Define keymaster HAL v0.4.

Change-Id: I040412443bbbe25bce3d44759d710b78eac36caa

1 files changed, 614 insertions, 0 deletions

diff --git a/include/hardware/keymaster_defs.h b/include/hardware/keymaster_defs.h
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+++ b/include/hardware/keymaster_defs.h
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+/*
+ * Copyright (C) 2014 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 ANDROID_HARDWARE_KEYMASTER_DEFS_H
+#define ANDROID_HARDWARE_KEYMASTER_DEFS_H
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif  // defined(__cplusplus)
+
+/*!
+ * \deprecated Flags for keymaster_device::flags
+ *
+ * keymaster_device::flags is deprecated and will be removed in the
+ * next version of the API in favor of the more detailed information
+ * available from TODO:
+ */
+enum {
+    /*
+     * Indicates this keymaster implementation does not have hardware that
+     * keeps private keys out of user space.
+     *
+     * This should not be implemented on anything other than the default
+     * implementation.
+     */
+    KEYMASTER_SOFTWARE_ONLY = 1 << 0,
+
+    /*
+     * This indicates that the key blobs returned via all the primitives
+     * are sufficient to operate on their own without the trusted OS
+     * querying userspace to retrieve some other data. Key blobs of
+     * this type are normally returned encrypted with a
+     * Key Encryption Key (KEK).
+     *
+     * This is currently used by "vold" to know whether the whole disk
+     * encryption secret can be unwrapped without having some external
+     * service started up beforehand since the "/data" partition will
+     * be unavailable at that point.
+     */
+    KEYMASTER_BLOBS_ARE_STANDALONE = 1 << 1,
+
+    /*
+     * Indicates that the keymaster module supports DSA keys.
+     */
+    KEYMASTER_SUPPORTS_DSA = 1 << 2,
+
+    /*
+     * Indicates that the keymaster module supports EC keys.
+     */
+    KEYMASTER_SUPPORTS_EC = 1 << 3,
+};
+
+/**
+ * \deprecated Asymmetric key pair types.
+ */
+typedef enum {
+    TYPE_RSA = 1,
+    TYPE_DSA = 2,
+    TYPE_EC = 3,
+} keymaster_keypair_t;
+
+/**
+ * Authorization tags each have an associated type.  This enumeration facilitates tagging each with
+ * a type, by using the high four bits (of an implied 32-bit unsigned enum value) to specify up to
+ * 16 data types.  These values are ORed with tag IDs to generate the final tag ID values.
+ */
+typedef enum {
+    KM_INVALID = 0 << 28, /* Invalid type, used to designate a tag as uninitialized */
+    KM_ENUM = 1 << 28,
+    KM_ENUM_REP = 2 << 28, /* Repeatable enumeration value. */
+    KM_INT = 3 << 28,
+    KM_INT_REP = 4 << 28, /* Repeatable integer value */
+    KM_LONG = 5 << 28,
+    KM_DATE = 6 << 28,
+    KM_BOOL = 7 << 28,
+    KM_BIGNUM = 8 << 28,
+    KM_BYTES = 9 << 28,
+} keymaster_tag_type_t;
+
+typedef enum {
+    KM_TAG_INVALID = KM_INVALID | 0,
+
+    /*
+     * Tags that must be semantically enforced by hardware and software implementations.
+     */
+
+    /* Crypto parameters */
+    KM_TAG_PURPOSE = KM_ENUM_REP | 1, /* keymaster_purpose_t. */
+    KM_TAG_ALGORITHM = KM_ENUM | 2,   /* keymaster_algorithm_t. */
+    KM_TAG_KEY_SIZE = KM_INT | 3,     /* Key size in bits. */
+    KM_TAG_BLOCK_MODE = KM_ENUM | 4,  /* keymaster_block_mode_t. */
+    KM_TAG_DIGEST = KM_ENUM | 5,      /* keymaster_digest_t. */
+    KM_TAG_MAC_LENGTH = KM_INT | 6,   /* MAC length in bits. */
+    KM_TAG_PADDING = KM_ENUM | 7,     /* keymaster_padding_t. */
+    KM_TAG_CHUNK_LENGTH = KM_INT | 8, /* AEAD mode minimum decryption chunk size, in bytes. */
+    KM_TAG_NONCE = KM_BYTES | 9,      /* Nonce or Initialization Vector */
+
+    /* Other hardware-enforced. */
+    KM_TAG_RESCOPING_ADD = KM_ENUM_REP | 101, /* Tags authorized for addition via rescoping. */
+    KM_TAG_RESCOPING_DEL = KM_ENUM_REP | 102, /* Tags authorized for removal via rescoping. */
+    KM_TAG_BLOB_USAGE_REQUIREMENTS = KM_ENUM | 705, /* keymaster_key_blob_usage_requirements_t */
+
+    /* Algorithm-specific. */
+    KM_TAG_RSA_PUBLIC_EXPONENT = KM_LONG | 200, /* Defaults to 2^16+1 */
+    KM_TAG_DSA_GENERATOR = KM_BIGNUM | 201,
+    KM_TAG_DSA_P = KM_BIGNUM | 202,
+    KM_TAG_DSA_Q = KM_BIGNUM | 203,
+    /* Note there are no EC-specific params.  Field size is defined by KM_TAG_KEY_SIZE, and the
+       curve is chosen from NIST recommendations for field size */
+
+    /*
+     * Tags that should be semantically enforced by hardware if possible and will otherwise be
+     * enforced by software (keystore).
+     */
+
+    /* Key validity period */
+    KM_TAG_ACTIVE_DATETIME = KM_DATE | 400,             /* Start of validity */
+    KM_TAG_ORIGINATION_EXPIRE_DATETIME = KM_DATE | 401, /* Date when new "messages" should no
+                                                           longer be created. */
+    KM_TAG_USAGE_EXPIRE_DATETIME = KM_DATE | 402,       /* Date when existing "messages" should no
+                                                           longer be trusted. */
+    KM_TAG_MIN_SECONDS_BETWEEN_OPS = KM_INT | 403,      /* Minimum elapsed time between
+                                                           cryptographic operations with the key. */
+    KM_TAG_SINGLE_USE_PER_BOOT = KM_BOOL | 404,         /* If true, the key can only be used once
+                                                           per boot. */
+
+    /* User authentication */
+    KM_TAG_ALL_USERS = KM_BOOL | 500, /* If key is usable by all users. */
+    KM_TAG_USER_ID = KM_INT | 501,    /* ID of authorized user.  Disallowed if KM_TAG_ALL_USERS is
+                                         present. */
+    KM_TAG_NO_AUTH_REQUIRED = KM_BOOL | 502,    /* If key is usable without authentication. */
+    KM_TAG_USER_AUTH_ID = KM_INT_REP | 503,     /* ID of the authenticator to use (e.g. password,
+                                                   fingerprint, etc.).  Repeatable to support
+                                                   multi-factor auth.  Disallowed if
+                                                   KM_TAG_NO_AUTH_REQUIRED is present. */
+    KM_TAG_AUTH_TIMEOUT = KM_INT | 504,         /* Required freshness of user authentication for
+                                                   private/secret key operations, in seconds.
+                                                   Public key operations require no authentication.
+                                                   If absent, authentication is required for every
+                                                   use.  Authentication state is lost when the
+                                                   device is powered off. */
+    KM_TAG_RESCOPE_AUTH_TIMEOUT = KM_INT | 505, /* Required freshness of user authentication for key
+                                                   rescoping operations, in seconds.  Public key
+                                                   operations require no authentication.  If absent,
+                                                   authentication required for every rescoping. */
+
+    /* Application access control */
+    KM_TAG_ALL_APPLICATIONS = KM_BOOL | 600, /* If key is usable by all applications. */
+    KM_TAG_APPLICATION_ID = KM_BYTES | 601,  /* ID of authorized application. Disallowed if
+                                                KM_TAG_ALL_APPLICATIONS is present. */
+
+    /*
+     * Semantically unenforceable tags, either because they have no specific meaning or because
+     * they're informational only.
+     */
+    KM_TAG_APPLICATION_DATA = KM_BYTES | 700,  /* Data provided by authorized application. */
+    KM_TAG_CREATION_DATETIME = KM_DATE | 701,  /* Key creation time */
+    KM_TAG_ORIGIN = KM_ENUM | 702,             /* keymaster_key_origin_t. */
+    KM_TAG_ROLLBACK_RESISTANT = KM_BOOL | 703, /* Whether key is rollback-resistant. */
+    KM_TAG_ROOT_OF_TRUST = KM_BYTES | 704,     /* Root of trust ID.  Empty array means usable by all
+                                                  roots. */
+
+    /* Tags used only to provide data to operations */
+    KM_TAG_ADDITIONAL_DATA = KM_BYTES | 1000, /* Used to provide additional data for AEAD modes. */
+} keymaster_tag_t;
+
+/**
+ * Algorithms that may be provided by keymaster implementations.  Those that must be provided by all
+ * implementations are tagged as "required".  Note that where the values in this enumeration overlap
+ * with the values for the deprecated keymaster_keypair_t, the same algorithm must be
+ * specified. This type is new in 0_4 and replaces the deprecated keymaster_keypair_t.
+ */
+typedef enum {
+    /* Asymmetric algorithms. */
+    KM_ALGORITHM_RSA = 1,   /* required */
+    KM_ALGORITHM_DSA = 2,   /* required */
+    KM_ALGORITHM_ECDSA = 3, /* required */
+    KM_ALGORITHM_ECIES = 4,
+    /* FIPS Approved Ciphers */
+    KM_ALGORITHM_AES = 32, /* required */
+    KM_ALGORITHM_3DES = 33,
+    KM_ALGORITHM_SKIPJACK = 34,
+    /* AES Finalists */
+    KM_ALGORITHM_MARS = 48,
+    KM_ALGORITHM_RC6 = 49,
+    KM_ALGORITHM_SERPENT = 50,
+    KM_ALGORITHM_TWOFISH = 51,
+    /* Other common block ciphers */
+    KM_ALGORITHM_IDEA = 52,
+    KM_ALGORITHM_RC5 = 53,
+    KM_ALGORITHM_CAST5 = 54,
+    KM_ALGORITHM_BLOWFISH = 55,
+    /* Common stream ciphers */
+    KM_ALGORITHM_RC4 = 64,
+    KM_ALGORITHM_CHACHA20 = 65,
+    /* MAC algorithms */
+    KM_ALGORITHM_HMAC = 128, /* required */
+} keymaster_algorithm_t;
+
+/**
+ * Symmetric block cipher modes that may be provided by keymaster implementations.  Those that must
+ * be provided by all implementations are tagged as "required".  This type is new in 0_4.
+ *
+ * KM_MODE_FIRST_UNAUTHENTICATED, KM_MODE_FIRST_AUTHENTICATED and KM_MODE_FIRST_MAC are not modes,
+ * but markers used to separate the available modes into classes.
+ */
+typedef enum {
+    /* Unauthenticated modes, usable only for encryption/decryption and not generally recommended
+     * except for compatibility with existing other protocols. */
+    KM_MODE_FIRST_UNAUTHENTICATED = 1,
+    KM_MODE_ECB = KM_MODE_FIRST_UNAUTHENTICATED, /* required */
+    KM_MODE_CBC = 2,                             /* required */
+    KM_MODE_CBC_CTS = 3,                         /* recommended */
+    KM_MODE_CTR = 4,                             /* recommended */
+    KM_MODE_OFB = 5,
+    KM_MODE_CFB = 6,
+    KM_MODE_XTS = 7, /* Note: requires double-length keys */
+    /* Authenticated modes, usable for encryption/decryption and signing/verification.  Recommended
+     * over unauthenticated modes for all purposes.  One of KM_MODE_GCM and KM_MODE_OCB is
+     * required. */
+    KM_MODE_FIRST_AUTHENTICATED = 32,
+    KM_MODE_GCM = KM_MODE_FIRST_AUTHENTICATED,
+    KM_MODE_OCB = 33,
+    KM_MODE_CCM = 34,
+    /* MAC modes -- only for signing/verification */
+    KM_MODE_FIRST_MAC = 128,
+    KM_MODE_CMAC = KM_MODE_FIRST_MAC,
+    KM_MODE_POLY1305 = 129,
+} keymaster_block_mode_t;
+
+/**
+ * Padding modes that may be applied to plaintext for encryption operations.  This list includes
+ * padding modes for both symmetric and asymmetric algorithms.  Note that implementations should not
+ * provide all possible combinations of algorithm and padding, only the
+ * cryptographically-appropriate pairs.
+ */
+typedef enum {
+    KM_PAD_NONE = 1,     /* required, deprecated */
+    KM_PAD_RSA_OAEP = 2, /* required */
+    KM_PAD_RSA_PSS = 3,  /* required */
+    KM_PAD_RSA_PKCS1_1_5_ENCRYPT = 4,
+    KM_PAD_RSA_PKCS1_1_5_SIGN = 5,
+    KM_PAD_ANSI_X923 = 32,
+    KM_PAD_ISO_10126 = 33,
+    KM_PAD_ZERO = 64,  /* required */
+    KM_PAD_PKCS7 = 65, /* required */
+    KM_PAD_ISO_7816_4 = 66,
+} keymaster_padding_t;
+
+/**
+ * Digests that may be provided by keymaster implementations.  Those that must be provided by all
+ * implementations are tagged as "required".  Those that have been added since version 0_2 of the
+ * API are tagged as "new".
+ */
+typedef enum {
+    KM_DIGEST_NONE = 0,           /* new, required */
+    DIGEST_NONE = KM_DIGEST_NONE, /* For 0_2 compatibility */
+    KM_DIGEST_MD5 = 1,            /* new, for compatibility with old protocols only */
+    KM_DIGEST_SHA1 = 2,           /* new */
+    KM_DIGEST_SHA_2_224 = 3,      /* new */
+    KM_DIGEST_SHA_2_256 = 4,      /* new, required */
+    KM_DIGEST_SHA_2_384 = 5,      /* new, recommended */
+    KM_DIGEST_SHA_2_512 = 6,      /* new, recommended */
+    KM_DIGEST_SHA_3_256 = 7,      /* new */
+    KM_DIGEST_SHA_3_384 = 8,      /* new */
+    KM_DIGEST_SHA_3_512 = 9,      /* new */
+} keymaster_digest_t;
+
+/**
+ * The origin of a key (or pair), i.e. where it was generated.  Origin and can be used together to
+ * determine whether a key may have existed outside of secure hardware.  This type is new in 0_4.
+ */
+typedef enum {
+    KM_ORIGIN_HARDWARE = 0, /* Generated in secure hardware */
+    KM_ORIGIN_SOFTWARE = 1, /* Generated in non-secure software */
+    KM_ORIGIN_IMPORTED = 2, /* Imported, origin unknown */
+} keymaster_key_origin_t;
+
+/**
+ * Usability requirements of key blobs.  This defines what system functionality must be available
+ * for the key to function.  For example, key "blobs" which are actually handles referencing
+ * encrypted key material stored in the file system cannot be used until the file system is
+ * available, and should have BLOB_REQUIRES_FILE_SYSTEM.  Other requirements entries will be added
+ * as needed for implementations.  This type is new in 0_4.
+ */
+typedef enum {
+    KM_BLOB_STANDALONE = 0,
+    KM_BLOB_REQUIRES_FILE_SYSTEM = 1,
+} keymaster_key_blob_usage_requirements_t;
+
+/**
+ * Possible purposes of a key (or pair). This type is new in 0_4.
+ */
+typedef enum {
+    KM_PURPOSE_ENCRYPT = 0,
+    KM_PURPOSE_DECRYPT = 1,
+    KM_PURPOSE_SIGN = 2,
+    KM_PURPOSE_VERIFY = 3,
+} keymaster_purpose_t;
+
+typedef struct {
+    const uint8_t* data;
+    size_t data_length;
+} keymaster_blob_t;
+
+typedef struct {
+    keymaster_tag_t tag;
+    union {
+        uint32_t enumerated;   /* KM_ENUM and KM_ENUM_REP */
+        bool boolean;          /* KM_BOOL */
+        uint32_t integer;      /* KM_INT and KM_INT_REP */
+        uint64_t long_integer; /* KM_LONG */
+        uint64_t date_time;    /* KM_DATE */
+        keymaster_blob_t blob; /* KM_BIGNUM and KM_BYTES*/
+    };
+} keymaster_key_param_t;
+
+typedef struct {
+    keymaster_key_param_t* params; /* may be NULL if length == 0 */
+    size_t length;
+} keymaster_key_param_set_t;
+
+/**
+ * Parameters that define a key's characteristics, including authorized modes of usage and access
+ * control restrictions.  The parameters are divided into two categories, those that are enforced by
+ * secure hardware, and those that are not.  For a software-only keymaster implementation the
+ * enforced array must NULL.  Hardware implementations must enforce everything in the enforced
+ * array.
+ */
+typedef struct {
+    keymaster_key_param_set_t hw_enforced;
+    keymaster_key_param_set_t sw_enforced;
+} keymaster_key_characteristics_t;
+
+typedef struct {
+    const uint8_t* key_material;
+    size_t key_material_size;
+} keymaster_key_blob_t;
+
+/**
+ * Formats for key import and export.  At present, only asymmetric key import/export is supported.
+ * In the future this list will expand greatly to accommodate asymmetric key import/export.
+ */
+typedef enum {
+    KM_KEY_FORMAT_X509,   /* for public key export, required */
+    KM_KEY_FORMAT_PKCS8,  /* for asymmetric key pair import, required */
+    KM_KEY_FORMAT_PKCS12, /* for asymmetric key pair import, not required */
+} keymaster_key_format_t;
+
+/**
+ * The keymaster operation API consists of begin, update, finish and abort. This is the type of the
+ * handle used to tie the sequence of calls together.  A 64-bit value is used because it's important
+ * that handles not be predictable.  Implementations must use strong random numbers for handle
+ * values.
+ */
+typedef uint64_t keymaster_operation_handle_t;
+
+typedef enum {
+    KM_ERROR_OK = 0,
+    KM_ERROR_ROOT_OF_TRUST_ALREADY_SET = -1,
+    KM_ERROR_UNSUPPORTED_PURPOSE = -2,
+    KM_ERROR_INCOMPATIBLE_PURPOSE = -3,
+    KM_ERROR_UNSUPPORTED_ALGORITHM = -4,
+    KM_ERROR_INCOMPATIBLE_ALGORITHM = -5,
+    KM_ERROR_UNSUPPORTED_KEY_SIZE = -6,
+    KM_ERROR_UNSUPPORTED_BLOCK_MODE = -7,
+    KM_ERROR_INCOMPATIBLE_BLOCK_MODE = -8,
+    KM_ERROR_UNSUPPORTED_TAG_LENGTH = -9,
+    KM_ERROR_UNSUPPORTED_PADDING_MODE = -10,
+    KM_ERROR_INCOMPATIBLE_PADDING_MODE = -11,
+    KM_ERROR_UNSUPPORTED_DIGEST = -12,
+    KM_ERROR_INCOMPATIBLE_DIGEST = -13,
+    KM_ERROR_INVALID_EXPIRATION_TIME = -14,
+    KM_ERROR_INVALID_USER_ID = -15,
+    KM_ERROR_INVALID_AUTHORIZATION_TIMEOUT = -16,
+    KM_ERROR_UNSUPPORTED_KEY_FORMAT = -17,
+    KM_ERROR_INCOMPATIBLE_KEY_FORMAT = -18,
+    KM_ERROR_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM = -19,   /* For PKCS8 & PKCS12 */
+    KM_ERROR_UNSUPPORTED_KEY_VERIFICATION_ALGORITHM = -20, /* For PKCS8 & PKCS12 */
+    KM_ERROR_INVALID_INPUT_LENGTH = -21,
+    KM_ERROR_KEY_EXPORT_OPTIONS_INVALID = -22,
+    KM_ERROR_DELEGATION_NOT_ALLOWED = -23,
+    KM_ERROR_KEY_NOT_YET_VALID = -24,
+    KM_ERROR_KEY_EXPIRED = -25,
+    KM_ERROR_KEY_USER_NOT_AUTHENTICATED = -26,
+    KM_ERROR_OUTPUT_PARAMETER_NULL = -27,
+    KM_ERROR_INVALID_OPERATION_HANDLE = -28,
+    KM_ERROR_INSUFFICIENT_BUFFER_SPACE = -29,
+    KM_ERROR_VERIFICATION_FAILED = -30,
+    KM_ERROR_TOO_MANY_OPERATIONS = -31,
+    KM_ERROR_UNEXPECTED_NULL_POINTER = -32,
+    KM_ERROR_INVALID_KEY_BLOB = -33,
+    KM_ERROR_IMPORTED_KEY_NOT_ENCRYPTED = -34,
+    KM_ERROR_IMPORTED_KEY_DECRYPTION_FAILED = -35,
+    KM_ERROR_IMPORTED_KEY_NOT_SIGNED = -36,
+    KM_ERROR_IMPORTED_KEY_VERIFICATION_FAILED = -37,
+    KM_ERROR_INVALID_ARGUMENT = -38,
+    KM_ERROR_UNSUPPORTED_TAG = -39,
+    KM_ERROR_INVALID_TAG = -40,
+    KM_ERROR_MEMORY_ALLOCATION_FAILED = -41,
+    KM_ERROR_INVALID_RESCOPING = -42,
+    KM_ERROR_INVALID_DSA_PARAMS = -43,
+    KM_ERROR_IMPORT_PARAMETER_MISMATCH = -44,
+    KM_ERROR_SECURE_HW_ACCESS_DENIED = -45,
+    KM_ERROR_OPERATION_CANCELLED = -46,
+    KM_ERROR_CONCURRENT_ACCESS_CONFLICT = -47,
+    KM_ERROR_SECURE_HW_BUSY = -48,
+    KM_ERROR_SECURE_HW_COMMUNICATION_FAILED = -49,
+    KM_ERROR_UNSUPPORTED_EC_FIELD = -50,
+    KM_ERROR_UNIMPLEMENTED = -100,
+    KM_ERROR_VERSION_MISMATCH = -101,
+
+    /* Additional error codes may be added by implementations, but implementers should coordinate
+     * with Google to avoid code collision. */
+    KM_ERROR_UNKNOWN_ERROR = -1000,
+} keymaster_error_t;
+
+/**
+ * \deprecated Parameters needed to generate an RSA key.
+ */
+typedef struct {
+    uint32_t modulus_size; /* bits */
+    uint64_t public_exponent;
+} keymaster_rsa_keygen_params_t;
+
+/**
+ * \deprecated Parameters needed to generate a DSA key.
+ */
+typedef struct {
+    uint32_t key_size; /* bits */
+    uint32_t generator_len;
+    uint32_t prime_p_len;
+    uint32_t prime_q_len;
+    const uint8_t* generator;
+    const uint8_t* prime_p;
+    const uint8_t* prime_q;
+} keymaster_dsa_keygen_params_t;
+
+/**
+ * \deprecated Parameters needed to generate an EC key.
+ *
+ * Field size is the only parameter in version 4. The sizes correspond to these required curves:
+ *
+ * 192 = NIST P-192
+ * 224 = NIST P-224
+ * 256 = NIST P-256
+ * 384 = NIST P-384
+ * 521 = NIST P-521
+ *
+ * The parameters for these curves are available at: http://www.nsa.gov/ia/_files/nist-routines.pdf
+ * in Chapter 4.
+ */
+typedef struct { uint32_t field_size; /* bits */ } keymaster_ec_keygen_params_t;
+
+/**
+ * \deprecated Type of padding used for RSA operations.
+ */
+typedef enum {
+    PADDING_NONE,
+} keymaster_rsa_padding_t;
+
+/**
+ * \deprecated
+ */
+typedef struct { keymaster_digest_t digest_type; } keymaster_dsa_sign_params_t;
+
+/**
+ * \deprecated
+ */
+typedef struct { keymaster_digest_t digest_type; } keymaster_ec_sign_params_t;
+
+/**
+ *\deprecated
+ */
+typedef struct {
+    keymaster_digest_t digest_type;
+    keymaster_rsa_padding_t padding_type;
+} keymaster_rsa_sign_params_t;
+
+/* Convenience functions for manipulating keymaster tag types */
+
+static inline keymaster_tag_type_t keymaster_tag_get_type(keymaster_tag_t tag) {
+    return (keymaster_tag_type_t)(tag & (0xF << 28));
+}
+
+static inline uint32_t keymaster_tag_mask_type(keymaster_tag_t tag) {
+    return tag & 0x0FFFFFFF;
+}
+
+static inline bool keymaster_tag_type_repeatable(keymaster_tag_type_t type) {
+    switch (type) {
+    case KM_INT_REP:
+    case KM_ENUM_REP:
+        return true;
+    default:
+        return false;
+    }
+}
+
+static inline bool keymaster_tag_repeatable(keymaster_tag_t tag) {
+    return keymaster_tag_type_repeatable(keymaster_tag_get_type(tag));
+}
+
+/* Convenience functions for manipulating keymaster_key_param_t structs */
+
+inline keymaster_key_param_t keymaster_param_enum(keymaster_tag_t tag, uint32_t value) {
+    // assert(keymaster_tag_get_type(tag) == KM_ENUM || keymaster_tag_get_type(tag) == KM_ENUM_REP);
+    keymaster_key_param_t param;
+    memset(&param, 0, sizeof(param));
+    param.tag = tag;
+    param.enumerated = value;
+    return param;
+}
+
+inline keymaster_key_param_t keymaster_param_int(keymaster_tag_t tag, uint32_t value) {
+    // assert(keymaster_tag_get_type(tag) == KM_INT || keymaster_tag_get_type(tag) == KM_INT_REP);
+    keymaster_key_param_t param;
+    memset(&param, 0, sizeof(param));
+    param.tag = tag;
+    param.integer = value;
+    return param;
+}
+
+inline keymaster_key_param_t keymaster_param_long(keymaster_tag_t tag, uint64_t value) {
+    // assert(keymaster_tag_get_type(tag) == KM_LONG);
+    keymaster_key_param_t param;
+    memset(&param, 0, sizeof(param));
+    param.tag = tag;
+    param.long_integer = value;
+    return param;
+}
+
+inline keymaster_key_param_t keymaster_param_blob(keymaster_tag_t tag, const uint8_t* bytes,
+                                                  size_t bytes_len) {
+    // assert(keymaster_tag_get_type(tag) == KM_BYTES || keymaster_tag_get_type(tag) == KM_BIGNUM);
+    keymaster_key_param_t param;
+    memset(&param, 0, sizeof(param));
+    param.tag = tag;
+    param.blob.data = (uint8_t*)bytes;
+    param.blob.data_length = bytes_len;
+    return param;
+}
+
+inline keymaster_key_param_t keymaster_param_bool(keymaster_tag_t tag) {
+    // assert(keymaster_tag_get_type(tag) == KM_BOOL);
+    keymaster_key_param_t param;
+    memset(&param, 0, sizeof(param));
+    param.tag = tag;
+    param.boolean = true;
+    return param;
+}
+
+inline keymaster_key_param_t keymaster_param_date(keymaster_tag_t tag, uint64_t value) {
+    // assert(keymaster_tag_get_type(tag) == KM_DATE);
+    keymaster_key_param_t param;
+    memset(&param, 0, sizeof(param));
+    param.tag = tag;
+    param.date_time = value;
+    return param;
+}
+
+inline void keymaster_free_param_values(keymaster_key_param_t* param, size_t param_count) {
+    while (param_count-- > 0) {
+        switch (keymaster_tag_get_type(param->tag)) {
+        case KM_BIGNUM:
+        case KM_BYTES:
+            free((void*)param->blob.data);
+            param->blob.data = NULL;
+            break;
+        default:
+            // NOP
+            break;
+        }
+        ++param;
+    }
+}
+
+inline void keymaster_free_param_set(keymaster_key_param_set_t* set) {
+    if (set) {
+        keymaster_free_param_values(set->params, set->length);
+        free(set->params);
+        set->params = NULL;
+    }
+}
+
+inline void keymaster_free_characteristics(keymaster_key_characteristics_t* characteristics) {
+    if (characteristics) {
+        keymaster_free_param_set(&characteristics->hw_enforced);
+        keymaster_free_param_set(&characteristics->sw_enforced);
+    }
+}
+
+#if defined(__cplusplus)
+}  // extern "C"
+#endif  // defined(__cplusplus)
+
+#endif  // ANDROID_HARDWARE_KEYMASTER_DEFS_H