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

/*
 * Copyright 2018 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_numbers.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/evp.h>
#include <openssl/err.h>

#include "internal/providercommonerr.h"
#include "internal/provider_algs.h"
#include "internal/provider_ctx.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_OP_mac_newctx_fn kmac128_new;
static OSSL_OP_mac_newctx_fn kmac256_new;
static OSSL_OP_mac_dupctx_fn kmac_dup;
static OSSL_OP_mac_freectx_fn kmac_free;
static OSSL_OP_mac_gettable_ctx_params_fn kmac_gettable_ctx_params;
static OSSL_OP_mac_ctx_get_params_fn kmac_ctx_get_params;
static OSSL_OP_mac_settable_ctx_params_fn kmac_settable_ctx_params;
static OSSL_OP_mac_ctx_set_params_fn kmac_ctx_set_params;
static OSSL_OP_mac_size_fn kmac_size;
static OSSL_OP_mac_init_fn kmac_init;
static OSSL_OP_mac_update_fn kmac_update;
static OSSL_OP_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;

    /*
     * References to the underlying keccak_kmac implementation.  |md|
     * caches the digest, always.  |alloc_md| only holds a reference to an
     * explicitly fetched digest.
     * |md| is cleared after a EVP_DigestInit call.
     */
    const EVP_MD *md;            /* Cache KMAC digest */
    EVP_MD *alloc_md;            /* Fetched 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);
        EVP_MD_meth_free(kctx->alloc_md);
        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 void *kmac_new(void *provctx, EVP_MD *fetched_md, const EVP_MD *md)
{
    struct kmac_data_st *kctx = NULL;

    if (md == NULL)
        return NULL;

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

static void *kmac_fetch_new(void *provctx, const char *mdname)
{
    EVP_MD *fetched_md = EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(provctx),
                                      mdname, NULL);
    const EVP_MD *md = fetched_md;
    void *ret = NULL;

#ifndef FIPS_MODE /* Inside the FIPS module, we don't support legacy digests */
    /* TODO(3.0) BEGIN legacy stuff, to be removed */
    if (md == NULL)
        md = EVP_get_digestbyname(mdname);
    /* TODO(3.0) END of legacy stuff */
#endif

    ret = kmac_new(provctx, fetched_md, md);
    if (ret == NULL)
        EVP_MD_meth_free(fetched_md);
    return ret;
}

static void *kmac128_new(void *provctx)
{
    return kmac_fetch_new(provctx, "KMAC128");
}

static void *kmac256_new(void *provctx)
{
    return kmac_fetch_new(provctx, "KMAC256");
}

static void *kmac_dup(void *vsrc)
{
    struct kmac_data_st *src = vsrc;
    struct kmac_data_st *dst = kmac_new(src->provctx, src->alloc_md, src->md);

    if (dst == NULL)
        return NULL;

    if (!EVP_MD_CTX_copy(dst->ctx, src->ctx)
        || (src->alloc_md != NULL && !EVP_MD_up_ref(src->alloc_md))) {
        kmac_free(dst);
        return NULL;
    }

    dst->md = src->md;
    dst->alloc_md = src->alloc_md;
    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, kctx->md, NULL))
        return 0;

    block_len = EVP_MD_block_size(kctx->md);

    /* 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_ctx_set_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_OUTLEN, NULL),
    OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL), /* Same as "outlen" */
    OSSL_PARAM_size_t(OSSL_MAC_PARAM_DIGESTSIZE, NULL), /* Same as "outlen" */
    OSSL_PARAM_END
};
static const OSSL_PARAM *kmac_gettable_ctx_params(void)
{
    return known_gettable_ctx_params;
}

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

    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_OUTLEN)) != NULL
        || (p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
        || (p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_DIGESTSIZE)) != 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_OUTLEN, 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_ctx_set_params(void *vmacctx, const OSSL_PARAM *params)
{
    struct kmac_data_st *kctx = vmacctx;
    const OSSL_PARAM *p;

    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_OUTLEN)) != NULL
         ||
         (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(kctx->md)))
            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_CTX_GET_PARAMS, (void (*)(void))kmac_ctx_get_params },
    { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
      (void (*)(void))kmac_settable_ctx_params },
    { OSSL_FUNC_MAC_CTX_SET_PARAMS, (void (*)(void))kmac_ctx_set_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_CTX_GET_PARAMS, (void (*)(void))kmac_ctx_get_params },
    { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
      (void (*)(void))kmac_settable_ctx_params },
    { OSSL_FUNC_MAC_CTX_SET_PARAMS, (void (*)(void))kmac_ctx_set_params },
    { 0, NULL }
};
Commit	Line	Data
6e624a64 SL	1	/*
	2	* Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
	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 RL	50	#include <string.h>
	51	#include <openssl/core_numbers.h>
	52	#include <openssl/core_names.h>
	53	#include <openssl/params.h>
6e624a64	54	#include <openssl/evp.h>
e23cda00 RL	55	#include <openssl/err.h>
	56
	57	#include "internal/providercommonerr.h"
	58	#include "internal/provider_algs.h"
	59	#include "internal/provider_ctx.h"
	60
	61	/*
	62	* Forward declaration of everything implemented here. This is not strictly
	63	* necessary for the compiler, but provides an assurance that the signatures
	64	* of the functions in the dispatch table are correct.
	65	*/
	66	static OSSL_OP_mac_newctx_fn kmac128_new;
	67	static OSSL_OP_mac_newctx_fn kmac256_new;
	68	static OSSL_OP_mac_dupctx_fn kmac_dup;
	69	static OSSL_OP_mac_freectx_fn kmac_free;
	70	static OSSL_OP_mac_gettable_ctx_params_fn kmac_gettable_ctx_params;
	71	static OSSL_OP_mac_ctx_get_params_fn kmac_ctx_get_params;
	72	static OSSL_OP_mac_settable_ctx_params_fn kmac_settable_ctx_params;
	73	static OSSL_OP_mac_ctx_set_params_fn kmac_ctx_set_params;
	74	static OSSL_OP_mac_size_fn kmac_size;
	75	static OSSL_OP_mac_init_fn kmac_init;
	76	static OSSL_OP_mac_update_fn kmac_update;
	77	static OSSL_OP_mac_final_fn kmac_final;
6e624a64 SL	78
	79	#define KMAC_MAX_BLOCKSIZE ((1600 - 1282) / 8) / 168 */
	80	#define KMAC_MIN_BLOCKSIZE ((1600 - 2562) / 8) / 136 */
	81
	82	/* Length encoding will be a 1 byte size + length in bits (2 bytes max) */
	83	#define KMAC_MAX_ENCODED_HEADER_LEN 3
	84
	85	/*
	86	* Custom string max size is chosen such that:
	87	* len(encoded_string(custom) + len(kmac_encoded_string) <= KMAC_MIN_BLOCKSIZE
	88	* i.e: (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_LEN) + 6 <= 136
	89	*/
	90	#define KMAC_MAX_CUSTOM 127
	91
	92	/* Maximum size of encoded custom string */
	93	#define KMAC_MAX_CUSTOM_ENCODED (KMAC_MAX_CUSTOM + KMAC_MAX_ENCODED_HEADER_LEN)
	94
	95	/* Maximum key size in bytes = 2040 / 8 */
	96	#define KMAC_MAX_KEY 255
	97
	98	/*
	99	* Maximum Encoded Key size will be padded to a multiple of the blocksize
	100	* i.e KMAC_MAX_KEY + KMAC_MAX_ENCODED_LEN = 258
	101	* Padded to a multiple of KMAC_MAX_BLOCKSIZE
	102	*/
	103	#define KMAC_MAX_KEY_ENCODED (KMAC_MAX_BLOCKSIZE * 2)
	104
	105	/* Fixed value of encode_string("KMAC") */
	106	static const unsigned char kmac_string[] = {
	107	0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43
	108	};
	109
	110
	111	#define KMAC_FLAG_XOF_MODE 1
	112
e23cda00 RL	113	struct kmac_data_st {
e23cda00 RL	114	void *provctx;
6e624a64	115	EVP_MD_CTX *ctx;
e23cda00 RL	116
	117	/*
	118	* References to the underlying keccak_kmac implementation. \|md\|
	119	* caches the digest, always. \|alloc_md\| only holds a reference to an
	120	* explicitly fetched digest.
	121	* \|md\| is cleared after a EVP_DigestInit call.
	122	*/
	123	const EVP_MD md; / Cache KMAC digest */
	124	EVP_MD alloc_md; / Fetched digest */
	125
6e624a64 SL	126	size_t out_len;
	127	int key_len;
	128	int custom_len;
	129	/* If xof_mode = 1 then we use right_encode(0) */
	130	int xof_mode;
	131	/* key and custom are stored in encoded form */
	132	unsigned char key[KMAC_MAX_KEY_ENCODED];
	133	unsigned char custom[KMAC_MAX_CUSTOM_ENCODED];
	134	};
	135
	136	static int encode_string(unsigned char out, int out_len,
	137	const unsigned char *in, int in_len);
	138	static int right_encode(unsigned char out, int out_len, size_t bits);
	139	static int bytepad(unsigned char out, int out_len,
	140	const unsigned char *in1, int in1_len,
	141	const unsigned char *in2, int in2_len,
	142	int w);
	143	static int kmac_bytepad_encode_key(unsigned char out, int out_len,
	144	const unsigned char *in, int in_len,
	145	int w);
6e624a64	146
e23cda00	147	static void kmac_free(void *vmacctx)
6e624a64	148	{
e23cda00 RL	149	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	150
6e624a64 SL	151	if (kctx != NULL) {
6e624a64 SL	152	EVP_MD_CTX_free(kctx->ctx);
e23cda00	153	EVP_MD_meth_free(kctx->alloc_md);
6e624a64 SL	154	OPENSSL_cleanse(kctx->key, kctx->key_len);
	155	OPENSSL_cleanse(kctx->custom, kctx->custom_len);
	156	OPENSSL_free(kctx);
	157	}
	158	}
	159
e23cda00 RL	160	/*
	161	* We have KMAC implemented as a hash, which we can use instead of
	162	* reimplementing the EVP functionality with direct use of
	163	* keccak_mac_init() and friends.
	164	*/
	165	static void kmac_new(void provctx, EVP_MD fetched_md, const EVP_MD md)
6e624a64	166	{
e23cda00 RL	167	struct kmac_data_st *kctx = NULL;
	168
	169	if (md == NULL)
	170	return NULL;
6e624a64 SL	171
	172	if ((kctx = OPENSSL_zalloc(sizeof(*kctx))) == NULL
	173	\|\| (kctx->ctx = EVP_MD_CTX_new()) == NULL) {
	174	kmac_free(kctx);
	175	return NULL;
	176	}
e23cda00	177	kctx->provctx = provctx;
6e624a64	178	kctx->md = md;
e23cda00 RL	179	kctx->alloc_md = fetched_md;
e23cda00 RL	180	kctx->out_len = EVP_MD_size(md);
6e624a64 SL	181	return kctx;
	182	}
	183
e23cda00	184	static void kmac_fetch_new(void provctx, const char *mdname)
6e624a64	185	{
e23cda00 RL	186	EVP_MD *fetched_md = EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(provctx),
	187	mdname, NULL);
	188	const EVP_MD *md = fetched_md;
	189	void *ret = NULL;
	190
	191	#ifndef FIPS_MODE /* Inside the FIPS module, we don't support legacy digests */
	192	/* TODO(3.0) BEGIN legacy stuff, to be removed */
	193	if (md == NULL)
	194	md = EVP_get_digestbyname(mdname);
	195	/* TODO(3.0) END of legacy stuff */
	196	#endif
	197
	198	ret = kmac_new(provctx, fetched_md, md);
	199	if (ret == NULL)
	200	EVP_MD_meth_free(fetched_md);
	201	return ret;
6e624a64 SL	202	}
6e624a64 SL	203
e23cda00	204	static void kmac128_new(void provctx)
6e624a64	205	{
e23cda00	206	return kmac_fetch_new(provctx, "KMAC128");
6e624a64 SL	207	}
6e624a64 SL	208
e23cda00	209	static void kmac256_new(void provctx)
6e624a64	210	{
e23cda00 RL	211	return kmac_fetch_new(provctx, "KMAC256");
	212	}
	213
	214	static void kmac_dup(void vsrc)
	215	{
	216	struct kmac_data_st *src = vsrc;
	217	struct kmac_data_st *dst = kmac_new(src->provctx, src->alloc_md, src->md);
7ed66e26	218
e23cda00	219	if (dst == NULL)
7ed66e26 KR	220	return NULL;
7ed66e26 KR	221
e23cda00 RL	222	if (!EVP_MD_CTX_copy(dst->ctx, src->ctx)
	223	\|\| (src->alloc_md != NULL && !EVP_MD_up_ref(src->alloc_md))) {
	224	kmac_free(dst);
7ed66e26 KR	225	return NULL;
	226	}
	227
e23cda00 RL	228	dst->md = src->md;
	229	dst->alloc_md = src->alloc_md;
	230	dst->out_len = src->out_len;
	231	dst->key_len = src->key_len;
	232	dst->custom_len = src->custom_len;
	233	dst->xof_mode = src->xof_mode;
	234	memcpy(dst->key, src->key, src->key_len);
	235	memcpy(dst->custom, src->custom, dst->custom_len);
6e624a64	236
e23cda00	237	return dst;
6e624a64 SL	238	}
	239
	240	/*
	241	* The init() assumes that any ctrl methods are set beforehand for
	242	* md, key and custom. Setting the fields afterwards will have no
	243	* effect on the output mac.
	244	*/
e23cda00	245	static int kmac_init(void *vmacctx)
6e624a64	246	{
e23cda00	247	struct kmac_data_st *kctx = vmacctx;
6e624a64 SL	248	EVP_MD_CTX *ctx = kctx->ctx;
	249	unsigned char out[KMAC_MAX_BLOCKSIZE];
	250	int out_len, block_len;
	251
e23cda00	252
6e624a64 SL	253	/* Check key has been set */
	254	if (kctx->key_len == 0) {
	255	EVPerr(EVP_F_KMAC_INIT, EVP_R_NO_KEY_SET);
	256	return 0;
	257	}
	258	if (!EVP_DigestInit_ex(kctx->ctx, kctx->md, NULL))
	259	return 0;
	260
	261	block_len = EVP_MD_block_size(kctx->md);
	262
	263	/* Set default custom string if it is not already set */
e23cda00 RL	264	if (kctx->custom_len == 0) {
	265	const OSSL_PARAM params[] = {
	266	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, "", 0),
	267	OSSL_PARAM_END
	268	};
	269	(void)kmac_ctx_set_params(kctx, params);
	270	}
6e624a64 SL	271
	272	return bytepad(out, &out_len, kmac_string, sizeof(kmac_string),
	273	kctx->custom, kctx->custom_len, block_len)
	274	&& EVP_DigestUpdate(ctx, out, out_len)
	275	&& EVP_DigestUpdate(ctx, kctx->key, kctx->key_len);
	276	}
	277
e23cda00	278	static size_t kmac_size(void *vmacctx)
6e624a64	279	{
e23cda00 RL	280	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	281
6e624a64 SL	282	return kctx->out_len;
	283	}
	284
e23cda00	285	static int kmac_update(void vmacctx, const unsigned char data,
6e624a64 SL	286	size_t datalen)
6e624a64 SL	287	{
e23cda00 RL	288	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	289
6e624a64 SL	290	return EVP_DigestUpdate(kctx->ctx, data, datalen);
	291	}
	292
e23cda00 RL	293	static int kmac_final(void vmacctx, unsigned char out, size_t *outl,
e23cda00 RL	294	size_t outsize)
6e624a64	295	{
e23cda00	296	struct kmac_data_st *kctx = vmacctx;
6e624a64 SL	297	EVP_MD_CTX *ctx = kctx->ctx;
	298	int lbits, len;
	299	unsigned char encoded_outlen[KMAC_MAX_ENCODED_HEADER_LEN];
e23cda00	300	int ok;
6e624a64 SL	301
	302	/* KMAC XOF mode sets the encoded length to 0 */
	303	lbits = (kctx->xof_mode ? 0 : (kctx->out_len * 8));
	304
e23cda00 RL	305	ok = right_encode(encoded_outlen, &len, lbits)
	306	&& EVP_DigestUpdate(ctx, encoded_outlen, len)
	307	&& EVP_DigestFinalXOF(ctx, out, kctx->out_len);
	308	if (ok && outl != NULL)
	309	*outl = kctx->out_len;
	310	return ok;
6e624a64 SL	311	}
6e624a64 SL	312
e23cda00 RL	313	static const OSSL_PARAM known_gettable_ctx_params[] = {
	314	OSSL_PARAM_size_t(OSSL_MAC_PARAM_OUTLEN, NULL),
	315	OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL), /* Same as "outlen" */
	316	OSSL_PARAM_size_t(OSSL_MAC_PARAM_DIGESTSIZE, NULL), /* Same as "outlen" */
	317	OSSL_PARAM_END
	318	};
	319	static const OSSL_PARAM *kmac_gettable_ctx_params(void)
6e624a64	320	{
e23cda00	321	return known_gettable_ctx_params;
6e624a64 SL	322	}
6e624a64 SL	323
e23cda00	324	static int kmac_ctx_get_params(void *vmacctx, OSSL_PARAM params[])
6e624a64	325	{
e23cda00	326	OSSL_PARAM *p;
6e624a64	327
e23cda00 RL	328	if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_OUTLEN)) != NULL
	329	\|\| (p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
	330	\|\| (p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_DIGESTSIZE)) != NULL)
	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[] = {
	337	OSSL_PARAM_int(OSSL_MAC_PARAM_XOF, NULL),
	338	OSSL_PARAM_size_t(OSSL_MAC_PARAM_OUTLEN, NULL),
	339	OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
	340	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
	341	OSSL_PARAM_octet_string(OSSL_MAC_PARAM_CUSTOM, NULL, 0),
	342	OSSL_PARAM_END
	343	};
	344	static const OSSL_PARAM *kmac_settable_ctx_params(void)
6e624a64	345	{
e23cda00	346	return known_settable_ctx_params;
6e624a64 SL	347	}
6e624a64 SL	348
e23cda00 RL	349	/*
	350	* The following params can be set any time before final():
	351	* - "outlen" or "size": The requested output length.
	352	* - "xof": If set, this indicates that right_encoded(0)
	353	* is part of the digested data, otherwise it
	354	* uses right_encoded(requested output length).
	355	*
	356	* All other params should be set before init().
	357	*/
	358	static int kmac_ctx_set_params(void vmacctx, const OSSL_PARAM params)
6e624a64	359	{
e23cda00 RL	360	struct kmac_data_st *kctx = vmacctx;
e23cda00 RL	361	const OSSL_PARAM *p;
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;
	366	if (((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_OUTLEN)) != NULL
	367	\|\|
	368	(p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_SIZE)) != NULL)
	369	&& !OSSL_PARAM_get_size_t(p, &kctx->out_len))
	370	return 0;
	371	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
	372	if (p->data_size < 4 \|\| p->data_size > KMAC_MAX_KEY) {
	373	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
	374	return 0;
	375	}
	376	if (!kmac_bytepad_encode_key(kctx->key, &kctx->key_len,
	377	p->data, p->data_size,
	378	EVP_MD_block_size(kctx->md)))
	379	return 0;
	380	}
	381	if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_CUSTOM))
	382	!= NULL) {
	383	if (p->data_size > KMAC_MAX_CUSTOM) {
	384	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CUSTOM_LENGTH);
	385	return 0;
	386	}
	387	if (!encode_string(kctx->custom, &kctx->custom_len,
	388	p->data, p->data_size))
	389	return 0;
	390	}
	391	return 1;
6e624a64 SL	392	}
	393
	394	/*
	395	* Encoding/Padding Methods.
	396	*/
	397
	398	/* Returns the number of bytes required to store 'bits' into a byte array */
	399	static unsigned int get_encode_size(size_t bits)
	400	{
	401	unsigned int cnt = 0, sz = sizeof(size_t);
	402
	403	while (bits && (cnt < sz)) {
	404	++cnt;
	405	bits >>= 8;
	406	}
	407	/* If bits is zero 1 byte is required */
	408	if (cnt == 0)
	409	cnt = 1;
	410	return cnt;
	411	}
	412
	413	/*
	414	* Convert an integer into bytes . The number of bytes is appended
	415	* to the end of the buffer. Returns an array of bytes 'out' of size
	416	* *out_len.
	417	*
	418	* e.g if bits = 32, out[2] = { 0x20, 0x01 }
	419	*
	420	*/
	421	static int right_encode(unsigned char out, int out_len, size_t bits)
	422	{
	423	unsigned int len = get_encode_size(bits);
	424	int i;
	425
	426	/* The length is constrained to a single byte: 2040/8 = 255 */
	427	if (len > 0xFF)
	428	return 0;
	429
	430	/* MSB's are at the start of the bytes array */
	431	for (i = len - 1; i >= 0; --i) {
	432	out[i] = (unsigned char)(bits & 0xFF);
	433	bits >>= 8;
	434	}
	435	/* Tack the length onto the end */
	436	out[len] = (unsigned char)len;
	437
	438	/* The Returned length includes the tacked on byte */
	439	*out_len = len + 1;
	440	return 1;
	441	}
	442
	443	/*
	444	* Encodes a string with a left encoded length added. Note that the
	445	* in_len is converted to bits (*8).
	446	*
	447	* e.g- in="KMAC" gives out[6] = { 0x01, 0x20, 0x4B, 0x4D, 0x41, 0x43 }
	448	* len bits K M A C
	449	*/
	450	static int encode_string(unsigned char out, int out_len,
	451	const unsigned char *in, int in_len)
	452	{
	453	if (in == NULL) {
	454	*out_len = 0;
	455	} else {
456	int i, bits, len;
457
458	bits = 8 * in_len;
459	len = get_encode_size(bits);
460	if (len > 0xFF)
461	return 0;
462
463	out[0] = len;
464	for (i = len; i > 0; --i) {
465	out[i] = (bits & 0xFF);
466	bits >>= 8;
467	}
468	memcpy(out + len + 1, in, in_len);
469	*out_len = (1 + len + in_len);
470	}
471	return 1;
472	}
473
474	/*
475	* Returns a zero padded encoding of the inputs in1 and an optional
476	* in2 (can be NULL). The padded output must be a multiple of the blocksize 'w'.
477	* The value of w is in bytes (< 256).
478	*
479	* The returned output is:
480	* zero_padded(multiple of w, (left_encode(w) \|\| in1 [\|\| in2])
481	*/
482	static int bytepad(unsigned char out, int out_len,
483	const unsigned char *in1, int in1_len,
484	const unsigned char *in2, int in2_len, int w)
485	{
486	int len;
487	unsigned char *p = out;
488	int sz = w;
489
490	/* Left encoded w */
491	*p++ = 1;
492	*p++ = w;
493	/* \|\| in1 */
494	memcpy(p, in1, in1_len);
495	p += in1_len;
496	/* [ \|\| in2 ] */
497	if (in2 != NULL && in2_len > 0) {
498	memcpy(p, in2, in2_len);
499	p += in2_len;
500	}
501	/* Figure out the pad size (divisible by w) */
502	len = p - out;
503	while (len > sz) {
504	sz += w;
505	}
506	/* zero pad the end of the buffer */
507	memset(p, 0, sz - len);
508	*out_len = sz;
509	return 1;
510	}
511
512	/*
513	* Returns out = bytepad(encode_string(in), w)
514	*/
515	static int kmac_bytepad_encode_key(unsigned char out, int out_len,
516	const unsigned char *in, int in_len,
517	int w)
518	{
519	unsigned char tmp[KMAC_MAX_KEY + KMAC_MAX_ENCODED_HEADER_LEN];
520	int tmp_len;
521
522	if (!encode_string(tmp, &tmp_len, in, in_len))
523	return 0;
524
525	return bytepad(out, out_len, tmp, tmp_len, NULL, 0, w);
526	}
527
e23cda00 RL	528	const OSSL_DISPATCH kmac128_functions[] = {
	529	{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac128_new },
	530	{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
	531	{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
	532	{ OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
	533	{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
	534	{ OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
	535	{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
	536	(void (*)(void))kmac_gettable_ctx_params },
	537	{ OSSL_FUNC_MAC_CTX_GET_PARAMS, (void (*)(void))kmac_ctx_get_params },
	538	{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
	539	(void (*)(void))kmac_settable_ctx_params },
	540	{ OSSL_FUNC_MAC_CTX_SET_PARAMS, (void (*)(void))kmac_ctx_set_params },
	541	{ 0, NULL }
6e624a64 SL	542	};
6e624a64 SL	543
e23cda00 RL	544	const OSSL_DISPATCH kmac256_functions[] = {
	545	{ OSSL_FUNC_MAC_NEWCTX, (void (*)(void))kmac256_new },
	546	{ OSSL_FUNC_MAC_DUPCTX, (void (*)(void))kmac_dup },
	547	{ OSSL_FUNC_MAC_FREECTX, (void (*)(void))kmac_free },
	548	{ OSSL_FUNC_MAC_INIT, (void (*)(void))kmac_init },
	549	{ OSSL_FUNC_MAC_UPDATE, (void (*)(void))kmac_update },
	550	{ OSSL_FUNC_MAC_FINAL, (void (*)(void))kmac_final },
	551	{ OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
	552	(void (*)(void))kmac_gettable_ctx_params },
	553	{ OSSL_FUNC_MAC_CTX_GET_PARAMS, (void (*)(void))kmac_ctx_get_params },
	554	{ OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
	555	(void (*)(void))kmac_settable_ctx_params },
	556	{ OSSL_FUNC_MAC_CTX_SET_PARAMS, (void (*)(void))kmac_ctx_set_params },
	557	{ 0, NULL }
6e624a64	558	};