/*

 * Copyright 1999-2023 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

 */

#include <openssl/trace.h>

#include <stdlib.h>

#include <stdarg.h>

#include <string.h>

#include <openssl/evp.h>

#include <openssl/kdf.h>

#include <openssl/core_names.h>

#include <openssl/proverr.h>

#include "internal/cryptlib.h"

#include "internal/numbers.h"

#include "crypto/evp.h"

#include "prov/provider_ctx.h"

#include "prov/providercommon.h"

#include "prov/implementations.h"

#include "prov/provider_util.h"

static OSSL_FUNC_kdf_newctx_fn kdf_pkcs12_new;

static OSSL_FUNC_kdf_dupctx_fn kdf_pkcs12_dup;

static OSSL_FUNC_kdf_freectx_fn kdf_pkcs12_free;

static OSSL_FUNC_kdf_reset_fn kdf_pkcs12_reset;

static OSSL_FUNC_kdf_derive_fn kdf_pkcs12_derive;

static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_pkcs12_settable_ctx_params;

static OSSL_FUNC_kdf_set_ctx_params_fn kdf_pkcs12_set_ctx_params;

static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_pkcs12_gettable_ctx_params;

static OSSL_FUNC_kdf_get_ctx_params_fn kdf_pkcs12_get_ctx_params;

typedef struct {

    void *provctx;

    PROV_DIGEST digest;

    unsigned char *pass;

    size_t pass_len;

    unsigned char *salt;

    size_t salt_len;

    uint64_t iter;

    int id;

} KDF_PKCS12;

/* PKCS12 compatible key/IV generation */

static int pkcs12kdf_derive(const unsigned char *pass, size_t passlen,

    const unsigned char *salt, size_t saltlen,

    int id, uint64_t iter, const EVP_MD *md_type,

    unsigned char *out, size_t n)

{

    unsigned char *B = NULL, *D = NULL, *I = NULL, *p = NULL, *Ai = NULL;

    size_t Slen, Plen, Ilen;

    size_t i, j, k, u, v;

    uint64_t iter_cnt;

    int ret = 0, ui, vi;

    EVP_MD_CTX *ctx = NULL;

    ctx = EVP_MD_CTX_new();

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_PROV, ERR_R_EVP_LIB);

        goto end;

    }

    vi = EVP_MD_get_block_size(md_type);

    ui = EVP_MD_get_size(md_type);

    if (ui <= 0 || vi <= 0) {

        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST_SIZE);

        goto end;

    }

    u = (size_t)ui;

    v = (size_t)vi;

    D = OPENSSL_malloc(v);

    Ai = OPENSSL_malloc(u);

    B = OPENSSL_malloc(v + 1);

    Slen = v * ((saltlen + v - 1) / v);

    if (passlen != 0)

        Plen = v * ((passlen + v - 1) / v);

    else

        Plen = 0;

    Ilen = Slen + Plen;

    I = OPENSSL_malloc(Ilen);

    if (D == NULL || Ai == NULL || B == NULL || I == NULL)

        goto end;

    for (i = 0; i < v; i++)

        D[i] = id;

    p = I;

    for (i = 0; i < Slen; i++)

        *p++ = salt[i % saltlen];

    for (i = 0; i < Plen; i++)

        *p++ = pass[i % passlen];

    for (;;) {

        if (!EVP_DigestInit_ex(ctx, md_type, NULL)

            || !EVP_DigestUpdate(ctx, D, v)

            || !EVP_DigestUpdate(ctx, I, Ilen)

            || !EVP_DigestFinal_ex(ctx, Ai, NULL))

            goto end;

        for (iter_cnt = 1; iter_cnt < iter; iter_cnt++) {

            if (!EVP_DigestInit_ex(ctx, md_type, NULL)

                || !EVP_DigestUpdate(ctx, Ai, u)

                || !EVP_DigestFinal_ex(ctx, Ai, NULL))

                goto end;

        }

        memcpy(out, Ai, n < u ? n : u);

        if (u >= n) {

            ret = 1;

            break;

        }

        n -= u;

        out += u;

        for (j = 0; j < v; j++)

            B[j] = Ai[j % u];

        for (j = 0; j < Ilen; j += v) {

            unsigned char *Ij = I + j;

            uint16_t c = 1;

            /* Work out Ij = Ij + B + 1 */

            for (k = v; k > 0;) {

                k--;

                c += Ij[k] + B[k];

                Ij[k] = (unsigned char)c;

                c >>= 8;

            }

        }

    }

end:

    OPENSSL_free(Ai);

    OPENSSL_free(B);

    OPENSSL_free(D);

    OPENSSL_free(I);

    EVP_MD_CTX_free(ctx);

    return ret;

}

static void *kdf_pkcs12_new(void *provctx)

{

    KDF_PKCS12 *ctx;

    if (!ossl_prov_is_running())

        return NULL;

    ctx = OPENSSL_zalloc(sizeof(*ctx));

    if (ctx == NULL)

        return NULL;

    ctx->provctx = provctx;

    return ctx;

}

static void kdf_pkcs12_cleanup(KDF_PKCS12 *ctx)

{

    ossl_prov_digest_reset(&ctx->digest);

    OPENSSL_free(ctx->salt);

    OPENSSL_clear_free(ctx->pass, ctx->pass_len);

    memset(ctx, 0, sizeof(*ctx));

}

static void kdf_pkcs12_free(void *vctx)

{

    KDF_PKCS12 *ctx = (KDF_PKCS12 *)vctx;

    if (ctx != NULL) {

        kdf_pkcs12_cleanup(ctx);

        OPENSSL_free(ctx);

    }

}

static void kdf_pkcs12_reset(void *vctx)

{

    KDF_PKCS12 *ctx = (KDF_PKCS12 *)vctx;

    void *provctx = ctx->provctx;

    kdf_pkcs12_cleanup(ctx);

    ctx->provctx = provctx;

}

static void *kdf_pkcs12_dup(void *vctx)

{

    const KDF_PKCS12 *src = (const KDF_PKCS12 *)vctx;

    KDF_PKCS12 *dest;

    dest = kdf_pkcs12_new(src->provctx);

    if (dest != NULL) {

        if (!ossl_prov_memdup(src->salt, src->salt_len,

                &dest->salt, &dest->salt_len)

            || !ossl_prov_memdup(src->pass, src->pass_len,

                &dest->pass, &dest->pass_len)

            || !ossl_prov_digest_copy(&dest->digest, &src->digest))

            goto err;

        dest->iter = src->iter;

        dest->id = src->id;

    }

    return dest;

err:

    kdf_pkcs12_free(dest);

    return NULL;

}

static int pkcs12kdf_set_membuf(unsigned char **buffer, size_t *buflen,

    const OSSL_PARAM *p)

{

    OPENSSL_clear_free(*buffer, *buflen);

    *buffer = NULL;

    *buflen = 0;

    if (p->data_size == 0) {

        if ((*buffer = OPENSSL_malloc(1)) == NULL)

            return 0;

    } else if (p->data != NULL) {

        if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))

            return 0;

    }

    return 1;

}

static int kdf_pkcs12_derive(void *vctx, unsigned char *key, size_t keylen,

    const OSSL_PARAM params[])

{

    KDF_PKCS12 *ctx = (KDF_PKCS12 *)vctx;

    const EVP_MD *md;

    if (!ossl_prov_is_running() || !kdf_pkcs12_set_ctx_params(ctx, params))

        return 0;

    if (ctx->pass == NULL) {

        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);

        return 0;

    }

    if (ctx->salt == NULL) {

        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);

        return 0;

    }

    md = ossl_prov_digest_md(&ctx->digest);

    return pkcs12kdf_derive(ctx->pass, ctx->pass_len, ctx->salt, ctx->salt_len,

        ctx->id, ctx->iter, md, key, keylen);

}

static int kdf_pkcs12_set_ctx_params(void *vctx, const OSSL_PARAM params[])

{

    const OSSL_PARAM *p;

    KDF_PKCS12 *ctx = vctx;

    OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);

    if (params == NULL)

        return 1;

    if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))

        return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)

        if (!pkcs12kdf_set_membuf(&ctx->pass, &ctx->pass_len, p))

            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)

        if (!pkcs12kdf_set_membuf(&ctx->salt, &ctx->salt_len, p))

            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PKCS12_ID)) != NULL)

        if (!OSSL_PARAM_get_int(p, &ctx->id))

            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_ITER)) != NULL)

        if (!OSSL_PARAM_get_uint64(p, &ctx->iter))

            return 0;

#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION

    /*

     * If we're running the fuzzer, limit iteration count to

     * 100 so we don't time out running the derivation for

     * a really long time

     */

    if (getenv("OPENSSL_RUNNING_UNIT_TESTS") == NULL && p != NULL && ctx->iter > 100)

        ctx->iter = 100;

#endif

    return 1;

}

static const OSSL_PARAM *kdf_pkcs12_settable_ctx_params(

    ossl_unused void *ctx, ossl_unused void *provctx)

{

    static const OSSL_PARAM known_settable_ctx_params[] = {

        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),

        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),

        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),

        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),

        OSSL_PARAM_uint64(OSSL_KDF_PARAM_ITER, NULL),

        OSSL_PARAM_int(OSSL_KDF_PARAM_PKCS12_ID, NULL),

        OSSL_PARAM_END

    };

    return known_settable_ctx_params;

}

static int kdf_pkcs12_get_ctx_params(void *vctx, OSSL_PARAM params[])

{

    OSSL_PARAM *p;

    if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)

        return OSSL_PARAM_set_size_t(p, SIZE_MAX);

    return -2;

}

static const OSSL_PARAM *kdf_pkcs12_gettable_ctx_params(

    ossl_unused void *ctx, ossl_unused void *provctx)

{

    static const OSSL_PARAM known_gettable_ctx_params[] = {

        OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),

        OSSL_PARAM_END

    };

    return known_gettable_ctx_params;

}

const OSSL_DISPATCH ossl_kdf_pkcs12_functions[] = {

    { OSSL_FUNC_KDF_NEWCTX, (void (*)(void))kdf_pkcs12_new },

    { OSSL_FUNC_KDF_DUPCTX, (void (*)(void))kdf_pkcs12_dup },

    { OSSL_FUNC_KDF_FREECTX, (void (*)(void))kdf_pkcs12_free },

    { OSSL_FUNC_KDF_RESET, (void (*)(void))kdf_pkcs12_reset },

    { OSSL_FUNC_KDF_DERIVE, (void (*)(void))kdf_pkcs12_derive },

    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,

        (void (*)(void))kdf_pkcs12_settable_ctx_params },

    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void (*)(void))kdf_pkcs12_set_ctx_params },

    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,

        (void (*)(void))kdf_pkcs12_gettable_ctx_params },

    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void (*)(void))kdf_pkcs12_get_ctx_params },

    OSSL_DISPATCH_END

};