762 lines
25 KiB
C
762 lines
25 KiB
C
/*
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* Copyright 2016-2023 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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/*
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* HMAC low level APIs are deprecated for public use, but still ok for internal
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* use.
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*/
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#include "internal/deprecated.h"
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#include <stdlib.h>
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#include <stdarg.h>
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#include <string.h>
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#include <openssl/hmac.h>
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#include <openssl/evp.h>
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#include <openssl/kdf.h>
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#include <openssl/core_names.h>
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#include <openssl/proverr.h>
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#include "internal/cryptlib.h"
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#include "internal/numbers.h"
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#include "internal/packet.h"
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#include "crypto/evp.h"
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#include "prov/provider_ctx.h"
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#include "prov/providercommon.h"
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#include "prov/implementations.h"
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#include "prov/provider_util.h"
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#include "internal/e_os.h"
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#include "internal/params.h"
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#define HKDF_MAXBUF 2048
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#define HKDF_MAXINFO (32*1024)
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static OSSL_FUNC_kdf_newctx_fn kdf_hkdf_new;
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static OSSL_FUNC_kdf_dupctx_fn kdf_hkdf_dup;
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static OSSL_FUNC_kdf_freectx_fn kdf_hkdf_free;
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static OSSL_FUNC_kdf_reset_fn kdf_hkdf_reset;
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static OSSL_FUNC_kdf_derive_fn kdf_hkdf_derive;
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static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_hkdf_settable_ctx_params;
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static OSSL_FUNC_kdf_set_ctx_params_fn kdf_hkdf_set_ctx_params;
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static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_hkdf_gettable_ctx_params;
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static OSSL_FUNC_kdf_get_ctx_params_fn kdf_hkdf_get_ctx_params;
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static OSSL_FUNC_kdf_derive_fn kdf_tls1_3_derive;
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static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_tls1_3_settable_ctx_params;
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static OSSL_FUNC_kdf_set_ctx_params_fn kdf_tls1_3_set_ctx_params;
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static int HKDF(OSSL_LIB_CTX *libctx, const EVP_MD *evp_md,
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const unsigned char *salt, size_t salt_len,
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const unsigned char *key, size_t key_len,
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const unsigned char *info, size_t info_len,
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unsigned char *okm, size_t okm_len);
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static int HKDF_Extract(OSSL_LIB_CTX *libctx, const EVP_MD *evp_md,
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const unsigned char *salt, size_t salt_len,
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const unsigned char *ikm, size_t ikm_len,
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unsigned char *prk, size_t prk_len);
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static int HKDF_Expand(const EVP_MD *evp_md,
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const unsigned char *prk, size_t prk_len,
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const unsigned char *info, size_t info_len,
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unsigned char *okm, size_t okm_len);
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/* Settable context parameters that are common across HKDF and the TLS KDF */
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#define HKDF_COMMON_SETTABLES \
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OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0), \
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OSSL_PARAM_int(OSSL_KDF_PARAM_MODE, NULL), \
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OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0), \
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OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0), \
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OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0), \
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OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0)
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typedef struct {
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void *provctx;
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int mode;
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PROV_DIGEST digest;
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unsigned char *salt;
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size_t salt_len;
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unsigned char *key;
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size_t key_len;
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unsigned char *prefix;
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size_t prefix_len;
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unsigned char *label;
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size_t label_len;
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unsigned char *data;
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size_t data_len;
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unsigned char *info;
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size_t info_len;
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} KDF_HKDF;
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static void *kdf_hkdf_new(void *provctx)
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{
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KDF_HKDF *ctx;
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if (!ossl_prov_is_running())
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return NULL;
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if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL)
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ctx->provctx = provctx;
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return ctx;
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}
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static void kdf_hkdf_free(void *vctx)
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{
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KDF_HKDF *ctx = (KDF_HKDF *)vctx;
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if (ctx != NULL) {
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kdf_hkdf_reset(ctx);
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OPENSSL_free(ctx);
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}
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}
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static void kdf_hkdf_reset(void *vctx)
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{
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KDF_HKDF *ctx = (KDF_HKDF *)vctx;
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void *provctx = ctx->provctx;
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ossl_prov_digest_reset(&ctx->digest);
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OPENSSL_free(ctx->salt);
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OPENSSL_free(ctx->prefix);
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OPENSSL_free(ctx->label);
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OPENSSL_clear_free(ctx->data, ctx->data_len);
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OPENSSL_clear_free(ctx->key, ctx->key_len);
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OPENSSL_clear_free(ctx->info, ctx->info_len);
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memset(ctx, 0, sizeof(*ctx));
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ctx->provctx = provctx;
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}
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static void *kdf_hkdf_dup(void *vctx)
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{
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const KDF_HKDF *src = (const KDF_HKDF *)vctx;
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KDF_HKDF *dest;
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dest = kdf_hkdf_new(src->provctx);
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if (dest != NULL) {
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if (!ossl_prov_memdup(src->salt, src->salt_len, &dest->salt,
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&dest->salt_len)
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|| !ossl_prov_memdup(src->key, src->key_len,
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&dest->key , &dest->key_len)
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|| !ossl_prov_memdup(src->prefix, src->prefix_len,
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&dest->prefix, &dest->prefix_len)
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|| !ossl_prov_memdup(src->label, src->label_len,
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&dest->label, &dest->label_len)
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|| !ossl_prov_memdup(src->data, src->data_len,
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&dest->data, &dest->data_len)
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|| !ossl_prov_memdup(src->info, src->info_len,
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&dest->info, &dest->info_len)
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|| !ossl_prov_digest_copy(&dest->digest, &src->digest))
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goto err;
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dest->mode = src->mode;
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}
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return dest;
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err:
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kdf_hkdf_free(dest);
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return NULL;
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}
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static size_t kdf_hkdf_size(KDF_HKDF *ctx)
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{
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int sz;
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const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
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if (ctx->mode != EVP_KDF_HKDF_MODE_EXTRACT_ONLY)
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return SIZE_MAX;
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if (md == NULL) {
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ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
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return 0;
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}
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sz = EVP_MD_get_size(md);
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if (sz < 0)
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return 0;
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return sz;
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}
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static int kdf_hkdf_derive(void *vctx, unsigned char *key, size_t keylen,
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const OSSL_PARAM params[])
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{
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KDF_HKDF *ctx = (KDF_HKDF *)vctx;
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OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
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const EVP_MD *md;
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if (!ossl_prov_is_running() || !kdf_hkdf_set_ctx_params(ctx, params))
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return 0;
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md = ossl_prov_digest_md(&ctx->digest);
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if (md == NULL) {
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ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
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return 0;
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}
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if (ctx->key == NULL) {
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ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
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return 0;
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}
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if (keylen == 0) {
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ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
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return 0;
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}
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switch (ctx->mode) {
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case EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND:
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default:
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return HKDF(libctx, md, ctx->salt, ctx->salt_len,
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ctx->key, ctx->key_len, ctx->info, ctx->info_len, key, keylen);
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case EVP_KDF_HKDF_MODE_EXTRACT_ONLY:
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return HKDF_Extract(libctx, md, ctx->salt, ctx->salt_len,
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ctx->key, ctx->key_len, key, keylen);
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case EVP_KDF_HKDF_MODE_EXPAND_ONLY:
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return HKDF_Expand(md, ctx->key, ctx->key_len, ctx->info,
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ctx->info_len, key, keylen);
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}
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}
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static int hkdf_common_set_ctx_params(KDF_HKDF *ctx, const OSSL_PARAM params[])
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{
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OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
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const OSSL_PARAM *p;
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int n;
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if (params == NULL)
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return 1;
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if (!ossl_prov_digest_load_from_params(&ctx->digest, params, libctx))
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return 0;
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if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE)) != NULL) {
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if (p->data_type == OSSL_PARAM_UTF8_STRING) {
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if (OPENSSL_strcasecmp(p->data, "EXTRACT_AND_EXPAND") == 0) {
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ctx->mode = EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND;
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} else if (OPENSSL_strcasecmp(p->data, "EXTRACT_ONLY") == 0) {
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ctx->mode = EVP_KDF_HKDF_MODE_EXTRACT_ONLY;
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} else if (OPENSSL_strcasecmp(p->data, "EXPAND_ONLY") == 0) {
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ctx->mode = EVP_KDF_HKDF_MODE_EXPAND_ONLY;
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} else {
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ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
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return 0;
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}
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} else if (OSSL_PARAM_get_int(p, &n)) {
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if (n != EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND
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&& n != EVP_KDF_HKDF_MODE_EXTRACT_ONLY
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&& n != EVP_KDF_HKDF_MODE_EXPAND_ONLY) {
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ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
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return 0;
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}
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ctx->mode = n;
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} else {
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ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
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return 0;
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}
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}
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if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL) {
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OPENSSL_clear_free(ctx->key, ctx->key_len);
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ctx->key = NULL;
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if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->key, 0,
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&ctx->key_len))
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return 0;
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}
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if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) {
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if (p->data_size != 0 && p->data != NULL) {
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OPENSSL_free(ctx->salt);
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ctx->salt = NULL;
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if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->salt, 0,
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&ctx->salt_len))
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return 0;
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}
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}
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return 1;
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}
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static int kdf_hkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
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{
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KDF_HKDF *ctx = vctx;
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if (params == NULL)
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return 1;
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if (!hkdf_common_set_ctx_params(ctx, params))
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return 0;
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if (ossl_param_get1_concat_octet_string(params, OSSL_KDF_PARAM_INFO,
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&ctx->info, &ctx->info_len,
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HKDF_MAXINFO) == 0)
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return 0;
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return 1;
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}
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static const OSSL_PARAM *kdf_hkdf_settable_ctx_params(ossl_unused void *ctx,
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ossl_unused void *provctx)
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{
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static const OSSL_PARAM known_settable_ctx_params[] = {
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HKDF_COMMON_SETTABLES,
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OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
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OSSL_PARAM_END
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};
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return known_settable_ctx_params;
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}
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static int kdf_hkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
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{
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KDF_HKDF *ctx = (KDF_HKDF *)vctx;
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OSSL_PARAM *p;
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if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL) {
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size_t sz = kdf_hkdf_size(ctx);
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if (sz == 0)
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return 0;
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return OSSL_PARAM_set_size_t(p, sz);
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}
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return -2;
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}
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static const OSSL_PARAM *kdf_hkdf_gettable_ctx_params(ossl_unused void *ctx,
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ossl_unused void *provctx)
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{
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static const OSSL_PARAM known_gettable_ctx_params[] = {
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OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
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OSSL_PARAM_END
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};
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return known_gettable_ctx_params;
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}
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const OSSL_DISPATCH ossl_kdf_hkdf_functions[] = {
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{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_hkdf_new },
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{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_hkdf_dup },
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{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_hkdf_free },
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{ OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_hkdf_reset },
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{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_hkdf_derive },
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{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
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(void(*)(void))kdf_hkdf_settable_ctx_params },
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{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_hkdf_set_ctx_params },
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{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
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(void(*)(void))kdf_hkdf_gettable_ctx_params },
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{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_hkdf_get_ctx_params },
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OSSL_DISPATCH_END
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};
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/*
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* Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)"
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* Section 2 (https://tools.ietf.org/html/rfc5869#section-2) and
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* "Cryptographic Extraction and Key Derivation: The HKDF Scheme"
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* Section 4.2 (https://eprint.iacr.org/2010/264.pdf).
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*
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* From the paper:
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* The scheme HKDF is specified as:
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* HKDF(XTS, SKM, CTXinfo, L) = K(1) | K(2) | ... | K(t)
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*
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* where:
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* SKM is source key material
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* XTS is extractor salt (which may be null or constant)
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* CTXinfo is context information (may be null)
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* L is the number of key bits to be produced by KDF
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* k is the output length in bits of the hash function used with HMAC
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* t = ceil(L/k)
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* the value K(t) is truncated to its first d = L mod k bits.
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*
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* From RFC 5869:
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* 2.2. Step 1: Extract
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* HKDF-Extract(salt, IKM) -> PRK
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* 2.3. Step 2: Expand
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* HKDF-Expand(PRK, info, L) -> OKM
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*/
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static int HKDF(OSSL_LIB_CTX *libctx, const EVP_MD *evp_md,
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const unsigned char *salt, size_t salt_len,
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const unsigned char *ikm, size_t ikm_len,
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const unsigned char *info, size_t info_len,
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unsigned char *okm, size_t okm_len)
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{
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unsigned char prk[EVP_MAX_MD_SIZE];
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int ret, sz;
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size_t prk_len;
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sz = EVP_MD_get_size(evp_md);
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if (sz < 0)
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return 0;
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prk_len = (size_t)sz;
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/* Step 1: HKDF-Extract(salt, IKM) -> PRK */
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if (!HKDF_Extract(libctx, evp_md,
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salt, salt_len, ikm, ikm_len, prk, prk_len))
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return 0;
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/* Step 2: HKDF-Expand(PRK, info, L) -> OKM */
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ret = HKDF_Expand(evp_md, prk, prk_len, info, info_len, okm, okm_len);
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OPENSSL_cleanse(prk, sizeof(prk));
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return ret;
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}
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/*
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* Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)"
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* Section 2.2 (https://tools.ietf.org/html/rfc5869#section-2.2).
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*
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* 2.2. Step 1: Extract
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*
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* HKDF-Extract(salt, IKM) -> PRK
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*
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* Options:
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* Hash a hash function; HashLen denotes the length of the
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* hash function output in octets
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*
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* Inputs:
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* salt optional salt value (a non-secret random value);
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* if not provided, it is set to a string of HashLen zeros.
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* IKM input keying material
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*
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* Output:
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* PRK a pseudorandom key (of HashLen octets)
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*
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* The output PRK is calculated as follows:
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*
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* PRK = HMAC-Hash(salt, IKM)
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*/
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static int HKDF_Extract(OSSL_LIB_CTX *libctx, const EVP_MD *evp_md,
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const unsigned char *salt, size_t salt_len,
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const unsigned char *ikm, size_t ikm_len,
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unsigned char *prk, size_t prk_len)
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{
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int sz = EVP_MD_get_size(evp_md);
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if (sz < 0)
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return 0;
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if (prk_len != (size_t)sz) {
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ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_OUTPUT_BUFFER_SIZE);
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return 0;
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}
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/* calc: PRK = HMAC-Hash(salt, IKM) */
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return
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EVP_Q_mac(libctx, "HMAC", NULL, EVP_MD_get0_name(evp_md), NULL, salt,
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salt_len, ikm, ikm_len, prk, EVP_MD_get_size(evp_md), NULL)
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!= NULL;
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}
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/*
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* Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)"
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* Section 2.3 (https://tools.ietf.org/html/rfc5869#section-2.3).
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*
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* 2.3. Step 2: Expand
|
|
*
|
|
* HKDF-Expand(PRK, info, L) -> OKM
|
|
*
|
|
* Options:
|
|
* Hash a hash function; HashLen denotes the length of the
|
|
* hash function output in octets
|
|
*
|
|
* Inputs:
|
|
* PRK a pseudorandom key of at least HashLen octets
|
|
* (usually, the output from the extract step)
|
|
* info optional context and application specific information
|
|
* (can be a zero-length string)
|
|
* L length of output keying material in octets
|
|
* (<= 255*HashLen)
|
|
*
|
|
* Output:
|
|
* OKM output keying material (of L octets)
|
|
*
|
|
* The output OKM is calculated as follows:
|
|
*
|
|
* N = ceil(L/HashLen)
|
|
* T = T(1) | T(2) | T(3) | ... | T(N)
|
|
* OKM = first L octets of T
|
|
*
|
|
* where:
|
|
* T(0) = empty string (zero length)
|
|
* T(1) = HMAC-Hash(PRK, T(0) | info | 0x01)
|
|
* T(2) = HMAC-Hash(PRK, T(1) | info | 0x02)
|
|
* T(3) = HMAC-Hash(PRK, T(2) | info | 0x03)
|
|
* ...
|
|
*
|
|
* (where the constant concatenated to the end of each T(n) is a
|
|
* single octet.)
|
|
*/
|
|
static int HKDF_Expand(const EVP_MD *evp_md,
|
|
const unsigned char *prk, size_t prk_len,
|
|
const unsigned char *info, size_t info_len,
|
|
unsigned char *okm, size_t okm_len)
|
|
{
|
|
HMAC_CTX *hmac;
|
|
int ret = 0, sz;
|
|
unsigned int i;
|
|
unsigned char prev[EVP_MAX_MD_SIZE];
|
|
size_t done_len = 0, dig_len, n;
|
|
|
|
sz = EVP_MD_get_size(evp_md);
|
|
if (sz <= 0)
|
|
return 0;
|
|
dig_len = (size_t)sz;
|
|
|
|
/* calc: N = ceil(L/HashLen) */
|
|
n = okm_len / dig_len;
|
|
if (okm_len % dig_len)
|
|
n++;
|
|
|
|
if (n > 255 || okm == NULL)
|
|
return 0;
|
|
|
|
if ((hmac = HMAC_CTX_new()) == NULL)
|
|
return 0;
|
|
|
|
if (!HMAC_Init_ex(hmac, prk, prk_len, evp_md, NULL))
|
|
goto err;
|
|
|
|
for (i = 1; i <= n; i++) {
|
|
size_t copy_len;
|
|
const unsigned char ctr = i;
|
|
|
|
/* calc: T(i) = HMAC-Hash(PRK, T(i - 1) | info | i) */
|
|
if (i > 1) {
|
|
if (!HMAC_Init_ex(hmac, NULL, 0, NULL, NULL))
|
|
goto err;
|
|
|
|
if (!HMAC_Update(hmac, prev, dig_len))
|
|
goto err;
|
|
}
|
|
|
|
if (!HMAC_Update(hmac, info, info_len))
|
|
goto err;
|
|
|
|
if (!HMAC_Update(hmac, &ctr, 1))
|
|
goto err;
|
|
|
|
if (!HMAC_Final(hmac, prev, NULL))
|
|
goto err;
|
|
|
|
copy_len = (dig_len > okm_len - done_len) ?
|
|
okm_len - done_len :
|
|
dig_len;
|
|
|
|
memcpy(okm + done_len, prev, copy_len);
|
|
|
|
done_len += copy_len;
|
|
}
|
|
ret = 1;
|
|
|
|
err:
|
|
OPENSSL_cleanse(prev, sizeof(prev));
|
|
HMAC_CTX_free(hmac);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* TLS uses slight variations of the above and for FIPS validation purposes,
|
|
* they need to be present here.
|
|
* Refer to RFC 8446 section 7 for specific details.
|
|
*/
|
|
|
|
/*
|
|
* Given a |secret|; a |label| of length |labellen|; and |data| of length
|
|
* |datalen| (e.g. typically a hash of the handshake messages), derive a new
|
|
* secret |outlen| bytes long and store it in the location pointed to be |out|.
|
|
* The |data| value may be zero length. Returns 1 on success and 0 on failure.
|
|
*/
|
|
static int prov_tls13_hkdf_expand(const EVP_MD *md,
|
|
const unsigned char *key, size_t keylen,
|
|
const unsigned char *prefix, size_t prefixlen,
|
|
const unsigned char *label, size_t labellen,
|
|
const unsigned char *data, size_t datalen,
|
|
unsigned char *out, size_t outlen)
|
|
{
|
|
size_t hkdflabellen;
|
|
unsigned char hkdflabel[HKDF_MAXBUF];
|
|
WPACKET pkt;
|
|
|
|
/*
|
|
* 2 bytes for length of derived secret + 1 byte for length of combined
|
|
* prefix and label + bytes for the label itself + 1 byte length of hash
|
|
* + bytes for the hash itself. We've got the maximum the KDF can handle
|
|
* which should always be sufficient.
|
|
*/
|
|
if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
|
|
|| !WPACKET_put_bytes_u16(&pkt, outlen)
|
|
|| !WPACKET_start_sub_packet_u8(&pkt)
|
|
|| !WPACKET_memcpy(&pkt, prefix, prefixlen)
|
|
|| !WPACKET_memcpy(&pkt, label, labellen)
|
|
|| !WPACKET_close(&pkt)
|
|
|| !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
|
|
|| !WPACKET_get_total_written(&pkt, &hkdflabellen)
|
|
|| !WPACKET_finish(&pkt)) {
|
|
WPACKET_cleanup(&pkt);
|
|
return 0;
|
|
}
|
|
|
|
return HKDF_Expand(md, key, keylen, hkdflabel, hkdflabellen,
|
|
out, outlen);
|
|
}
|
|
|
|
static int prov_tls13_hkdf_generate_secret(OSSL_LIB_CTX *libctx,
|
|
const EVP_MD *md,
|
|
const unsigned char *prevsecret,
|
|
size_t prevsecretlen,
|
|
const unsigned char *insecret,
|
|
size_t insecretlen,
|
|
const unsigned char *prefix,
|
|
size_t prefixlen,
|
|
const unsigned char *label,
|
|
size_t labellen,
|
|
unsigned char *out, size_t outlen)
|
|
{
|
|
size_t mdlen;
|
|
int ret;
|
|
unsigned char preextractsec[EVP_MAX_MD_SIZE];
|
|
/* Always filled with zeros */
|
|
static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
|
|
|
|
ret = EVP_MD_get_size(md);
|
|
/* Ensure cast to size_t is safe */
|
|
if (ret <= 0)
|
|
return 0;
|
|
mdlen = (size_t)ret;
|
|
|
|
if (insecret == NULL) {
|
|
insecret = default_zeros;
|
|
insecretlen = mdlen;
|
|
}
|
|
if (prevsecret == NULL) {
|
|
prevsecret = default_zeros;
|
|
prevsecretlen = 0;
|
|
} else {
|
|
EVP_MD_CTX *mctx = EVP_MD_CTX_new();
|
|
unsigned char hash[EVP_MAX_MD_SIZE];
|
|
|
|
/* The pre-extract derive step uses a hash of no messages */
|
|
if (mctx == NULL
|
|
|| EVP_DigestInit_ex(mctx, md, NULL) <= 0
|
|
|| EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
|
|
EVP_MD_CTX_free(mctx);
|
|
return 0;
|
|
}
|
|
EVP_MD_CTX_free(mctx);
|
|
|
|
/* Generate the pre-extract secret */
|
|
if (!prov_tls13_hkdf_expand(md, prevsecret, mdlen,
|
|
prefix, prefixlen, label, labellen,
|
|
hash, mdlen, preextractsec, mdlen))
|
|
return 0;
|
|
prevsecret = preextractsec;
|
|
prevsecretlen = mdlen;
|
|
}
|
|
|
|
ret = HKDF_Extract(libctx, md, prevsecret, prevsecretlen,
|
|
insecret, insecretlen, out, outlen);
|
|
|
|
if (prevsecret == preextractsec)
|
|
OPENSSL_cleanse(preextractsec, mdlen);
|
|
return ret;
|
|
}
|
|
|
|
static int kdf_tls1_3_derive(void *vctx, unsigned char *key, size_t keylen,
|
|
const OSSL_PARAM params[])
|
|
{
|
|
KDF_HKDF *ctx = (KDF_HKDF *)vctx;
|
|
const EVP_MD *md;
|
|
|
|
if (!ossl_prov_is_running() || !kdf_tls1_3_set_ctx_params(ctx, params))
|
|
return 0;
|
|
|
|
md = ossl_prov_digest_md(&ctx->digest);
|
|
if (md == NULL) {
|
|
ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
|
|
return 0;
|
|
}
|
|
|
|
switch (ctx->mode) {
|
|
default:
|
|
return 0;
|
|
|
|
case EVP_KDF_HKDF_MODE_EXTRACT_ONLY:
|
|
return prov_tls13_hkdf_generate_secret(PROV_LIBCTX_OF(ctx->provctx),
|
|
md,
|
|
ctx->salt, ctx->salt_len,
|
|
ctx->key, ctx->key_len,
|
|
ctx->prefix, ctx->prefix_len,
|
|
ctx->label, ctx->label_len,
|
|
key, keylen);
|
|
|
|
case EVP_KDF_HKDF_MODE_EXPAND_ONLY:
|
|
return prov_tls13_hkdf_expand(md, ctx->key, ctx->key_len,
|
|
ctx->prefix, ctx->prefix_len,
|
|
ctx->label, ctx->label_len,
|
|
ctx->data, ctx->data_len,
|
|
key, keylen);
|
|
}
|
|
}
|
|
|
|
static int kdf_tls1_3_set_ctx_params(void *vctx, const OSSL_PARAM params[])
|
|
{
|
|
const OSSL_PARAM *p;
|
|
KDF_HKDF *ctx = vctx;
|
|
|
|
if (params == NULL)
|
|
return 1;
|
|
|
|
if (!hkdf_common_set_ctx_params(ctx, params))
|
|
return 0;
|
|
|
|
if (ctx->mode == EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND) {
|
|
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
|
|
return 0;
|
|
}
|
|
|
|
if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PREFIX)) != NULL) {
|
|
OPENSSL_free(ctx->prefix);
|
|
ctx->prefix = NULL;
|
|
if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->prefix, 0,
|
|
&ctx->prefix_len))
|
|
return 0;
|
|
}
|
|
|
|
if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_LABEL)) != NULL) {
|
|
OPENSSL_free(ctx->label);
|
|
ctx->label = NULL;
|
|
if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->label, 0,
|
|
&ctx->label_len))
|
|
return 0;
|
|
}
|
|
|
|
OPENSSL_clear_free(ctx->data, ctx->data_len);
|
|
ctx->data = NULL;
|
|
if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DATA)) != NULL
|
|
&& !OSSL_PARAM_get_octet_string(p, (void **)&ctx->data, 0,
|
|
&ctx->data_len))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static const OSSL_PARAM *kdf_tls1_3_settable_ctx_params(ossl_unused void *ctx,
|
|
ossl_unused void *provctx)
|
|
{
|
|
static const OSSL_PARAM known_settable_ctx_params[] = {
|
|
HKDF_COMMON_SETTABLES,
|
|
OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PREFIX, NULL, 0),
|
|
OSSL_PARAM_octet_string(OSSL_KDF_PARAM_LABEL, NULL, 0),
|
|
OSSL_PARAM_octet_string(OSSL_KDF_PARAM_DATA, NULL, 0),
|
|
OSSL_PARAM_END
|
|
};
|
|
return known_settable_ctx_params;
|
|
}
|
|
|
|
const OSSL_DISPATCH ossl_kdf_tls1_3_kdf_functions[] = {
|
|
{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_hkdf_new },
|
|
{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_hkdf_dup },
|
|
{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_hkdf_free },
|
|
{ OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_hkdf_reset },
|
|
{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_tls1_3_derive },
|
|
{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
|
|
(void(*)(void))kdf_tls1_3_settable_ctx_params },
|
|
{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_tls1_3_set_ctx_params },
|
|
{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
|
|
(void(*)(void))kdf_hkdf_gettable_ctx_params },
|
|
{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_hkdf_get_ctx_params },
|
|
OSSL_DISPATCH_END
|
|
};
|