diff options
Diffstat (limited to 'crypto/asymmetric_keys/pkcs7_verify.c')
-rw-r--r-- | crypto/asymmetric_keys/pkcs7_verify.c | 102 |
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); |