blob: 388264ed305b6bca59ce8dcc1eccc7ff078bb93b [file] [log] [blame]
/*
* Copyright (c) 2017-2023 ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <stddef.h>
#include <string.h>
#include <mbedtls/oid.h>
#include <mbedtls/x509.h>
#include <drivers/arm/cryptocell/713/bsv_api.h>
#include <drivers/arm/cryptocell/713/bsv_crypto_asym_api.h>
#include <drivers/auth/crypto_mod.h>
#include <platform_def.h>
#define LIB_NAME "CryptoCell 713 SBROM"
#define RSA_SALT_LEN 32
#define RSA_EXPONENT 65537
/*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL
* }
*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING
* }
*
* DigestInfo ::= SEQUENCE {
* digestAlgorithm AlgorithmIdentifier,
* digest OCTET STRING
* }
*
* RSASSA-PSS-params ::= SEQUENCE {
* hashAlgorithm [0] HashAlgorithm,
* maskGenAlgorithm [1] MaskGenAlgorithm,
* saltLength [2] INTEGER,
* trailerField [3] TrailerField DEFAULT trailerFieldBC
* }
*/
/*
* Initialize the library and export the descriptor
*/
static void init(void)
{
CCError_t ret;
uint32_t lcs;
/* Initialize CC SBROM */
ret = CC_BsvInit((uintptr_t)PLAT_CRYPTOCELL_BASE);
if (ret != CC_OK) {
ERROR("CryptoCell CC_BsvInit() error %x\n", ret);
panic();
}
/* Initialize lifecycle state */
ret = CC_BsvGetAndInitLcs((uintptr_t)PLAT_CRYPTOCELL_BASE, &lcs);
if (ret != CC_OK) {
ERROR("CryptoCell CC_BsvGetAndInitLcs() error %x\n", ret);
panic();
}
}
/*
* Verify a signature.
*
* Parameters are passed using the DER encoding format following the ASN.1
* structures detailed above.
*/
static int verify_signature(void *data_ptr, unsigned int data_len,
void *sig_ptr, unsigned int sig_len,
void *sig_alg, unsigned int sig_alg_len,
void *pk_ptr, unsigned int pk_len)
{
CCError_t error;
CCBsvNBuff_t NBuff;
CCBsvSignature_t signature;
int rc, exp, expected_salt_len;
mbedtls_asn1_buf sig_oid, alg_oid, params;
mbedtls_md_type_t md_alg, mgf1_hash_id;
mbedtls_pk_type_t pk_alg;
size_t len;
uint8_t *p, *end;
CCHashResult_t digest;
CCBool_t is_verified;
/* This is a rather large array, we don't want it on stack */
static uint32_t workspace[BSV_RSA_WORKSPACE_MIN_SIZE];
/* Verify the signature algorithm */
/* Get pointers to signature OID and parameters */
p = sig_alg;
end = p + sig_alg_len;
rc = mbedtls_asn1_get_alg(&p, end, &sig_oid, &params);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
/* Get the actual signature algorithm (MD + PK) */
rc = mbedtls_oid_get_sig_alg(&sig_oid, &md_alg, &pk_alg);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
/* The CryptoCell only supports RSASSA-PSS signature */
if (pk_alg != MBEDTLS_PK_RSASSA_PSS || md_alg != MBEDTLS_MD_NONE) {
return CRYPTO_ERR_SIGNATURE;
}
/* Verify the RSASSA-PSS params */
/* The trailer field is verified to be 0xBC internally by this API */
rc = mbedtls_x509_get_rsassa_pss_params(&params, &md_alg,
&mgf1_hash_id,
&expected_salt_len);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
/* The CryptoCell only supports SHA256 as hash algorithm */
if (md_alg != MBEDTLS_MD_SHA256 ||
mgf1_hash_id != MBEDTLS_MD_SHA256) {
return CRYPTO_ERR_SIGNATURE;
}
if (expected_salt_len != RSA_SALT_LEN) {
return CRYPTO_ERR_SIGNATURE;
}
/* Parse the public key */
p = pk_ptr;
end = p + pk_len;
rc = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
end = p + len;
rc = mbedtls_asn1_get_alg_null(&p, end, &alg_oid);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
if (mbedtls_oid_get_pk_alg(&alg_oid, &pk_alg) != 0) {
return CRYPTO_ERR_SIGNATURE;
}
if (pk_alg != MBEDTLS_PK_RSA) {
return CRYPTO_ERR_SIGNATURE;
}
rc = mbedtls_asn1_get_bitstring_null(&p, end, &len);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
rc = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
rc = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_INTEGER);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
if (*p == 0) {
p++; len--;
}
if (len != BSV_CERT_RSA_KEY_SIZE_IN_BYTES || ((p + len) > end)) {
return CRYPTO_ERR_SIGNATURE;
}
/*
* Copy N from certificate.
*/
memcpy(NBuff, p, BSV_CERT_RSA_KEY_SIZE_IN_BYTES);
/* Verify the RSA exponent */
p += len;
rc = mbedtls_asn1_get_int(&p, end, &exp);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
if (exp != RSA_EXPONENT) {
return CRYPTO_ERR_SIGNATURE;
}
/* Get the signature (bitstring) */
p = sig_ptr;
end = p + sig_len;
rc = mbedtls_asn1_get_bitstring_null(&p, end, &len);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
if (len != BSV_CERT_RSA_KEY_SIZE_IN_BYTES || ((p + len) > end)) {
return CRYPTO_ERR_SIGNATURE;
}
/*
* Copy the signature (in BE format)
*/
memcpy((uint8_t *)signature, p, BSV_CERT_RSA_KEY_SIZE_IN_BYTES);
error = CC_BsvSha256((uintptr_t)PLAT_CRYPTOCELL_BASE,
data_ptr, data_len, digest);
if (error != CC_OK) {
return CRYPTO_ERR_SIGNATURE;
}
/* Verify the signature */
error = CC_BsvRsaPssVerify((uintptr_t)PLAT_CRYPTOCELL_BASE, NBuff,
NULL, signature, digest, workspace,
BSV_RSA_WORKSPACE_MIN_SIZE, &is_verified);
if ((error != CC_OK) || (is_verified != CC_TRUE)) {
return CRYPTO_ERR_SIGNATURE;
}
/* Signature verification success */
return CRYPTO_SUCCESS;
}
/*
* Match a hash
*
* Digest info is passed in DER format following the ASN.1 structure detailed
* above.
*/
static int verify_hash(void *data_ptr, unsigned int data_len,
void *digest_info_ptr, unsigned int digest_info_len)
{
mbedtls_asn1_buf hash_oid, params;
mbedtls_md_type_t md_alg;
uint8_t *p, *end, *hash;
CCHashResult_t pubKeyHash;
size_t len;
int rc;
CCError_t error;
/* Digest info should be an MBEDTLS_ASN1_SEQUENCE */
p = digest_info_ptr;
end = p + digest_info_len;
rc = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE);
if (rc != 0) {
return CRYPTO_ERR_HASH;
}
/* Get the hash algorithm */
rc = mbedtls_asn1_get_alg(&p, end, &hash_oid, &params);
if (rc != 0) {
return CRYPTO_ERR_HASH;
}
rc = mbedtls_oid_get_md_alg(&hash_oid, &md_alg);
if (rc != 0) {
return CRYPTO_ERR_HASH;
}
/* Verify that hash algorithm is SHA256 */
if (md_alg != MBEDTLS_MD_SHA256) {
return CRYPTO_ERR_HASH;
}
/* Hash should be octet string type */
rc = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING);
if (rc != 0) {
return CRYPTO_ERR_HASH;
}
/* Length of hash must match the algorithm's size */
if (len != HASH_RESULT_SIZE_IN_BYTES) {
return CRYPTO_ERR_HASH;
}
hash = p;
error = CC_BsvSha256((uintptr_t)PLAT_CRYPTOCELL_BASE, data_ptr,
data_len, pubKeyHash);
if (error != CC_OK) {
return CRYPTO_ERR_HASH;
}
rc = memcmp(pubKeyHash, hash, HASH_RESULT_SIZE_IN_BYTES);
if (rc != 0) {
return CRYPTO_ERR_HASH;
}
return CRYPTO_SUCCESS;
}
/*
* Register crypto library descriptor
*/
REGISTER_CRYPTO_LIB(LIB_NAME, init, verify_signature, verify_hash, NULL);