Security framework.
Security callback: selects which parameters are permitted including
sensible defaults based on bits of security.
The "parameters" which can be selected include: ciphersuites,
curves, key sizes, certificate signature algorithms, supported
signature algorithms, DH parameters, SSL/TLS version, session tickets
and compression.
In some cases prohibiting the use of a parameters will mean they are
not advertised to the peer: for example cipher suites and ECC curves.
In other cases it will abort the handshake: e.g DH parameters or the
peer key size.
Documentation to follow...
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 37cc6f6..26fc45c 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -222,36 +222,46 @@
#ifndef OPENSSL_NO_EC
-static int nid_list[] =
+typedef struct
{
- NID_sect163k1, /* sect163k1 (1) */
- NID_sect163r1, /* sect163r1 (2) */
- NID_sect163r2, /* sect163r2 (3) */
- NID_sect193r1, /* sect193r1 (4) */
- NID_sect193r2, /* sect193r2 (5) */
- NID_sect233k1, /* sect233k1 (6) */
- NID_sect233r1, /* sect233r1 (7) */
- NID_sect239k1, /* sect239k1 (8) */
- NID_sect283k1, /* sect283k1 (9) */
- NID_sect283r1, /* sect283r1 (10) */
- NID_sect409k1, /* sect409k1 (11) */
- NID_sect409r1, /* sect409r1 (12) */
- NID_sect571k1, /* sect571k1 (13) */
- NID_sect571r1, /* sect571r1 (14) */
- NID_secp160k1, /* secp160k1 (15) */
- NID_secp160r1, /* secp160r1 (16) */
- NID_secp160r2, /* secp160r2 (17) */
- NID_secp192k1, /* secp192k1 (18) */
- NID_X9_62_prime192v1, /* secp192r1 (19) */
- NID_secp224k1, /* secp224k1 (20) */
- NID_secp224r1, /* secp224r1 (21) */
- NID_secp256k1, /* secp256k1 (22) */
- NID_X9_62_prime256v1, /* secp256r1 (23) */
- NID_secp384r1, /* secp384r1 (24) */
- NID_secp521r1, /* secp521r1 (25) */
- NID_brainpoolP256r1, /* brainpoolP256r1 (26) */
- NID_brainpoolP384r1, /* brainpoolP384r1 (27) */
- NID_brainpoolP512r1 /* brainpool512r1 (28) */
+ int nid; /* Curve NID */
+ int secbits; /* Bits of security (from SP800-57) */
+ unsigned int flags; /* Flags: currently just field type */
+ } tls_curve_info;
+
+#define TLS_CURVE_CHAR2 0x1
+#define TLS_CURVE_PRIME 0x0
+
+static tls_curve_info nid_list[] =
+ {
+ {NID_sect163k1, 80, TLS_CURVE_CHAR2},/* sect163k1 (1) */
+ {NID_sect163r1, 80, TLS_CURVE_CHAR2},/* sect163r1 (2) */
+ {NID_sect163r2, 80, TLS_CURVE_CHAR2},/* sect163r2 (3) */
+ {NID_sect193r1, 80, TLS_CURVE_CHAR2},/* sect193r1 (4) */
+ {NID_sect193r2, 80, TLS_CURVE_CHAR2},/* sect193r2 (5) */
+ {NID_sect233k1, 112, TLS_CURVE_CHAR2},/* sect233k1 (6) */
+ {NID_sect233r1, 112, TLS_CURVE_CHAR2},/* sect233r1 (7) */
+ {NID_sect239k1, 112, TLS_CURVE_CHAR2},/* sect239k1 (8) */
+ {NID_sect283k1, 128, TLS_CURVE_CHAR2},/* sect283k1 (9) */
+ {NID_sect283r1, 128, TLS_CURVE_CHAR2},/* sect283r1 (10) */
+ {NID_sect409k1, 192, TLS_CURVE_CHAR2},/* sect409k1 (11) */
+ {NID_sect409r1, 192, TLS_CURVE_CHAR2},/* sect409r1 (12) */
+ {NID_sect571k1, 256, TLS_CURVE_CHAR2},/* sect571k1 (13) */
+ {NID_sect571r1, 256, TLS_CURVE_CHAR2},/* sect571r1 (14) */
+ {NID_secp160k1, 80, TLS_CURVE_PRIME},/* secp160k1 (15) */
+ {NID_secp160r1, 80, TLS_CURVE_PRIME},/* secp160r1 (16) */
+ {NID_secp160r2, 80, TLS_CURVE_PRIME},/* secp160r2 (17) */
+ {NID_secp192k1, 80, TLS_CURVE_PRIME},/* secp192k1 (18) */
+ {NID_X9_62_prime192v1, 80, TLS_CURVE_PRIME},/* secp192r1 (19) */
+ {NID_secp224k1, 112, TLS_CURVE_PRIME},/* secp224k1 (20) */
+ {NID_secp224r1, 112, TLS_CURVE_PRIME},/* secp224r1 (21) */
+ {NID_secp256k1, 128, TLS_CURVE_PRIME},/* secp256k1 (22) */
+ {NID_X9_62_prime256v1, 128, TLS_CURVE_PRIME},/* secp256r1 (23) */
+ {NID_secp384r1, 192, TLS_CURVE_PRIME},/* secp384r1 (24) */
+ {NID_secp521r1, 256, TLS_CURVE_PRIME},/* secp521r1 (25) */
+ {NID_brainpoolP256r1, 128, TLS_CURVE_PRIME}, /* brainpoolP256r1 (26) */
+ {NID_brainpoolP384r1, 192, TLS_CURVE_PRIME}, /* brainpoolP384r1 (27) */
+ {NID_brainpoolP512r1, 256, TLS_CURVE_PRIME},/* brainpool512r1 (28) */
};
@@ -306,7 +316,7 @@
if ((curve_id < 1) || ((unsigned int)curve_id >
sizeof(nid_list)/sizeof(nid_list[0])))
return 0;
- return nid_list[curve_id-1];
+ return nid_list[curve_id-1].nid;
}
int tls1_ec_nid2curve_id(int nid)
@@ -414,6 +424,20 @@
*pcurveslen = sizeof(eccurves_default);
}
}
+
+/* See if curve is allowed by security callback */
+static int tls_curve_allowed(SSL *s, const unsigned char *curve, int op)
+ {
+ tls_curve_info *cinfo;
+ if (curve[0])
+ return 1;
+ if ((curve[1] < 1) || ((size_t)curve[1] >
+ sizeof(nid_list)/sizeof(nid_list[0])))
+ return 0;
+ cinfo = &nid_list[curve[1]-1];
+ return ssl_security(s, op, cinfo->secbits, cinfo->nid, (void *)curve);
+ }
+
/* Check a curve is one of our preferences */
int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
{
@@ -445,7 +469,7 @@
for (i = 0; i < curveslen; i += 2, curves += 2)
{
if (p[1] == curves[0] && p[2] == curves[1])
- return 1;
+ return tls_curve_allowed(s, p + 1, SSL_SECOP_CURVE_CHECK);
}
return 0;
}
@@ -496,6 +520,8 @@
{
if (pref[0] == tsupp[0] && pref[1] == tsupp[1])
{
+ if (!tls_curve_allowed(s, pref, SSL_SECOP_CURVE_SHARED))
+ continue;
if (nmatch == k)
{
int id = (pref[0] << 8) | pref[1];
@@ -678,7 +704,7 @@
return 0;
/* For clients can only check sent curve list */
if (!s->server)
- return 1;
+ break;
}
return 1;
}
@@ -1005,6 +1031,14 @@
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_UNKNOWN_DIGEST);
return 0;
}
+ /* Make sure security callback allows algorithm */
+ if (!ssl_security(s, SSL_SECOP_SIGALG_CHECK,
+ EVP_MD_size(*pmd) * 4, EVP_MD_type(*pmd),
+ (void *)sig))
+ {
+ SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
+ return 0;
+ }
/* Store the digest used so applications can retrieve it if they
* wish.
*/
@@ -1012,6 +1046,7 @@
s->session->sess_cert->peer_key->digest = *pmd;
return 1;
}
+
/* 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
@@ -1021,9 +1056,6 @@
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;
/* Don't allow TLS 1.2 only ciphers if we don't suppport them */
@@ -1031,50 +1063,16 @@
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
+ ssl_set_sig_mask(&c->mask_a, s, SSL_SECOP_SIGALG_MASK);
+ /* Disable static DH if we don't include any appropriate
* signature algorithms.
*/
- if (!have_rsa)
- {
- c->mask_a |= SSL_aRSA;
+ if (c->mask_a & SSL_aRSA)
c->mask_k |= SSL_kDHr|SSL_kECDHr;
- }
- if (!have_dsa)
- {
- c->mask_a |= SSL_aDSS;
+ if (c->mask_a & SSL_aDSS)
c->mask_k |= SSL_kDHd;
- }
- if (!have_ecdsa)
- {
- c->mask_a |= SSL_aECDSA;
+ if (c->mask_a & SSL_aECDSA)
c->mask_k |= SSL_kECDHe;
- }
#ifndef OPENSSL_NO_KRB5
if (!kssl_tgt_is_available(s->kssl_ctx))
{
@@ -1093,12 +1091,19 @@
c->valid = 1;
}
-int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c)
+int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op)
{
CERT *ct = s->cert;
if (c->algorithm_ssl & ct->mask_ssl || c->algorithm_mkey & ct->mask_k || c->algorithm_auth & ct->mask_a)
return 1;
- return 0;
+ return !ssl_security(s, op, c->strength_bits, 0, (void *)c);
+ }
+
+static int tls_use_ticket(SSL *s)
+ {
+ if (s->options & SSL_OP_NO_TICKET)
+ return 0;
+ return ssl_security(s, SSL_SECOP_TICKET, 0, 0, NULL);
}
unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit, int *al)
@@ -1231,6 +1236,8 @@
long lenmax;
const unsigned char *plist;
size_t plistlen;
+ size_t i;
+ unsigned char *etmp;
tls1_get_formatlist(s, &plist, &plistlen);
@@ -1259,22 +1266,34 @@
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
+
s2n(TLSEXT_TYPE_elliptic_curves,ret);
- s2n(plistlen + 2, ret);
+ etmp = ret + 4;
+ /* Copy curve ID if supported */
+ for (i = 0; i < plistlen; i += 2, plist += 2)
+ {
+ if (tls_curve_allowed(s, plist, SSL_SECOP_CURVE_SUPPORTED))
+ {
+ *etmp++ = plist[0];
+ *etmp++ = plist[1];
+ }
+ }
+
+ plistlen = etmp - ret - 4;
/* NB: draft-ietf-tls-ecc-12.txt uses a one-byte prefix for
* elliptic_curve_list, but the examples use two bytes.
* http://www1.ietf.org/mail-archive/web/tls/current/msg00538.html
* resolves this to two bytes.
*/
+ s2n(plistlen + 2, ret);
s2n(plistlen, ret);
- memcpy(ret, plist, plistlen);
ret+=plistlen;
}
#endif /* OPENSSL_NO_EC */
- if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
+ if (tls_use_ticket(s))
{
int ticklen;
if (!s->new_session && s->session && s->session->tlsext_tick)
@@ -1314,13 +1333,18 @@
{
size_t salglen;
const unsigned char *salg;
+ unsigned char *etmp;
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);
- memcpy(ret, salg, salglen);
+ etmp = ret;
+ /* Skip over lengths for now */
+ ret += 4;
+ salglen = tls12_copy_sigalgs(s, etmp, salg, salglen);
+ /* Fill in lengths */
+ s2n(salglen + 2, etmp);
+ s2n(salglen, etmp);
ret += salglen;
}
@@ -1603,8 +1627,7 @@
/* Currently the server should not respond with a SupportedCurves extension */
#endif /* OPENSSL_NO_EC */
- if (s->tlsext_ticket_expected
- && !(SSL_get_options(s) & SSL_OP_NO_TICKET))
+ if (s->tlsext_ticket_expected && tls_use_ticket(s))
{
if ((long)(limit - ret - 4) < 0) return NULL;
s2n(TLSEXT_TYPE_session_ticket,ret);
@@ -2644,8 +2667,7 @@
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
- if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
- || (size > 0))
+ if (!tls_use_ticket(s) || (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
@@ -3271,7 +3293,7 @@
/* If tickets disabled behave as if no ticket present
* to permit stateful resumption.
*/
- if (SSL_get_options(s) & SSL_OP_NO_TICKET)
+ if (!tls_use_ticket(s))
return 0;
if ((s->version <= SSL3_VERSION) || !limit)
return 0;
@@ -3525,40 +3547,60 @@
sizeof(tls12_sig)/sizeof(tls12_lookup));
}
+typedef struct
+ {
+ int nid;
+ int secbits;
+ const EVP_MD *(*mfunc)(void);
+ } tls12_hash_info;
+
+static const tls12_hash_info tls12_md_info[] = {
+#ifdef OPENSSL_NO_MD5
+ {NID_md5, 64, 0},
+#else
+ {NID_md5, 64, EVP_md5},
+#endif
+#ifdef OPENSSL_NO_SHA
+ {NID_sha1, 80, 0},
+#else
+ {NID_sha1, 80, EVP_sha1},
+#endif
+#ifdef OPENSSL_NO_SHA256
+ {NID_sha224, 112, 0},
+ {NID_sha256, 128, 0},
+#else
+ {NID_sha224, 112, EVP_sha224},
+ {NID_sha256, 128, EVP_sha256},
+#endif
+#ifdef OPENSSL_NO_SHA512
+ {NID_sha384, 192, 0},
+ {NID_sha512, 256, 0}
+#else
+ {NID_sha384, 192, EVP_sha384},
+ {NID_sha512, 256, EVP_sha512}
+#endif
+};
+
+static const tls12_hash_info *tls12_get_hash_info(unsigned char hash_alg)
+ {
+ if (hash_alg == 0)
+ return NULL;
+ if (hash_alg > sizeof(tls12_md_info)/sizeof(tls12_md_info[0]))
+ return NULL;
+ return tls12_md_info + hash_alg - 1;
+ }
+
const EVP_MD *tls12_get_hash(unsigned char hash_alg)
{
- switch(hash_alg)
- {
-#ifndef OPENSSL_NO_MD5
- case TLSEXT_hash_md5:
-#ifdef OPENSSL_FIPS
- if (FIPS_mode())
- return NULL;
-#endif
- return EVP_md5();
-#endif
-#ifndef OPENSSL_NO_SHA
- case TLSEXT_hash_sha1:
- return EVP_sha1();
-#endif
-#ifndef OPENSSL_NO_SHA256
- case TLSEXT_hash_sha224:
- return EVP_sha224();
-
- case TLSEXT_hash_sha256:
- return EVP_sha256();
-#endif
-#ifndef OPENSSL_NO_SHA512
- case TLSEXT_hash_sha384:
- return EVP_sha384();
-
- case TLSEXT_hash_sha512:
- return EVP_sha512();
-#endif
- default:
+ const tls12_hash_info *inf;
+#ifndef OPENSSL_FIPS
+ if (hash_alg == TLSEXT_hash_md5 && FIPS_mode())
return NULL;
-
- }
+#endif
+ inf = tls12_get_hash_info(hash_alg);
+ if (!inf || !inf->mfunc)
+ return NULL;
+ return inf->mfunc();
}
static int tls12_get_pkey_idx(unsigned char sig_alg)
@@ -3611,8 +3653,86 @@
*psignhash_nid = NID_undef;
}
}
+/* Check to see if a signature algorithm is allowed */
+static int tls12_sigalg_allowed(SSL *s, int op, const unsigned char *ptmp)
+ {
+ /* See if we have an entry in the hash table and it is enabled */
+ const tls12_hash_info *hinf = tls12_get_hash_info(ptmp[0]);
+ if (!hinf || !hinf->mfunc)
+ return 0;
+ /* See if public key algorithm allowed */
+ if (tls12_get_pkey_idx(ptmp[1]) == -1)
+ return 0;
+ /* Finally see if security callback allows it */
+ return ssl_security(s, op, hinf->secbits, hinf->nid, (void *)ptmp);
+ }
+
+/* Get a mask of disabled public key algorithms based on supported
+ * signature algorithms. For example if no signature algorithm supports RSA
+ * then RSA is disabled.
+ */
+
+void ssl_set_sig_mask(unsigned long *pmask_a, SSL *s, int op)
+ {
+ const unsigned char *sigalgs;
+ size_t i, sigalgslen;
+ int have_rsa = 0, have_dsa = 0, have_ecdsa = 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. To keep down calls to security callback only check
+ * if we have to.
+ */
+ 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:
+ if (!have_rsa && tls12_sigalg_allowed(s, op, sigalgs))
+ have_rsa = 1;
+ break;
+#endif
+#ifndef OPENSSL_NO_DSA
+ case TLSEXT_signature_dsa:
+ if (!have_dsa && tls12_sigalg_allowed(s, op, sigalgs))
+ have_dsa = 1;
+ break;
+#endif
+#ifndef OPENSSL_NO_ECDSA
+ case TLSEXT_signature_ecdsa:
+ if (!have_ecdsa && tls12_sigalg_allowed(s, op, sigalgs))
+ have_ecdsa = 1;
+ break;
+#endif
+ }
+ }
+ if (!have_rsa)
+ *pmask_a |= SSL_aRSA;
+ if (!have_dsa)
+ *pmask_a |= SSL_aDSS;
+ if (!have_ecdsa)
+ *pmask_a |= SSL_aECDSA;
+ }
+
+size_t tls12_copy_sigalgs(SSL *s, unsigned char *out,
+ const unsigned char *psig, size_t psiglen)
+ {
+ unsigned char *tmpout = out;
+ size_t i;
+ for (i = 0; i < psiglen; i += 2, psig += 2)
+ {
+ if (tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, psig))
+ {
+ *tmpout++ = psig[0];
+ *tmpout++ = psig[1];
+ }
+ }
+ return tmpout - out;
+ }
+
/* Given preference and allowed sigalgs set shared sigalgs */
-static int tls12_do_shared_sigalgs(TLS_SIGALGS *shsig,
+static int tls12_shared_sigalgs(SSL *s, TLS_SIGALGS *shsig,
const unsigned char *pref, size_t preflen,
const unsigned char *allow, size_t allowlen)
{
@@ -3621,9 +3741,7 @@
for (i = 0, ptmp = pref; i < preflen; i+=2, ptmp+=2)
{
/* Skip disabled hashes or signature algorithms */
- if (tls12_get_hash(ptmp[0]) == NULL)
- continue;
- if (tls12_get_pkey_idx(ptmp[1]) == -1)
+ if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SHARED, ptmp))
continue;
for (j = 0, atmp = allow; j < allowlen; j+=2, atmp+=2)
{
@@ -3688,13 +3806,13 @@
pref = c->peer_sigalgs;
preflen = c->peer_sigalgslen;
}
- nmatch = tls12_do_shared_sigalgs(NULL, pref, preflen, allow, allowlen);
+ nmatch = tls12_shared_sigalgs(s, NULL, pref, preflen, allow, allowlen);
if (!nmatch)
return 1;
salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS));
if (!salgs)
return 0;
- nmatch = tls12_do_shared_sigalgs(salgs, pref, preflen, allow, allowlen);
+ nmatch = tls12_shared_sigalgs(s, salgs, pref, preflen, allow, allowlen);
c->shared_sigalgs = salgs;
c->shared_sigalgslen = nmatch;
return 1;
@@ -4495,3 +4613,87 @@
return DH_get_1024_160();
}
#endif
+
+static int ssl_security_cert_key(SSL *s, SSL_CTX *ctx, X509 *x, int op)
+ {
+ int secbits;
+ EVP_PKEY *pkey = X509_get_pubkey(x);
+ if (pkey)
+ {
+ secbits = EVP_PKEY_security_bits(pkey);
+ EVP_PKEY_free(pkey);
+ }
+ else
+ secbits = -1;
+ if (s)
+ return ssl_security(s, op, secbits, 0, x);
+ else
+ return ssl_ctx_security(ctx, op, secbits, 0, x);
+ }
+
+static int ssl_security_cert_sig(SSL *s, SSL_CTX *ctx, X509 *x, int op)
+ {
+ /* Lookup signature algorithm digest */
+ int secbits = -1, md_nid = NID_undef, sig_nid;
+ sig_nid = X509_get_signature_nid(x);
+ if (sig_nid && OBJ_find_sigid_algs(sig_nid, &md_nid, NULL))
+ {
+ const EVP_MD *md;
+ if (md_nid && (md = EVP_get_digestbynid(md_nid)))
+ secbits = EVP_MD_size(md) * 4;
+ }
+ if (s)
+ return ssl_security(s, op, secbits, md_nid, x);
+ else
+ return ssl_ctx_security(ctx, op, secbits, md_nid, x);
+ }
+
+int ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee)
+ {
+ if (vfy)
+ vfy = SSL_SECOP_PEER;
+ if (is_ee)
+ {
+ if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_EE_KEY | vfy))
+ return SSL_R_EE_KEY_TOO_SMALL;
+ }
+ else
+ {
+ if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_CA_KEY | vfy))
+ return SSL_R_CA_KEY_TOO_SMALL;
+ }
+ if (!ssl_security_cert_sig(s, ctx, x, SSL_SECOP_CA_MD | vfy))
+ return SSL_R_CA_MD_TOO_WEAK;
+ return 1;
+ }
+
+/* Check security of a chain, if sk includes the end entity certificate
+ * then x is NULL. If vfy is 1 then we are verifying a peer chain and
+ * not sending one to the peer.
+ * Return values: 1 if ok otherwise error code to use
+ */
+
+int ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *x, int vfy)
+ {
+ int rv, start_idx, i;
+ if (x == NULL)
+ {
+ x = sk_X509_value(sk, 0);
+ start_idx = 1;
+ }
+ else
+ start_idx = 0;
+
+ rv = ssl_security_cert(s, NULL, x, vfy, 1);
+ if (rv != 1)
+ return rv;
+
+ for (i = start_idx; i < sk_X509_num(sk); i++)
+ {
+ x = sk_X509_value(sk, i);
+ rv = ssl_security_cert(s, NULL, x, vfy, 0);
+ if (rv != 1)
+ return rv;
+ }
+ return 1;
+ }
