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/*
* Copyright 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SYSTEM_KEYMASTER_ATTESTATION_RECORD_H_
#define SYSTEM_KEYMASTER_ATTESTATION_RECORD_H_
#include <hardware/keymaster_defs.h>
#include <keymaster/authorization_set.h>
#include <openssl/asn1t.h>
namespace keymaster {
struct stack_st_ASN1_TYPE_Delete {
void operator()(stack_st_ASN1_TYPE* p) { sk_ASN1_TYPE_free(p); }
};
struct ASN1_STRING_Delete {
void operator()(ASN1_STRING* p) { ASN1_STRING_free(p); }
};
struct ASN1_TYPE_Delete {
void operator()(ASN1_TYPE* p) { ASN1_TYPE_free(p); }
};
#define ASN1_INTEGER_SET STACK_OF(ASN1_INTEGER)
typedef struct km_root_of_trust {
ASN1_OCTET_STRING* verified_boot_key;
ASN1_BOOLEAN* device_locked;
ASN1_ENUMERATED* verified_boot_state;
} KM_ROOT_OF_TRUST;
ASN1_SEQUENCE(KM_ROOT_OF_TRUST) = {
ASN1_SIMPLE(KM_ROOT_OF_TRUST, verified_boot_key, ASN1_OCTET_STRING),
ASN1_SIMPLE(KM_ROOT_OF_TRUST, device_locked, ASN1_BOOLEAN),
ASN1_SIMPLE(KM_ROOT_OF_TRUST, verified_boot_state, ASN1_ENUMERATED),
} ASN1_SEQUENCE_END(KM_ROOT_OF_TRUST);
DECLARE_ASN1_FUNCTIONS(KM_ROOT_OF_TRUST);
typedef struct km_auth_list {
ASN1_INTEGER_SET* purpose;
ASN1_INTEGER* algorithm;
ASN1_INTEGER* key_size;
ASN1_INTEGER_SET* block_mode;
ASN1_INTEGER_SET* digest;
ASN1_INTEGER_SET* padding;
ASN1_NULL* caller_nonce;
ASN1_INTEGER* min_mac_length;
ASN1_INTEGER_SET* kdf;
ASN1_INTEGER* ec_curve;
ASN1_INTEGER* rsa_public_exponent;
ASN1_INTEGER* active_date_time;
ASN1_INTEGER* origination_expire_date_time;
ASN1_INTEGER* usage_expire_date_time;
ASN1_NULL* no_auth_required;
ASN1_INTEGER* user_auth_type;
ASN1_INTEGER* auth_timeout;
ASN1_NULL* allow_while_on_body;
ASN1_NULL* unlocked_device_required;
ASN1_NULL* all_applications;
ASN1_OCTET_STRING* application_id;
ASN1_INTEGER* creation_date_time;
ASN1_INTEGER* origin;
ASN1_NULL* rollback_resistant;
KM_ROOT_OF_TRUST* root_of_trust;
ASN1_INTEGER* os_version;
ASN1_INTEGER* os_patchlevel;
ASN1_OCTET_STRING* attestation_application_id;
ASN1_OCTET_STRING* attestation_id_brand;
ASN1_OCTET_STRING* attestation_id_device;
ASN1_OCTET_STRING* attestation_id_product;
ASN1_OCTET_STRING* attestation_id_serial;
ASN1_OCTET_STRING* attestation_id_imei;
ASN1_OCTET_STRING* attestation_id_meid;
ASN1_OCTET_STRING* attestation_id_manufacturer;
ASN1_OCTET_STRING* attestation_id_model;
} KM_AUTH_LIST;
ASN1_SEQUENCE(KM_AUTH_LIST) = {
ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, purpose, ASN1_INTEGER, TAG_PURPOSE.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, algorithm, ASN1_INTEGER, TAG_ALGORITHM.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, key_size, ASN1_INTEGER, TAG_KEY_SIZE.masked_tag()),
ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, block_mode, ASN1_INTEGER, TAG_BLOCK_MODE.masked_tag()),
ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, digest, ASN1_INTEGER, TAG_DIGEST.masked_tag()),
ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, padding, ASN1_INTEGER, TAG_PADDING.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, caller_nonce, ASN1_NULL, TAG_CALLER_NONCE.masked_tag()),
ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, min_mac_length, ASN1_INTEGER,
TAG_MIN_MAC_LENGTH.masked_tag()),
ASN1_EXP_SET_OF_OPT(KM_AUTH_LIST, kdf, ASN1_INTEGER, TAG_KDF.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, ec_curve, ASN1_INTEGER, TAG_EC_CURVE.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, rsa_public_exponent, ASN1_INTEGER,
TAG_RSA_PUBLIC_EXPONENT.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, active_date_time, ASN1_INTEGER, TAG_ACTIVE_DATETIME.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, origination_expire_date_time, ASN1_INTEGER,
TAG_ORIGINATION_EXPIRE_DATETIME.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, usage_expire_date_time, ASN1_INTEGER,
TAG_USAGE_EXPIRE_DATETIME.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, no_auth_required, ASN1_NULL, TAG_NO_AUTH_REQUIRED.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, user_auth_type, ASN1_INTEGER, TAG_USER_AUTH_TYPE.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, auth_timeout, ASN1_INTEGER, TAG_AUTH_TIMEOUT.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, allow_while_on_body, ASN1_NULL,
TAG_ALLOW_WHILE_ON_BODY.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, all_applications, ASN1_NULL, TAG_ALL_APPLICATIONS.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, application_id, ASN1_OCTET_STRING, TAG_APPLICATION_ID.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, creation_date_time, ASN1_INTEGER,
TAG_CREATION_DATETIME.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, origin, ASN1_INTEGER, TAG_ORIGIN.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, rollback_resistant, ASN1_NULL, TAG_ROLLBACK_RESISTANT.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, root_of_trust, KM_ROOT_OF_TRUST, TAG_ROOT_OF_TRUST.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, os_version, ASN1_INTEGER, TAG_OS_VERSION.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, os_patchlevel, ASN1_INTEGER, TAG_OS_PATCHLEVEL.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_application_id, ASN1_OCTET_STRING,
TAG_ATTESTATION_APPLICATION_ID.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_brand, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_BRAND.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_device, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_DEVICE.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_product, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_PRODUCT.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_serial, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_SERIAL.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_imei, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_IMEI.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_meid, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_MEID.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_manufacturer, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_MANUFACTURER.masked_tag()),
ASN1_EXP_OPT(KM_AUTH_LIST, attestation_id_model, ASN1_OCTET_STRING,
TAG_ATTESTATION_ID_MODEL.masked_tag()),
} ASN1_SEQUENCE_END(KM_AUTH_LIST);
DECLARE_ASN1_FUNCTIONS(KM_AUTH_LIST);
typedef struct km_key_description {
ASN1_INTEGER* attestation_version;
ASN1_ENUMERATED* attestation_security_level;
ASN1_INTEGER* keymaster_version;
ASN1_ENUMERATED* keymaster_security_level;
ASN1_OCTET_STRING* attestation_challenge;
KM_AUTH_LIST* software_enforced;
KM_AUTH_LIST* tee_enforced;
ASN1_INTEGER* unique_id;
} KM_KEY_DESCRIPTION;
ASN1_SEQUENCE(KM_KEY_DESCRIPTION) = {
ASN1_SIMPLE(KM_KEY_DESCRIPTION, attestation_version, ASN1_INTEGER),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, attestation_security_level, ASN1_ENUMERATED),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, keymaster_version, ASN1_INTEGER),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, keymaster_security_level, ASN1_ENUMERATED),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, attestation_challenge, ASN1_OCTET_STRING),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, unique_id, ASN1_OCTET_STRING),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, software_enforced, KM_AUTH_LIST),
ASN1_SIMPLE(KM_KEY_DESCRIPTION, tee_enforced, KM_AUTH_LIST),
} ASN1_SEQUENCE_END(KM_KEY_DESCRIPTION);
DECLARE_ASN1_FUNCTIONS(KM_KEY_DESCRIPTION);
class AttestationRecordContext {
protected:
virtual ~AttestationRecordContext() {}
public:
/**
* Returns the security level (SW or TEE) of this keymaster implementation.
*/
virtual keymaster_security_level_t GetSecurityLevel() const {
return KM_SECURITY_LEVEL_SOFTWARE;
}
/**
* Verify that the device IDs provided in the attestation_params match the device's actual IDs
* and copy them to attestation. If *any* of the IDs do not match or verification is not
* possible, return KM_ERROR_CANNOT_ATTEST_IDS. If *all* IDs provided are successfully verified
* or no IDs were provided, return KM_ERROR_OK.
*
* If you do not support device ID attestation, ignore all arguments and return
* KM_ERROR_UNIMPLEMENTED.
*/
virtual keymaster_error_t VerifyAndCopyDeviceIds(
const AuthorizationSet& /* attestation_params */,
AuthorizationSet* /* attestation */) const {
return KM_ERROR_UNIMPLEMENTED;
}
/**
* Generate the current unique ID.
*/
virtual keymaster_error_t GenerateUniqueId(uint64_t /*creation_date_time*/,
const keymaster_blob_t& /*application_id*/,
bool /*reset_since_rotation*/,
Buffer* /*unique_id*/) const {
return KM_ERROR_UNIMPLEMENTED;
}
/**
* Returns verified boot parameters for the Attestation Extension. For hardware-based
* implementations, these will be the values reported by the bootloader. By default, verified
* boot state is unknown, and KM_ERROR_UNIMPLEMENTED is returned.
*/
virtual keymaster_error_t
GetVerifiedBootParams(keymaster_blob_t* /* verified_boot_key */,
keymaster_verified_boot_t* /* verified_boot_state */,
bool* /* device_locked */) const {
return KM_ERROR_UNIMPLEMENTED;
}
};
/**
* The OID for Android attestation records. For the curious, it breaks down as follows:
*
* 1 = ISO
* 3 = org
* 6 = DoD (Huh? OIDs are weird.)
* 1 = IANA
* 4 = Private
* 1 = Enterprises
* 11129 = Google
* 2 = Google security
* 1 = certificate extension
* 17 = Android attestation extension.
*/
static const char kAttestionRecordOid[] = "1.3.6.1.4.1.11129.2.1.17";
keymaster_error_t build_attestation_record(const AuthorizationSet& attestation_params,
AuthorizationSet software_enforced,
AuthorizationSet tee_enforced,
const AttestationRecordContext& context,
UniquePtr<uint8_t[]>* asn1_key_desc,
size_t* asn1_key_desc_len);
/**
* helper function for attestation record test.
*/
keymaster_error_t parse_attestation_record(const uint8_t* asn1_key_desc, size_t asn1_key_desc_len,
uint32_t* attestation_version, //
keymaster_security_level_t* attestation_security_level,
uint32_t* keymaster_version,
keymaster_security_level_t* keymaster_security_level,
keymaster_blob_t* attestation_challenge,
AuthorizationSet* software_enforced,
AuthorizationSet* tee_enforced,
keymaster_blob_t* unique_id);
keymaster_error_t build_auth_list(const AuthorizationSet& auth_list, KM_AUTH_LIST* record);
keymaster_error_t extract_auth_list(const KM_AUTH_LIST* record, AuthorizationSet* auth_list);
} // namespace keymaster
#endif // SYSTEM_KEYMASTER_ATTESTATION_RECORD_H_
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