mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
285 lines
6.6 KiB
285 lines
6.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* Instantiate a public key crypto key from an X.509 Certificate |
|
* |
|
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. |
|
* Written by David Howells ([email protected]) |
|
*/ |
|
|
|
#define pr_fmt(fmt) "X.509: "fmt |
|
#include <linux/module.h> |
|
#include <linux/kernel.h> |
|
#include <linux/slab.h> |
|
#include <keys/asymmetric-subtype.h> |
|
#include <keys/asymmetric-parser.h> |
|
#include <keys/system_keyring.h> |
|
#include <crypto/hash.h> |
|
#include "asymmetric_keys.h" |
|
#include "x509_parser.h" |
|
|
|
/* |
|
* Set up the signature parameters in an X.509 certificate. This involves |
|
* digesting the signed data and extracting the signature. |
|
*/ |
|
int x509_get_sig_params(struct x509_certificate *cert) |
|
{ |
|
struct public_key_signature *sig = cert->sig; |
|
struct crypto_shash *tfm; |
|
struct shash_desc *desc; |
|
size_t desc_size; |
|
int ret; |
|
|
|
pr_devel("==>%s()\n", __func__); |
|
|
|
sig->data = cert->tbs; |
|
sig->data_size = cert->tbs_size; |
|
|
|
if (!cert->pub->pkey_algo) |
|
cert->unsupported_key = true; |
|
|
|
if (!sig->pkey_algo) |
|
cert->unsupported_sig = true; |
|
|
|
/* We check the hash if we can - even if we can't then verify it */ |
|
if (!sig->hash_algo) { |
|
cert->unsupported_sig = true; |
|
return 0; |
|
} |
|
|
|
sig->s = kmemdup(cert->raw_sig, cert->raw_sig_size, GFP_KERNEL); |
|
if (!sig->s) |
|
return -ENOMEM; |
|
|
|
sig->s_size = cert->raw_sig_size; |
|
|
|
/* Allocate the hashing algorithm we're going to need and find out how |
|
* big the hash operational data will be. |
|
*/ |
|
tfm = crypto_alloc_shash(sig->hash_algo, 0, 0); |
|
if (IS_ERR(tfm)) { |
|
if (PTR_ERR(tfm) == -ENOENT) { |
|
cert->unsupported_sig = true; |
|
return 0; |
|
} |
|
return PTR_ERR(tfm); |
|
} |
|
|
|
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); |
|
sig->digest_size = crypto_shash_digestsize(tfm); |
|
|
|
ret = -ENOMEM; |
|
sig->digest = kmalloc(sig->digest_size, GFP_KERNEL); |
|
if (!sig->digest) |
|
goto error; |
|
|
|
desc = kzalloc(desc_size, GFP_KERNEL); |
|
if (!desc) |
|
goto error; |
|
|
|
desc->tfm = tfm; |
|
|
|
ret = crypto_shash_digest(desc, cert->tbs, cert->tbs_size, sig->digest); |
|
if (ret < 0) |
|
goto error_2; |
|
|
|
ret = is_hash_blacklisted(sig->digest, sig->digest_size, "tbs"); |
|
if (ret == -EKEYREJECTED) { |
|
pr_err("Cert %*phN is blacklisted\n", |
|
sig->digest_size, sig->digest); |
|
cert->blacklisted = true; |
|
ret = 0; |
|
} |
|
|
|
error_2: |
|
kfree(desc); |
|
error: |
|
crypto_free_shash(tfm); |
|
pr_devel("<==%s() = %d\n", __func__, ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Check for self-signedness in an X.509 cert and if found, check the signature |
|
* immediately if we can. |
|
*/ |
|
int x509_check_for_self_signed(struct x509_certificate *cert) |
|
{ |
|
int ret = 0; |
|
|
|
pr_devel("==>%s()\n", __func__); |
|
|
|
if (cert->raw_subject_size != cert->raw_issuer_size || |
|
memcmp(cert->raw_subject, cert->raw_issuer, |
|
cert->raw_issuer_size) != 0) |
|
goto not_self_signed; |
|
|
|
if (cert->sig->auth_ids[0] || cert->sig->auth_ids[1]) { |
|
/* If the AKID is present it may have one or two parts. If |
|
* both are supplied, both must match. |
|
*/ |
|
bool a = asymmetric_key_id_same(cert->skid, cert->sig->auth_ids[1]); |
|
bool b = asymmetric_key_id_same(cert->id, cert->sig->auth_ids[0]); |
|
|
|
if (!a && !b) |
|
goto not_self_signed; |
|
|
|
ret = -EKEYREJECTED; |
|
if (((a && !b) || (b && !a)) && |
|
cert->sig->auth_ids[0] && cert->sig->auth_ids[1]) |
|
goto out; |
|
} |
|
|
|
ret = -EKEYREJECTED; |
|
if (strcmp(cert->pub->pkey_algo, cert->sig->pkey_algo) != 0 && |
|
(strncmp(cert->pub->pkey_algo, "ecdsa-", 6) != 0 || |
|
strcmp(cert->sig->pkey_algo, "ecdsa") != 0)) |
|
goto out; |
|
|
|
ret = public_key_verify_signature(cert->pub, cert->sig); |
|
if (ret < 0) { |
|
if (ret == -ENOPKG) { |
|
cert->unsupported_sig = true; |
|
ret = 0; |
|
} |
|
goto out; |
|
} |
|
|
|
pr_devel("Cert Self-signature verified"); |
|
cert->self_signed = true; |
|
|
|
out: |
|
pr_devel("<==%s() = %d\n", __func__, ret); |
|
return ret; |
|
|
|
not_self_signed: |
|
pr_devel("<==%s() = 0 [not]\n", __func__); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Attempt to parse a data blob for a key as an X509 certificate. |
|
*/ |
|
static int x509_key_preparse(struct key_preparsed_payload *prep) |
|
{ |
|
struct asymmetric_key_ids *kids; |
|
struct x509_certificate *cert; |
|
const char *q; |
|
size_t srlen, sulen; |
|
char *desc = NULL, *p; |
|
int ret; |
|
|
|
cert = x509_cert_parse(prep->data, prep->datalen); |
|
if (IS_ERR(cert)) |
|
return PTR_ERR(cert); |
|
|
|
pr_devel("Cert Issuer: %s\n", cert->issuer); |
|
pr_devel("Cert Subject: %s\n", cert->subject); |
|
|
|
if (cert->unsupported_key) { |
|
ret = -ENOPKG; |
|
goto error_free_cert; |
|
} |
|
|
|
pr_devel("Cert Key Algo: %s\n", cert->pub->pkey_algo); |
|
pr_devel("Cert Valid period: %lld-%lld\n", cert->valid_from, cert->valid_to); |
|
|
|
cert->pub->id_type = "X509"; |
|
|
|
if (cert->unsupported_sig) { |
|
public_key_signature_free(cert->sig); |
|
cert->sig = NULL; |
|
} else { |
|
pr_devel("Cert Signature: %s + %s\n", |
|
cert->sig->pkey_algo, cert->sig->hash_algo); |
|
} |
|
|
|
/* Don't permit addition of blacklisted keys */ |
|
ret = -EKEYREJECTED; |
|
if (cert->blacklisted) |
|
goto error_free_cert; |
|
|
|
/* Propose a description */ |
|
sulen = strlen(cert->subject); |
|
if (cert->raw_skid) { |
|
srlen = cert->raw_skid_size; |
|
q = cert->raw_skid; |
|
} else { |
|
srlen = cert->raw_serial_size; |
|
q = cert->raw_serial; |
|
} |
|
|
|
ret = -ENOMEM; |
|
desc = kmalloc(sulen + 2 + srlen * 2 + 1, GFP_KERNEL); |
|
if (!desc) |
|
goto error_free_cert; |
|
p = memcpy(desc, cert->subject, sulen); |
|
p += sulen; |
|
*p++ = ':'; |
|
*p++ = ' '; |
|
p = bin2hex(p, q, srlen); |
|
*p = 0; |
|
|
|
kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL); |
|
if (!kids) |
|
goto error_free_desc; |
|
kids->id[0] = cert->id; |
|
kids->id[1] = cert->skid; |
|
kids->id[2] = asymmetric_key_generate_id(cert->raw_subject, |
|
cert->raw_subject_size, |
|
"", 0); |
|
if (IS_ERR(kids->id[2])) { |
|
ret = PTR_ERR(kids->id[2]); |
|
goto error_free_kids; |
|
} |
|
|
|
/* We're pinning the module by being linked against it */ |
|
__module_get(public_key_subtype.owner); |
|
prep->payload.data[asym_subtype] = &public_key_subtype; |
|
prep->payload.data[asym_key_ids] = kids; |
|
prep->payload.data[asym_crypto] = cert->pub; |
|
prep->payload.data[asym_auth] = cert->sig; |
|
prep->description = desc; |
|
prep->quotalen = 100; |
|
|
|
/* We've finished with the certificate */ |
|
cert->pub = NULL; |
|
cert->id = NULL; |
|
cert->skid = NULL; |
|
cert->sig = NULL; |
|
desc = NULL; |
|
kids = NULL; |
|
ret = 0; |
|
|
|
error_free_kids: |
|
kfree(kids); |
|
error_free_desc: |
|
kfree(desc); |
|
error_free_cert: |
|
x509_free_certificate(cert); |
|
return ret; |
|
} |
|
|
|
static struct asymmetric_key_parser x509_key_parser = { |
|
.owner = THIS_MODULE, |
|
.name = "x509", |
|
.parse = x509_key_preparse, |
|
}; |
|
|
|
/* |
|
* Module stuff |
|
*/ |
|
static int __init x509_key_init(void) |
|
{ |
|
return register_asymmetric_key_parser(&x509_key_parser); |
|
} |
|
|
|
static void __exit x509_key_exit(void) |
|
{ |
|
unregister_asymmetric_key_parser(&x509_key_parser); |
|
} |
|
|
|
module_init(x509_key_init); |
|
module_exit(x509_key_exit); |
|
|
|
MODULE_DESCRIPTION("X.509 certificate parser"); |
|
MODULE_AUTHOR("Red Hat, Inc."); |
|
MODULE_LICENSE("GPL");
|
|
|