diff options
Diffstat (limited to 'drivers/auth/cryptocell/713/cryptocell_crypto.c')
| -rw-r--r-- | drivers/auth/cryptocell/713/cryptocell_crypto.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/drivers/auth/cryptocell/713/cryptocell_crypto.c b/drivers/auth/cryptocell/713/cryptocell_crypto.c new file mode 100644 index 0000000..3ac16af --- /dev/null +++ b/drivers/auth/cryptocell/713/cryptocell_crypto.c @@ -0,0 +1,276 @@ +/* + * Copyright (c) 2017-2020 ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <assert.h> +#include <stddef.h> +#include <string.h> + +#include <platform_def.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 <mbedtls/oid.h> +#include <mbedtls/x509.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; + 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; + 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, ¶ms); + 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(¶ms, &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 != 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, ¶ms); + 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); |