blob: d9cbfc7cf2334e7c8bf127895c55de0fbe72471f [file] [log] [blame]
/* Copyright (c) 2022, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/evp.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/hkdf.h>
#include <openssl/kdf.h>
#include <openssl/mem.h>
#include "../internal.h"
#include "internal.h"
typedef struct {
int mode;
const EVP_MD *md;
uint8_t *key;
size_t key_len;
uint8_t *salt;
size_t salt_len;
CBB info;
} HKDF_PKEY_CTX;
static int pkey_hkdf_init(EVP_PKEY_CTX *ctx) {
HKDF_PKEY_CTX *hctx = OPENSSL_zalloc(sizeof(HKDF_PKEY_CTX));
if (hctx == NULL) {
return 0;
}
if (!CBB_init(&hctx->info, 0)) {
OPENSSL_free(hctx);
return 0;
}
ctx->data = hctx;
return 1;
}
static int pkey_hkdf_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) {
if (!pkey_hkdf_init(dst)) {
return 0;
}
HKDF_PKEY_CTX *hctx_dst = dst->data;
const HKDF_PKEY_CTX *hctx_src = src->data;
hctx_dst->mode = hctx_src->mode;
hctx_dst->md = hctx_src->md;
if (hctx_src->key_len != 0) {
hctx_dst->key = OPENSSL_memdup(hctx_src->key, hctx_src->key_len);
if (hctx_dst->key == NULL) {
return 0;
}
hctx_dst->key_len = hctx_src->key_len;
}
if (hctx_src->salt_len != 0) {
hctx_dst->salt = OPENSSL_memdup(hctx_src->salt, hctx_src->salt_len);
if (hctx_dst->salt == NULL) {
return 0;
}
hctx_dst->salt_len = hctx_src->salt_len;
}
if (!CBB_add_bytes(&hctx_dst->info, CBB_data(&hctx_src->info),
CBB_len(&hctx_src->info))) {
return 0;
}
return 1;
}
static void pkey_hkdf_cleanup(EVP_PKEY_CTX *ctx) {
HKDF_PKEY_CTX *hctx = ctx->data;
if (hctx != NULL) {
OPENSSL_free(hctx->key);
OPENSSL_free(hctx->salt);
CBB_cleanup(&hctx->info);
OPENSSL_free(hctx);
ctx->data = NULL;
}
}
static int pkey_hkdf_derive(EVP_PKEY_CTX *ctx, uint8_t *out, size_t *out_len) {
HKDF_PKEY_CTX *hctx = ctx->data;
if (hctx->md == NULL) {
OPENSSL_PUT_ERROR(EVP, EVP_R_MISSING_PARAMETERS);
return 0;
}
if (hctx->key_len == 0) {
OPENSSL_PUT_ERROR(EVP, EVP_R_NO_KEY_SET);
return 0;
}
if (out == NULL) {
if (hctx->mode == EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) {
*out_len = EVP_MD_size(hctx->md);
}
// HKDF-Expand is variable-length and returns |*out_len| bytes. "Output" the
// input length by leaving it alone.
return 1;
}
switch (hctx->mode) {
case EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND:
return HKDF(out, *out_len, hctx->md, hctx->key, hctx->key_len, hctx->salt,
hctx->salt_len, CBB_data(&hctx->info), CBB_len(&hctx->info));
case EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY:
if (*out_len < EVP_MD_size(hctx->md)) {
OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
return 0;
}
return HKDF_extract(out, out_len, hctx->md, hctx->key, hctx->key_len,
hctx->salt, hctx->salt_len);
case EVP_PKEY_HKDEF_MODE_EXPAND_ONLY:
return HKDF_expand(out, *out_len, hctx->md, hctx->key, hctx->key_len,
CBB_data(&hctx->info), CBB_len(&hctx->info));
}
OPENSSL_PUT_ERROR(EVP, ERR_R_INTERNAL_ERROR);
return 0;
}
static int pkey_hkdf_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) {
HKDF_PKEY_CTX *hctx = ctx->data;
switch (type) {
case EVP_PKEY_CTRL_HKDF_MODE:
if (p1 != EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND &&
p1 != EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY &&
p1 != EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) {
OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_OPERATION);
return 0;
}
hctx->mode = p1;
return 1;
case EVP_PKEY_CTRL_HKDF_MD:
hctx->md = p2;
return 1;
case EVP_PKEY_CTRL_HKDF_KEY: {
const CBS *key = p2;
if (!CBS_stow(key, &hctx->key, &hctx->key_len)) {
return 0;
}
return 1;
}
case EVP_PKEY_CTRL_HKDF_SALT: {
const CBS *salt = p2;
if (!CBS_stow(salt, &hctx->salt, &hctx->salt_len)) {
return 0;
}
return 1;
}
case EVP_PKEY_CTRL_HKDF_INFO: {
const CBS *info = p2;
// |EVP_PKEY_CTX_add1_hkdf_info| appends to the info string, rather than
// replacing it.
if (!CBB_add_bytes(&hctx->info, CBS_data(info), CBS_len(info))) {
return 0;
}
return 1;
}
default:
OPENSSL_PUT_ERROR(EVP, EVP_R_COMMAND_NOT_SUPPORTED);
return 0;
}
}
const EVP_PKEY_METHOD hkdf_pkey_meth = {
EVP_PKEY_HKDF,
pkey_hkdf_init,
pkey_hkdf_copy,
pkey_hkdf_cleanup,
/*keygen=*/NULL,
/*sign=*/NULL,
/*sign_message=*/NULL,
/*verify=*/NULL,
/*verify_message=*/NULL,
/*verify_recover=*/NULL,
/*encrypt=*/NULL,
/*decrypt=*/NULL,
pkey_hkdf_derive,
/*paramgen=*/NULL,
pkey_hkdf_ctrl,
};
int EVP_PKEY_CTX_hkdf_mode(EVP_PKEY_CTX *ctx, int mode) {
return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_HKDF, EVP_PKEY_OP_DERIVE,
EVP_PKEY_CTRL_HKDF_MODE, mode, NULL);
}
int EVP_PKEY_CTX_set_hkdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md) {
return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_HKDF, EVP_PKEY_OP_DERIVE,
EVP_PKEY_CTRL_HKDF_MD, 0, (void *)md);
}
int EVP_PKEY_CTX_set1_hkdf_key(EVP_PKEY_CTX *ctx, const uint8_t *key,
size_t key_len) {
CBS cbs;
CBS_init(&cbs, key, key_len);
return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_HKDF, EVP_PKEY_OP_DERIVE,
EVP_PKEY_CTRL_HKDF_KEY, 0, &cbs);
}
int EVP_PKEY_CTX_set1_hkdf_salt(EVP_PKEY_CTX *ctx, const uint8_t *salt,
size_t salt_len) {
CBS cbs;
CBS_init(&cbs, salt, salt_len);
return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_HKDF, EVP_PKEY_OP_DERIVE,
EVP_PKEY_CTRL_HKDF_SALT, 0, &cbs);
}
int EVP_PKEY_CTX_add1_hkdf_info(EVP_PKEY_CTX *ctx, const uint8_t *info,
size_t info_len) {
CBS cbs;
CBS_init(&cbs, info, info_len);
return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_HKDF, EVP_PKEY_OP_DERIVE,
EVP_PKEY_CTRL_HKDF_INFO, 0, &cbs);
}