drivers/auth/cryptocell/cryptocell_crypto.c - imx-atf - Git at Google

 /*
  * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */

 #include <arch_helpers.h>
 #include <crypto_mod.h>
 #include <crypto_driver.h>
 #include <debug.h>
 #include <mbedtls_common.h>
 #include <platform_def.h>
 #include <rsa.h>
 #include <sbrom_bsv_api.h>
 #include <secureboot_base_func.h>
 #include <secureboot_gen_defs.h>
 #include <stddef.h>
 #include <string.h>
 #include <utils.h>
 #include <util.h>

 #include <mbedtls/oid.h>

 #define LIB_NAME		"CryptoCell 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_BsvSbromInit((uintptr_t)PLAT_CRYPTOCELL_BASE);
 	if (ret != CC_OK) {
 		ERROR("CryptoCell CC_BsvSbromInit() error %x\n", ret);
 		panic();
 	}

 	/* Initialize lifecycle state */
 	ret = CC_BsvLcsGetAndInit((uintptr_t)PLAT_CRYPTOCELL_BASE, &lcs);
 	if (ret != CC_OK) {
 		ERROR("CryptoCell CC_BsvLcsGetAndInit() error %x\n", ret);
 		panic();
 	}

 	/* If the lifecyclestate is `SD`, then stop further execution */
 	if (lcs == CC_BSV_SECURITY_DISABLED_LCS) {
 		ERROR("CryptoCell LCS is security-disabled\n");
 		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;
 	CCSbNParams_t pk;
 	CCSbSignature_t signature;
 	int rc, exp;
 	mbedtls_asn1_buf sig_oid, alg_oid, params;
 	mbedtls_md_type_t md_alg;
 	mbedtls_pk_type_t pk_alg;
 	mbedtls_pk_rsassa_pss_options pss_opts;
 	size_t len;
 	uint8_t *p, *end;
 	/* Temp buf to store the public key modulo (N) in LE format */
 	uint32_t RevN[SB_RSA_MOD_SIZE_IN_WORDS];

 	/* 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,
 			&pss_opts.mgf1_hash_id,
 			&pss_opts.expected_salt_len);
 	if (rc != 0)
 		return CRYPTO_ERR_SIGNATURE;

 	/* The CryptoCell only supports SHA256 as hash algorithm */
 	if (md_alg != MBEDTLS_MD_SHA256 || pss_opts.mgf1_hash_id != MBEDTLS_MD_SHA256)
 		return CRYPTO_ERR_SIGNATURE;

 	if (pss_opts.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 != RSA_MOD_SIZE_IN_BYTES || ((p + len) > end))
 		return CRYPTO_ERR_SIGNATURE;

 	/*
 	 * The CCSbVerifySignature() API expects N and Np in BE format and
 	 * the signature in LE format. Copy N from certificate.
 	 */
 	memcpy(pk.N, p, RSA_MOD_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;

 	/*
 	 * Calculate the Np (Barrett n' value). The RSA_CalcNp() API expects
 	 * N in LE format. Hence reverse N into a temporary buffer `RevN`.
 	 */
 	UTIL_ReverseMemCopy((uint8_t *)RevN, (uint8_t *)pk.N, sizeof(RevN));

 	RSA_CalcNp((uintptr_t)PLAT_CRYPTOCELL_BASE, RevN, pk.Np);

 	/* Np is in LE format. Reverse it to BE */
 	UTIL_ReverseBuff((uint8_t *)pk.Np, sizeof(pk.Np));

 	/* 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 != RSA_MOD_SIZE_IN_BYTES || ((p + len) > end))
 		return CRYPTO_ERR_SIGNATURE;

 	/*
 	 *  The signature is BE format. Convert it to LE before calling
 	 *  CCSbVerifySignature().
 	 */
 	UTIL_ReverseMemCopy((uint8_t *)signature.sig, p, RSA_MOD_SIZE_IN_BYTES);

 	/*
 	 * CryptoCell utilises DMA internally to transfer data. Flush the data
 	 * from caches.
 	 */
 	flush_dcache_range((uintptr_t)data_ptr, data_len);

 	/* Verify the signature */
 	error = CCSbVerifySignature((uintptr_t)PLAT_CRYPTOCELL_BASE,
 			(uint32_t *)data_ptr, &pk, &signature,
 			data_len, RSA_PSS_2048);
 	if (error != CC_OK)
 		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;

 	/*
 	 * CryptoCell utilises DMA internally to transfer data. Flush the data
 	 * from caches.
 	 */
 	flush_dcache_range((uintptr_t)data_ptr, data_len);

 	hash = p;
 	error = SBROM_CryptoHash((uintptr_t)PLAT_CRYPTOCELL_BASE,
 			(uintptr_t)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);
	/*
	* Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
	*
	* SPDX-License-Identifier: BSD-3-Clause
	*/

	#include <arch_helpers.h>
	#include <crypto_mod.h>
	#include <crypto_driver.h>
	#include <debug.h>
	#include <mbedtls_common.h>
	#include <platform_def.h>
	#include <rsa.h>
	#include <sbrom_bsv_api.h>
	#include <secureboot_base_func.h>
	#include <secureboot_gen_defs.h>
	#include <stddef.h>
	#include <string.h>
	#include <utils.h>
	#include <util.h>

	#include <mbedtls/oid.h>

	#define LIB_NAME "CryptoCell 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_BsvSbromInit((uintptr_t)PLAT_CRYPTOCELL_BASE);
	if (ret != CC_OK) {
	ERROR("CryptoCell CC_BsvSbromInit() error %x\n", ret);
	panic();
	}

	/* Initialize lifecycle state */
	ret = CC_BsvLcsGetAndInit((uintptr_t)PLAT_CRYPTOCELL_BASE, &lcs);
	if (ret != CC_OK) {
	ERROR("CryptoCell CC_BsvLcsGetAndInit() error %x\n", ret);
	panic();
	}

	/* If the lifecyclestate is `SD`, then stop further execution */
	if (lcs == CC_BSV_SECURITY_DISABLED_LCS) {
	ERROR("CryptoCell LCS is security-disabled\n");
	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;
	CCSbNParams_t pk;
	CCSbSignature_t signature;
	int rc, exp;
	mbedtls_asn1_buf sig_oid, alg_oid, params;
	mbedtls_md_type_t md_alg;
	mbedtls_pk_type_t pk_alg;
	mbedtls_pk_rsassa_pss_options pss_opts;
	size_t len;
	uint8_t p, end;
	/* Temp buf to store the public key modulo (N) in LE format */
	uint32_t RevN[SB_RSA_MOD_SIZE_IN_WORDS];

	/* 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,
	&pss_opts.mgf1_hash_id,
	&pss_opts.expected_salt_len);
	if (rc != 0)
	return CRYPTO_ERR_SIGNATURE;

	/* The CryptoCell only supports SHA256 as hash algorithm */
	if (md_alg != MBEDTLS_MD_SHA256 \|\| pss_opts.mgf1_hash_id != MBEDTLS_MD_SHA256)
	return CRYPTO_ERR_SIGNATURE;

	if (pss_opts.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 != RSA_MOD_SIZE_IN_BYTES \|\| ((p + len) > end))
	return CRYPTO_ERR_SIGNATURE;

	/*
	* The CCSbVerifySignature() API expects N and Np in BE format and
	* the signature in LE format. Copy N from certificate.
	*/
	memcpy(pk.N, p, RSA_MOD_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;

	/*
	* Calculate the Np (Barrett n' value). The RSA_CalcNp() API expects
	* N in LE format. Hence reverse N into a temporary buffer `RevN`.
	*/
	UTIL_ReverseMemCopy((uint8_t )RevN, (uint8_t )pk.N, sizeof(RevN));

	RSA_CalcNp((uintptr_t)PLAT_CRYPTOCELL_BASE, RevN, pk.Np);

	/* Np is in LE format. Reverse it to BE */
	UTIL_ReverseBuff((uint8_t *)pk.Np, sizeof(pk.Np));

	/* 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 != RSA_MOD_SIZE_IN_BYTES \|\| ((p + len) > end))
	return CRYPTO_ERR_SIGNATURE;

	/*
	* The signature is BE format. Convert it to LE before calling
	* CCSbVerifySignature().
	*/
	UTIL_ReverseMemCopy((uint8_t *)signature.sig, p, RSA_MOD_SIZE_IN_BYTES);

	/*
	* CryptoCell utilises DMA internally to transfer data. Flush the data
	* from caches.
	*/
	flush_dcache_range((uintptr_t)data_ptr, data_len);

	/* Verify the signature */
	error = CCSbVerifySignature((uintptr_t)PLAT_CRYPTOCELL_BASE,
	(uint32_t *)data_ptr, &pk, &signature,
	data_len, RSA_PSS_2048);
	if (error != CC_OK)
	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;

	/*
	* CryptoCell utilises DMA internally to transfer data. Flush the data
	* from caches.
	*/
	flush_dcache_range((uintptr_t)data_ptr, data_len);

	hash = p;
	error = SBROM_CryptoHash((uintptr_t)PLAT_CRYPTOCELL_BASE,
	(uintptr_t)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);