linux/crypto/asymmetric_keys/public_key.c
Pan Bian fbb726302a crypto: asymmetric_keys - set error code on failure
In function public_key_verify_signature(), returns variable ret on
error paths. When the call to kmalloc() fails, the value of ret is 0,
and it is not set to an errno before returning. This patch fixes the
bug.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188891

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-12-14 18:33:13 +08:00

186 lines
4.6 KiB
C

/* In-software asymmetric public-key crypto subtype
*
* See Documentation/crypto/asymmetric-keys.txt
*
* 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) "PKEY: "fmt
#include <linux/module.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/scatterlist.h>
#include <keys/asymmetric-subtype.h>
#include <crypto/public_key.h>
#include <crypto/akcipher.h>
MODULE_LICENSE("GPL");
/*
* Provide a part of a description of the key for /proc/keys.
*/
static void public_key_describe(const struct key *asymmetric_key,
struct seq_file *m)
{
struct public_key *key = asymmetric_key->payload.data[asym_crypto];
if (key)
seq_printf(m, "%s.%s", key->id_type, key->pkey_algo);
}
/*
* Destroy a public key algorithm key.
*/
void public_key_free(struct public_key *key)
{
if (key) {
kfree(key->key);
kfree(key);
}
}
EXPORT_SYMBOL_GPL(public_key_free);
/*
* Destroy a public key algorithm key.
*/
static void public_key_destroy(void *payload0, void *payload3)
{
public_key_free(payload0);
public_key_signature_free(payload3);
}
struct public_key_completion {
struct completion completion;
int err;
};
static void public_key_verify_done(struct crypto_async_request *req, int err)
{
struct public_key_completion *compl = req->data;
if (err == -EINPROGRESS)
return;
compl->err = err;
complete(&compl->completion);
}
/*
* Verify a signature using a public key.
*/
int public_key_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig)
{
struct public_key_completion compl;
struct crypto_akcipher *tfm;
struct akcipher_request *req;
struct scatterlist sig_sg, digest_sg;
const char *alg_name;
char alg_name_buf[CRYPTO_MAX_ALG_NAME];
void *output;
unsigned int outlen;
int ret = -ENOMEM;
pr_devel("==>%s()\n", __func__);
BUG_ON(!pkey);
BUG_ON(!sig);
BUG_ON(!sig->digest);
BUG_ON(!sig->s);
alg_name = sig->pkey_algo;
if (strcmp(sig->pkey_algo, "rsa") == 0) {
/* The data wangled by the RSA algorithm is typically padded
* and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447
* sec 8.2].
*/
if (snprintf(alg_name_buf, CRYPTO_MAX_ALG_NAME,
"pkcs1pad(rsa,%s)", sig->hash_algo
) >= CRYPTO_MAX_ALG_NAME)
return -EINVAL;
alg_name = alg_name_buf;
}
tfm = crypto_alloc_akcipher(alg_name, 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
req = akcipher_request_alloc(tfm, GFP_KERNEL);
if (!req)
goto error_free_tfm;
ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen);
if (ret)
goto error_free_req;
ret = -ENOMEM;
outlen = crypto_akcipher_maxsize(tfm);
output = kmalloc(outlen, GFP_KERNEL);
if (!output)
goto error_free_req;
sg_init_one(&sig_sg, sig->s, sig->s_size);
sg_init_one(&digest_sg, output, outlen);
akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
outlen);
init_completion(&compl.completion);
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
CRYPTO_TFM_REQ_MAY_SLEEP,
public_key_verify_done, &compl);
/* Perform the verification calculation. This doesn't actually do the
* verification, but rather calculates the hash expected by the
* signature and returns that to us.
*/
ret = crypto_akcipher_verify(req);
if (ret == -EINPROGRESS) {
wait_for_completion(&compl.completion);
ret = compl.err;
}
if (ret < 0)
goto out_free_output;
/* Do the actual verification step. */
if (req->dst_len != sig->digest_size ||
memcmp(sig->digest, output, sig->digest_size) != 0)
ret = -EKEYREJECTED;
out_free_output:
kfree(output);
error_free_req:
akcipher_request_free(req);
error_free_tfm:
crypto_free_akcipher(tfm);
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
EXPORT_SYMBOL_GPL(public_key_verify_signature);
static int public_key_verify_signature_2(const struct key *key,
const struct public_key_signature *sig)
{
const struct public_key *pk = key->payload.data[asym_crypto];
return public_key_verify_signature(pk, sig);
}
/*
* Public key algorithm asymmetric key subtype
*/
struct asymmetric_key_subtype public_key_subtype = {
.owner = THIS_MODULE,
.name = "public_key",
.name_len = sizeof("public_key") - 1,
.describe = public_key_describe,
.destroy = public_key_destroy,
.verify_signature = public_key_verify_signature_2,
};
EXPORT_SYMBOL_GPL(public_key_subtype);