diff options
Diffstat (limited to 'crypto/asymmetric_keys/pkcs7_verify.c')
| -rw-r--r-- | crypto/asymmetric_keys/pkcs7_verify.c | 145 |
1 files changed, 127 insertions, 18 deletions
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c index cd455450b069..d20c0b4b880e 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); @@ -170,6 +176,7 @@ 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 +194,14 @@ 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->authority) - pr_debug("- authkeyid %*phN\n", - x509->authority->len, x509->authority->data); - - if (!x509->authority || + 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.skid %*phN\n", + x509->akid_skid->len, x509->akid_skid->data); + + 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 +225,42 @@ 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->authority->len, x509->authority->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->authority)) - 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) { @@ -289,6 +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) @@ -303,6 +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 @@ -314,6 +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: * @@ -325,7 +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; @@ -334,12 +382,48 @@ 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) return ret; - pr_debug("X.509[%u] %*phN\n", - n, x509->authority->len, x509->authority->data); } for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) { @@ -359,3 +443,28 @@ int pkcs7_verify(struct pkcs7_message *pkcs7) return enopkg; } EXPORT_SYMBOL_GPL(pkcs7_verify); + +/** + * pkcs7_supply_detached_data - Supply the data needed to verify a PKCS#7 message + * @pkcs7: The PKCS#7 message + * @data: The data to be verified + * @datalen: The amount of data + * + * Supply the detached data needed to verify a PKCS#7 message. Note that no + * attempt to retain/pin the data is made. That is left to the caller. The + * data will not be modified by pkcs7_verify() and will not be freed when the + * PKCS#7 message is freed. + * + * Returns -EINVAL if data is already supplied in the message, 0 otherwise. + */ +int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7, + const void *data, size_t datalen) +{ + if (pkcs7->data) { + pr_debug("Data already supplied\n"); + return -EINVAL; + } + pkcs7->data = data; + pkcs7->data_len = datalen; + return 0; +} |