353 lines
9.2 KiB
C
353 lines
9.2 KiB
C
/*
|
|
* Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
|
|
*
|
|
* Licensed under the OpenSSL license (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 <stdlib.h>
|
|
#include <string.h>
|
|
#include <openssl/hmac.h>
|
|
#include <openssl/kdf.h>
|
|
#include <openssl/evp.h>
|
|
#include "internal/cryptlib.h"
|
|
#include "crypto/evp.h"
|
|
|
|
#define HKDF_MAXBUF 1024
|
|
|
|
static unsigned char *HKDF(const EVP_MD *evp_md,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *key, size_t key_len,
|
|
const unsigned char *info, size_t info_len,
|
|
unsigned char *okm, size_t okm_len);
|
|
|
|
static unsigned char *HKDF_Extract(const EVP_MD *evp_md,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *key, size_t key_len,
|
|
unsigned char *prk, size_t *prk_len);
|
|
|
|
static unsigned char *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);
|
|
|
|
typedef struct {
|
|
int mode;
|
|
const EVP_MD *md;
|
|
unsigned char *salt;
|
|
size_t salt_len;
|
|
unsigned char *key;
|
|
size_t key_len;
|
|
unsigned char info[HKDF_MAXBUF];
|
|
size_t info_len;
|
|
} HKDF_PKEY_CTX;
|
|
|
|
static int pkey_hkdf_init(EVP_PKEY_CTX *ctx)
|
|
{
|
|
HKDF_PKEY_CTX *kctx;
|
|
|
|
if ((kctx = OPENSSL_zalloc(sizeof(*kctx))) == NULL) {
|
|
KDFerr(KDF_F_PKEY_HKDF_INIT, ERR_R_MALLOC_FAILURE);
|
|
return 0;
|
|
}
|
|
|
|
ctx->data = kctx;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void pkey_hkdf_cleanup(EVP_PKEY_CTX *ctx)
|
|
{
|
|
HKDF_PKEY_CTX *kctx = ctx->data;
|
|
OPENSSL_clear_free(kctx->salt, kctx->salt_len);
|
|
OPENSSL_clear_free(kctx->key, kctx->key_len);
|
|
OPENSSL_cleanse(kctx->info, kctx->info_len);
|
|
OPENSSL_free(kctx);
|
|
}
|
|
|
|
static int pkey_hkdf_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
|
|
{
|
|
HKDF_PKEY_CTX *kctx = ctx->data;
|
|
|
|
switch (type) {
|
|
case EVP_PKEY_CTRL_HKDF_MD:
|
|
if (p2 == NULL)
|
|
return 0;
|
|
|
|
kctx->md = p2;
|
|
return 1;
|
|
|
|
case EVP_PKEY_CTRL_HKDF_MODE:
|
|
kctx->mode = p1;
|
|
return 1;
|
|
|
|
case EVP_PKEY_CTRL_HKDF_SALT:
|
|
if (p1 == 0 || p2 == NULL)
|
|
return 1;
|
|
|
|
if (p1 < 0)
|
|
return 0;
|
|
|
|
if (kctx->salt != NULL)
|
|
OPENSSL_clear_free(kctx->salt, kctx->salt_len);
|
|
|
|
kctx->salt = OPENSSL_memdup(p2, p1);
|
|
if (kctx->salt == NULL)
|
|
return 0;
|
|
|
|
kctx->salt_len = p1;
|
|
return 1;
|
|
|
|
case EVP_PKEY_CTRL_HKDF_KEY:
|
|
if (p1 < 0)
|
|
return 0;
|
|
|
|
if (kctx->key != NULL)
|
|
OPENSSL_clear_free(kctx->key, kctx->key_len);
|
|
|
|
kctx->key = OPENSSL_memdup(p2, p1);
|
|
if (kctx->key == NULL)
|
|
return 0;
|
|
|
|
kctx->key_len = p1;
|
|
return 1;
|
|
|
|
case EVP_PKEY_CTRL_HKDF_INFO:
|
|
if (p1 == 0 || p2 == NULL)
|
|
return 1;
|
|
|
|
if (p1 < 0 || p1 > (int)(HKDF_MAXBUF - kctx->info_len))
|
|
return 0;
|
|
|
|
memcpy(kctx->info + kctx->info_len, p2, p1);
|
|
kctx->info_len += p1;
|
|
return 1;
|
|
|
|
default:
|
|
return -2;
|
|
|
|
}
|
|
}
|
|
|
|
static int pkey_hkdf_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
|
|
const char *value)
|
|
{
|
|
if (strcmp(type, "mode") == 0) {
|
|
int mode;
|
|
|
|
if (strcmp(value, "EXTRACT_AND_EXPAND") == 0)
|
|
mode = EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND;
|
|
else if (strcmp(value, "EXTRACT_ONLY") == 0)
|
|
mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
|
|
else if (strcmp(value, "EXPAND_ONLY") == 0)
|
|
mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
|
|
else
|
|
return 0;
|
|
|
|
return EVP_PKEY_CTX_hkdf_mode(ctx, mode);
|
|
}
|
|
|
|
if (strcmp(type, "md") == 0)
|
|
return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_DERIVE,
|
|
EVP_PKEY_CTRL_HKDF_MD, value);
|
|
|
|
if (strcmp(type, "salt") == 0)
|
|
return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_HKDF_SALT, value);
|
|
|
|
if (strcmp(type, "hexsalt") == 0)
|
|
return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_HKDF_SALT, value);
|
|
|
|
if (strcmp(type, "key") == 0)
|
|
return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_HKDF_KEY, value);
|
|
|
|
if (strcmp(type, "hexkey") == 0)
|
|
return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_HKDF_KEY, value);
|
|
|
|
if (strcmp(type, "info") == 0)
|
|
return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_HKDF_INFO, value);
|
|
|
|
if (strcmp(type, "hexinfo") == 0)
|
|
return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_HKDF_INFO, value);
|
|
|
|
KDFerr(KDF_F_PKEY_HKDF_CTRL_STR, KDF_R_UNKNOWN_PARAMETER_TYPE);
|
|
return -2;
|
|
}
|
|
|
|
static int pkey_hkdf_derive_init(EVP_PKEY_CTX *ctx)
|
|
{
|
|
HKDF_PKEY_CTX *kctx = ctx->data;
|
|
|
|
OPENSSL_clear_free(kctx->key, kctx->key_len);
|
|
OPENSSL_clear_free(kctx->salt, kctx->salt_len);
|
|
OPENSSL_cleanse(kctx->info, kctx->info_len);
|
|
memset(kctx, 0, sizeof(*kctx));
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int pkey_hkdf_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
|
|
size_t *keylen)
|
|
{
|
|
HKDF_PKEY_CTX *kctx = ctx->data;
|
|
|
|
if (kctx->md == NULL) {
|
|
KDFerr(KDF_F_PKEY_HKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
|
|
return 0;
|
|
}
|
|
if (kctx->key == NULL) {
|
|
KDFerr(KDF_F_PKEY_HKDF_DERIVE, KDF_R_MISSING_KEY);
|
|
return 0;
|
|
}
|
|
|
|
switch (kctx->mode) {
|
|
case EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND:
|
|
return HKDF(kctx->md, kctx->salt, kctx->salt_len, kctx->key,
|
|
kctx->key_len, kctx->info, kctx->info_len, key,
|
|
*keylen) != NULL;
|
|
|
|
case EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY:
|
|
if (key == NULL) {
|
|
*keylen = EVP_MD_size(kctx->md);
|
|
return 1;
|
|
}
|
|
return HKDF_Extract(kctx->md, kctx->salt, kctx->salt_len, kctx->key,
|
|
kctx->key_len, key, keylen) != NULL;
|
|
|
|
case EVP_PKEY_HKDEF_MODE_EXPAND_ONLY:
|
|
return HKDF_Expand(kctx->md, kctx->key, kctx->key_len, kctx->info,
|
|
kctx->info_len, key, *keylen) != NULL;
|
|
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
const EVP_PKEY_METHOD hkdf_pkey_meth = {
|
|
EVP_PKEY_HKDF,
|
|
0,
|
|
pkey_hkdf_init,
|
|
0,
|
|
pkey_hkdf_cleanup,
|
|
|
|
0, 0,
|
|
0, 0,
|
|
|
|
0,
|
|
0,
|
|
|
|
0,
|
|
0,
|
|
|
|
0, 0,
|
|
|
|
0, 0, 0, 0,
|
|
|
|
0, 0,
|
|
|
|
0, 0,
|
|
|
|
pkey_hkdf_derive_init,
|
|
pkey_hkdf_derive,
|
|
pkey_hkdf_ctrl,
|
|
pkey_hkdf_ctrl_str
|
|
};
|
|
|
|
static unsigned char *HKDF(const EVP_MD *evp_md,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *key, size_t key_len,
|
|
const unsigned char *info, size_t info_len,
|
|
unsigned char *okm, size_t okm_len)
|
|
{
|
|
unsigned char prk[EVP_MAX_MD_SIZE];
|
|
unsigned char *ret;
|
|
size_t prk_len;
|
|
|
|
if (!HKDF_Extract(evp_md, salt, salt_len, key, key_len, prk, &prk_len))
|
|
return NULL;
|
|
|
|
ret = HKDF_Expand(evp_md, prk, prk_len, info, info_len, okm, okm_len);
|
|
OPENSSL_cleanse(prk, sizeof(prk));
|
|
|
|
return ret;
|
|
}
|
|
|
|
static unsigned char *HKDF_Extract(const EVP_MD *evp_md,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *key, size_t key_len,
|
|
unsigned char *prk, size_t *prk_len)
|
|
{
|
|
unsigned int tmp_len;
|
|
|
|
if (!HMAC(evp_md, salt, salt_len, key, key_len, prk, &tmp_len))
|
|
return NULL;
|
|
|
|
*prk_len = tmp_len;
|
|
return prk;
|
|
}
|
|
|
|
static unsigned char *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;
|
|
unsigned char *ret = NULL;
|
|
|
|
unsigned int i;
|
|
|
|
unsigned char prev[EVP_MAX_MD_SIZE];
|
|
|
|
size_t done_len = 0, dig_len = EVP_MD_size(evp_md);
|
|
|
|
size_t n = okm_len / dig_len;
|
|
if (okm_len % dig_len)
|
|
n++;
|
|
|
|
if (n > 255 || okm == NULL)
|
|
return NULL;
|
|
|
|
if ((hmac = HMAC_CTX_new()) == NULL)
|
|
return NULL;
|
|
|
|
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;
|
|
|
|
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 = (done_len + dig_len > okm_len) ?
|
|
okm_len - done_len :
|
|
dig_len;
|
|
|
|
memcpy(okm + done_len, prev, copy_len);
|
|
|
|
done_len += copy_len;
|
|
}
|
|
ret = okm;
|
|
|
|
err:
|
|
OPENSSL_cleanse(prev, sizeof(prev));
|
|
HMAC_CTX_free(hmac);
|
|
return ret;
|
|
}
|