn't support RI so for the immediate future tolerate RI
* absence on initial connect only.
*/
if (!renegotiate_seen
&& !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
&& !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
