add suite B chain validation flags and associated verify errors

1 files changed, 124 insertions, 0 deletions

diff --git a/crypto/x509/x509_cmp.c b/crypto/x509/x509_cmp.c
index 352aa37434..74e076c7ba 100644
--- a/crypto/x509/x509_cmp.c
+++ b/crypto/x509/x509_cmp.c
@@ -341,3 +341,127 @@ int X509_check_private_key(X509 *x, EVP_PKEY *k)
 		return 1;
 	return 0;
 	}
+
+/* Check a suite B algorithm is permitted: pass in a public key and
+ * the NID of its signature (or 0 if no signature). The pflags is
+ * a pointer to a flags field which must contain the suite B verification
+ * flags.
+ */
+
+static int check_suite_b(EVP_PKEY *pkey, int sign_nid, unsigned long *pflags)
+	{
+	const EC_GROUP *grp = NULL;
+	int curve_nid;
+	if (pkey && pkey->type == EVP_PKEY_EC)
+		grp = EC_KEY_get0_group(pkey->pkey.ec);
+	if (!grp)
+		return X509_V_ERR_SUITE_B_INVALID_ALGORITHM;
+	curve_nid = EC_GROUP_get_curve_name(grp);
+	/* Check curve is consistent with LOS */
+	if (curve_nid == NID_secp384r1) /* P-384 */
+		{
+		/* Check signature algorithm is consistent with
+		 * curve.
+		 */
+		if (sign_nid != -1 && sign_nid != NID_ecdsa_with_SHA384)
+			return X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM;
+		if (!(*pflags & X509_V_FLAG_SUITEB_192_LOS))
+			return X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED;
+		/* If we encounter P-384 we cannot use P-256 later */
+		*pflags &= ~X509_V_FLAG_SUITEB_128_LOS_ONLY;
+		}
+	else if (curve_nid == NID_X9_62_prime256v1) /* P-256 */
+		{
+		if (sign_nid != -1 && sign_nid != NID_ecdsa_with_SHA256)
+			return X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM;
+		if (!(*pflags & X509_V_FLAG_SUITEB_128_LOS_ONLY))
+			return X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED;
+		}
+	else
+		return X509_V_ERR_SUITE_B_INVALID_CURVE;
+
+	return X509_V_OK;
+	}
+
+int X509_check_suiteb_chain(int *perror_depth, X509 *x, STACK_OF(X509) *chain,
+							unsigned long flags)
+	{
+	int rv, i, sign_nid;
+	EVP_PKEY *pk = NULL;
+	unsigned long tflags;
+	if (!(flags & X509_V_FLAG_SUITEB_128_LOS))
+		return X509_V_OK;
+	tflags = flags;
+	/* If no EE certificate passed in must be first in chain */
+	if (x == NULL)
+		{
+		x = sk_X509_value(chain, 0);
+		i = 1;
+		}
+	else
+		i = 0;
+
+	if (X509_get_version(x) != 2)
+		{
+		rv = X509_V_ERR_SUITE_B_INVALID_VERSION;
+		/* Correct error depth */
+		i = 0;
+		goto end;
+		}
+
+	pk = X509_get_pubkey(x);
+	/* Check EE key only */
+	rv = check_suite_b(pk, -1, &tflags);
+	if (rv != X509_V_OK)
+		{
+		/* Correct error depth */
+		i = 0;
+		goto end;
+		}
+	for(; i < sk_X509_num(chain); i++)
+		{
+		sign_nid = X509_get_signature_nid(x);
+		x = sk_X509_value(chain, i);
+		if (X509_get_version(x) != 2)
+			{
+			rv = X509_V_ERR_SUITE_B_INVALID_VERSION;
+			goto end;
+			}
+		EVP_PKEY_free(pk);
+		pk = X509_get_pubkey(x);
+		rv = check_suite_b(pk, sign_nid, &tflags);
+		if (rv != X509_V_OK)
+			goto end;
+		}
+
+	/* Final check: root CA signature */
+	rv = check_suite_b(pk, X509_get_signature_nid(x), &tflags);
+	end:
+	if (pk)
+		EVP_PKEY_free(pk);
+	if (rv != X509_V_OK)
+		{
+		/* Invalid signature or LOS errors are for previous cert */
+		if ((rv == X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM
+		    || rv == X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED) && i)
+			i--;
+		/* If we have LOS error and flags changed then we are signing
+		 * P-384 with P-256. Use more meaninggul error.
+		 */
+		if (rv == X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED && flags != tflags)
+			rv = X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256;
+		if (perror_depth)
+			*perror_depth = i;
+		}
+	return rv;
+	}
+
+int X509_check_suiteb_crl(X509_CRL *crl, EVP_PKEY *pk, unsigned long flags)
+	{
+	int sign_nid;
+	if (!(flags & X509_V_FLAG_SUITEB_128_LOS))
+		return X509_V_OK;
+	sign_nid = OBJ_obj2nid(crl->crl->sig_alg->algorithm);
+	return check_suite_b(pk, sign_nid, &flags);
+	}
+