providers/implementations/kdfs/pbkdf2.c - third_party/openssl - Git at Google

 /*
  * Copyright 2018-2022 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
  */

 /*
  * HMAC low level APIs are deprecated for public use, but still ok for internal
  * use.
  */
 #include "internal/deprecated.h"

 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
 #include <openssl/hmac.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"
 #include "pbkdf2.h"

 /* Constants specified in SP800-132 */
 #define KDF_PBKDF2_MIN_KEY_LEN_BITS  112
 #define KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO 0xFFFFFFFF
 #define KDF_PBKDF2_MIN_ITERATIONS 1000
 #define KDF_PBKDF2_MIN_SALT_LEN   (128 / 8)

 static OSSL_FUNC_kdf_newctx_fn kdf_pbkdf2_new;
 static OSSL_FUNC_kdf_dupctx_fn kdf_pbkdf2_dup;
 static OSSL_FUNC_kdf_freectx_fn kdf_pbkdf2_free;
 static OSSL_FUNC_kdf_reset_fn kdf_pbkdf2_reset;
 static OSSL_FUNC_kdf_derive_fn kdf_pbkdf2_derive;
 static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_pbkdf2_settable_ctx_params;
 static OSSL_FUNC_kdf_set_ctx_params_fn kdf_pbkdf2_set_ctx_params;
 static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_pbkdf2_gettable_ctx_params;
 static OSSL_FUNC_kdf_get_ctx_params_fn kdf_pbkdf2_get_ctx_params;

 static int pbkdf2_derive(const char *pass, size_t passlen,
                          const unsigned char *salt, int saltlen, uint64_t iter,
                          const EVP_MD *digest, unsigned char *key,
                          size_t keylen, int extra_checks);

 typedef struct {
     void *provctx;
     unsigned char *pass;
     size_t pass_len;
     unsigned char *salt;
     size_t salt_len;
     uint64_t iter;
     PROV_DIGEST digest;
     int lower_bound_checks;
 } KDF_PBKDF2;

 static void kdf_pbkdf2_init(KDF_PBKDF2 *ctx);

 static void *kdf_pbkdf2_new_no_init(void *provctx)
 {
     KDF_PBKDF2 *ctx;

     if (!ossl_prov_is_running())
         return NULL;

     ctx = OPENSSL_zalloc(sizeof(*ctx));
     if (ctx == NULL) {
         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
         return NULL;
     }
     ctx->provctx = provctx;
     return ctx;
 }

 static void *kdf_pbkdf2_new(void *provctx)
 {
     KDF_PBKDF2 *ctx = kdf_pbkdf2_new_no_init(provctx);

     if (ctx != NULL)
         kdf_pbkdf2_init(ctx);
     return ctx;
 }

 static void kdf_pbkdf2_cleanup(KDF_PBKDF2 *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_pbkdf2_free(void *vctx)
 {
     KDF_PBKDF2 *ctx = (KDF_PBKDF2 *)vctx;

     if (ctx != NULL) {
         kdf_pbkdf2_cleanup(ctx);
         OPENSSL_free(ctx);
     }
 }

 static void kdf_pbkdf2_reset(void *vctx)
 {
     KDF_PBKDF2 *ctx = (KDF_PBKDF2 *)vctx;
     void *provctx = ctx->provctx;

     kdf_pbkdf2_cleanup(ctx);
     ctx->provctx = provctx;
     kdf_pbkdf2_init(ctx);
 }

 static void *kdf_pbkdf2_dup(void *vctx)
 {
     const KDF_PBKDF2 *src = (const KDF_PBKDF2 *)vctx;
     KDF_PBKDF2 *dest;

     /* We need a new PBKDF2 object but uninitialised since we're filling it */
     dest = kdf_pbkdf2_new_no_init(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->lower_bound_checks = src->lower_bound_checks;
     }
     return dest;

  err:
     kdf_pbkdf2_free(dest);
     return NULL;
 }

 static void kdf_pbkdf2_init(KDF_PBKDF2 *ctx)
 {
     OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
     OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);

     params[0] = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
                                                  SN_sha1, 0);
     if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
         /* This is an error, but there is no way to indicate such directly */
         ossl_prov_digest_reset(&ctx->digest);
     ctx->iter = PKCS5_DEFAULT_ITER;
     ctx->lower_bound_checks = ossl_kdf_pbkdf2_default_checks;
 }

 static int pbkdf2_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) {
             ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
             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_pbkdf2_derive(void *vctx, unsigned char *key, size_t keylen,
                              const OSSL_PARAM params[])
 {
     KDF_PBKDF2 *ctx = (KDF_PBKDF2 *)vctx;
     const EVP_MD *md;

     if (!ossl_prov_is_running() || !kdf_pbkdf2_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 pbkdf2_derive((char *)ctx->pass, ctx->pass_len,
                          ctx->salt, ctx->salt_len, ctx->iter,
                          md, key, keylen, ctx->lower_bound_checks);
 }

 static int kdf_pbkdf2_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 {
     const OSSL_PARAM *p;
     KDF_PBKDF2 *ctx = vctx;
     OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
     int pkcs5;
     uint64_t iter, min_iter;

     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_PKCS5)) != NULL) {
         if (!OSSL_PARAM_get_int(p, &pkcs5))
             return 0;
         ctx->lower_bound_checks = pkcs5 == 0;
     }

     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
         if (!pbkdf2_set_membuf(&ctx->pass, &ctx->pass_len, p))
             return 0;

     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) {
         if (ctx->lower_bound_checks != 0
             && p->data_size < KDF_PBKDF2_MIN_SALT_LEN) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SALT_LENGTH);
             return 0;
         }
         if (!pbkdf2_set_membuf(&ctx->salt, &ctx->salt_len, p))
             return 0;
     }

     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_ITER)) != NULL) {
         if (!OSSL_PARAM_get_uint64(p, &iter))
             return 0;
         min_iter = ctx->lower_bound_checks != 0 ? KDF_PBKDF2_MIN_ITERATIONS : 1;
         if (iter < min_iter) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_ITERATION_COUNT);
             return 0;
         }
         ctx->iter = iter;
     }
     return 1;
 }

 static const OSSL_PARAM *kdf_pbkdf2_settable_ctx_params(ossl_unused void *ctx,
                                                         ossl_unused void *p_ctx)
 {
     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_PKCS5, NULL),
         OSSL_PARAM_END
     };
     return known_settable_ctx_params;
 }

 static int kdf_pbkdf2_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_pbkdf2_gettable_ctx_params(ossl_unused void *ctx,
                                                         ossl_unused void *p_ctx)
 {
     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_pbkdf2_functions[] = {
     { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_pbkdf2_new },
     { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_pbkdf2_dup },
     { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_pbkdf2_free },
     { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_pbkdf2_reset },
     { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_pbkdf2_derive },
     { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
       (void(*)(void))kdf_pbkdf2_settable_ctx_params },
     { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_pbkdf2_set_ctx_params },
     { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
       (void(*)(void))kdf_pbkdf2_gettable_ctx_params },
     { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_pbkdf2_get_ctx_params },
     { 0, NULL }
 };

 /*
  * This is an implementation of PKCS#5 v2.0 password based encryption key
  * derivation function PBKDF2. SHA1 version verified against test vectors
  * posted by Peter Gutmann to the PKCS-TNG mailing list.
  *
  * The constraints specified by SP800-132 have been added i.e.
  *  - Check the range of the key length.
  *  - Minimum iteration count of 1000.
  *  - Randomly-generated portion of the salt shall be at least 128 bits.
  */
 static int pbkdf2_derive(const char *pass, size_t passlen,
                          const unsigned char *salt, int saltlen, uint64_t iter,
                          const EVP_MD *digest, unsigned char *key,
                          size_t keylen, int lower_bound_checks)
 {
     int ret = 0;
     unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
     int cplen, k, tkeylen, mdlen;
     uint64_t j;
     unsigned long i = 1;
     HMAC_CTX *hctx_tpl = NULL, *hctx = NULL;

     mdlen = EVP_MD_get_size(digest);
     if (mdlen <= 0)
         return 0;

     /*
      * This check should always be done because keylen / mdlen >= (2^32 - 1)
      * results in an overflow of the loop counter 'i'.
      */
     if ((keylen / mdlen) >= KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO) {
         ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
         return 0;
     }

     if (lower_bound_checks) {
         if ((keylen * 8) < KDF_PBKDF2_MIN_KEY_LEN_BITS) {
             ERR_raise(ERR_LIB_PROV, PROV_R_KEY_SIZE_TOO_SMALL);
             return 0;
         }
         if (saltlen < KDF_PBKDF2_MIN_SALT_LEN) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SALT_LENGTH);
             return 0;
         }
         if (iter < KDF_PBKDF2_MIN_ITERATIONS) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_ITERATION_COUNT);
             return 0;
         }
     }

     hctx_tpl = HMAC_CTX_new();
     if (hctx_tpl == NULL)
         return 0;
     p = key;
     tkeylen = keylen;
     if (!HMAC_Init_ex(hctx_tpl, pass, passlen, digest, NULL))
         goto err;
     hctx = HMAC_CTX_new();
     if (hctx == NULL)
         goto err;
     while (tkeylen) {
         if (tkeylen > mdlen)
             cplen = mdlen;
         else
             cplen = tkeylen;
         /*
          * We are unlikely to ever use more than 256 blocks (5120 bits!) but
          * just in case...
          */
         itmp[0] = (unsigned char)((i >> 24) & 0xff);
         itmp[1] = (unsigned char)((i >> 16) & 0xff);
         itmp[2] = (unsigned char)((i >> 8) & 0xff);
         itmp[3] = (unsigned char)(i & 0xff);
         if (!HMAC_CTX_copy(hctx, hctx_tpl))
             goto err;
         if (!HMAC_Update(hctx, salt, saltlen)
                 || !HMAC_Update(hctx, itmp, 4)
                 || !HMAC_Final(hctx, digtmp, NULL))
             goto err;
         memcpy(p, digtmp, cplen);
         for (j = 1; j < iter; j++) {
             if (!HMAC_CTX_copy(hctx, hctx_tpl))
                 goto err;
             if (!HMAC_Update(hctx, digtmp, mdlen)
                     || !HMAC_Final(hctx, digtmp, NULL))
                 goto err;
             for (k = 0; k < cplen; k++)
                 p[k] ^= digtmp[k];
         }
         tkeylen -= cplen;
         i++;
         p += cplen;
     }
     ret = 1;

 err:
     HMAC_CTX_free(hctx);
     HMAC_CTX_free(hctx_tpl);
     return ret;
 }
	/*
	* Copyright 2018-2022 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
	*/

	/*
	* HMAC low level APIs are deprecated for public use, but still ok for internal
	* use.
	*/
	#include "internal/deprecated.h"

	#include <stdlib.h>
	#include <stdarg.h>
	#include <string.h>
	#include <openssl/hmac.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"
	#include "pbkdf2.h"

	/* Constants specified in SP800-132 */
	#define KDF_PBKDF2_MIN_KEY_LEN_BITS 112
	#define KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO 0xFFFFFFFF
	#define KDF_PBKDF2_MIN_ITERATIONS 1000
	#define KDF_PBKDF2_MIN_SALT_LEN (128 / 8)

	static OSSL_FUNC_kdf_newctx_fn kdf_pbkdf2_new;
	static OSSL_FUNC_kdf_dupctx_fn kdf_pbkdf2_dup;
	static OSSL_FUNC_kdf_freectx_fn kdf_pbkdf2_free;
	static OSSL_FUNC_kdf_reset_fn kdf_pbkdf2_reset;
	static OSSL_FUNC_kdf_derive_fn kdf_pbkdf2_derive;
	static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_pbkdf2_settable_ctx_params;
	static OSSL_FUNC_kdf_set_ctx_params_fn kdf_pbkdf2_set_ctx_params;
	static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_pbkdf2_gettable_ctx_params;
	static OSSL_FUNC_kdf_get_ctx_params_fn kdf_pbkdf2_get_ctx_params;

	static int pbkdf2_derive(const char *pass, size_t passlen,
	const unsigned char *salt, int saltlen, uint64_t iter,
	const EVP_MD digest, unsigned char key,
	size_t keylen, int extra_checks);

	typedef struct {
	void *provctx;
	unsigned char *pass;
	size_t pass_len;
	unsigned char *salt;
	size_t salt_len;
	uint64_t iter;
	PROV_DIGEST digest;
	int lower_bound_checks;
	} KDF_PBKDF2;

	static void kdf_pbkdf2_init(KDF_PBKDF2 *ctx);

	static void kdf_pbkdf2_new_no_init(void provctx)
	{
	KDF_PBKDF2 *ctx;

	if (!ossl_prov_is_running())
	return NULL;

	ctx = OPENSSL_zalloc(sizeof(*ctx));
	if (ctx == NULL) {
	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
	return NULL;
	}
	ctx->provctx = provctx;
	return ctx;
	}

	static void kdf_pbkdf2_new(void provctx)
	{
	KDF_PBKDF2 *ctx = kdf_pbkdf2_new_no_init(provctx);

	if (ctx != NULL)
	kdf_pbkdf2_init(ctx);
	return ctx;
	}

	static void kdf_pbkdf2_cleanup(KDF_PBKDF2 *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_pbkdf2_free(void *vctx)
	{
	KDF_PBKDF2 ctx = (KDF_PBKDF2 )vctx;

	if (ctx != NULL) {
	kdf_pbkdf2_cleanup(ctx);
	OPENSSL_free(ctx);
	}
	}

	static void kdf_pbkdf2_reset(void *vctx)
	{
	KDF_PBKDF2 ctx = (KDF_PBKDF2 )vctx;
	void *provctx = ctx->provctx;

	kdf_pbkdf2_cleanup(ctx);
	ctx->provctx = provctx;
	kdf_pbkdf2_init(ctx);
	}

	static void kdf_pbkdf2_dup(void vctx)
	{
	const KDF_PBKDF2 src = (const KDF_PBKDF2 )vctx;
	KDF_PBKDF2 *dest;

	/* We need a new PBKDF2 object but uninitialised since we're filling it */
	dest = kdf_pbkdf2_new_no_init(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->lower_bound_checks = src->lower_bound_checks;
	}
	return dest;

	err:
	kdf_pbkdf2_free(dest);
	return NULL;
	}

	static void kdf_pbkdf2_init(KDF_PBKDF2 *ctx)
	{
	OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
	OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);

	params[0] = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
	SN_sha1, 0);
	if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
	/* This is an error, but there is no way to indicate such directly */
	ossl_prov_digest_reset(&ctx->digest);
	ctx->iter = PKCS5_DEFAULT_ITER;
	ctx->lower_bound_checks = ossl_kdf_pbkdf2_default_checks;
	}

	static int pbkdf2_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) {
	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
	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_pbkdf2_derive(void vctx, unsigned char key, size_t keylen,
	const OSSL_PARAM params[])
	{
	KDF_PBKDF2 ctx = (KDF_PBKDF2 )vctx;
	const EVP_MD *md;

	if (!ossl_prov_is_running() \|\| !kdf_pbkdf2_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 pbkdf2_derive((char *)ctx->pass, ctx->pass_len,
	ctx->salt, ctx->salt_len, ctx->iter,
	md, key, keylen, ctx->lower_bound_checks);
	}

	static int kdf_pbkdf2_set_ctx_params(void *vctx, const OSSL_PARAM params[])
	{
	const OSSL_PARAM *p;
	KDF_PBKDF2 *ctx = vctx;
	OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
	int pkcs5;
	uint64_t iter, min_iter;

	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_PKCS5)) != NULL) {
	if (!OSSL_PARAM_get_int(p, &pkcs5))
	return 0;
	ctx->lower_bound_checks = pkcs5 == 0;
	}

	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PASSWORD)) != NULL)
	if (!pbkdf2_set_membuf(&ctx->pass, &ctx->pass_len, p))
	return 0;

	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) {
	if (ctx->lower_bound_checks != 0
	&& p->data_size < KDF_PBKDF2_MIN_SALT_LEN) {
	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SALT_LENGTH);
	return 0;
	}
	if (!pbkdf2_set_membuf(&ctx->salt, &ctx->salt_len, p))
	return 0;
	}

	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_ITER)) != NULL) {
	if (!OSSL_PARAM_get_uint64(p, &iter))
	return 0;
	min_iter = ctx->lower_bound_checks != 0 ? KDF_PBKDF2_MIN_ITERATIONS : 1;
	if (iter < min_iter) {
	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_ITERATION_COUNT);
	return 0;
	}
	ctx->iter = iter;
	}
	return 1;
	}

	static const OSSL_PARAM kdf_pbkdf2_settable_ctx_params(ossl_unused void ctx,
	ossl_unused void *p_ctx)
	{
	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_PKCS5, NULL),
	OSSL_PARAM_END
	};
	return known_settable_ctx_params;
	}

	static int kdf_pbkdf2_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_pbkdf2_gettable_ctx_params(ossl_unused void ctx,
	ossl_unused void *p_ctx)
	{
	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_pbkdf2_functions[] = {
	{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_pbkdf2_new },
	{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_pbkdf2_dup },
	{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_pbkdf2_free },
	{ OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_pbkdf2_reset },
	{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_pbkdf2_derive },
	{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
	(void(*)(void))kdf_pbkdf2_settable_ctx_params },
	{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_pbkdf2_set_ctx_params },
	{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
	(void(*)(void))kdf_pbkdf2_gettable_ctx_params },
	{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_pbkdf2_get_ctx_params },
	{ 0, NULL }
	};

	/*
	* This is an implementation of PKCS#5 v2.0 password based encryption key
	* derivation function PBKDF2. SHA1 version verified against test vectors
	* posted by Peter Gutmann to the PKCS-TNG mailing list.
	*
	* The constraints specified by SP800-132 have been added i.e.
	* - Check the range of the key length.
	* - Minimum iteration count of 1000.
	* - Randomly-generated portion of the salt shall be at least 128 bits.
	*/
	static int pbkdf2_derive(const char *pass, size_t passlen,
	const unsigned char *salt, int saltlen, uint64_t iter,
	const EVP_MD digest, unsigned char key,
	size_t keylen, int lower_bound_checks)
	{
	int ret = 0;
	unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
	int cplen, k, tkeylen, mdlen;
	uint64_t j;
	unsigned long i = 1;
	HMAC_CTX hctx_tpl = NULL, hctx = NULL;

	mdlen = EVP_MD_get_size(digest);
	if (mdlen <= 0)
	return 0;

	/*
	* This check should always be done because keylen / mdlen >= (2^32 - 1)
	* results in an overflow of the loop counter 'i'.
	*/
	if ((keylen / mdlen) >= KDF_PBKDF2_MAX_KEY_LEN_DIGEST_RATIO) {
	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
	return 0;
	}

	if (lower_bound_checks) {
	if ((keylen * 8) < KDF_PBKDF2_MIN_KEY_LEN_BITS) {
	ERR_raise(ERR_LIB_PROV, PROV_R_KEY_SIZE_TOO_SMALL);
	return 0;
	}
	if (saltlen < KDF_PBKDF2_MIN_SALT_LEN) {
	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SALT_LENGTH);
	return 0;
	}
	if (iter < KDF_PBKDF2_MIN_ITERATIONS) {
	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_ITERATION_COUNT);
	return 0;
	}
	}

	hctx_tpl = HMAC_CTX_new();
	if (hctx_tpl == NULL)
	return 0;
	p = key;
	tkeylen = keylen;
	if (!HMAC_Init_ex(hctx_tpl, pass, passlen, digest, NULL))
	goto err;
	hctx = HMAC_CTX_new();
	if (hctx == NULL)
	goto err;
	while (tkeylen) {
	if (tkeylen > mdlen)
	cplen = mdlen;
	else
	cplen = tkeylen;
	/*
	* We are unlikely to ever use more than 256 blocks (5120 bits!) but
	* just in case...
	*/
	itmp[0] = (unsigned char)((i >> 24) & 0xff);
	itmp[1] = (unsigned char)((i >> 16) & 0xff);
	itmp[2] = (unsigned char)((i >> 8) & 0xff);
	itmp[3] = (unsigned char)(i & 0xff);
	if (!HMAC_CTX_copy(hctx, hctx_tpl))
	goto err;
	if (!HMAC_Update(hctx, salt, saltlen)
	\|\| !HMAC_Update(hctx, itmp, 4)
	\|\| !HMAC_Final(hctx, digtmp, NULL))
	goto err;
	memcpy(p, digtmp, cplen);
	for (j = 1; j < iter; j++) {
	if (!HMAC_CTX_copy(hctx, hctx_tpl))
	goto err;
	if (!HMAC_Update(hctx, digtmp, mdlen)
	\|\| !HMAC_Final(hctx, digtmp, NULL))
	goto err;
	for (k = 0; k < cplen; k++)
	p[k] ^= digtmp[k];
	}
	tkeylen -= cplen;
	i++;
	p += cplen;
	}
	ret = 1;

	err:
	HMAC_CTX_free(hctx);
	HMAC_CTX_free(hctx_tpl);
	return ret;
	}