generic-library/openssl
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Allow initial connection (but no renegoriation) to servers which don't support

Browse Source 
RI.

Reorganise RI checking code and handle some missing cases.
This commit is contained in:
Dr. Stephen Henson 2009-12-14 13:56:04 +00:00
parent 22c2155595
commit c27c9cb4f7
1 changed files with 40 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

84
ssl/t1_lib.c
View File

@ -636,21 +636,11 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
s->tlsext_status_type = -1;
if (data >= (d+n-2))
{
if (s->new_session
&& !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
/* We should always see one extension: the renegotiate extension */
*al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
goto ri_check;
n2s(data,len);
if (data > (d+n-len))
return 1;
goto ri_check;
while (data <= (d+n-4))
{
@ -658,7 +648,7 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
n2s(data,size);
if (data+size > (d+n))
return 1;
goto ri_check;
#if 0
fprintf(stderr,"Received extension type %d size %d\n",type,size);
#endif
@ -972,16 +962,22 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
data+=size;
}
if (s->new_session && !renegotiate_seen
&& !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
*al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
return 0;
}
*p = data;
ri_check:
/* Need RI if renegotiating */
if (!renegotiate_seen && s->new_session &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
/* FIXME: Spec currently doesn't give alert to use */
*al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
@ -995,19 +991,7 @@ int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
int renegotiate_seen = 0;
if (data >= (d+n-2))
{
/* Because the client does not see any renegotiation during an
attack, we must enforce this on all server hellos, even the
first */
if (!(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
/* We should always see one extension: the renegotiate extension */
*al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
goto ri_check;
n2s(data,len);
@ -1017,7 +1001,7 @@ int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
n2s(data,size);
if (data+size > (d+n))
return 1;
goto ri_check;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size,
@ -1141,14 +1125,6 @@ int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
return 0;
}
if (!renegotiate_seen
&& !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
*al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
if (!s->hit && tlsext_servername == 1)
{
if (s->tlsext_hostname)
@ -1171,6 +1147,26 @@ int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
}
*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->new_session &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
/* FIXME: Spec currently doesn't give alert to use */
*al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}