linux/crypto/asymmetric_keys/x509_public_key.c
Linus Torvalds 4c1cc40a2d Revert "KEYS: verify a certificate is signed by a 'trusted' key"
This reverts commit 09fbc47373, which
caused the following build errors:

  crypto/asymmetric_keys/x509_public_key.c: In function ‘x509_key_preparse’:
  crypto/asymmetric_keys/x509_public_key.c:237:35: error: ‘system_trusted_keyring’ undeclared (first use in this function)
   ret = x509_validate_trust(cert, system_trusted_keyring);
                                   ^
  crypto/asymmetric_keys/x509_public_key.c:237:35: note: each undeclared identifier is reported only once for each function it appears in

reported by Jim Davis. Mimi says:

 "I made the classic mistake of requesting this patch to be upstreamed
  at the last second, rather than waiting until the next open window.

  At this point, the best course would probably be to revert the two
  commits and fix them for the next open window"

Reported-by: Jim Davis <jim.epost@gmail.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-23 16:38:17 -08:00

219 lines
5.8 KiB
C

/* Instantiate a public key crypto key from an X.509 Certificate
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#define pr_fmt(fmt) "X.509: "fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/mpi.h>
#include <linux/asn1_decoder.h>
#include <keys/asymmetric-subtype.h>
#include <keys/asymmetric-parser.h>
#include <crypto/hash.h>
#include "asymmetric_keys.h"
#include "public_key.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 crypto_shash *tfm;
struct shash_desc *desc;
size_t digest_size, desc_size;
void *digest;
int ret;
pr_devel("==>%s()\n", __func__);
if (cert->sig.rsa.s)
return 0;
cert->sig.rsa.s = mpi_read_raw_data(cert->raw_sig, cert->raw_sig_size);
if (!cert->sig.rsa.s)
return -ENOMEM;
cert->sig.nr_mpi = 1;
/* Allocate the hashing algorithm we're going to need and find out how
* 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);
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
digest_size = crypto_shash_digestsize(tfm);
/* We allocate the hash operational data storage on the end of the
* digest storage space.
*/
ret = -ENOMEM;
digest = kzalloc(digest_size + desc_size, GFP_KERNEL);
if (!digest)
goto error;
cert->sig.digest = digest;
cert->sig.digest_size = digest_size;
desc = digest + digest_size;
desc->tfm = tfm;
desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
ret = crypto_shash_init(desc);
if (ret < 0)
goto error;
might_sleep();
ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, digest);
error:
crypto_free_shash(tfm);
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
EXPORT_SYMBOL_GPL(x509_get_sig_params);
/*
* Check the signature on a certificate using the provided public key
*/
int x509_check_signature(const struct public_key *pub,
struct x509_certificate *cert)
{
int ret;
pr_devel("==>%s()\n", __func__);
ret = x509_get_sig_params(cert);
if (ret < 0)
return ret;
ret = public_key_verify_signature(pub, &cert->sig);
pr_debug("Cert Verification: %d\n", ret);
return ret;
}
EXPORT_SYMBOL_GPL(x509_check_signature);
/*
* Attempt to parse a data blob for a key as an X509 certificate.
*/
static int x509_key_preparse(struct key_preparsed_payload *prep)
{
struct x509_certificate *cert;
size_t srlen, sulen;
char *desc = NULL;
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->pub->pkey_algo >= PKEY_ALGO__LAST ||
cert->sig.pkey_algo >= PKEY_ALGO__LAST ||
cert->sig.pkey_hash_algo >= PKEY_HASH__LAST ||
!pkey_algo[cert->pub->pkey_algo] ||
!pkey_algo[cert->sig.pkey_algo] ||
!hash_algo_name[cert->sig.pkey_hash_algo]) {
ret = -ENOPKG;
goto error_free_cert;
}
pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]);
pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n",
cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1,
cert->valid_from.tm_mday, cert->valid_from.tm_hour,
cert->valid_from.tm_min, cert->valid_from.tm_sec);
pr_devel("Cert Valid To: %04ld-%02d-%02d %02d:%02d:%02d\n",
cert->valid_to.tm_year + 1900, cert->valid_to.tm_mon + 1,
cert->valid_to.tm_mday, cert->valid_to.tm_hour,
cert->valid_to.tm_min, cert->valid_to.tm_sec);
pr_devel("Cert Signature: %s + %s\n",
pkey_algo_name[cert->sig.pkey_algo],
hash_algo_name[cert->sig.pkey_hash_algo]);
if (!cert->fingerprint) {
pr_warn("Cert for '%s' must have a SubjKeyId extension\n",
cert->subject);
ret = -EKEYREJECTED;
goto error_free_cert;
}
cert->pub->algo = pkey_algo[cert->pub->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
/* Check the signature on the key if it appears to be self-signed */
if (!cert->authority ||
strcmp(cert->fingerprint, cert->authority) == 0) {
ret = x509_check_signature(cert->pub, cert);
if (ret < 0)
goto error_free_cert;
}
/* Propose a description */
sulen = strlen(cert->subject);
srlen = strlen(cert->fingerprint);
ret = -ENOMEM;
desc = kmalloc(sulen + 2 + srlen + 1, GFP_KERNEL);
if (!desc)
goto error_free_cert;
memcpy(desc, cert->subject, sulen);
desc[sulen] = ':';
desc[sulen + 1] = ' ';
memcpy(desc + sulen + 2, cert->fingerprint, srlen);
desc[sulen + 2 + srlen] = 0;
/* We're pinning the module by being linked against it */
__module_get(public_key_subtype.owner);
prep->type_data[0] = &public_key_subtype;
prep->type_data[1] = cert->fingerprint;
prep->payload = cert->pub;
prep->description = desc;
prep->quotalen = 100;
/* We've finished with the certificate */
cert->pub = NULL;
cert->fingerprint = NULL;
desc = NULL;
ret = 0;
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_LICENSE("GPL");