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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_HARDWARE_KEYMASTER_DEFS_H
     18 #define ANDROID_HARDWARE_KEYMASTER_DEFS_H
     19 
     20 #include <stdint.h>
     21 #include <stdlib.h>
     22 #include <string.h>
     23 
     24 #ifdef __cplusplus
     25 extern "C" {
     26 #endif  // __cplusplus
     27 
     28 /**
     29  * Authorization tags each have an associated type.  This enumeration facilitates tagging each with
     30  * a type, by using the high four bits (of an implied 32-bit unsigned enum value) to specify up to
     31  * 16 data types.  These values are ORed with tag IDs to generate the final tag ID values.
     32  */
     33 typedef enum {
     34     KM_INVALID = 0 << 28, /* Invalid type, used to designate a tag as uninitialized */
     35     KM_ENUM = 1 << 28,
     36     KM_ENUM_REP = 2 << 28, /* Repeatable enumeration value. */
     37     KM_UINT = 3 << 28,
     38     KM_UINT_REP = 4 << 28, /* Repeatable integer value */
     39     KM_ULONG = 5 << 28,
     40     KM_DATE = 6 << 28,
     41     KM_BOOL = 7 << 28,
     42     KM_BIGNUM = 8 << 28,
     43     KM_BYTES = 9 << 28,
     44     KM_ULONG_REP = 10 << 28, /* Repeatable long value */
     45 } keymaster_tag_type_t;
     46 
     47 typedef enum {
     48     KM_TAG_INVALID = KM_INVALID | 0,
     49 
     50     /*
     51      * Tags that must be semantically enforced by hardware and software implementations.
     52      */
     53 
     54     /* Crypto parameters */
     55     KM_TAG_PURPOSE = KM_ENUM_REP | 1,    /* keymaster_purpose_t. */
     56     KM_TAG_ALGORITHM = KM_ENUM | 2,      /* keymaster_algorithm_t. */
     57     KM_TAG_KEY_SIZE = KM_UINT | 3,       /* Key size in bits. */
     58     KM_TAG_BLOCK_MODE = KM_ENUM_REP | 4, /* keymaster_block_mode_t. */
     59     KM_TAG_DIGEST = KM_ENUM_REP | 5,     /* keymaster_digest_t. */
     60     KM_TAG_PADDING = KM_ENUM_REP | 6,    /* keymaster_padding_t. */
     61     KM_TAG_CALLER_NONCE = KM_BOOL | 7,   /* Allow caller to specify nonce or IV. */
     62     KM_TAG_MIN_MAC_LENGTH = KM_UINT | 8, /* Minimum length of MAC or AEAD authentication tag in
     63                                           * bits. */
     64     KM_TAG_KDF = KM_ENUM_REP | 9,        /* keymaster_kdf_t (keymaster2) */
     65     KM_TAG_EC_CURVE = KM_ENUM | 10,      /* keymaster_ec_curve_t (keymaster2) */
     66 
     67     /* Algorithm-specific. */
     68     KM_TAG_RSA_PUBLIC_EXPONENT = KM_ULONG | 200,
     69     KM_TAG_ECIES_SINGLE_HASH_MODE = KM_BOOL | 201, /* Whether the ephemeral public key is fed into
     70                                                     * the KDF */
     71     KM_TAG_INCLUDE_UNIQUE_ID = KM_BOOL | 202,      /* If true, attestation certificates for this key
     72                                                     * will contain an application-scoped and
     73                                                     * time-bounded device-unique ID. (keymaster2) */
     74 
     75     /* Other hardware-enforced. */
     76     KM_TAG_BLOB_USAGE_REQUIREMENTS = KM_ENUM | 301, /* keymaster_key_blob_usage_requirements_t */
     77     KM_TAG_BOOTLOADER_ONLY = KM_BOOL | 302,         /* Usable only by bootloader */
     78 
     79     /*
     80      * Tags that should be semantically enforced by hardware if possible and will otherwise be
     81      * enforced by software (keystore).
     82      */
     83 
     84     /* Key validity period */
     85     KM_TAG_ACTIVE_DATETIME = KM_DATE | 400,             /* Start of validity */
     86     KM_TAG_ORIGINATION_EXPIRE_DATETIME = KM_DATE | 401, /* Date when new "messages" should no
     87                                                            longer be created. */
     88     KM_TAG_USAGE_EXPIRE_DATETIME = KM_DATE | 402,       /* Date when existing "messages" should no
     89                                                            longer be trusted. */
     90     KM_TAG_MIN_SECONDS_BETWEEN_OPS = KM_UINT | 403,     /* Minimum elapsed time between
     91                                                            cryptographic operations with the key. */
     92     KM_TAG_MAX_USES_PER_BOOT = KM_UINT | 404,           /* Number of times the key can be used per
     93                                                            boot. */
     94 
     95     /* User authentication */
     96     KM_TAG_ALL_USERS = KM_BOOL | 500,           /* Reserved for future use -- ignore */
     97     KM_TAG_USER_ID = KM_UINT | 501,             /* Reserved for future use -- ignore */
     98     KM_TAG_USER_SECURE_ID = KM_ULONG_REP | 502, /* Secure ID of authorized user or authenticator(s).
     99                                                    Disallowed if KM_TAG_ALL_USERS or
    100                                                    KM_TAG_NO_AUTH_REQUIRED is present. */
    101     KM_TAG_NO_AUTH_REQUIRED = KM_BOOL | 503,    /* If key is usable without authentication. */
    102     KM_TAG_USER_AUTH_TYPE = KM_ENUM | 504,      /* Bitmask of authenticator types allowed when
    103                                                  * KM_TAG_USER_SECURE_ID contains a secure user ID,
    104                                                  * rather than a secure authenticator ID.  Defined in
    105                                                  * hw_authenticator_type_t in hw_auth_token.h. */
    106     KM_TAG_AUTH_TIMEOUT = KM_UINT | 505,        /* Required freshness of user authentication for
    107                                                    private/secret key operations, in seconds.
    108                                                    Public key operations require no authentication.
    109                                                    If absent, authentication is required for every
    110                                                    use.  Authentication state is lost when the
    111                                                    device is powered off. */
    112     KM_TAG_ALLOW_WHILE_ON_BODY = KM_BOOL | 506, /* Allow key to be used after authentication timeout
    113                                                  * if device is still on-body (requires secure
    114                                                  * on-body sensor. */
    115 
    116     /* Application access control */
    117     KM_TAG_ALL_APPLICATIONS = KM_BOOL | 600, /* Specified to indicate key is usable by all
    118                                               * applications. */
    119     KM_TAG_APPLICATION_ID = KM_BYTES | 601,  /* Byte string identifying the authorized
    120                                               * application. */
    121     KM_TAG_EXPORTABLE = KM_BOOL | 602,       /* If true, private/secret key can be exported, but
    122                                               * only if all access control requirements for use are
    123                                               * met. (keymaster2) */
    124 
    125     /*
    126      * Semantically unenforceable tags, either because they have no specific meaning or because
    127      * they're informational only.
    128      */
    129     KM_TAG_APPLICATION_DATA = KM_BYTES | 700,      /* Data provided by authorized application. */
    130     KM_TAG_CREATION_DATETIME = KM_DATE | 701,      /* Key creation time */
    131     KM_TAG_ORIGIN = KM_ENUM | 702,                 /* keymaster_key_origin_t. */
    132     KM_TAG_ROLLBACK_RESISTANT = KM_BOOL | 703,     /* Whether key is rollback-resistant. */
    133     KM_TAG_ROOT_OF_TRUST = KM_BYTES | 704,         /* Root of trust ID. */
    134     KM_TAG_OS_VERSION = KM_UINT | 705,             /* Version of system (keymaster2) */
    135     KM_TAG_OS_PATCHLEVEL = KM_UINT | 706,          /* Patch level of system (keymaster2) */
    136     KM_TAG_UNIQUE_ID = KM_BYTES | 707,             /* Used to provide unique ID in attestation */
    137     KM_TAG_ATTESTATION_CHALLENGE = KM_BYTES | 708, /* Used to provide challenge in attestation */
    138 
    139     /* Tags used only to provide data to or receive data from operations */
    140     KM_TAG_ASSOCIATED_DATA = KM_BYTES | 1000, /* Used to provide associated data for AEAD modes. */
    141     KM_TAG_NONCE = KM_BYTES | 1001,           /* Nonce or Initialization Vector */
    142     KM_TAG_AUTH_TOKEN = KM_BYTES | 1002,      /* Authentication token that proves secure user
    143                                                  authentication has been performed.  Structure
    144                                                  defined in hw_auth_token_t in hw_auth_token.h. */
    145     KM_TAG_MAC_LENGTH = KM_UINT | 1003,       /* MAC or AEAD authentication tag length in
    146                                                * bits. */
    147 
    148     KM_TAG_RESET_SINCE_ID_ROTATION = KM_BOOL | 1004, /* Whether the device has beeen factory reset
    149                                                         since the last unique ID rotation.  Used for
    150                                                         key attestation. */
    151 } keymaster_tag_t;
    152 
    153 /**
    154  * Algorithms that may be provided by keymaster implementations.  Those that must be provided by all
    155  * implementations are tagged as "required".
    156  */
    157 typedef enum {
    158     /* Asymmetric algorithms. */
    159     KM_ALGORITHM_RSA = 1,
    160     // KM_ALGORITHM_DSA = 2, -- Removed, do not re-use value 2.
    161     KM_ALGORITHM_EC = 3,
    162 
    163     /* Block ciphers algorithms */
    164     KM_ALGORITHM_AES = 32,
    165 
    166     /* MAC algorithms */
    167     KM_ALGORITHM_HMAC = 128,
    168 } keymaster_algorithm_t;
    169 
    170 /**
    171  * Symmetric block cipher modes provided by keymaster implementations.
    172  */
    173 typedef enum {
    174     /* Unauthenticated modes, usable only for encryption/decryption and not generally recommended
    175      * except for compatibility with existing other protocols. */
    176     KM_MODE_ECB = 1,
    177     KM_MODE_CBC = 2,
    178     KM_MODE_CTR = 3,
    179 
    180     /* Authenticated modes, usable for encryption/decryption and signing/verification.  Recommended
    181      * over unauthenticated modes for all purposes. */
    182     KM_MODE_GCM = 32,
    183 } keymaster_block_mode_t;
    184 
    185 /**
    186  * Padding modes that may be applied to plaintext for encryption operations.  This list includes
    187  * padding modes for both symmetric and asymmetric algorithms.  Note that implementations should not
    188  * provide all possible combinations of algorithm and padding, only the
    189  * cryptographically-appropriate pairs.
    190  */
    191 typedef enum {
    192     KM_PAD_NONE = 1, /* deprecated */
    193     KM_PAD_RSA_OAEP = 2,
    194     KM_PAD_RSA_PSS = 3,
    195     KM_PAD_RSA_PKCS1_1_5_ENCRYPT = 4,
    196     KM_PAD_RSA_PKCS1_1_5_SIGN = 5,
    197     KM_PAD_PKCS7 = 64,
    198 } keymaster_padding_t;
    199 
    200 /**
    201  * Digests provided by keymaster implementations.
    202  */
    203 typedef enum {
    204     KM_DIGEST_NONE = 0,
    205     KM_DIGEST_MD5 = 1, /* Optional, may not be implemented in hardware, will be handled in software
    206                         * if needed. */
    207     KM_DIGEST_SHA1 = 2,
    208     KM_DIGEST_SHA_2_224 = 3,
    209     KM_DIGEST_SHA_2_256 = 4,
    210     KM_DIGEST_SHA_2_384 = 5,
    211     KM_DIGEST_SHA_2_512 = 6,
    212 } keymaster_digest_t;
    213 
    214 /*
    215  * Key derivation functions, mostly used in ECIES.
    216  */
    217 typedef enum {
    218     /* Do not apply a key derivation function; use the raw agreed key */
    219     KM_KDF_NONE = 0,
    220     /* HKDF defined in RFC 5869 with SHA256 */
    221     KM_KDF_RFC5869_SHA256 = 1,
    222     /* KDF1 defined in ISO 18033-2 with SHA1 */
    223     KM_KDF_ISO18033_2_KDF1_SHA1 = 2,
    224     /* KDF1 defined in ISO 18033-2 with SHA256 */
    225     KM_KDF_ISO18033_2_KDF1_SHA256 = 3,
    226     /* KDF2 defined in ISO 18033-2 with SHA1 */
    227     KM_KDF_ISO18033_2_KDF2_SHA1 = 4,
    228     /* KDF2 defined in ISO 18033-2 with SHA256 */
    229     KM_KDF_ISO18033_2_KDF2_SHA256 = 5,
    230 } keymaster_kdf_t;
    231 
    232 /**
    233  * Supported EC curves, used in ECDSA/ECIES.
    234  */
    235 typedef enum {
    236     KM_EC_CURVE_P_224 = 0,
    237     KM_EC_CURVE_P_256 = 1,
    238     KM_EC_CURVE_P_384 = 2,
    239     KM_EC_CURVE_P_521 = 3,
    240 } keymaster_ec_curve_t;
    241 
    242 /**
    243  * The origin of a key (or pair), i.e. where it was generated.  Note that KM_TAG_ORIGIN can be found
    244  * in either the hardware-enforced or software-enforced list for a key, indicating whether the key
    245  * is hardware or software-based.  Specifically, a key with KM_ORIGIN_GENERATED in the
    246  * hardware-enforced list is guaranteed never to have existed outide the secure hardware.
    247  */
    248 typedef enum {
    249     KM_ORIGIN_GENERATED = 0, /* Generated in keymaster.  Should not exist outside the TEE. */
    250     KM_ORIGIN_DERIVED = 1,   /* Derived inside keymaster.  Likely exists off-device. */
    251     KM_ORIGIN_IMPORTED = 2,  /* Imported into keymaster.  Existed as cleartext in Android. */
    252     KM_ORIGIN_UNKNOWN = 3,   /* Keymaster did not record origin.  This value can only be seen on
    253                               * keys in a keymaster0 implementation.  The keymaster0 adapter uses
    254                               * this value to document the fact that it is unkown whether the key
    255                               * was generated inside or imported into keymaster. */
    256 } keymaster_key_origin_t;
    257 
    258 /**
    259  * Usability requirements of key blobs.  This defines what system functionality must be available
    260  * for the key to function.  For example, key "blobs" which are actually handles referencing
    261  * encrypted key material stored in the file system cannot be used until the file system is
    262  * available, and should have BLOB_REQUIRES_FILE_SYSTEM.  Other requirements entries will be added
    263  * as needed for implementations.
    264  */
    265 typedef enum {
    266     KM_BLOB_STANDALONE = 0,
    267     KM_BLOB_REQUIRES_FILE_SYSTEM = 1,
    268 } keymaster_key_blob_usage_requirements_t;
    269 
    270 /**
    271  * Possible purposes of a key (or pair).
    272  */
    273 typedef enum {
    274     KM_PURPOSE_ENCRYPT = 0,    /* Usable with RSA, EC and AES keys. */
    275     KM_PURPOSE_DECRYPT = 1,    /* Usable with RSA, EC and AES keys. */
    276     KM_PURPOSE_SIGN = 2,       /* Usable with RSA, EC and HMAC keys. */
    277     KM_PURPOSE_VERIFY = 3,     /* Usable with RSA, EC and HMAC keys. */
    278     KM_PURPOSE_DERIVE_KEY = 4, /* Usable with EC keys. */
    279 } keymaster_purpose_t;
    280 
    281 typedef struct {
    282     const uint8_t* data;
    283     size_t data_length;
    284 } keymaster_blob_t;
    285 
    286 typedef struct {
    287     keymaster_tag_t tag;
    288     union {
    289         uint32_t enumerated;   /* KM_ENUM and KM_ENUM_REP */
    290         bool boolean;          /* KM_BOOL */
    291         uint32_t integer;      /* KM_INT and KM_INT_REP */
    292         uint64_t long_integer; /* KM_LONG */
    293         uint64_t date_time;    /* KM_DATE */
    294         keymaster_blob_t blob; /* KM_BIGNUM and KM_BYTES*/
    295     };
    296 } keymaster_key_param_t;
    297 
    298 typedef struct {
    299     keymaster_key_param_t* params; /* may be NULL if length == 0 */
    300     size_t length;
    301 } keymaster_key_param_set_t;
    302 
    303 /**
    304  * Parameters that define a key's characteristics, including authorized modes of usage and access
    305  * control restrictions.  The parameters are divided into two categories, those that are enforced by
    306  * secure hardware, and those that are not.  For a software-only keymaster implementation the
    307  * enforced array must NULL.  Hardware implementations must enforce everything in the enforced
    308  * array.
    309  */
    310 typedef struct {
    311     keymaster_key_param_set_t hw_enforced;
    312     keymaster_key_param_set_t sw_enforced;
    313 } keymaster_key_characteristics_t;
    314 
    315 typedef struct {
    316     const uint8_t* key_material;
    317     size_t key_material_size;
    318 } keymaster_key_blob_t;
    319 
    320 typedef struct {
    321     keymaster_blob_t* entries;
    322     size_t entry_count;
    323 } keymaster_cert_chain_t;
    324 
    325 typedef enum {
    326     KM_VERIFIED_BOOT_VERIFIED = 0,    /* Full chain of trust extending from the bootloader to
    327                                        * verified partitions, including the bootloader, boot
    328                                        * partition, and all verified partitions*/
    329     KM_VERIFIED_BOOT_SELF_SIGNED = 1, /* The boot partition has been verified using the embedded
    330                                        * certificate, and the signature is valid. The bootloader
    331                                        * displays a warning and the fingerprint of the public
    332                                        * key before allowing the boot process to continue.*/
    333     KM_VERIFIED_BOOT_UNVERIFIED = 2,  /* The device may be freely modified. Device integrity is left
    334                                        * to the user to verify out-of-band. The bootloader
    335                                        * displays a warning to the user before allowing the boot
    336                                        * process to continue */
    337     KM_VERIFIED_BOOT_FAILED = 3,      /* The device failed verification. The bootloader displays a
    338                                        * warning and stops the boot process, so no keymaster
    339                                        * implementation should ever actually return this value,
    340                                        * since it should not run.  Included here only for
    341                                        * completeness. */
    342 } keymaster_verified_boot_t;
    343 
    344 typedef enum {
    345     KM_SECURITY_LEVEL_SOFTWARE = 0,
    346     KM_SECURITY_LEVEL_TRUSTED_ENVIRONMENT = 1,
    347 } keymaster_security_level_t;
    348 
    349 /**
    350  * Formats for key import and export.
    351  */
    352 typedef enum {
    353     KM_KEY_FORMAT_X509 = 0,  /* for public key export */
    354     KM_KEY_FORMAT_PKCS8 = 1, /* for asymmetric key pair import */
    355     KM_KEY_FORMAT_RAW = 3,   /* for symmetric key import and export*/
    356 } keymaster_key_format_t;
    357 
    358 /**
    359  * The keymaster operation API consists of begin, update, finish and abort. This is the type of the
    360  * handle used to tie the sequence of calls together.  A 64-bit value is used because it's important
    361  * that handles not be predictable.  Implementations must use strong random numbers for handle
    362  * values.
    363  */
    364 typedef uint64_t keymaster_operation_handle_t;
    365 
    366 typedef enum {
    367     KM_ERROR_OK = 0,
    368     KM_ERROR_ROOT_OF_TRUST_ALREADY_SET = -1,
    369     KM_ERROR_UNSUPPORTED_PURPOSE = -2,
    370     KM_ERROR_INCOMPATIBLE_PURPOSE = -3,
    371     KM_ERROR_UNSUPPORTED_ALGORITHM = -4,
    372     KM_ERROR_INCOMPATIBLE_ALGORITHM = -5,
    373     KM_ERROR_UNSUPPORTED_KEY_SIZE = -6,
    374     KM_ERROR_UNSUPPORTED_BLOCK_MODE = -7,
    375     KM_ERROR_INCOMPATIBLE_BLOCK_MODE = -8,
    376     KM_ERROR_UNSUPPORTED_MAC_LENGTH = -9,
    377     KM_ERROR_UNSUPPORTED_PADDING_MODE = -10,
    378     KM_ERROR_INCOMPATIBLE_PADDING_MODE = -11,
    379     KM_ERROR_UNSUPPORTED_DIGEST = -12,
    380     KM_ERROR_INCOMPATIBLE_DIGEST = -13,
    381     KM_ERROR_INVALID_EXPIRATION_TIME = -14,
    382     KM_ERROR_INVALID_USER_ID = -15,
    383     KM_ERROR_INVALID_AUTHORIZATION_TIMEOUT = -16,
    384     KM_ERROR_UNSUPPORTED_KEY_FORMAT = -17,
    385     KM_ERROR_INCOMPATIBLE_KEY_FORMAT = -18,
    386     KM_ERROR_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM = -19,   /* For PKCS8 & PKCS12 */
    387     KM_ERROR_UNSUPPORTED_KEY_VERIFICATION_ALGORITHM = -20, /* For PKCS8 & PKCS12 */
    388     KM_ERROR_INVALID_INPUT_LENGTH = -21,
    389     KM_ERROR_KEY_EXPORT_OPTIONS_INVALID = -22,
    390     KM_ERROR_DELEGATION_NOT_ALLOWED = -23,
    391     KM_ERROR_KEY_NOT_YET_VALID = -24,
    392     KM_ERROR_KEY_EXPIRED = -25,
    393     KM_ERROR_KEY_USER_NOT_AUTHENTICATED = -26,
    394     KM_ERROR_OUTPUT_PARAMETER_NULL = -27,
    395     KM_ERROR_INVALID_OPERATION_HANDLE = -28,
    396     KM_ERROR_INSUFFICIENT_BUFFER_SPACE = -29,
    397     KM_ERROR_VERIFICATION_FAILED = -30,
    398     KM_ERROR_TOO_MANY_OPERATIONS = -31,
    399     KM_ERROR_UNEXPECTED_NULL_POINTER = -32,
    400     KM_ERROR_INVALID_KEY_BLOB = -33,
    401     KM_ERROR_IMPORTED_KEY_NOT_ENCRYPTED = -34,
    402     KM_ERROR_IMPORTED_KEY_DECRYPTION_FAILED = -35,
    403     KM_ERROR_IMPORTED_KEY_NOT_SIGNED = -36,
    404     KM_ERROR_IMPORTED_KEY_VERIFICATION_FAILED = -37,
    405     KM_ERROR_INVALID_ARGUMENT = -38,
    406     KM_ERROR_UNSUPPORTED_TAG = -39,
    407     KM_ERROR_INVALID_TAG = -40,
    408     KM_ERROR_MEMORY_ALLOCATION_FAILED = -41,
    409     KM_ERROR_IMPORT_PARAMETER_MISMATCH = -44,
    410     KM_ERROR_SECURE_HW_ACCESS_DENIED = -45,
    411     KM_ERROR_OPERATION_CANCELLED = -46,
    412     KM_ERROR_CONCURRENT_ACCESS_CONFLICT = -47,
    413     KM_ERROR_SECURE_HW_BUSY = -48,
    414     KM_ERROR_SECURE_HW_COMMUNICATION_FAILED = -49,
    415     KM_ERROR_UNSUPPORTED_EC_FIELD = -50,
    416     KM_ERROR_MISSING_NONCE = -51,
    417     KM_ERROR_INVALID_NONCE = -52,
    418     KM_ERROR_MISSING_MAC_LENGTH = -53,
    419     KM_ERROR_KEY_RATE_LIMIT_EXCEEDED = -54,
    420     KM_ERROR_CALLER_NONCE_PROHIBITED = -55,
    421     KM_ERROR_KEY_MAX_OPS_EXCEEDED = -56,
    422     KM_ERROR_INVALID_MAC_LENGTH = -57,
    423     KM_ERROR_MISSING_MIN_MAC_LENGTH = -58,
    424     KM_ERROR_UNSUPPORTED_MIN_MAC_LENGTH = -59,
    425     KM_ERROR_UNSUPPORTED_KDF = -60,
    426     KM_ERROR_UNSUPPORTED_EC_CURVE = -61,
    427     KM_ERROR_KEY_REQUIRES_UPGRADE = -62,
    428     KM_ERROR_ATTESTATION_CHALLENGE_MISSING = -63,
    429     KM_ERROR_KEYMASTER_NOT_CONFIGURED = -64,
    430 
    431     KM_ERROR_UNIMPLEMENTED = -100,
    432     KM_ERROR_VERSION_MISMATCH = -101,
    433 
    434     KM_ERROR_UNKNOWN_ERROR = -1000,
    435 } keymaster_error_t;
    436 
    437 /* Convenience functions for manipulating keymaster tag types */
    438 
    439 static inline keymaster_tag_type_t keymaster_tag_get_type(keymaster_tag_t tag) {
    440     return (keymaster_tag_type_t)(tag & (0xF << 28));
    441 }
    442 
    443 static inline uint32_t keymaster_tag_mask_type(keymaster_tag_t tag) {
    444     return tag & 0x0FFFFFFF;
    445 }
    446 
    447 static inline bool keymaster_tag_type_repeatable(keymaster_tag_type_t type) {
    448     switch (type) {
    449     case KM_UINT_REP:
    450     case KM_ENUM_REP:
    451         return true;
    452     default:
    453         return false;
    454     }
    455 }
    456 
    457 static inline bool keymaster_tag_repeatable(keymaster_tag_t tag) {
    458     return keymaster_tag_type_repeatable(keymaster_tag_get_type(tag));
    459 }
    460 
    461 /* Convenience functions for manipulating keymaster_key_param_t structs */
    462 
    463 inline keymaster_key_param_t keymaster_param_enum(keymaster_tag_t tag, uint32_t value) {
    464     // assert(keymaster_tag_get_type(tag) == KM_ENUM || keymaster_tag_get_type(tag) == KM_ENUM_REP);
    465     keymaster_key_param_t param;
    466     memset(&param, 0, sizeof(param));
    467     param.tag = tag;
    468     param.enumerated = value;
    469     return param;
    470 }
    471 
    472 inline keymaster_key_param_t keymaster_param_int(keymaster_tag_t tag, uint32_t value) {
    473     // assert(keymaster_tag_get_type(tag) == KM_INT || keymaster_tag_get_type(tag) == KM_INT_REP);
    474     keymaster_key_param_t param;
    475     memset(&param, 0, sizeof(param));
    476     param.tag = tag;
    477     param.integer = value;
    478     return param;
    479 }
    480 
    481 inline keymaster_key_param_t keymaster_param_long(keymaster_tag_t tag, uint64_t value) {
    482     // assert(keymaster_tag_get_type(tag) == KM_LONG);
    483     keymaster_key_param_t param;
    484     memset(&param, 0, sizeof(param));
    485     param.tag = tag;
    486     param.long_integer = value;
    487     return param;
    488 }
    489 
    490 inline keymaster_key_param_t keymaster_param_blob(keymaster_tag_t tag, const uint8_t* bytes,
    491                                                   size_t bytes_len) {
    492     // assert(keymaster_tag_get_type(tag) == KM_BYTES || keymaster_tag_get_type(tag) == KM_BIGNUM);
    493     keymaster_key_param_t param;
    494     memset(&param, 0, sizeof(param));
    495     param.tag = tag;
    496     param.blob.data = (uint8_t*)bytes;
    497     param.blob.data_length = bytes_len;
    498     return param;
    499 }
    500 
    501 inline keymaster_key_param_t keymaster_param_bool(keymaster_tag_t tag) {
    502     // assert(keymaster_tag_get_type(tag) == KM_BOOL);
    503     keymaster_key_param_t param;
    504     memset(&param, 0, sizeof(param));
    505     param.tag = tag;
    506     param.boolean = true;
    507     return param;
    508 }
    509 
    510 inline keymaster_key_param_t keymaster_param_date(keymaster_tag_t tag, uint64_t value) {
    511     // assert(keymaster_tag_get_type(tag) == KM_DATE);
    512     keymaster_key_param_t param;
    513     memset(&param, 0, sizeof(param));
    514     param.tag = tag;
    515     param.date_time = value;
    516     return param;
    517 }
    518 
    519 #define KEYMASTER_SIMPLE_COMPARE(a, b) (a < b) ? -1 : ((a > b) ? 1 : 0)
    520 inline int keymaster_param_compare(const keymaster_key_param_t* a, const keymaster_key_param_t* b) {
    521     int retval = KEYMASTER_SIMPLE_COMPARE(a->tag, b->tag);
    522     if (retval != 0)
    523         return retval;
    524 
    525     switch (keymaster_tag_get_type(a->tag)) {
    526     case KM_INVALID:
    527     case KM_BOOL:
    528         return 0;
    529     case KM_ENUM:
    530     case KM_ENUM_REP:
    531         return KEYMASTER_SIMPLE_COMPARE(a->enumerated, b->enumerated);
    532     case KM_UINT:
    533     case KM_UINT_REP:
    534         return KEYMASTER_SIMPLE_COMPARE(a->integer, b->integer);
    535     case KM_ULONG:
    536     case KM_ULONG_REP:
    537         return KEYMASTER_SIMPLE_COMPARE(a->long_integer, b->long_integer);
    538     case KM_DATE:
    539         return KEYMASTER_SIMPLE_COMPARE(a->date_time, b->date_time);
    540     case KM_BIGNUM:
    541     case KM_BYTES:
    542         // Handle the empty cases.
    543         if (a->blob.data_length != 0 && b->blob.data_length == 0)
    544             return -1;
    545         if (a->blob.data_length == 0 && b->blob.data_length == 0)
    546             return 0;
    547         if (a->blob.data_length == 0 && b->blob.data_length > 0)
    548             return 1;
    549 
    550         retval = memcmp(a->blob.data, b->blob.data, a->blob.data_length < b->blob.data_length
    551                                                         ? a->blob.data_length
    552                                                         : b->blob.data_length);
    553         if (retval != 0)
    554             return retval;
    555         else if (a->blob.data_length != b->blob.data_length) {
    556             // Equal up to the common length; longer one is larger.
    557             if (a->blob.data_length < b->blob.data_length)
    558                 return -1;
    559             if (a->blob.data_length > b->blob.data_length)
    560                 return 1;
    561         };
    562     }
    563 
    564     return 0;
    565 }
    566 #undef KEYMASTER_SIMPLE_COMPARE
    567 
    568 inline void keymaster_free_param_values(keymaster_key_param_t* param, size_t param_count) {
    569     while (param_count > 0) {
    570         param_count--;
    571         switch (keymaster_tag_get_type(param->tag)) {
    572         case KM_BIGNUM:
    573         case KM_BYTES:
    574             free((void*)param->blob.data);
    575             param->blob.data = NULL;
    576             break;
    577         default:
    578             // NOP
    579             break;
    580         }
    581         ++param;
    582     }
    583 }
    584 
    585 inline void keymaster_free_param_set(keymaster_key_param_set_t* set) {
    586     if (set) {
    587         keymaster_free_param_values(set->params, set->length);
    588         free(set->params);
    589         set->params = NULL;
    590         set->length = 0;
    591     }
    592 }
    593 
    594 inline void keymaster_free_characteristics(keymaster_key_characteristics_t* characteristics) {
    595     if (characteristics) {
    596         keymaster_free_param_set(&characteristics->hw_enforced);
    597         keymaster_free_param_set(&characteristics->sw_enforced);
    598     }
    599 }
    600 
    601 inline void keymaster_free_cert_chain(keymaster_cert_chain_t* chain) {
    602     if (chain) {
    603         for (size_t i = 0; i < chain->entry_count; ++i) {
    604             free((uint8_t*)chain->entries[i].data);
    605             chain->entries[i].data = NULL;
    606             chain->entries[i].data_length = 0;
    607         }
    608         free(chain->entries);
    609         chain->entries = NULL;
    610         chain->entry_count = 0;
    611     }
    612 }
    613 
    614 #ifdef __cplusplus
    615 }  // extern "C"
    616 #endif  // __cplusplus
    617 
    618 #endif  // ANDROID_HARDWARE_KEYMASTER_DEFS_H
    619