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// SPDX-License-Identifier: BSD-2-Clause
/*
* Copyright (c) 2015-2017, Linaro Limited
*/
#include <crypto/crypto.h>
#include <signed_hdr.h>
#include <stdlib.h>
#include <string.h>
#include <ta_pub_key.h>
#include <tee_api_types.h>
#include <tee/tee_cryp_utl.h>
#include <utee_defines.h>
#include <util.h>
struct shdr *shdr_alloc_and_copy(const struct shdr *img, size_t img_size)
{
size_t shdr_size;
struct shdr *shdr;
vaddr_t img_va = (vaddr_t)img;
vaddr_t tmp = 0;
if (img_size < sizeof(struct shdr))
return NULL;
shdr_size = SHDR_GET_SIZE(img);
if (img_size < shdr_size)
return NULL;
if (ADD_OVERFLOW(img_va, shdr_size, &tmp))
return NULL;
shdr = malloc(shdr_size);
if (!shdr)
return NULL;
memcpy(shdr, img, shdr_size);
/* Check that the data wasn't modified before the copy was completed */
if (shdr_size != SHDR_GET_SIZE(shdr)) {
free(shdr);
return NULL;
}
return shdr;
}
TEE_Result shdr_verify_signature(const struct shdr *shdr)
{
struct rsa_public_key key;
TEE_Result res;
uint32_t e = TEE_U32_TO_BIG_ENDIAN(ta_pub_key_exponent);
size_t hash_size;
if (shdr->magic != SHDR_MAGIC)
return TEE_ERROR_SECURITY;
if (TEE_ALG_GET_MAIN_ALG(shdr->algo) != TEE_MAIN_ALGO_RSA)
return TEE_ERROR_SECURITY;
res = tee_hash_get_digest_size(TEE_DIGEST_HASH_TO_ALGO(shdr->algo),
&hash_size);
if (res)
return TEE_ERROR_SECURITY;
if (hash_size != shdr->hash_size)
return TEE_ERROR_SECURITY;
res = crypto_acipher_alloc_rsa_public_key(&key, shdr->sig_size);
if (res)
return TEE_ERROR_SECURITY;
res = crypto_bignum_bin2bn((uint8_t *)&e, sizeof(e), key.e);
if (res)
goto out;
res = crypto_bignum_bin2bn(ta_pub_key_modulus, ta_pub_key_modulus_size,
key.n);
if (res)
goto out;
res = crypto_acipher_rsassa_verify(shdr->algo, &key, -1,
SHDR_GET_HASH(shdr), shdr->hash_size,
SHDR_GET_SIG(shdr), shdr->sig_size);
out:
crypto_acipher_free_rsa_public_key(&key);
if (res)
return TEE_ERROR_SECURITY;
return TEE_SUCCESS;
}
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