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-rw-r--r--crypto/asymmetric_keys/pkcs7_parser.h1
-rw-r--r--crypto/asymmetric_keys/pkcs7_trust.c29
-rw-r--r--crypto/asymmetric_keys/pkcs7_verify.c46
-rw-r--r--crypto/asymmetric_keys/x509_parser.h1
-rw-r--r--crypto/asymmetric_keys/x509_public_key.c13
5 files changed, 74 insertions, 16 deletions
diff --git a/crypto/asymmetric_keys/pkcs7_parser.h b/crypto/asymmetric_keys/pkcs7_parser.h
index 91949f92bc72..efc7dc9b8f9c 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.h
+++ b/crypto/asymmetric_keys/pkcs7_parser.h
@@ -23,6 +23,7 @@ struct pkcs7_signed_info {
struct x509_certificate *signer; /* Signing certificate (in msg->certs) */
unsigned index;
bool trusted;
+ bool unsupported_crypto; /* T if not usable due to missing crypto */
/* Message digest - the digest of the Content Data (or NULL) */
const void *msgdigest;
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 09197e50fa82..8bd474e5e706 100644
--- a/crypto/asymmetric_keys/pkcs7_trust.c
+++ b/crypto/asymmetric_keys/pkcs7_trust.c
@@ -35,6 +35,11 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
kenter(",%u,", sinfo->index);
+ if (sinfo->unsupported_crypto) {
+ kleave(" = -ENOPKG [cached]");
+ return -ENOPKG;
+ }
+
for (x509 = sinfo->signer; x509; x509 = x509->signer) {
if (x509->seen) {
if (x509->verified) {
@@ -139,24 +144,28 @@ int pkcs7_validate_trust(struct pkcs7_message *pkcs7,
{
struct pkcs7_signed_info *sinfo;
struct x509_certificate *p;
- int cached_ret = 0, ret;
+ int cached_ret = -ENOKEY;
+ int ret;
for (p = pkcs7->certs; p; p = p->next)
p->seen = false;
for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
ret = pkcs7_validate_trust_one(pkcs7, sinfo, trust_keyring);
- if (ret < 0) {
- if (ret == -ENOPKG) {
+ switch (ret) {
+ case -ENOKEY:
+ continue;
+ case -ENOPKG:
+ if (cached_ret == -ENOKEY)
cached_ret = -ENOPKG;
- } else if (ret == -ENOKEY) {
- if (cached_ret == 0)
- cached_ret = -ENOKEY;
- } else {
- return ret;
- }
+ continue;
+ case 0:
+ *_trusted |= sinfo->trusted;
+ cached_ret = 0;
+ continue;
+ default:
+ return ret;
}
- *_trusted |= sinfo->trusted;
}
return cached_ret;
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 57e90fa17f2b..bd264052f751 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -181,7 +181,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
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)
@@ -203,7 +203,7 @@ 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;
@@ -245,6 +245,17 @@ 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;
}
/*
@@ -286,11 +297,33 @@ 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("");
@@ -306,12 +339,17 @@ int pkcs7_verify(struct pkcs7_message *pkcs7)
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);
diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
index 0e8d59b010fb..4e1a384901ed 100644
--- a/crypto/asymmetric_keys/x509_parser.h
+++ b/crypto/asymmetric_keys/x509_parser.h
@@ -38,6 +38,7 @@ struct x509_certificate {
bool seen; /* Infinite recursion prevention */
bool verified;
bool trusted;
+ bool unsupported_crypto; /* T if can't be verified due to missing crypto */
};
/*
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index c60905c3f4d2..1d9a4c555376 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -115,6 +115,8 @@ int x509_get_sig_params(struct x509_certificate *cert)
pr_devel("==>%s()\n", __func__);
+ if (cert->unsupported_crypto)
+ return -ENOPKG;
if (cert->sig.rsa.s)
return 0;
@@ -127,8 +129,13 @@ int x509_get_sig_params(struct x509_certificate *cert)
* big the hash operational data will be.
*/
tfm = crypto_alloc_shash(hash_algo_name[cert->sig.pkey_hash_algo], 0, 0);
- if (IS_ERR(tfm))
- return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm);
+ if (IS_ERR(tfm)) {
+ if (PTR_ERR(tfm) == -ENOENT) {
+ cert->unsupported_crypto = true;
+ return -ENOPKG;
+ }
+ return PTR_ERR(tfm);
+ }
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
digest_size = crypto_shash_digestsize(tfm);
@@ -175,6 +182,8 @@ int x509_check_signature(const struct public_key *pub,
return ret;
ret = public_key_verify_signature(pub, &cert->sig);
+ if (ret == -ENOPKG)
+ cert->unsupported_crypto = true;
pr_debug("Cert Verification: %d\n", ret);
return ret;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.