/*
* Copyright 2019-2021 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
*/
/*
* This file uses the low level AES functions (which are deprecated for
* non-internal use) in order to implement provider AES ciphers.
*/
#include "internal/deprecated.h"
#include <openssl/proverr.h>
#include "cipher_aes.h"
#include "prov/providercommon.h"
#include "prov/implementations.h"
/* AES wrap with padding has IV length of 4, without padding 8 */
#define AES_WRAP_PAD_IVLEN 4
#define AES_WRAP_NOPAD_IVLEN 8
#define WRAP_FLAGS (PROV_CIPHER_FLAG_CUSTOM_IV)
#define WRAP_FLAGS_INV (WRAP_FLAGS | PROV_CIPHER_FLAG_INVERSE_CIPHER)
typedef size_t (*aeswrap_fn)(void *key, const unsigned char *iv,
unsigned char *out, const unsigned char *in,
size_t inlen, block128_f block);
static OSSL_FUNC_cipher_encrypt_init_fn aes_wrap_einit;
static OSSL_FUNC_cipher_decrypt_init_fn aes_wrap_dinit;
static OSSL_FUNC_cipher_update_fn aes_wrap_cipher;
static OSSL_FUNC_cipher_final_fn aes_wrap_final;
static OSSL_FUNC_cipher_freectx_fn aes_wrap_freectx;
static OSSL_FUNC_cipher_set_ctx_params_fn aes_wrap_set_ctx_params;
typedef struct prov_aes_wrap_ctx_st {
PROV_CIPHER_CTX base;
union {
OSSL_UNION_ALIGN;
AES_KEY ks;
} ks;
aeswrap_fn wrapfn;
} PROV_AES_WRAP_CTX;
static void *aes_wrap_newctx(size_t kbits, size_t blkbits,
size_t ivbits, unsigned int mode, uint64_t flags)
{
PROV_AES_WRAP_CTX *wctx;
PROV_CIPHER_CTX *ctx;
if (!ossl_prov_is_running())
return NULL;
wctx = OPENSSL_zalloc(sizeof(*wctx));
ctx = (PROV_CIPHER_CTX *)wctx;
if (ctx != NULL) {
ossl_cipher_generic_initkey(ctx, kbits, blkbits, ivbits, mode, flags,
NULL, NULL);
ctx->pad = (ctx->ivlen == AES_WRAP_PAD_IVLEN);
}
return wctx;
}
static void aes_wrap_freectx(void *vctx)
{
PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
ossl_cipher_generic_reset_ctx((PROV_CIPHER_CTX *)vctx);
OPENSSL_clear_free(wctx, sizeof(*wctx));
}
static int aes_wrap_init(void *vctx, const unsigned char *key,
size_t keylen, const unsigned char *iv,
size_t ivlen, const OSSL_PARAM params[], int enc)
{
PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
if (!ossl_prov_is_running())
return 0;
ctx->enc = enc;
if (ctx->pad)
wctx->wrapfn = enc ? CRYPTO_128_wrap_pad : CRYPTO_128_unwrap_pad;
else
wctx->wrapfn = enc ? CRYPTO_128_wrap : CRYPTO_128_unwrap;
if (iv != NULL) {
if (!ossl_cipher_generic_initiv(ctx, iv, ivlen))
return 0;
}
if (key != NULL) {
int use_forward_transform;
if (keylen != ctx->keylen) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
return 0;
}
/*
* See SP800-38F : Section 5.1
* The forward and inverse transformations for the AES block
* cipher—called “cipher” and “inverse cipher” are informally known as
* the AES encryption and AES decryption functions, respectively.
* If the designated cipher function for a key-wrap algorithm is chosen
* to be the AES decryption function, then CIPH-1K will be the AES
* encryption function.
*/
if (ctx->inverse_cipher == 0)
use_forward_transform = ctx->enc;
else
use_forward_transform = !ctx->enc;
if (use_forward_transform) {
AES_set_encrypt_key(key, keylen * 8, &wctx->ks.ks);
ctx->block = (block128_f)AES_encrypt;
} else {
AES_set_decrypt_key(key, keylen * 8, &wctx->ks.ks);
ctx->block = (block128_f)AES_decrypt;
}
}
return aes_wrap_set_ctx_params(ctx, params);
}
static int aes_wrap_einit(void *ctx, const unsigned char *key, size_t keylen,
const unsigned char *iv, size_t ivlen,
const OSSL_PARAM params[])
{
return aes_wrap_init(ctx, key, keylen, iv, ivlen, params, 1);
}
static int aes_wrap_dinit(void *ctx, const unsigned char *key, size_t keylen,
const unsigned char *iv, size_t ivlen,
const OSSL_PARAM params[])
{
return aes_wrap_init(ctx, key, keylen, iv, ivlen, params, 0);
}
static int aes_wrap_cipher_internal(void *vctx, unsigned char *out,
const unsigned char *in, size_t inlen)
{
PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
size_t rv;
int pad = ctx->pad;
/* No final operation so always return zero length */
if (in == NULL)
return 0;
/* Input length must always be non-zero */
if (inlen == 0) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH);
return -1;
}
/* If decrypting need at least 16 bytes and multiple of 8 */
if (!ctx->enc && (inlen < 16 || inlen & 0x7)) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH);
return -1;
}
/* If not padding input must be multiple of 8 */
if (!pad && inlen & 0x7) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH);
return -1;
}
if (out == NULL) {
if (ctx->enc) {
/* If padding round up to multiple of 8 */
if (pad)
inlen = (inlen + 7) / 8 * 8;
/* 8 byte prefix */
return inlen + 8;
} else {
/*
* If not padding output will be exactly 8 bytes smaller than
* input. If padding it will be at least 8 bytes smaller but we
* don't know how much.
*/
return inlen - 8;
}
}
rv = wctx->wrapfn(&wctx->ks.ks, ctx->iv_set ? ctx->iv : NULL, out, in,
inlen, ctx->block);
if (!rv) {
ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
return -1;
}
if (rv > INT_MAX) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_OUTPUT_LENGTH);
return -1;
}
return (int)rv;
}
static int aes_wrap_final(void *vctx, unsigned char *out, size_t *outl,
size_t outsize)
{
if (!ossl_prov_is_running())
return 0;
*outl = 0;
return 1;
}
static int aes_wrap_cipher(void *vctx,
unsigned char *out, size_t *outl, size_t outsize,
const unsigned char *in, size_t inl)
{
PROV_AES_WRAP_CTX *ctx = (PROV_AES_WRAP_CTX *)vctx;
size_t len;
if (!ossl_prov_is_running())
return 0;
if (inl == 0) {
*outl = 0;
return 1;
}
if (outsize < inl) {
ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
return 0;
}
len = aes_wrap_cipher_internal(ctx, out, in, inl);
if (len <= 0)
return 0;
*outl = len;
return 1;
}
static int aes_wrap_set_ctx_params(void *vctx, const OSSL_PARAM params[])
{
PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
const OSSL_PARAM *p;
size_t keylen = 0;
if (params == NULL)
return 1;
p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_KEYLEN);
if (p != NULL) {
if (!OSSL_PARAM_get_size_t(p, &keylen)) {
ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
return 0;
}
if (ctx->keylen != keylen) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
return 0;
}
}
return 1;
}
#define IMPLEMENT_cipher(mode, fname, UCMODE, flags, kbits, blkbits, ivbits) \
static OSSL_FUNC_cipher_get_params_fn aes_##kbits##_##fname##_get_params; \
static int aes_##kbits##_##fname##_get_params(OSSL_PARAM params[]) \
{ \
return ossl_cipher_generic_get_params(params, EVP_CIPH_##UCMODE##_MODE,\
flags, kbits, blkbits, ivbits); \
} \
static OSSL_FUNC_cipher_newctx_fn aes_##kbits##fname##_newctx; \
static void *aes_##kbits##fname##_newctx(void *provctx) \
{ \
return aes_##mode##_newctx(kbits, blkbits, ivbits, \
EVP_CIPH_##UCMODE##_MODE, flags); \
} \
const OSSL_DISPATCH ossl_##aes##kbits##fname##_functions[] = { \
{ OSSL_FUNC_CIPHER_NEWCTX, \
(void (*)(void))aes_##kbits##fname##_newctx }, \
{ OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))aes_##mode##_einit }, \
{ OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))aes_##mode##_dinit }, \
{ OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))aes_##mode##_cipher }, \
{ OSSL_FUNC_CIPHER_FINAL, (void (*)(void))aes_##mode##_final }, \
{ OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))aes_##mode##_freectx }, \
{ OSSL_FUNC_CIPHER_GET_PARAMS, \
(void (*)(void))aes_##kbits##_##fname##_get_params }, \
{ OSSL_FUNC_CIPHER_GETTABLE_PARAMS, \
(void (*)(void))ossl_cipher_generic_gettable_params }, \
{ OSSL_FUNC_CIPHER_GET_CTX_PARAMS, \
(void (*)(void))ossl_cipher_generic_get_ctx_params }, \
{ OSSL_FUNC_CIPHER_SET_CTX_PARAMS, \
(void (*)(void))aes_wrap_set_ctx_params }, \
{ OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS, \
(void (*)(void))ossl_cipher_generic_gettable_ctx_params }, \
{ OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS, \
(void (*)(void))ossl_cipher_generic_settable_ctx_params }, \
{ 0, NULL } \
}
IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_NOPAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_NOPAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_NOPAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_NOPAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_NOPAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_NOPAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_PAD_IVLEN * 8);