[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 "prov/providercommonerr.h"
#include "prov/implementations.h"
#include "prov/provider_ctx.h"
#include "prov/provider_util.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_size_fn kmac_size;
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 ((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_LIBRARY_CONTEXT_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 = 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;
}

/*
 * 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;


    /* Check key has been set */
    if (kctx->key_len == 0) {
        EVPerr(EVP_F_KMAC_INIT, EVP_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 size_t kmac_size(void *vmacctx)
{
    struct kmac_data_st *kctx = vmacctx;

    return kctx->out_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;

    /* 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);
    if (ok && outl != NULL)
        *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(void)
{
    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(void)
{
    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 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 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 RL	55	#include <openssl/err.h>
e23cda00 RL	56
ddd21319	57	#include "prov/providercommonerr.h"
af3e7e1b	58	#include "prov/implementations.h"
ddd21319 RL	59	#include "prov/provider_ctx.h"
ddd21319 RL	60	#include "prov/provider_util.h"
e23cda00 RL	61
	62	/*
	63	* Forward declaration of everything implemented here. This is not strictly
	64	* necessary for the compiler, but provides an assurance that the signatures
	65	* of the functions in the dispatch table are correct.
	66	*/
363b1e5d DMSP	67	static OSSL_FUNC_mac_newctx_fn kmac128_new;
	68	static OSSL_FUNC_mac_newctx_fn kmac256_new;
	69	static OSSL_FUNC_mac_dupctx_fn kmac_dup;
	70	static OSSL_FUNC_mac_freectx_fn kmac_free;
	71	static OSSL_FUNC_mac_gettable_ctx_params_fn kmac_gettable_ctx_params;
	72	static OSSL_FUNC_mac_get_ctx_params_fn kmac_get_ctx_params;
	73	static OSSL_FUNC_mac_settable_ctx_params_fn kmac_settable_ctx_params;
	74	static OSSL_FUNC_mac_set_ctx_params_fn kmac_set_ctx_params;
	75	static OSSL_FUNC_mac_size_fn kmac_size;
	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 SL	160
	161	if ((kctx = OPENSSL_zalloc(sizeof(*kctx))) == NULL
	162	\|\| (kctx->ctx = EVP_MD_CTX_new()) == NULL) {
	163	kmac_free(kctx);
	164	return NULL;
	165	}
e23cda00	166	kctx->provctx = provctx;
6e624a64 SL	167	return kctx;
	168	}
	169
96d7e273	170	static void kmac_fetch_new(void provctx, const OSSL_PARAM *params)
6e624a64	171	{
96d7e273 P	172	struct kmac_data_st *kctx = kmac_new(provctx);
	173
	174	if (kctx == NULL)
	175	return 0;
	176	if (!ossl_prov_digest_load_from_params(&kctx->digest, params,
f20a59cb P	177	PROV_LIBRARY_CONTEXT_OF(provctx))) {
f20a59cb P	178	kmac_free(kctx);
96d7e273	179	return 0;
f20a59cb	180	}
96d7e273 P	181
	182	kctx->out_len = EVP_MD_size(ossl_prov_digest_md(&kctx->digest));
	183	return kctx;
6e624a64 SL	184	}
6e624a64 SL	185
e23cda00	186	static void kmac128_new(void provctx)
6e624a64	187	{
96d7e273 P	188	static const OSSL_PARAM kmac128_params[] = {
	189	OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC128,
	190	sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC128)),
	191	OSSL_PARAM_END
	192	};
	193	return kmac_fetch_new(provctx, kmac128_params);
6e624a64 SL	194	}
6e624a64 SL	195
e23cda00	196	static void kmac256_new(void provctx)
6e624a64	197	{
96d7e273 P	198	static const OSSL_PARAM kmac256_params[] = {
	199	OSSL_PARAM_utf8_string("digest", OSSL_DIGEST_NAME_KECCAK_KMAC256,
	200	sizeof(OSSL_DIGEST_NAME_KECCAK_KMAC256)),
	201	OSSL_PARAM_END
	202	};
	203	return kmac_fetch_new(provctx, kmac256_params);
e23cda00 RL	204	}
	205
	206	static void kmac_dup(void vsrc)
	207	{
	208	struct kmac_data_st *src = vsrc;
96d7e273	209	struct kmac_data_st *dst = kmac_new(src->provctx);
7ed66e26	210
e23cda00	211	if (dst == NULL)
7ed66e26 KR	212	return NULL;
7ed66e26 KR	213
e23cda00	214	if (!EVP_MD_CTX_copy(dst->ctx, src->ctx)
96d7e273	215	\|\| !ossl_prov_digest_copy(&dst->digest, &src->digest)) {
e23cda00	216	kmac_free(dst);
7ed66e26 KR	217	return NULL;
	218	}
	219
e23cda00 RL	220	dst->out_len = src->out_len;
	221	dst->key_len = src->key_len;
	222	dst->custom_len = src->custom_len;
	223	dst->xof_mode = src->xof_mode;
	224	memcpy(dst->key, src->key, src->key_len);
	225	memcpy(dst->custom, src->custom, dst->custom_len);
6e624a64	226
e23cda00	227	return dst;
6e624a64 SL	228	}
	229
	230	/*
	231	* The init() assumes that any ctrl methods are set beforehand for
	232	* md, key and custom. Setting the fields afterwards will have no
	233	* effect on the output mac.
	234	*/
e23cda00	235	static int kmac_init(void *vmacctx)
6e624a64	236	{
e23cda00	237	struct kmac_data_st *kctx = vmacctx;
6e624a64 SL	238	EVP_MD_CTX *ctx = kctx->ctx;
	239	unsigned char out[KMAC_MAX_BLOCKSIZE];
	240	int out_len, block_len;
	241
e23cda00	242
6e624a64 SL	243	/* Check key has been set */
	244	if (kctx->key_len == 0) {
	245	EVPerr(EVP_F_KMAC_INIT, EVP_R_NO_KEY_SET);
	246	return 0;
	247	}
96d7e273 P	248	if (!EVP_DigestInit_ex(kctx->ctx, ossl_prov_digest_md(&kctx->digest),
96d7e273 P	249	NULL))
6e624a64 SL	250	return 0;
6e624a64 SL	251
96d7e273	252	block_len = EVP_MD_block_size(ossl_prov_digest_md(&kctx->digest));
0e2b6091 P	253	if (block_len < 0)
0e2b6091 P	254	return 0;
6e624a64 SL	255
6e624a64 SL	256	/* Set default custom string if it is not already set */
e23cda00 RL	257	if (kctx->custom_len == 0) {
	258	const OSSL_PARAM params[] = {
	259	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, "", 0),
	260	OSSL_PARAM_END
	261	};
92d9d0ae	262	(void)kmac_set_ctx_params(kctx, params);
e23cda00	263	}
6e624a64 SL	264
	265	return bytepad(out, &out_len, kmac_string, sizeof(kmac_string),
	266	kctx->custom, kctx->custom_len, block_len)
	267	&& EVP_DigestUpdate(ctx, out, out_len)
	268	&& EVP_DigestUpdate(ctx, kctx->key, kctx->key_len);
	269	}
	270
e23cda00	271	static size_t kmac_size(void *vmacctx)
6e624a64	272	{
e23cda00 RL	273	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	274
6e624a64 SL	275	return kctx->out_len;
	276	}
	277
e23cda00	278	static int kmac_update(void vmacctx, const unsigned char data,
6e624a64 SL	279	size_t datalen)
6e624a64 SL	280	{
e23cda00 RL	281	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	282
6e624a64 SL	283	return EVP_DigestUpdate(kctx->ctx, data, datalen);
	284	}
	285
e23cda00 RL	286	static int kmac_final(void vmacctx, unsigned char out, size_t *outl,
e23cda00 RL	287	size_t outsize)
6e624a64	288	{
e23cda00	289	struct kmac_data_st *kctx = vmacctx;
6e624a64 SL	290	EVP_MD_CTX *ctx = kctx->ctx;
	291	int lbits, len;
	292	unsigned char encoded_outlen[KMAC_MAX_ENCODED_HEADER_LEN];
e23cda00	293	int ok;
6e624a64 SL	294
	295	/* KMAC XOF mode sets the encoded length to 0 */
	296	lbits = (kctx->xof_mode ? 0 : (kctx->out_len * 8));
	297
e23cda00 RL	298	ok = right_encode(encoded_outlen, &len, lbits)
	299	&& EVP_DigestUpdate(ctx, encoded_outlen, len)
	300	&& EVP_DigestFinalXOF(ctx, out, kctx->out_len);
	301	if (ok && outl != NULL)
	302	*outl = kctx->out_len;
	303	return ok;
6e624a64 SL	304	}
6e624a64 SL	305
e23cda00	306	static const OSSL_PARAM known_gettable_ctx_params[] = {
703170d4	307	OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
e23cda00 RL	308	OSSL_PARAM_END
	309	};
	310	static const OSSL_PARAM *kmac_gettable_ctx_params(void)
6e624a64	311	{
e23cda00	312	return known_gettable_ctx_params;
6e624a64 SL	313	}
6e624a64 SL	314
92d9d0ae	315	static int kmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
6e624a64	316	{
e23cda00	317	OSSL_PARAM *p;
6e624a64	318
703170d4	319	if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
e23cda00	320	return OSSL_PARAM_set_size_t(p, kmac_size(vmacctx));
6e624a64	321
e23cda00	322	return 1;
6e624a64 SL	323	}
6e624a64 SL	324
e23cda00 RL	325	static const OSSL_PARAM known_settable_ctx_params[] = {
e23cda00 RL	326	OSSL_PARAM_int(OSSL_MAC_PARAM_XOF, NULL),
e23cda00 RL	327	OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
	328	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
	329	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, NULL, 0),
	330	OSSL_PARAM_END
	331	};
	332	static const OSSL_PARAM *kmac_settable_ctx_params(void)
6e624a64	333	{
e23cda00	334	return known_settable_ctx_params;
6e624a64 SL	335	}
6e624a64 SL	336
e23cda00 RL	337	/*
	338	* The following params can be set any time before final():
	339	* - "outlen" or "size": The requested output length.
	340	* - "xof": If set, this indicates that right_encoded(0)
	341	* is part of the digested data, otherwise it
	342	* uses right_encoded(requested output length).
	343	*
	344	* All other params should be set before init().
	345	*/
92d9d0ae	346	static int kmac_set_ctx_params(void vmacctx, const OSSL_PARAM params)
6e624a64	347	{
e23cda00 RL	348	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	349	const OSSL_PARAM *p;
96d7e273	350	const EVP_MD *digest = ossl_prov_digest_md(&kctx->digest);
6e624a64	351
e23cda00 RL	352	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_XOF)) != NULL
	353	&& !OSSL_PARAM_get_int(p, &kctx->xof_mode))
	354	return 0;
703170d4	355	if (((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_SIZE)) != NULL)
e23cda00 RL	356	&& !OSSL_PARAM_get_size_t(p, &kctx->out_len))
	357	return 0;
	358	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
	359	if (p->data_size < 4 \|\| p->data_size > KMAC_MAX_KEY) {
	360	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
	361	return 0;
	362	}
	363	if (!kmac_bytepad_encode_key(kctx->key, &kctx->key_len,
	364	p->data, p->data_size,
96d7e273	365	EVP_MD_block_size(digest)))
e23cda00 RL	366	return 0;
	367	}
	368	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_CUSTOM))
	369	!= NULL) {
	370	if (p->data_size > KMAC_MAX_CUSTOM) {
	371	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CUSTOM_LENGTH);
	372	return 0;
	373	}
	374	if (!encode_string(kctx->custom, &kctx->custom_len,
	375	p->data, p->data_size))
	376	return 0;
	377	}
	378	return 1;
6e624a64 SL	379	}
	380
	381	/*
	382	* Encoding/Padding Methods.
	383	*/
	384
	385	/* Returns the number of bytes required to store 'bits' into a byte array */
	386	static unsigned int get_encode_size(size_t bits)
	387	{
	388	unsigned int cnt = 0, sz = sizeof(size_t);
	389
	390	while (bits && (cnt < sz)) {
	391	++cnt;
	392	bits >>= 8;
	393	}
	394	/* If bits is zero 1 byte is required */
	395	if (cnt == 0)
	396	cnt = 1;
	397	return cnt;
	398	}
	399
	400	/*
	401	* Convert an integer into bytes . The number of bytes is appended
	402	* to the end of the buffer. Returns an array of bytes 'out' of size
	403	* *out_len.
	404	*
	405	* e.g if bits = 32, out[2] = { 0x20, 0x01 }
	406	*
	407	*/
	408	static int right_encode(unsigned char out, int out_len, size_t bits)
	409	{
	410	unsigned int len = get_encode_size(bits);
	411	int i;
	412
	413	/* The length is constrained to a single byte: 2040/8 = 255 */
	414	if (len > 0xFF)
	415	return 0;
	416
	417	/* MSB's are at the start of the bytes array */
	418	for (i = len - 1; i >= 0; --i) {
	419	out[i] = (unsigned char)(bits & 0xFF);
	420	bits >>= 8;
	421	}
	422	/* Tack the length onto the end */
	423	out[len] = (unsigned char)len;
	424
	425	/* The Returned length includes the tacked on byte */
	426	*out_len = len + 1;
	427	return 1;
	428	}
	429
	430	/*
	431	* Encodes a string with a left encoded length added. Note that the
	432	* in_len is converted to bits (*8).
	433	*
	434	* e.g- in="KMAC" gives out[6] = { 0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43 }
	435	* len bits K M A C
	436	*/
	437	static int encode_string(unsigned char out, int out_len,
	438	const unsigned char *in, int in_len)
	439	{
	440	if (in == NULL) {
	441	*out_len = 0;
	442	} else {
443	int i, bits, len;
444
445	bits = 8 * in_len;
446	len = get_encode_size(bits);
447	if (len > 0xFF)
448	return 0;
449
450	out[0] = len;
451	for (i = len; i > 0; --i) {
452	out[i] = (bits & 0xFF);
453	bits >>= 8;
454	}
455	memcpy(out + len + 1, in, in_len);
456	*out_len = (1 + len + in_len);
457	}
458	return 1;
459	}
460
461	/*
462	* Returns a zero padded encoding of the inputs in1 and an optional
463	* in2 (can be NULL). The padded output must be a multiple of the blocksize 'w'.
464	* The value of w is in bytes (< 256).
465	*
466	* The returned output is:
467	* zero_padded(multiple of w, (left_encode(w) \|\| in1 [\|\| in2])
468	*/
469	static int bytepad(unsigned char out, int out_len,
470	const unsigned char *in1, int in1_len,
471	const unsigned char *in2, int in2_len, int w)
472	{
473	int len;
474	unsigned char *p = out;
475	int sz = w;
476
477	/* Left encoded w */
478	*p++ = 1;
479	*p++ = w;
480	/* \|\| in1 */
481	memcpy(p, in1, in1_len);
482	p += in1_len;
483	/* [ \|\| in2 ] */
484	if (in2 != NULL && in2_len > 0) {
485	memcpy(p, in2, in2_len);
486	p += in2_len;
487	}
488	/* Figure out the pad size (divisible by w) */
489	len = p - out;
490	while (len > sz) {
491	sz += w;
492	}
493	/* zero pad the end of the buffer */
494	memset(p, 0, sz - len);
495	*out_len = sz;
496	return 1;
497	}
498
499	/*
500	* Returns out = bytepad(encode_string(in), w)
501	*/
502	static int kmac_bytepad_encode_key(unsigned char out, int out_len,
503	const unsigned char *in, int in_len,
504	int w)
505	{
506	unsigned char tmp[KMAC_MAX_KEY + KMAC_MAX_ENCODED_HEADER_LEN];
507	int tmp_len;
508
509	if (!encode_string(tmp, &tmp_len, in, in_len))
510	return 0;
511
512	return bytepad(out, out_len, tmp, tmp_len, NULL, 0, w);
513	}
514
e23cda00 RL	515	const OSSL_DISPATCH kmac128_functions[] = {
	516	{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac128_new },
	517	{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
	518	{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
	519	{ OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
	520	{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
	521	{ OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
	522	{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
	523	(void (*)(void))kmac_gettable_ctx_params },
92d9d0ae	524	{ OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))kmac_get_ctx_params },
e23cda00 RL	525	{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
e23cda00 RL	526	(void (*)(void))kmac_settable_ctx_params },
92d9d0ae	527	{ OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))kmac_set_ctx_params },
e23cda00	528	{ 0, NULL }
6e624a64 SL	529	};
6e624a64 SL	530
e23cda00 RL	531	const OSSL_DISPATCH kmac256_functions[] = {
	532	{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac256_new },
	533	{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
	534	{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
	535	{ OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
	536	{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
	537	{ OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
	538	{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
	539	(void (*)(void))kmac_gettable_ctx_params },
92d9d0ae	540	{ OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))kmac_get_ctx_params },
e23cda00 RL	541	{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
e23cda00 RL	542	(void (*)(void))kmac_settable_ctx_params },
92d9d0ae	543	{ OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))kmac_set_ctx_params },
e23cda00	544	{ 0, NULL }
6e624a64	545	};