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-rw-r--r--crypto/asymmetric_keys/pkcs7_verify.c65
1 files changed, 63 insertions, 2 deletions
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 404f89a..d20c0b4 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -70,9 +70,15 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
* message digest attribute amongst them which corresponds to the
* digest we just calculated.
*/
- if (sinfo->msgdigest) {
+ if (sinfo->authattrs) {
u8 tag;
+ if (!sinfo->msgdigest) {
+ pr_warn("Sig %u: No messageDigest\n", sinfo->index);
+ ret = -EKEYREJECTED;
+ goto error;
+ }
+
if (sinfo->msgdigest_len != sinfo->sig.digest_size) {
pr_debug("Sig %u: Invalid digest size (%u)\n",
sinfo->index, sinfo->msgdigest_len);
@@ -314,6 +320,18 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
pr_devel("Using X.509[%u] for sig %u\n",
sinfo->signer->index, sinfo->index);
+ /* Check that the PKCS#7 signing time is valid according to the X.509
+ * certificate. We can't, however, check against the system clock
+ * since that may not have been set yet and may be wrong.
+ */
+ if (test_bit(sinfo_has_signing_time, &sinfo->aa_set)) {
+ if (sinfo->signing_time < sinfo->signer->valid_from ||
+ sinfo->signing_time > sinfo->signer->valid_to) {
+ pr_warn("Message signed outside of X.509 validity window\n");
+ return -EKEYREJECTED;
+ }
+ }
+
/* Verify the PKCS#7 binary against the key */
ret = public_key_verify_signature(sinfo->signer->pub, &sinfo->sig);
if (ret < 0)
@@ -328,6 +346,7 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
/**
* pkcs7_verify - Verify a PKCS#7 message
* @pkcs7: The PKCS#7 message to be verified
+ * @usage: The use to which the key is being put
*
* Verify a PKCS#7 message is internally consistent - that is, the data digest
* matches the digest in the AuthAttrs and any signature in the message or one
@@ -339,6 +358,9 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
*
* Returns, in order of descending priority:
*
+ * (*) -EKEYREJECTED if a key was selected that had a usage restriction at
+ * odds with the specified usage, or:
+ *
* (*) -EKEYREJECTED if a signature failed to match for which we found an
* appropriate X.509 certificate, or:
*
@@ -350,7 +372,8 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
* (*) 0 if all the signature chains that don't incur -ENOPKG can be verified
* (note that a signature chain may be of zero length), or:
*/
-int pkcs7_verify(struct pkcs7_message *pkcs7)
+int pkcs7_verify(struct pkcs7_message *pkcs7,
+ enum key_being_used_for usage)
{
struct pkcs7_signed_info *sinfo;
struct x509_certificate *x509;
@@ -359,6 +382,44 @@ int pkcs7_verify(struct pkcs7_message *pkcs7)
kenter("");
+ switch (usage) {
+ case VERIFYING_MODULE_SIGNATURE:
+ if (pkcs7->data_type != OID_data) {
+ pr_warn("Invalid module sig (not pkcs7-data)\n");
+ return -EKEYREJECTED;
+ }
+ if (pkcs7->have_authattrs) {
+ pr_warn("Invalid module sig (has authattrs)\n");
+ return -EKEYREJECTED;
+ }
+ break;
+ case VERIFYING_FIRMWARE_SIGNATURE:
+ if (pkcs7->data_type != OID_data) {
+ pr_warn("Invalid firmware sig (not pkcs7-data)\n");
+ return -EKEYREJECTED;
+ }
+ if (!pkcs7->have_authattrs) {
+ pr_warn("Invalid firmware sig (missing authattrs)\n");
+ return -EKEYREJECTED;
+ }
+ break;
+ case VERIFYING_KEXEC_PE_SIGNATURE:
+ if (pkcs7->data_type != OID_msIndirectData) {
+ pr_warn("Invalid kexec sig (not Authenticode)\n");
+ return -EKEYREJECTED;
+ }
+ /* Authattr presence checked in parser */
+ break;
+ case VERIFYING_UNSPECIFIED_SIGNATURE:
+ if (pkcs7->data_type != OID_data) {
+ pr_warn("Invalid unspecified sig (not pkcs7-data)\n");
+ return -EKEYREJECTED;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
for (n = 0, x509 = pkcs7->certs; x509; x509 = x509->next, n++) {
ret = x509_get_sig_params(x509);
if (ret < 0)
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