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Diffstat (limited to 'crypto/asymmetric_keys/pkcs7_verify.c')
-rw-r--r--crypto/asymmetric_keys/pkcs7_verify.c102
1 files changed, 71 insertions, 31 deletions
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index c62cf8006e1f..cd455450b069 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -131,8 +131,7 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7,
struct x509_certificate *x509;
unsigned certix = 1;
- kenter("%u,%u,%u",
- sinfo->index, sinfo->raw_serial_size, sinfo->raw_issuer_size);
+ kenter("%u", sinfo->index);
for (x509 = pkcs7->certs; x509; x509 = x509->next, certix++) {
/* I'm _assuming_ that the generator of the PKCS#7 message will
@@ -140,21 +139,11 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7,
* PKCS#7 message - but I can't be 100% sure of that. It's
* possible this will need element-by-element comparison.
*/
- if (x509->raw_serial_size != sinfo->raw_serial_size ||
- memcmp(x509->raw_serial, sinfo->raw_serial,
- sinfo->raw_serial_size) != 0)
+ if (!asymmetric_key_id_same(x509->id, sinfo->signing_cert_id))
continue;
pr_devel("Sig %u: Found cert serial match X.509[%u]\n",
sinfo->index, certix);
- if (x509->raw_issuer_size != sinfo->raw_issuer_size ||
- memcmp(x509->raw_issuer, sinfo->raw_issuer,
- sinfo->raw_issuer_size) != 0) {
- pr_warn("Sig %u: X.509 subject and PKCS#7 issuer don't match\n",
- sinfo->index);
- continue;
- }
-
if (x509->pub->pkey_algo != sinfo->sig.pkey_algo) {
pr_warn("Sig %u: X.509 algo and PKCS#7 sig algo don't match\n",
sinfo->index);
@@ -164,9 +153,14 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7,
sinfo->signer = x509;
return 0;
}
- pr_warn("Sig %u: Issuing X.509 cert not found (#%*ph)\n",
- sinfo->index, sinfo->raw_serial_size, sinfo->raw_serial);
- return -ENOKEY;
+
+ /* The relevant X.509 cert isn't found here, but it might be found in
+ * the trust keyring.
+ */
+ pr_debug("Sig %u: Issuing X.509 cert not found (#%*phN)\n",
+ sinfo->index,
+ sinfo->signing_cert_id->len, sinfo->signing_cert_id->data);
+ return 0;
}
/*
@@ -184,15 +178,18 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
p->seen = false;
for (;;) {
- pr_debug("verify %s: %s\n", x509->subject, x509->fingerprint);
+ pr_debug("verify %s: %*phN\n",
+ x509->subject,
+ x509->raw_serial_size, x509->raw_serial);
x509->seen = true;
ret = x509_get_sig_params(x509);
if (ret < 0)
- return ret;
+ goto maybe_missing_crypto_in_x509;
pr_debug("- issuer %s\n", x509->issuer);
if (x509->authority)
- pr_debug("- authkeyid %s\n", x509->authority);
+ pr_debug("- authkeyid %*phN\n",
+ x509->authority->len, x509->authority->data);
if (!x509->authority ||
strcmp(x509->subject, x509->issuer) == 0) {
@@ -209,7 +206,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
ret = x509_check_signature(x509->pub, x509);
if (ret < 0)
- return ret;
+ goto maybe_missing_crypto_in_x509;
x509->signer = x509;
pr_debug("- self-signed\n");
return 0;
@@ -218,13 +215,14 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
/* Look through the X.509 certificates in the PKCS#7 message's
* list to see if the next one is there.
*/
- pr_debug("- want %s\n", x509->authority);
+ pr_debug("- want %*phN\n",
+ x509->authority->len, x509->authority->data);
for (p = pkcs7->certs; p; p = p->next) {
- pr_debug("- cmp [%u] %s\n", p->index, p->fingerprint);
- if (p->raw_subject_size == x509->raw_issuer_size &&
- strcmp(p->fingerprint, x509->authority) == 0 &&
- memcmp(p->raw_subject, x509->raw_issuer,
- x509->raw_issuer_size) == 0)
+ if (!p->skid)
+ continue;
+ pr_debug("- cmp [%u] %*phN\n",
+ p->index, p->skid->len, p->skid->data);
+ if (asymmetric_key_id_same(p->skid, x509->authority))
goto found_issuer;
}
@@ -233,7 +231,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
return 0;
found_issuer:
- pr_debug("- issuer %s\n", p->subject);
+ pr_debug("- subject %s\n", p->subject);
if (p->seen) {
pr_warn("Sig %u: X.509 chain contains loop\n",
sinfo->index);
@@ -250,6 +248,17 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
x509 = p;
might_sleep();
}
+
+maybe_missing_crypto_in_x509:
+ /* Just prune the certificate chain at this point if we lack some
+ * crypto module to go further. Note, however, we don't want to set
+ * sinfo->missing_crypto as the signed info block may still be
+ * validatable against an X.509 cert lower in the chain that we have a
+ * trusted copy of.
+ */
+ if (ret == -ENOPKG)
+ return 0;
+ return ret;
}
/*
@@ -269,11 +278,14 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
if (ret < 0)
return ret;
- /* Find the key for the signature */
+ /* Find the key for the signature if there is one */
ret = pkcs7_find_key(pkcs7, sinfo);
if (ret < 0)
return ret;
+ if (!sinfo->signer)
+ return 0;
+
pr_devel("Using X.509[%u] for sig %u\n",
sinfo->signer->index, sinfo->index);
@@ -291,11 +303,33 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
/**
* pkcs7_verify - Verify a PKCS#7 message
* @pkcs7: The PKCS#7 message to be verified
+ *
+ * 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
+ * of the X.509 certificates it carries that matches another X.509 cert in the
+ * message can be verified.
+ *
+ * This does not look to match the contents of the PKCS#7 message against any
+ * external public keys.
+ *
+ * Returns, in order of descending priority:
+ *
+ * (*) -EKEYREJECTED if a signature failed to match for which we found an
+ * appropriate X.509 certificate, or:
+ *
+ * (*) -EBADMSG if some part of the message was invalid, or:
+ *
+ * (*) -ENOPKG if none of the signature chains are verifiable because suitable
+ * crypto modules couldn't be found, or:
+ *
+ * (*) 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)
{
struct pkcs7_signed_info *sinfo;
struct x509_certificate *x509;
+ int enopkg = -ENOPKG;
int ret, n;
kenter("");
@@ -304,18 +338,24 @@ int pkcs7_verify(struct pkcs7_message *pkcs7)
ret = x509_get_sig_params(x509);
if (ret < 0)
return ret;
- pr_debug("X.509[%u] %s\n", n, x509->authority);
+ pr_debug("X.509[%u] %*phN\n",
+ n, x509->authority->len, x509->authority->data);
}
for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
ret = pkcs7_verify_one(pkcs7, sinfo);
if (ret < 0) {
+ if (ret == -ENOPKG) {
+ sinfo->unsupported_crypto = true;
+ continue;
+ }
kleave(" = %d", ret);
return ret;
}
+ enopkg = 0;
}
- kleave(" = 0");
- return 0;
+ kleave(" = %d", enopkg);
+ return enopkg;
}
EXPORT_SYMBOL_GPL(pkcs7_verify);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 12:20:27 +0100