In particular the NSS_USE_ALG_IN_CERT_SIGNATURE flag can be specified to allow a
specific curve for certificate verification.
---
lib/certhigh/certvfy.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 63 insertions(+), 2 deletions(-)
diff --git a/lib/certhigh/certvfy.c b/lib/certhigh/certvfy.c
index 3141163..7618822 100644
--- a/lib/certhigh/certvfy.c
+++ b/lib/certhigh/certvfy.c
@@ -34,6 +34,62 @@ CERT_CertTimesValid(CERTCertificate *c)
return (valid == secCertTimeValid) ? SECSuccess : SECFailure;
}
+static SECOidTag
+params2ecTag(const SECKEYECParams * params)
+{
+ SECItem oid = { siBuffer, NULL, 0};
+ SECOidData *oidData = NULL;
+
+ /*
+ * params->data needs to contain the ASN encoding of an object ID (OID)
+ * representing a named curve. Here, we strip away everything
+ * before the actual OID and use the OID to look up a named curve.
+ */
+ if (params->data[0] != SEC_ASN1_OBJECT_ID) return 0;
+ oid.len = params->len - 2;
+ oid.data = params->data + 2;
+ if ((oidData = SECOID_FindOID(&oid)) == NULL) return 0;
+
+ return oidData->offset;
+}
+
+SECStatus CheckECDSACurves(const SECAlgorithmID *sigAlgorithm, const
SECKEYPublicKey *key)
+{
+SECOidTag sigAlg;
+SECOidTag curve;
+PRUint32 policyFlags = 0;
+
+ sigAlg = SECOID_GetAlgorithmTag(sigAlgorithm);
+
+ switch(sigAlg) {
+ case SEC_OID_ANSIX962_ECDSA_SHA1_SIGNATURE:
+ case SEC_OID_ANSIX962_ECDSA_SHA224_SIGNATURE:
+ case SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE:
+ case SEC_OID_ANSIX962_ECDSA_SHA384_SIGNATURE:
+ case SEC_OID_ANSIX962_ECDSA_SHA512_SIGNATURE:
+ if (key->keyType != ecKey) {
+ PORT_SetError(SEC_ERROR_INVALID_ALGORITHM);
+ return SECFailure;
+ }
+
+ curve = params2ecTag(&key->u.ec.DEREncodedParams);
+ if (curve != 0) {
+ if (NSS_GetAlgorithmPolicy(curve, &policyFlags) == SECFailure ||
+ !(policyFlags & NSS_USE_ALG_IN_CERT_SIGNATURE)) {
+ PORT_SetError(SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED);
+ return SECFailure;
+ } else {
+ return SECSuccess;
+ }
+ } else {
+ PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
+ return SECFailure;
+ }
+ default:
+ return SECSuccess;
+ }
+}
+
/*
* verify the signature of a signed data object with the given DER publickey
*/
@@ -50,7 +106,6 @@ CERT_VerifySignedDataWithPublicKey(const CERTSignedData *sd,
PORT_SetError(PR_INVALID_ARGUMENT_ERROR);
return SECFailure;
}
-
/* check the signature */
sig = sd->signature;
/* convert sig->len from bit counts to byte count. */
@@ -61,11 +116,17 @@ CERT_VerifySignedDataWithPublicKey(const CERTSignedData
*sd,
if (rv == SECSuccess) {
/* Are we honoring signatures for this algorithm? */
PRUint32 policyFlags = 0;
+ rv = CheckECDSACurves(&sd->signatureAlgorithm, pubKey);
+ if (rv != SECSuccess) {
+ PORT_SetError(SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED);
+ return SECFailure;
+ }
+
rv = NSS_GetAlgorithmPolicy(hashAlg, &policyFlags);
if (rv == SECSuccess &&
!(policyFlags & NSS_USE_ALG_IN_CERT_SIGNATURE)) {
PORT_SetError(SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED);
- rv = SECFailure;
+ return SECFailure;
}
}
return rv;
--
1.9.0
--
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