[thirdparty/openssl.git] / providers / implementations / macs / kmac_prov.c

/*
 * Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/*
 * See SP800-185 "Appendix A - KMAC, .... in Terms of Keccak[c]"
 *
 * Inputs are:
 *    K = Key                  (len(K) < 2^2040 bits)
 *    X = Input
 *    L = Output length        (0 <= L < 2^2040 bits)
 *    S = Customization String Default="" (len(S) < 2^2040 bits)
 *
 * KMAC128(K, X, L, S)
 * {
 *     newX = bytepad(encode_string(K), 168) ||  X || right_encode(L).
 *     T = bytepad(encode_string("KMAC") || encode_string(S), 168).
 *     return KECCAK[256](T || newX || 00, L).
 * }
 *
 * KMAC256(K, X, L, S)
 * {
 *     newX = bytepad(encode_string(K), 136) ||  X || right_encode(L).
 *     T = bytepad(encode_string("KMAC") || encode_string(S), 136).
 *     return KECCAK[512](T || newX || 00, L).
 * }
 *
 * KMAC128XOF(K, X, L, S)
 * {
 *     newX = bytepad(encode_string(K), 168) ||  X || right_encode(0).
 *     T = bytepad(encode_string("KMAC") || encode_string(S), 168).
 *     return KECCAK[256](T || newX || 00, L).
 * }
 *
 * KMAC256XOF(K, X, L, S)
 * {
 *     newX = bytepad(encode_string(K), 136) ||  X || right_encode(0).
 *     T = bytepad(encode_string("KMAC") || encode_string(S), 136).
 *     return KECCAK[512](T || newX || 00, L).
 * }
 *
 */

#include <stdlib.h>
#include <string.h>
#include <openssl/core_dispatch.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/proverr.h>

#include "prov/implementations.h"
#include "prov/provider_ctx.h"
#include "prov/provider_util.h"
#include "prov/providercommon.h"

/*
 * Forward declaration of everything implemented here.  This is not strictly
 * necessary for the compiler, but provides an assurance that the signatures
 * of the functions in the dispatch table are correct.
 */
static OSSL_FUNC_mac_newctx_fn kmac128_new;
static OSSL_FUNC_mac_newctx_fn kmac256_new;
static OSSL_FUNC_mac_dupctx_fn kmac_dup;
static OSSL_FUNC_mac_freectx_fn kmac_free;
static OSSL_FUNC_mac_gettable_ctx_params_fn kmac_gettable_ctx_params;
static OSSL_FUNC_mac_get_ctx_params_fn kmac_get_ctx_params;
static OSSL_FUNC_mac_settable_ctx_params_fn kmac_settable_ctx_params;
static OSSL_FUNC_mac_set_ctx_params_fn kmac_set_ctx_params;
static OSSL_FUNC_mac_init_fn kmac_init;
static OSSL_FUNC_mac_update_fn kmac_update;
static OSSL_FUNC_mac_final_fn kmac_final;

#define KMAC_MAX_BLOCKSIZE ((1600 - 128*2) / 8) /* 168 */
#define KMAC_MIN_BLOCKSIZE ((1600 - 256*2) / 8) /* 136 */

/* Length encoding will be  a 1 byte size + length in bits (2 bytes max) */
#define KMAC_MAX_ENCODED_HEADER_LEN 3

/*
 * Custom string max size is chosen such that:
 *   len(encoded_string(custom) + len(kmac_encoded_string) <= KMAC_MIN_BLOCKSIZE
 *   i.e: (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_LEN) + 6 <= 136
 */
#define KMAC_MAX_CUSTOM 127

/* Maximum size of encoded custom string */
#define KMAC_MAX_CUSTOM_ENCODED (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_HEADER_LEN)

/* Maximum key size in bytes = 2040 / 8 */
#define KMAC_MAX_KEY 255

/*
 * Maximum Encoded Key size will be padded to a multiple of the blocksize
 * i.e KMAC_MAX_KEY + KMAC_MAX_ENCODED_LEN = 258
 * Padded to a multiple of KMAC_MAX_BLOCKSIZE
 */
#define KMAC_MAX_KEY_ENCODED (KMAC_MAX_BLOCKSIZE * 2)

/* Fixed value of encode_string("KMAC") */
static const unsigned char kmac_string[] = {
    0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43
};


#define KMAC_FLAG_XOF_MODE          1

struct kmac_data_st {
    void  *provctx;
    EVP_MD_CTX *ctx;
    PROV_DIGEST digest;
    size_t out_len;
    int key_len;
    int custom_len;
    /* If xof_mode = 1 then we use right_encode(0) */
    int xof_mode;
    /* key and custom are stored in encoded form */
    unsigned char key[KMAC_MAX_KEY_ENCODED];
    unsigned char custom[KMAC_MAX_CUSTOM_ENCODED];
};

static int encode_string(unsigned char *out, int *out_len,
                         const unsigned char *in, int in_len);
static int right_encode(unsigned char *out, int *out_len, size_t bits);
static int bytepad(unsigned char *out, int *out_len,
                   const unsigned char *in1, int in1_len,
                   const unsigned char *in2, int in2_len,
                   int w);
static int kmac_bytepad_encode_key(unsigned char *out, int *out_len,
                                   const unsigned char *in, int in_len,
                                   int w);

static void kmac_free(void *vmacctx)
{
    struct kmac_data_st *kctx = vmacctx;

    if (kctx != NULL) {
        EVP_MD_CTX_free(kctx->ctx);
        ossl_prov_digest_reset(&kctx->digest);
        OPENSSL_cleanse(kctx->key, kctx->key_len);
        OPENSSL_cleanse(kctx->custom, kctx->custom_len);
        OPENSSL_free(kctx);
    }
}

/*
 * We have KMAC implemented as a hash, which we can use instead of
 * reimplementing the EVP functionality with direct use of
 * keccak_mac_init() and friends.
 */
static struct kmac_data_st *kmac_new(void *provctx)
{
    struct kmac_data_st *kctx;

    if (!ossl_prov_is_running())
        return NULL;

    if ((kctx = OPENSSL_zalloc(sizeof(*kctx))) == NULL
            || (kctx->ctx = EVP_MD_CTX_new()) == NULL) {
        kmac_free(kctx);
        return NULL;
    }
    kctx->provctx = provctx;
    return kctx;
}

static void *kmac_fetch_new(void *provctx, const OSSL_PARAM *params)
{
    struct kmac_data_st *kctx = kmac_new(provctx);

    if (kctx == NULL)
        return 0;
    if (!ossl_prov_digest_load_from_params(&kctx->digest, params,
                                      PROV_LIBCTX_OF(provctx))) {
        kmac_free(kctx);
        return 0;
    }

    kctx->out_len = EVP_MD_size(ossl_prov_digest_md(&kctx->digest));
    return kctx;
}

static void *kmac128_new(void *provctx)
{
    static const OSSL_PARAM kmac128_params[] = {
        OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC128,
                               sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC128)),
        OSSL_PARAM_END
    };
    return kmac_fetch_new(provctx, kmac128_params);
}

static void *kmac256_new(void *provctx)
{
    static const OSSL_PARAM kmac256_params[] = {
        OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC256,
                               sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC256)),
        OSSL_PARAM_END
    };
    return kmac_fetch_new(provctx, kmac256_params);
}

static void *kmac_dup(void *vsrc)
{
    struct kmac_data_st *src = vsrc;
    struct kmac_data_st *dst;

    if (!ossl_prov_is_running())
        return NULL;

    dst = kmac_new(src->provctx);
    if (dst == NULL)
        return NULL;

    if (!EVP_MD_CTX_copy(dst->ctx, src->ctx)
        || !ossl_prov_digest_copy(&dst->digest, &src->digest)) {
        kmac_free(dst);
        return NULL;
    }

    dst->out_len = src->out_len;
    dst->key_len = src->key_len;
    dst->custom_len = src->custom_len;
    dst->xof_mode = src->xof_mode;
    memcpy(dst->key, src->key, src->key_len);
    memcpy(dst->custom, src->custom, dst->custom_len);

    return dst;
}

static size_t kmac_size(void *vmacctx)
{
    struct kmac_data_st *kctx = vmacctx;

    return kctx->out_len;
}

/*
 * The init() assumes that any ctrl methods are set beforehand for
 * md, key and custom. Setting the fields afterwards will have no
 * effect on the output mac.
 */
static int kmac_init(void *vmacctx)
{
    struct kmac_data_st *kctx = vmacctx;
    EVP_MD_CTX *ctx = kctx->ctx;
    unsigned char out[KMAC_MAX_BLOCKSIZE];
    int out_len, block_len;

    if (!ossl_prov_is_running())
        return 0;

    /* Check key has been set */
    if (kctx->key_len == 0) {
        ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
        return 0;
    }
    if (!EVP_DigestInit_ex(kctx->ctx, ossl_prov_digest_md(&kctx->digest),
                           NULL))
        return 0;

    block_len = EVP_MD_block_size(ossl_prov_digest_md(&kctx->digest));
    if (block_len < 0)
        return 0;

    /* Set default custom string if it is not already set */
    if (kctx->custom_len == 0) {
        const OSSL_PARAM params[] = {
            OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, "", 0),
            OSSL_PARAM_END
        };
        (void)kmac_set_ctx_params(kctx, params);
    }

    return bytepad(out, &out_len, kmac_string, sizeof(kmac_string),
                   kctx->custom, kctx->custom_len, block_len)
           && EVP_DigestUpdate(ctx, out, out_len)
           && EVP_DigestUpdate(ctx, kctx->key, kctx->key_len);
}

static int kmac_update(void *vmacctx, const unsigned char *data,
                       size_t datalen)
{
    struct kmac_data_st *kctx = vmacctx;

    return EVP_DigestUpdate(kctx->ctx, data, datalen);
}

static int kmac_final(void *vmacctx, unsigned char *out, size_t *outl,
                      size_t outsize)
{
    struct kmac_data_st *kctx = vmacctx;
    EVP_MD_CTX *ctx = kctx->ctx;
    int lbits, len;
    unsigned char encoded_outlen[KMAC_MAX_ENCODED_HEADER_LEN];
    int ok;

    if (!ossl_prov_is_running())
        return 0;

    /* KMAC XOF mode sets the encoded length to 0 */
    lbits = (kctx->xof_mode ? 0 : (kctx->out_len * 8));

    ok = right_encode(encoded_outlen, &len, lbits)
        && EVP_DigestUpdate(ctx, encoded_outlen, len)
        && EVP_DigestFinalXOF(ctx, out, kctx->out_len);
    *outl = kctx->out_len;
    return ok;
}

static const OSSL_PARAM known_gettable_ctx_params[] = {
    OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
    OSSL_PARAM_END
};
static const OSSL_PARAM *kmac_gettable_ctx_params(ossl_unused void *provctx)
{
    return known_gettable_ctx_params;
}

static int kmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
{
    OSSL_PARAM *p;

    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
        return OSSL_PARAM_set_size_t(p, kmac_size(vmacctx));

    return 1;
}

static const OSSL_PARAM known_settable_ctx_params[] = {
    OSSL_PARAM_int(OSSL_MAC_PARAM_XOF, NULL),
    OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
    OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
    OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, NULL, 0),
    OSSL_PARAM_END
};
static const OSSL_PARAM *kmac_settable_ctx_params(ossl_unused void *provctx)
{
    return known_settable_ctx_params;
}

/*
 * The following params can be set any time before final():
 *     - "outlen" or "size":    The requested output length.
 *     - "xof":                 If set, this indicates that right_encoded(0)
 *                              is part of the digested data, otherwise it
 *                              uses right_encoded(requested output length).
 *
 * All other params should be set before init().
 */
static int kmac_set_ctx_params(void *vmacctx, const OSSL_PARAM *params)
{
    struct kmac_data_st *kctx = vmacctx;
    const OSSL_PARAM *p;
    const EVP_MD *digest = ossl_prov_digest_md(&kctx->digest);

    if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_XOF)) != NULL
        && !OSSL_PARAM_get_int(p, &kctx->xof_mode))
        return 0;
    if (((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_SIZE)) != NULL)
        && !OSSL_PARAM_get_size_t(p, &kctx->out_len))
        return 0;
    if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
        if (p->data_size < 4 || p->data_size > KMAC_MAX_KEY) {
            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
            return 0;
        }
        if (!kmac_bytepad_encode_key(kctx->key, &kctx->key_len,
                                     p->data, p->data_size,
                                     EVP_MD_block_size(digest)))
            return 0;
    }
    if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_CUSTOM))
        != NULL) {
        if (p->data_size > KMAC_MAX_CUSTOM) {
            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CUSTOM_LENGTH);
            return 0;
        }
        if (!encode_string(kctx->custom, &kctx->custom_len,
                           p->data, p->data_size))
            return 0;
    }
    return 1;
}

/*
 * Encoding/Padding Methods.
 */

/* Returns the number of bytes required to store 'bits' into a byte array */
static unsigned int get_encode_size(size_t bits)
{
    unsigned int cnt = 0, sz = sizeof(size_t);

    while (bits && (cnt < sz)) {
        ++cnt;
        bits >>= 8;
    }
    /* If bits is zero 1 byte is required */
    if (cnt == 0)
        cnt = 1;
    return cnt;
}

/*
 * Convert an integer into bytes . The number of bytes is appended
 * to the end of the buffer. Returns an array of bytes 'out' of size
 * *out_len.
 *
 * e.g if bits = 32, out[2] = { 0x20, 0x01 }
 *
 */
static int right_encode(unsigned char *out, int *out_len, size_t bits)
{
    unsigned int len = get_encode_size(bits);
    int i;

    /* The length is constrained to a single byte: 2040/8 = 255 */
    if (len > 0xFF)
        return 0;

    /* MSB's are at the start of the bytes array */
    for (i = len - 1; i >= 0; --i) {
        out[i] = (unsigned char)(bits & 0xFF);
        bits >>= 8;
    }
    /* Tack the length onto the end */
    out[len] = (unsigned char)len;

    /* The Returned length includes the tacked on byte */
    *out_len = len + 1;
    return 1;
}

/*
 * Encodes a string with a left encoded length added. Note that the
 * in_len is converted to bits (*8).
 *
 * e.g- in="KMAC" gives out[6] = { 0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43 }
 *                                 len   bits    K     M     A     C
 */
static int encode_string(unsigned char *out, int *out_len,
                         const unsigned char *in, int in_len)
{
    if (in == NULL) {
        *out_len = 0;
    } else {
        int i, bits, len;

        bits = 8 * in_len;
        len = get_encode_size(bits);
        if (len > 0xFF)
            return 0;

        out[0] = len;
        for (i = len; i > 0; --i) {
            out[i] = (bits & 0xFF);
            bits >>= 8;
        }
        memcpy(out + len + 1, in, in_len);
        *out_len = (1 + len + in_len);
    }
    return 1;
}

/*
 * Returns a zero padded encoding of the inputs in1 and an optional
 * in2 (can be NULL). The padded output must be a multiple of the blocksize 'w'.
 * The value of w is in bytes (< 256).
 *
 * The returned output is:
 *    zero_padded(multiple of w, (left_encode(w) || in1 [|| in2])
 */
static int bytepad(unsigned char *out, int *out_len,
                   const unsigned char *in1, int in1_len,
                   const unsigned char *in2, int in2_len, int w)
{
    int len;
    unsigned char *p = out;
    int sz = w;

    /* Left encoded w */
    *p++ = 1;
    *p++ = w;
    /* || in1 */
    memcpy(p, in1, in1_len);
    p += in1_len;
    /* [ || in2 ] */
    if (in2 != NULL && in2_len > 0) {
        memcpy(p, in2, in2_len);
        p += in2_len;
    }
    /* Figure out the pad size (divisible by w) */
    len = p - out;
    while (len > sz) {
        sz += w;
    }
    /* zero pad the end of the buffer */
    memset(p, 0, sz - len);
    *out_len = sz;
    return 1;
}

/*
 * Returns out = bytepad(encode_string(in), w)
 */
static int kmac_bytepad_encode_key(unsigned char *out, int *out_len,
                                   const unsigned char *in, int in_len,
                                   int w)
{
    unsigned char tmp[KMAC_MAX_KEY + KMAC_MAX_ENCODED_HEADER_LEN];
    int tmp_len;

    if (!encode_string(tmp, &tmp_len, in, in_len))
        return 0;

    return bytepad(out, out_len, tmp, tmp_len, NULL, 0, w);
}

const OSSL_DISPATCH ossl_kmac128_functions[] = {
    { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac128_new },
    { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
    { OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
    { OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
    { OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
    { OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
    { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
      (void (*)(void))kmac_gettable_ctx_params },
    { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))kmac_get_ctx_params },
    { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
      (void (*)(void))kmac_settable_ctx_params },
    { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))kmac_set_ctx_params },
    { 0, NULL }
};

const OSSL_DISPATCH ossl_kmac256_functions[] = {
    { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac256_new },
    { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
    { OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
    { OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
    { OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
    { OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
    { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
      (void (*)(void))kmac_gettable_ctx_params },
    { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))kmac_get_ctx_params },
    { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
      (void (*)(void))kmac_settable_ctx_params },
    { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))kmac_set_ctx_params },
    { 0, NULL }
};
Commit	Line	Data
6e624a64	1	/*
454afd98	2	* Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.
6e624a64	3	*
e06785a5	4	* Licensed under the Apache License 2.0 (the "License"). You may not use
6e624a64 SL	5	* this file except in compliance with the License. You can obtain a copy
	6	* in the file LICENSE in the source distribution or at
	7	* https://www.openssl.org/source/license.html
	8	*/
	9
	10	/*
	11	* See SP800-185 "Appendix A - KMAC, .... in Terms of Keccak[c]"
	12	*
	13	* Inputs are:
	14	* K = Key (len(K) < 2^2040 bits)
	15	* X = Input
	16	* L = Output length (0 <= L < 2^2040 bits)
	17	* S = Customization String Default="" (len(S) < 2^2040 bits)
	18	*
	19	* KMAC128(K, X, L, S)
	20	* {
	21	* newX = bytepad(encode_string(K), 168) \|\| X \|\| right_encode(L).
97c21381	22	* T = bytepad(encode_string("KMAC") \|\| encode_string(S), 168).
6e624a64 SL	23	* return KECCAK[256](T \|\| newX \|\| 00, L).
	24	* }
	25	*
	26	* KMAC256(K, X, L, S)
	27	* {
	28	* newX = bytepad(encode_string(K), 136) \|\| X \|\| right_encode(L).
97c21381	29	* T = bytepad(encode_string("KMAC") \|\| encode_string(S), 136).
6e624a64 SL	30	* return KECCAK[512](T \|\| newX \|\| 00, L).
	31	* }
	32	*
	33	* KMAC128XOF(K, X, L, S)
	34	* {
	35	* newX = bytepad(encode_string(K), 168) \|\| X \|\| right_encode(0).
97c21381	36	* T = bytepad(encode_string("KMAC") \|\| encode_string(S), 168).
6e624a64 SL	37	* return KECCAK[256](T \|\| newX \|\| 00, L).
	38	* }
	39	*
	40	* KMAC256XOF(K, X, L, S)
	41	* {
	42	* newX = bytepad(encode_string(K), 136) \|\| X \|\| right_encode(0).
97c21381	43	* T = bytepad(encode_string("KMAC") \|\| encode_string(S), 136).
6e624a64 SL	44	* return KECCAK[512](T \|\| newX \|\| 00, L).
	45	* }
	46	*
	47	*/
	48
	49	#include <stdlib.h>
e23cda00	50	#include <string.h>
23c48d94	51	#include <openssl/core_dispatch.h>
e23cda00 RL	52	#include <openssl/core_names.h>
e23cda00 RL	53	#include <openssl/params.h>
6e624a64	54	#include <openssl/evp.h>
e23cda00	55	#include <openssl/err.h>
2741128e	56	#include <openssl/proverr.h>
e23cda00	57
af3e7e1b	58	#include "prov/implementations.h"
ddd21319 RL	59	#include "prov/provider_ctx.h"
ddd21319 RL	60	#include "prov/provider_util.h"
5b104a81	61	#include "prov/providercommon.h"
e23cda00 RL	62
	63	/*
	64	* Forward declaration of everything implemented here. This is not strictly
	65	* necessary for the compiler, but provides an assurance that the signatures
	66	* of the functions in the dispatch table are correct.
	67	*/
363b1e5d DMSP	68	static OSSL_FUNC_mac_newctx_fn kmac128_new;
	69	static OSSL_FUNC_mac_newctx_fn kmac256_new;
	70	static OSSL_FUNC_mac_dupctx_fn kmac_dup;
	71	static OSSL_FUNC_mac_freectx_fn kmac_free;
	72	static OSSL_FUNC_mac_gettable_ctx_params_fn kmac_gettable_ctx_params;
	73	static OSSL_FUNC_mac_get_ctx_params_fn kmac_get_ctx_params;
	74	static OSSL_FUNC_mac_settable_ctx_params_fn kmac_settable_ctx_params;
	75	static OSSL_FUNC_mac_set_ctx_params_fn kmac_set_ctx_params;
363b1e5d DMSP	76	static OSSL_FUNC_mac_init_fn kmac_init;
	77	static OSSL_FUNC_mac_update_fn kmac_update;
	78	static OSSL_FUNC_mac_final_fn kmac_final;
6e624a64 SL	79
	80	#define KMAC_MAX_BLOCKSIZE ((1600 - 1282) / 8) / 168 */
	81	#define KMAC_MIN_BLOCKSIZE ((1600 - 2562) / 8) / 136 */
	82
	83	/* Length encoding will be a 1 byte size + length in bits (2 bytes max) */
	84	#define KMAC_MAX_ENCODED_HEADER_LEN 3
	85
	86	/*
	87	* Custom string max size is chosen such that:
	88	* len(encoded_string(custom) + len(kmac_encoded_string) <= KMAC_MIN_BLOCKSIZE
	89	* i.e: (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_LEN) + 6 <= 136
	90	*/
	91	#define KMAC_MAX_CUSTOM 127
	92
	93	/* Maximum size of encoded custom string */
	94	#define KMAC_MAX_CUSTOM_ENCODED (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_HEADER_LEN)
	95
	96	/* Maximum key size in bytes = 2040 / 8 */
	97	#define KMAC_MAX_KEY 255
	98
	99	/*
	100	* Maximum Encoded Key size will be padded to a multiple of the blocksize
	101	* i.e KMAC_MAX_KEY + KMAC_MAX_ENCODED_LEN = 258
	102	* Padded to a multiple of KMAC_MAX_BLOCKSIZE
	103	*/
	104	#define KMAC_MAX_KEY_ENCODED (KMAC_MAX_BLOCKSIZE * 2)
	105
	106	/* Fixed value of encode_string("KMAC") */
	107	static const unsigned char kmac_string[] = {
	108	0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43
	109	};
	110
	111
	112	#define KMAC_FLAG_XOF_MODE 1
	113
e23cda00 RL	114	struct kmac_data_st {
e23cda00 RL	115	void *provctx;
6e624a64	116	EVP_MD_CTX *ctx;
96d7e273	117	PROV_DIGEST digest;
6e624a64 SL	118	size_t out_len;
	119	int key_len;
	120	int custom_len;
	121	/* If xof_mode = 1 then we use right_encode(0) */
	122	int xof_mode;
	123	/* key and custom are stored in encoded form */
	124	unsigned char key[KMAC_MAX_KEY_ENCODED];
	125	unsigned char custom[KMAC_MAX_CUSTOM_ENCODED];
	126	};
	127
	128	static int encode_string(unsigned char out, int out_len,
	129	const unsigned char *in, int in_len);
	130	static int right_encode(unsigned char out, int out_len, size_t bits);
	131	static int bytepad(unsigned char out, int out_len,
	132	const unsigned char *in1, int in1_len,
	133	const unsigned char *in2, int in2_len,
	134	int w);
	135	static int kmac_bytepad_encode_key(unsigned char out, int out_len,
	136	const unsigned char *in, int in_len,
	137	int w);
6e624a64	138
e23cda00	139	static void kmac_free(void *vmacctx)
6e624a64	140	{
e23cda00 RL	141	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	142
6e624a64 SL	143	if (kctx != NULL) {
6e624a64 SL	144	EVP_MD_CTX_free(kctx->ctx);
96d7e273	145	ossl_prov_digest_reset(&kctx->digest);
6e624a64 SL	146	OPENSSL_cleanse(kctx->key, kctx->key_len);
	147	OPENSSL_cleanse(kctx->custom, kctx->custom_len);
	148	OPENSSL_free(kctx);
	149	}
	150	}
	151
e23cda00 RL	152	/*
	153	* We have KMAC implemented as a hash, which we can use instead of
	154	* reimplementing the EVP functionality with direct use of
	155	* keccak_mac_init() and friends.
	156	*/
96d7e273	157	static struct kmac_data_st kmac_new(void provctx)
6e624a64	158	{
96d7e273	159	struct kmac_data_st *kctx;
6e624a64	160
5b104a81 P	161	if (!ossl_prov_is_running())
	162	return NULL;
	163
6e624a64 SL	164	if ((kctx = OPENSSL_zalloc(sizeof(*kctx))) == NULL
	165	\|\| (kctx->ctx = EVP_MD_CTX_new()) == NULL) {
	166	kmac_free(kctx);
	167	return NULL;
	168	}
e23cda00	169	kctx->provctx = provctx;
6e624a64 SL	170	return kctx;
	171	}
	172
96d7e273	173	static void kmac_fetch_new(void provctx, const OSSL_PARAM *params)
6e624a64	174	{
96d7e273 P	175	struct kmac_data_st *kctx = kmac_new(provctx);
	176
	177	if (kctx == NULL)
	178	return 0;
	179	if (!ossl_prov_digest_load_from_params(&kctx->digest, params,
a829b735	180	PROV_LIBCTX_OF(provctx))) {
f20a59cb	181	kmac_free(kctx);
96d7e273	182	return 0;
f20a59cb	183	}
96d7e273 P	184
	185	kctx->out_len = EVP_MD_size(ossl_prov_digest_md(&kctx->digest));
	186	return kctx;
6e624a64 SL	187	}
6e624a64 SL	188
e23cda00	189	static void kmac128_new(void provctx)
6e624a64	190	{
96d7e273 P	191	static const OSSL_PARAM kmac128_params[] = {
	192	OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC128,
	193	sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC128)),
	194	OSSL_PARAM_END
	195	};
	196	return kmac_fetch_new(provctx, kmac128_params);
6e624a64 SL	197	}
6e624a64 SL	198
e23cda00	199	static void kmac256_new(void provctx)
6e624a64	200	{
96d7e273 P	201	static const OSSL_PARAM kmac256_params[] = {
	202	OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC256,
	203	sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC256)),
	204	OSSL_PARAM_END
	205	};
	206	return kmac_fetch_new(provctx, kmac256_params);
e23cda00 RL	207	}
	208
	209	static void kmac_dup(void vsrc)
	210	{
	211	struct kmac_data_st *src = vsrc;
5b104a81 P	212	struct kmac_data_st *dst;
	213
	214	if (!ossl_prov_is_running())
	215	return NULL;
7ed66e26	216
5b104a81	217	dst = kmac_new(src->provctx);
e23cda00	218	if (dst == NULL)
7ed66e26 KR	219	return NULL;
7ed66e26 KR	220
e23cda00	221	if (!EVP_MD_CTX_copy(dst->ctx, src->ctx)
96d7e273	222	\|\| !ossl_prov_digest_copy(&dst->digest, &src->digest)) {
e23cda00	223	kmac_free(dst);
7ed66e26 KR	224	return NULL;
	225	}
	226
e23cda00 RL	227	dst->out_len = src->out_len;
	228	dst->key_len = src->key_len;
	229	dst->custom_len = src->custom_len;
	230	dst->xof_mode = src->xof_mode;
	231	memcpy(dst->key, src->key, src->key_len);
	232	memcpy(dst->custom, src->custom, dst->custom_len);
6e624a64	233
e23cda00	234	return dst;
6e624a64 SL	235	}
6e624a64 SL	236
8ce04db8 RL	237	static size_t kmac_size(void *vmacctx)
	238	{
	239	struct kmac_data_st *kctx = vmacctx;
	240
	241	return kctx->out_len;
	242	}
	243
6e624a64 SL	244	/*
	245	* The init() assumes that any ctrl methods are set beforehand for
	246	* md, key and custom. Setting the fields afterwards will have no
	247	* effect on the output mac.
	248	*/
e23cda00	249	static int kmac_init(void *vmacctx)
6e624a64	250	{
e23cda00	251	struct kmac_data_st *kctx = vmacctx;
6e624a64 SL	252	EVP_MD_CTX *ctx = kctx->ctx;
	253	unsigned char out[KMAC_MAX_BLOCKSIZE];
	254	int out_len, block_len;
	255
5b104a81 P	256	if (!ossl_prov_is_running())
5b104a81 P	257	return 0;
e23cda00	258
6e624a64 SL	259	/* Check key has been set */
6e624a64 SL	260	if (kctx->key_len == 0) {
f5f29796	261	ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
6e624a64 SL	262	return 0;
6e624a64 SL	263	}
96d7e273 P	264	if (!EVP_DigestInit_ex(kctx->ctx, ossl_prov_digest_md(&kctx->digest),
96d7e273 P	265	NULL))
6e624a64 SL	266	return 0;
6e624a64 SL	267
96d7e273	268	block_len = EVP_MD_block_size(ossl_prov_digest_md(&kctx->digest));
0e2b6091 P	269	if (block_len < 0)
0e2b6091 P	270	return 0;
6e624a64 SL	271
6e624a64 SL	272	/* Set default custom string if it is not already set */
e23cda00 RL	273	if (kctx->custom_len == 0) {
	274	const OSSL_PARAM params[] = {
	275	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, "", 0),
	276	OSSL_PARAM_END
	277	};
92d9d0ae	278	(void)kmac_set_ctx_params(kctx, params);
e23cda00	279	}
6e624a64 SL	280
	281	return bytepad(out, &out_len, kmac_string, sizeof(kmac_string),
	282	kctx->custom, kctx->custom_len, block_len)
	283	&& EVP_DigestUpdate(ctx, out, out_len)
	284	&& EVP_DigestUpdate(ctx, kctx->key, kctx->key_len);
	285	}
	286
e23cda00	287	static int kmac_update(void vmacctx, const unsigned char data,
6e624a64 SL	288	size_t datalen)
6e624a64 SL	289	{
e23cda00 RL	290	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	291
6e624a64 SL	292	return EVP_DigestUpdate(kctx->ctx, data, datalen);
	293	}
	294
e23cda00 RL	295	static int kmac_final(void vmacctx, unsigned char out, size_t *outl,
e23cda00 RL	296	size_t outsize)
6e624a64	297	{
e23cda00	298	struct kmac_data_st *kctx = vmacctx;
6e624a64 SL	299	EVP_MD_CTX *ctx = kctx->ctx;
	300	int lbits, len;
	301	unsigned char encoded_outlen[KMAC_MAX_ENCODED_HEADER_LEN];
e23cda00	302	int ok;
6e624a64	303
5b104a81 P	304	if (!ossl_prov_is_running())
	305	return 0;
	306
6e624a64 SL	307	/* KMAC XOF mode sets the encoded length to 0 */
	308	lbits = (kctx->xof_mode ? 0 : (kctx->out_len * 8));
	309
e23cda00 RL	310	ok = right_encode(encoded_outlen, &len, lbits)
	311	&& EVP_DigestUpdate(ctx, encoded_outlen, len)
	312	&& EVP_DigestFinalXOF(ctx, out, kctx->out_len);
5f6a0b2f	313	*outl = kctx->out_len;
e23cda00	314	return ok;
6e624a64 SL	315	}
6e624a64 SL	316
e23cda00	317	static const OSSL_PARAM known_gettable_ctx_params[] = {
703170d4	318	OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
e23cda00 RL	319	OSSL_PARAM_END
e23cda00 RL	320	};
1017ab21	321	static const OSSL_PARAM kmac_gettable_ctx_params(ossl_unused void provctx)
6e624a64	322	{
e23cda00	323	return known_gettable_ctx_params;
6e624a64 SL	324	}
6e624a64 SL	325
92d9d0ae	326	static int kmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
6e624a64	327	{
e23cda00	328	OSSL_PARAM *p;
6e624a64	329
703170d4	330	if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
e23cda00	331	return OSSL_PARAM_set_size_t(p, kmac_size(vmacctx));
6e624a64	332
e23cda00	333	return 1;
6e624a64 SL	334	}
6e624a64 SL	335
e23cda00 RL	336	static const OSSL_PARAM known_settable_ctx_params[] = {
e23cda00 RL	337	OSSL_PARAM_int(OSSL_MAC_PARAM_XOF, NULL),
e23cda00 RL	338	OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
	339	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
	340	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, NULL, 0),
	341	OSSL_PARAM_END
	342	};
1017ab21	343	static const OSSL_PARAM kmac_settable_ctx_params(ossl_unused void provctx)
6e624a64	344	{
e23cda00	345	return known_settable_ctx_params;
6e624a64 SL	346	}
6e624a64 SL	347
e23cda00 RL	348	/*
	349	* The following params can be set any time before final():
	350	* - "outlen" or "size": The requested output length.
	351	* - "xof": If set, this indicates that right_encoded(0)
	352	* is part of the digested data, otherwise it
	353	* uses right_encoded(requested output length).
	354	*
	355	* All other params should be set before init().
	356	*/
92d9d0ae	357	static int kmac_set_ctx_params(void vmacctx, const OSSL_PARAM params)
6e624a64	358	{
e23cda00 RL	359	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	360	const OSSL_PARAM *p;
96d7e273	361	const EVP_MD *digest = ossl_prov_digest_md(&kctx->digest);
6e624a64	362
e23cda00 RL	363	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_XOF)) != NULL
	364	&& !OSSL_PARAM_get_int(p, &kctx->xof_mode))
	365	return 0;
703170d4	366	if (((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_SIZE)) != NULL)
e23cda00 RL	367	&& !OSSL_PARAM_get_size_t(p, &kctx->out_len))
	368	return 0;
	369	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
	370	if (p->data_size < 4 \|\| p->data_size > KMAC_MAX_KEY) {
	371	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
	372	return 0;
	373	}
	374	if (!kmac_bytepad_encode_key(kctx->key, &kctx->key_len,
	375	p->data, p->data_size,
96d7e273	376	EVP_MD_block_size(digest)))
e23cda00 RL	377	return 0;
	378	}
	379	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_CUSTOM))
	380	!= NULL) {
	381	if (p->data_size > KMAC_MAX_CUSTOM) {
	382	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CUSTOM_LENGTH);
	383	return 0;
	384	}
	385	if (!encode_string(kctx->custom, &kctx->custom_len,
	386	p->data, p->data_size))
	387	return 0;
	388	}
	389	return 1;
6e624a64 SL	390	}
	391
	392	/*
	393	* Encoding/Padding Methods.
	394	*/
	395
	396	/* Returns the number of bytes required to store 'bits' into a byte array */
	397	static unsigned int get_encode_size(size_t bits)
	398	{
	399	unsigned int cnt = 0, sz = sizeof(size_t);
	400
	401	while (bits && (cnt < sz)) {
	402	++cnt;
	403	bits >>= 8;
	404	}
	405	/* If bits is zero 1 byte is required */
	406	if (cnt == 0)
	407	cnt = 1;
	408	return cnt;
	409	}
	410
	411	/*
	412	* Convert an integer into bytes . The number of bytes is appended
	413	* to the end of the buffer. Returns an array of bytes 'out' of size
	414	* *out_len.
	415	*
	416	* e.g if bits = 32, out[2] = { 0x20, 0x01 }
	417	*
	418	*/
	419	static int right_encode(unsigned char out, int out_len, size_t bits)
	420	{
	421	unsigned int len = get_encode_size(bits);
	422	int i;
	423
	424	/* The length is constrained to a single byte: 2040/8 = 255 */
	425	if (len > 0xFF)
	426	return 0;
	427
	428	/* MSB's are at the start of the bytes array */
	429	for (i = len - 1; i >= 0; --i) {
	430	out[i] = (unsigned char)(bits & 0xFF);
	431	bits >>= 8;
	432	}
	433	/* Tack the length onto the end */
	434	out[len] = (unsigned char)len;
	435
	436	/* The Returned length includes the tacked on byte */
	437	*out_len = len + 1;
	438	return 1;
	439	}
	440
	441	/*
	442	* Encodes a string with a left encoded length added. Note that the
	443	* in_len is converted to bits (*8).
	444	*
	445	* e.g- in="KMAC" gives out[6] = { 0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43 }
	446	* len bits K M A C
	447	*/
	448	static int encode_string(unsigned char out, int out_len,
	449	const unsigned char *in, int in_len)
	450	{
	451	if (in == NULL) {
	452	*out_len = 0;
	453	} else {
454	int i, bits, len;
455
456	bits = 8 * in_len;
457	len = get_encode_size(bits);
458	if (len > 0xFF)
459	return 0;
460
461	out[0] = len;
462	for (i = len; i > 0; --i) {
463	out[i] = (bits & 0xFF);
464	bits >>= 8;
465	}
466	memcpy(out + len + 1, in, in_len);
467	*out_len = (1 + len + in_len);
468	}
469	return 1;
470	}
471
472	/*
473	* Returns a zero padded encoding of the inputs in1 and an optional
474	* in2 (can be NULL). The padded output must be a multiple of the blocksize 'w'.
475	* The value of w is in bytes (< 256).
476	*
477	* The returned output is:
478	* zero_padded(multiple of w, (left_encode(w) \|\| in1 [\|\| in2])
479	*/
480	static int bytepad(unsigned char out, int out_len,
481	const unsigned char *in1, int in1_len,
482	const unsigned char *in2, int in2_len, int w)
483	{
484	int len;
485	unsigned char *p = out;
486	int sz = w;
487
488	/* Left encoded w */
489	*p++ = 1;
490	*p++ = w;
491	/* \|\| in1 */
492	memcpy(p, in1, in1_len);
493	p += in1_len;
494	/* [ \|\| in2 ] */
495	if (in2 != NULL && in2_len > 0) {
496	memcpy(p, in2, in2_len);
497	p += in2_len;
498	}
499	/* Figure out the pad size (divisible by w) */
500	len = p - out;
501	while (len > sz) {
502	sz += w;
503	}
504	/* zero pad the end of the buffer */
505	memset(p, 0, sz - len);
506	*out_len = sz;
507	return 1;
508	}
509
510	/*
511	* Returns out = bytepad(encode_string(in), w)
512	*/
513	static int kmac_bytepad_encode_key(unsigned char out, int out_len,
514	const unsigned char *in, int in_len,
515	int w)
516	{
517	unsigned char tmp[KMAC_MAX_KEY + KMAC_MAX_ENCODED_HEADER_LEN];
518	int tmp_len;
519
520	if (!encode_string(tmp, &tmp_len, in, in_len))
521	return 0;
522
523	return bytepad(out, out_len, tmp, tmp_len, NULL, 0, w);
524	}
525
1be63951	526	const OSSL_DISPATCH ossl_kmac128_functions[] = {
e23cda00 RL	527	{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac128_new },
	528	{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
	529	{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
	530	{ OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
	531	{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
	532	{ OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
	533	{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
	534	(void (*)(void))kmac_gettable_ctx_params },
92d9d0ae	535	{ OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))kmac_get_ctx_params },
e23cda00 RL	536	{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
e23cda00 RL	537	(void (*)(void))kmac_settable_ctx_params },
92d9d0ae	538	{ OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))kmac_set_ctx_params },
e23cda00	539	{ 0, NULL }
6e624a64 SL	540	};
6e624a64 SL	541
1be63951	542	const OSSL_DISPATCH ossl_kmac256_functions[] = {
e23cda00 RL	543	{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac256_new },
	544	{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
	545	{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
	546	{ OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
	547	{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
	548	{ OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
	549	{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
	550	(void (*)(void))kmac_gettable_ctx_params },
92d9d0ae	551	{ OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))kmac_get_ctx_params },
e23cda00 RL	552	{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
e23cda00 RL	553	(void (*)(void))kmac_settable_ctx_params },
92d9d0ae	554	{ OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))kmac_set_ctx_params },
e23cda00	555	{ 0, NULL }
6e624a64	556	};