diff options
| -rw-r--r-- | crypto/asymmetric_keys/pkcs7_trust.c | 10 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/pkcs7_verify.c | 47 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/x509_public_key.c | 84 | ||||
| -rw-r--r-- | include/crypto/public_key.h | 3 |
4 files changed, 103 insertions, 41 deletions
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c index 0f6463b6692b..90d6d47965b0 100644 --- a/crypto/asymmetric_keys/pkcs7_trust.c +++ b/crypto/asymmetric_keys/pkcs7_trust.c @@ -54,7 +54,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7, /* Look to see if this certificate is present in the trusted * keys. */ - key = x509_request_asymmetric_key(trust_keyring, x509->id, + key = x509_request_asymmetric_key(trust_keyring, + x509->id, x509->skid, false); if (!IS_ERR(key)) { /* One of the X.509 certificates in the PKCS#7 message @@ -85,8 +86,10 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7, /* No match - see if the root certificate has a signer amongst the * trusted keys. */ - if (last && last->akid_skid) { - key = x509_request_asymmetric_key(trust_keyring, last->akid_skid, + if (last && (last->akid_id || last->akid_skid)) { + key = x509_request_asymmetric_key(trust_keyring, + last->akid_id, + last->akid_skid, false); if (!IS_ERR(key)) { x509 = last; @@ -103,6 +106,7 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7, */ key = x509_request_asymmetric_key(trust_keyring, sinfo->signing_cert_id, + NULL, false); if (!IS_ERR(key)) { pr_devel("sinfo %u: Direct signer is key %x\n", diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c index a4d083f7e9e1..42bfc9de0d79 100644 --- a/crypto/asymmetric_keys/pkcs7_verify.c +++ b/crypto/asymmetric_keys/pkcs7_verify.c @@ -170,6 +170,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7, struct pkcs7_signed_info *sinfo) { struct x509_certificate *x509 = sinfo->signer, *p; + struct asymmetric_key_id *auth; int ret; kenter(""); @@ -187,11 +188,14 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7, goto maybe_missing_crypto_in_x509; pr_debug("- issuer %s\n", x509->issuer); + if (x509->akid_id) + pr_debug("- authkeyid.id %*phN\n", + x509->akid_id->len, x509->akid_id->data); if (x509->akid_skid) - pr_debug("- authkeyid %*phN\n", + pr_debug("- authkeyid.skid %*phN\n", x509->akid_skid->len, x509->akid_skid->data); - if (!x509->akid_skid || + if ((!x509->akid_id && !x509->akid_skid) || strcmp(x509->subject, x509->issuer) == 0) { /* If there's no authority certificate specified, then * the certificate must be self-signed and is the root @@ -215,21 +219,42 @@ 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 %*phN\n", - x509->akid_skid->len, x509->akid_skid->data); - for (p = pkcs7->certs; p; p = p->next) { - 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->akid_skid)) - goto found_issuer; + auth = x509->akid_id; + if (auth) { + pr_debug("- want %*phN\n", auth->len, auth->data); + for (p = pkcs7->certs; p; p = p->next) { + pr_debug("- cmp [%u] %*phN\n", + p->index, p->id->len, p->id->data); + if (asymmetric_key_id_same(p->id, auth)) + goto found_issuer_check_skid; + } + } else { + auth = x509->akid_skid; + pr_debug("- want %*phN\n", auth->len, auth->data); + for (p = pkcs7->certs; p; p = p->next) { + 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, auth)) + goto found_issuer; + } } /* We didn't find the root of this chain */ pr_debug("- top\n"); return 0; + found_issuer_check_skid: + /* We matched issuer + serialNumber, but if there's an + * authKeyId.keyId, that must match the CA subjKeyId also. + */ + if (x509->akid_skid && + !asymmetric_key_id_same(p->skid, x509->akid_skid)) { + pr_warn("Sig %u: X.509 chain contains auth-skid nonmatch (%u->%u)\n", + sinfo->index, x509->index, p->index); + return -EKEYREJECTED; + } found_issuer: pr_debug("- subject %s\n", p->subject); if (p->seen) { diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index bb55d6074d5f..6b060b290e77 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -65,23 +65,37 @@ __setup("ca_keys=", ca_keys_setup); /** * x509_request_asymmetric_key - Request a key by X.509 certificate params. * @keyring: The keys to search. - * @kid: The key ID. + * @id: The issuer & serialNumber to look for or NULL. + * @skid: The subjectKeyIdentifier to look for or NULL. * @partial: Use partial match if true, exact if false. * - * Find a key in the given keyring by subject name and key ID. These might, - * for instance, be the issuer name and the authority key ID of an X.509 - * certificate that needs to be verified. + * Find a key in the given keyring by identifier. The preferred identifier is + * the issuer + serialNumber and the fallback identifier is the + * subjectKeyIdentifier. If both are given, the lookup is by the former, but + * the latter must also match. */ struct key *x509_request_asymmetric_key(struct key *keyring, - const struct asymmetric_key_id *kid, + const struct asymmetric_key_id *id, + const struct asymmetric_key_id *skid, bool partial) { - key_ref_t key; - char *id, *p; - + struct key *key; + key_ref_t ref; + const char *lookup; + char *req, *p; + int len; + + if (id) { + lookup = id->data; + len = id->len; + } else { + lookup = skid->data; + len = skid->len; + } + /* Construct an identifier "id:<keyid>". */ - p = id = kmalloc(2 + 1 + kid->len * 2 + 1, GFP_KERNEL); - if (!id) + p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL); + if (!req) return ERR_PTR(-ENOMEM); if (partial) { @@ -92,32 +106,48 @@ struct key *x509_request_asymmetric_key(struct key *keyring, *p++ = 'x'; } *p++ = ':'; - p = bin2hex(p, kid->data, kid->len); + p = bin2hex(p, lookup, len); *p = 0; - pr_debug("Look up: \"%s\"\n", id); + pr_debug("Look up: \"%s\"\n", req); - key = keyring_search(make_key_ref(keyring, 1), - &key_type_asymmetric, id); - if (IS_ERR(key)) - pr_debug("Request for key '%s' err %ld\n", id, PTR_ERR(key)); - kfree(id); + ref = keyring_search(make_key_ref(keyring, 1), + &key_type_asymmetric, req); + if (IS_ERR(ref)) + pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref)); + kfree(req); - if (IS_ERR(key)) { - switch (PTR_ERR(key)) { + if (IS_ERR(ref)) { + switch (PTR_ERR(ref)) { /* Hide some search errors */ case -EACCES: case -ENOTDIR: case -EAGAIN: return ERR_PTR(-ENOKEY); default: - return ERR_CAST(key); + return ERR_CAST(ref); + } + } + + key = key_ref_to_ptr(ref); + if (id && skid) { + const struct asymmetric_key_ids *kids = asymmetric_key_ids(key); + if (!kids->id[1]) { + pr_debug("issuer+serial match, but expected SKID missing\n"); + goto reject; + } + if (!asymmetric_key_id_same(skid, kids->id[1])) { + pr_debug("issuer+serial match, but SKID does not\n"); + goto reject; } } + + pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key)); + return key; - pr_devel("<==%s() = 0 [%x]\n", __func__, - key_serial(key_ref_to_ptr(key))); - return key_ref_to_ptr(key); +reject: + key_put(key); + return ERR_PTR(-EKEYREJECTED); } EXPORT_SYMBOL_GPL(x509_request_asymmetric_key); @@ -230,7 +260,8 @@ static int x509_validate_trust(struct x509_certificate *cert, if (ca_keyid && !asymmetric_key_id_partial(cert->akid_skid, ca_keyid)) return -EPERM; - key = x509_request_asymmetric_key(trust_keyring, cert->akid_skid, + key = x509_request_asymmetric_key(trust_keyring, + cert->akid_id, cert->akid_skid, false); if (!IS_ERR(key)) { if (!use_builtin_keys @@ -287,8 +318,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) cert->pub->id_type = PKEY_ID_X509; /* Check the signature on the key if it appears to be self-signed */ - if (!cert->akid_skid || - asymmetric_key_id_same(cert->skid, cert->akid_skid)) { + if ((!cert->akid_skid && !cert->akid_id) || + asymmetric_key_id_same(cert->skid, cert->akid_skid) || + asymmetric_key_id_same(cert->id, cert->akid_id)) { ret = x509_check_signature(cert->pub, cert); /* self-signed */ if (ret < 0) goto error_free_cert; diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 54add2069901..b6f27a240856 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -101,7 +101,8 @@ extern int verify_signature(const struct key *key, struct asymmetric_key_id; extern struct key *x509_request_asymmetric_key(struct key *keyring, - const struct asymmetric_key_id *kid, + const struct asymmetric_key_id *id, + const struct asymmetric_key_id *skid, bool partial); #endif /* _LINUX_PUBLIC_KEY_H */ |