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New function ssl_set_client_disabled to set masks for any ciphersuites

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that are disabled for this session (as opposed to always disabled by
configuration).
(backport from HEAD)
This commit is contained in:
Dr. Stephen Henson
2012-12-26 14:55:46 +00:00
parent a897502cd9
commit b28fbdfa7d
6 changed files with 124 additions and 41 deletions
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108
ssl/t1_lib.c
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@@ -635,35 +635,110 @@ static unsigned char tls12_sigalgs[] = {
#endif
};
size_t tls12_get_sig_algs(SSL *s, unsigned char *p)
size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
{
const unsigned char *sigs;
size_t sigslen;
/* If server use client authentication sigalgs if not NULL */
if (s->server && s->cert->client_sigalgs)
{
sigs = s->cert->client_sigalgs;
sigslen = s->cert->client_sigalgslen;
*psigs = s->cert->client_sigalgs;
return s->cert->client_sigalgslen;
}
else if (s->cert->conf_sigalgs)
{
sigs = s->cert->conf_sigalgs;
sigslen = s->cert->conf_sigalgslen;
*psigs = s->cert->conf_sigalgs;
return s->cert->conf_sigalgslen;
}
else
{
sigs = tls12_sigalgs;
sigslen = sizeof(tls12_sigalgs);
*psigs = tls12_sigalgs;
#ifdef OPENSSL_FIPS
/* If FIPS mode don't include MD5 which is last */
if (FIPS_mode())
sigslen -= 2;
return sizeof(tls12_sigalgs) - 2;
else
#endif
return sizeof(tls12_sigalgs);
}
if (p)
memcpy(p, sigs, sigslen);
return sigslen;
}
/* Get a mask of disabled algorithms: an algorithm is disabled
* if it isn't supported or doesn't appear in supported signature
* algorithms. Unlike ssl_cipher_get_disabled this applies to a specific
* session and not global settings.
*
*/
void ssl_set_client_disabled(SSL *s)
{
CERT *c = s->cert;
const unsigned char *sigalgs;
size_t i, sigalgslen;
int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
c->mask_a = 0;
c->mask_k = 0;
/* If less than TLS 1.2 don't allow TLS 1.2 only ciphers */
if (TLS1_get_version(s) < TLS1_2_VERSION)
c->mask_ssl = SSL_TLSV1_2;
else
c->mask_ssl = 0;
/* Now go through all signature algorithms seeing if we support
* any for RSA, DSA, ECDSA. Do this for all versions not just
* TLS 1.2.
*/
sigalgslen = tls12_get_psigalgs(s, &sigalgs);
for (i = 0; i < sigalgslen; i += 2, sigalgs += 2)
{
switch(sigalgs[1])
{
#ifndef OPENSSL_NO_RSA
case TLSEXT_signature_rsa:
have_rsa = 1;
break;
#endif
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
have_dsa = 1;
break;
#endif
#ifndef OPENSSL_NO_ECDSA
case TLSEXT_signature_ecdsa:
have_ecdsa = 1;
break;
#endif
}
}
/* Disable auth and static DH if we don't include any appropriate
* signature algorithms.
*/
if (!have_rsa)
{
c->mask_a |= SSL_aRSA;
c->mask_k |= SSL_kDHr|SSL_kECDHr;
}
if (!have_dsa)
{
c->mask_a |= SSL_aDSS;
c->mask_k |= SSL_kDHd;
}
if (!have_ecdsa)
{
c->mask_a |= SSL_aECDSA;
c->mask_k |= SSL_kECDHe;
}
#ifndef OPENSSL_NO_KRB5
if (!kssl_tgt_is_available(s->kssl_ctx))
{
c->mask_a |= SSL_aKRB5;
c->mask_k |= SSL_kKRB5;
}
#endif
#ifndef OPENSSL_NO_PSK
/* with PSK there must be client callback set */
if (!s->psk_client_callback)
{
c->mask_a |= SSL_aPSK;
c->mask_k |= SSL_kPSK;
}
#endif /* OPENSSL_NO_PSK */
c->valid = 1;
}
/* byte_compare is a compare function for qsort(3) that compares bytes. */
@@ -899,13 +974,14 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
if (TLS1_get_client_version(s) >= TLS1_2_VERSION)
{
size_t salglen;
salglen = tls12_get_sig_algs(s, NULL);
const unsigned char *salg;
salglen = tls12_get_psigalgs(s, &salg);
if ((size_t)(limit - ret) < salglen + 6)
return NULL;
s2n(TLSEXT_TYPE_signature_algorithms,ret);
s2n(salglen + 2, ret);
s2n(salglen, ret);
tls12_get_sig_algs(s, ret);
memcpy(ret, salg, salglen);
ret += salglen;
}