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3b94944cf2
openssl/crypto/evp/evp_enc.c
Matt Caswell 3b94944cf2 Add a maximum output length to update and final calls 
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8700)
2019-04-19 09:31:54 +01:00

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/*
* Copyright 1995-2018 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
*/
#include <stdio.h>
#include <assert.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/rand_drbg.h>
#include <openssl/engine.h>
#include <openssl/params.h>
#include <openssl/core_names.h>
#include "internal/evp_int.h"
#include "internal/provider.h"
#include "evp_locl.h"
int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *ctx)
{
if (ctx == NULL)
return 1;
if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
goto legacy;
if (ctx->provctx != NULL) {
if (ctx->cipher->freectx != NULL)
ctx->cipher->freectx(ctx->provctx);
ctx->provctx = NULL;
}
if (ctx->fetched_cipher != NULL)
EVP_CIPHER_meth_free(ctx->fetched_cipher);
memset(ctx, 0, sizeof(*ctx));
return 1;
/* TODO(3.0): Remove legacy code below */
legacy:
if (ctx->cipher != NULL) {
if (ctx->cipher->cleanup && !ctx->cipher->cleanup(ctx))
return 0;
/* Cleanse cipher context data */
if (ctx->cipher_data && ctx->cipher->ctx_size)
OPENSSL_cleanse(ctx->cipher_data, ctx->cipher->ctx_size);
}
OPENSSL_free(ctx->cipher_data);
#ifndef OPENSSL_NO_ENGINE
ENGINE_finish(ctx->engine);
#endif
memset(ctx, 0, sizeof(*ctx));
return 1;
}
EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
{
return OPENSSL_zalloc(sizeof(EVP_CIPHER_CTX));
}
void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
{
EVP_CIPHER_CTX_reset(ctx);
OPENSSL_free(ctx);
}
int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
const unsigned char *key, const unsigned char *iv, int enc)
{
if (cipher != NULL)
EVP_CIPHER_CTX_reset(ctx);
return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
}
int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
ENGINE *impl, const unsigned char *key,
const unsigned char *iv, int enc)
{
EVP_CIPHER *provciph = NULL;
ENGINE *tmpimpl = NULL;
const EVP_CIPHER *tmpcipher;
/*
* enc == 1 means we are encrypting.
* enc == 0 means we are decrypting.
* enc == -1 means, use the previously initialised value for encrypt/decrypt
*/
if (enc == -1) {
enc = ctx->encrypt;
} else {
if (enc)
enc = 1;
ctx->encrypt = enc;
}
if (cipher == NULL && ctx->cipher == NULL) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
return 0;
}
/* TODO(3.0): Legacy work around code below. Remove this */
#ifndef OPENSSL_NO_ENGINE
/*
* Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
* this context may already have an ENGINE! Try to avoid releasing the
* previous handle, re-querying for an ENGINE, and having a
* reinitialisation, when it may all be unnecessary.
*/
if (ctx->engine && ctx->cipher
&& (cipher == NULL || cipher->nid == ctx->cipher->nid))
goto skip_to_init;
if (cipher != NULL && impl == NULL) {
/* Ask if an ENGINE is reserved for this job */
tmpimpl = ENGINE_get_cipher_engine(cipher->nid);
}
#endif
/*
* If there are engines involved then we should use legacy handling for now.
*/
if (ctx->engine != NULL
|| impl != NULL
|| tmpimpl != NULL) {
if (ctx->cipher == ctx->fetched_cipher)
ctx->cipher = NULL;
EVP_CIPHER_meth_free(ctx->fetched_cipher);
ctx->fetched_cipher = NULL;
goto legacy;
}
tmpcipher = (cipher == NULL) ? ctx->cipher : cipher;
if (tmpcipher->prov == NULL) {
switch(tmpcipher->nid) {
case NID_aes_256_ecb:
case NID_aes_192_ecb:
case NID_aes_128_ecb:
case NID_aes_256_cbc:
case NID_aes_192_cbc:
case NID_aes_128_cbc:
case NID_aes_256_ofb128:
case NID_aes_192_ofb128:
case NID_aes_128_ofb128:
case NID_aes_256_cfb128:
case NID_aes_192_cfb128:
case NID_aes_128_cfb128:
case NID_aes_256_cfb1:
case NID_aes_192_cfb1:
case NID_aes_128_cfb1:
case NID_aes_256_cfb8:
case NID_aes_192_cfb8:
case NID_aes_128_cfb8:
case NID_aes_256_ctr:
case NID_aes_192_ctr:
case NID_aes_128_ctr:
break;
default:
goto legacy;
}
}
/*
* Ensure a context left lying around from last time is cleared
* (legacy code)
*/
if (cipher != NULL && ctx->cipher != NULL) {
OPENSSL_clear_free(ctx->cipher_data, ctx->cipher->ctx_size);
ctx->cipher_data = NULL;
}
/* TODO(3.0): Start of non-legacy code below */
/* Ensure a context left lying around from last time is cleared */
if (cipher != NULL && ctx->cipher != NULL) {
unsigned long flags = ctx->flags;
EVP_CIPHER_CTX_reset(ctx);
/* Restore encrypt and flags */
ctx->encrypt = enc;
ctx->flags = flags;
}
if (cipher != NULL)
ctx->cipher = cipher;
else
cipher = ctx->cipher;
if (cipher->prov == NULL) {
provciph = EVP_CIPHER_fetch(NULL, OBJ_nid2sn(cipher->nid), "");
if (provciph == NULL) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
cipher = provciph;
EVP_CIPHER_meth_free(ctx->fetched_cipher);
ctx->fetched_cipher = provciph;
}
ctx->cipher = cipher;
if (ctx->provctx == NULL) {
ctx->provctx = ctx->cipher->newctx();
if (ctx->provctx == NULL) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
}
if ((ctx->flags & EVP_CIPH_NO_PADDING) != 0) {
/*
* If this ctx was already set up for no padding then we need to tell
* the new cipher about it.
*/
if (!EVP_CIPHER_CTX_set_padding(ctx, 0))
return 0;
}
switch (EVP_CIPHER_mode(ctx->cipher)) {
case EVP_CIPH_CFB_MODE:
case EVP_CIPH_OFB_MODE:
case EVP_CIPH_CBC_MODE:
/* For these modes we remember the original IV for later use */
if (!ossl_assert(EVP_CIPHER_CTX_iv_length(ctx) <= (int)sizeof(ctx->oiv))) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
if (iv != NULL)
memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
}
if (enc) {
if (ctx->cipher->einit == NULL) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
return ctx->cipher->einit(ctx->provctx,
key,
EVP_CIPHER_CTX_key_length(ctx),
iv,
EVP_CIPHER_CTX_iv_length(ctx));
}
if (ctx->cipher->dinit == NULL) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
return ctx->cipher->dinit(ctx->provctx,
key,
EVP_CIPHER_CTX_key_length(ctx),
iv,
EVP_CIPHER_CTX_iv_length(ctx));
/* TODO(3.0): Remove legacy code below */
legacy:
if (cipher != NULL) {
/*
* Ensure a context left lying around from last time is cleared (we
* previously attempted to avoid this if the same ENGINE and
* EVP_CIPHER could be used).
*/
if (ctx->cipher) {
unsigned long flags = ctx->flags;
EVP_CIPHER_CTX_reset(ctx);
/* Restore encrypt and flags */
ctx->encrypt = enc;
ctx->flags = flags;
}
#ifndef OPENSSL_NO_ENGINE
if (impl != NULL) {
if (!ENGINE_init(impl)) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
} else {
impl = tmpimpl;
}
if (impl != NULL) {
/* There's an ENGINE for this job ... (apparently) */
const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
if (c == NULL) {
/*
* One positive side-effect of US's export control history,
* is that we should at least be able to avoid using US
* misspellings of "initialisation"?
*/
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
/* We'll use the ENGINE's private cipher definition */
cipher = c;
/*
* Store the ENGINE functional reference so we know 'cipher' came
* from an ENGINE and we need to release it when done.
*/
ctx->engine = impl;
} else {
ctx->engine = NULL;
}
#endif
ctx->cipher = cipher;
if (ctx->cipher->ctx_size) {
ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
if (ctx->cipher_data == NULL) {
ctx->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
return 0;
}
} else {
ctx->cipher_data = NULL;
}
ctx->key_len = cipher->key_len;
/* Preserve wrap enable flag, zero everything else */
ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
ctx->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
}
}
#ifndef OPENSSL_NO_ENGINE
skip_to_init:
#endif
/* we assume block size is a power of 2 in *cryptUpdate */
OPENSSL_assert(ctx->cipher->block_size == 1
|| ctx->cipher->block_size == 8
|| ctx->cipher->block_size == 16);
if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
&& EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
return 0;
}
if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
switch (EVP_CIPHER_CTX_mode(ctx)) {
case EVP_CIPH_STREAM_CIPHER:
case EVP_CIPH_ECB_MODE:
break;
case EVP_CIPH_CFB_MODE:
case EVP_CIPH_OFB_MODE:
ctx->num = 0;
/* fall-through */
case EVP_CIPH_CBC_MODE:
OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
(int)sizeof(ctx->iv));
if (iv)
memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
break;
case EVP_CIPH_CTR_MODE:
ctx->num = 0;
/* Don't reuse IV for CTR mode */
if (iv)
memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
break;
default:
return 0;
}
}
if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
if (!ctx->cipher->init(ctx, key, iv, enc))
return 0;
}
ctx->buf_len = 0;
ctx->final_used = 0;
ctx->block_mask = ctx->cipher->block_size - 1;
return 1;
}
int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
if (ctx->encrypt)
return EVP_EncryptUpdate(ctx, out, outl, in, inl);
else
return EVP_DecryptUpdate(ctx, out, outl, in, inl);
}
int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
if (ctx->encrypt)
return EVP_EncryptFinal_ex(ctx, out, outl);
else
return EVP_DecryptFinal_ex(ctx, out, outl);
}
int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
if (ctx->encrypt)
return EVP_EncryptFinal(ctx, out, outl);
else
return EVP_DecryptFinal(ctx, out, outl);
}
int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
const unsigned char *key, const unsigned char *iv)
{
return EVP_CipherInit(ctx, cipher, key, iv, 1);
}
int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
ENGINE *impl, const unsigned char *key,
const unsigned char *iv)
{
return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
}
int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
const unsigned char *key, const unsigned char *iv)
{
return EVP_CipherInit(ctx, cipher, key, iv, 0);
}
int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
ENGINE *impl, const unsigned char *key,
const unsigned char *iv)
{
return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
}
/*
* According to the letter of standard difference between pointers
* is specified to be valid only within same object. This makes
* it formally challenging to determine if input and output buffers
* are not partially overlapping with standard pointer arithmetic.
*/
#ifdef PTRDIFF_T
# undef PTRDIFF_T
#endif
#if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
/*
* Then we have VMS that distinguishes itself by adhering to
* sizeof(size_t)==4 even in 64-bit builds, which means that
* difference between two pointers might be truncated to 32 bits.
* In the context one can even wonder how comparison for
* equality is implemented. To be on the safe side we adhere to
* PTRDIFF_T even for comparison for equality.
*/
# define PTRDIFF_T uint64_t
#else
# define PTRDIFF_T size_t
#endif
int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
{
PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
/*
* Check for partially overlapping buffers. [Binary logical
* operations are used instead of boolean to minimize number
* of conditional branches.]
*/
int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
(diff > (0 - (PTRDIFF_T)len)));
return overlapped;
}
static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
int i, j, bl, cmpl = inl;
if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
cmpl = (cmpl + 7) / 8;
bl = ctx->cipher->block_size;
if (inl <= 0) {
*outl = 0;
return inl == 0;
}
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
/* If block size > 1 then the cipher will have to do this check */
if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
return 0;
}
i = ctx->cipher->do_cipher(ctx, out, in, inl);
if (i < 0)
return 0;
else
*outl = i;
return 1;
}
if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
return 0;
}
if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
*outl = inl;
return 1;
} else {
*outl = 0;
return 0;
}
}
i = ctx->buf_len;
OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
if (i != 0) {
if (bl - i > inl) {
memcpy(&(ctx->buf[i]), in, inl);
ctx->buf_len += inl;
*outl = 0;
return 1;
} else {
j = bl - i;
memcpy(&(ctx->buf[i]), in, j);
inl -= j;
in += j;
if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
return 0;
out += bl;
*outl = bl;
}
} else
*outl = 0;
i = inl & (bl - 1);
inl -= i;
if (inl > 0) {
if (!ctx->cipher->do_cipher(ctx, out, in, inl))
return 0;
*outl += inl;
}
if (i != 0)
memcpy(ctx->buf, &(in[inl]), i);
ctx->buf_len = i;
return 1;
}
int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
int ret;
size_t soutl;
int blocksize;
/* Prevent accidental use of decryption context when encrypting */
if (!ctx->encrypt) {
EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
return 0;
}
if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
goto legacy;
blocksize = EVP_CIPHER_CTX_block_size(ctx);
if (ctx->cipher->cupdate == NULL || blocksize < 1) {
EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
return 0;
}
ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
inl + (blocksize == 1 ? 0 : blocksize), in,
(size_t)inl);
if (soutl > INT_MAX) {
EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_UPDATE_ERROR);
return 0;
}
*outl = soutl;
return ret;
/* TODO(3.0): Remove legacy code below */
legacy:
return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
}
int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int ret;
ret = EVP_EncryptFinal_ex(ctx, out, outl);
return ret;
}
int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int n, ret;
unsigned int i, b, bl;
size_t soutl;
int blocksize;
/* Prevent accidental use of decryption context when encrypting */
if (!ctx->encrypt) {
EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
return 0;
}
if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
goto legacy;
blocksize = EVP_CIPHER_CTX_block_size(ctx);
if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
return 0;
}
ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
blocksize == 1 ? 0 : blocksize);
if (soutl > INT_MAX) {
EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_FINAL_ERROR);
return 0;
}
*outl = soutl;
return ret;
/* TODO(3.0): Remove legacy code below */
legacy:
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
if (ret < 0)
return 0;
else
*outl = ret;
return 1;
}
b = ctx->cipher->block_size;
OPENSSL_assert(b <= sizeof(ctx->buf));
if (b == 1) {
*outl = 0;
return 1;
}
bl = ctx->buf_len;
if (ctx->flags & EVP_CIPH_NO_PADDING) {
if (bl) {
EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
return 0;
}
*outl = 0;
return 1;
}
n = b - bl;
for (i = bl; i < b; i++)
ctx->buf[i] = n;
ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
if (ret)
*outl = b;
return ret;
}
int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
int fix_len, cmpl = inl, ret;
unsigned int b;
size_t soutl;
int blocksize;
/* Prevent accidental use of encryption context when decrypting */
if (ctx->encrypt) {
EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
return 0;
}
if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
goto legacy;
blocksize = EVP_CIPHER_CTX_block_size(ctx);
if (ctx->cipher->cupdate == NULL || blocksize < 1) {
EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
return 0;
}
ret = ctx->cipher->cupdate(ctx->provctx, out, &soutl,
inl + (blocksize == 1 ? 0 : blocksize), in,
(size_t)inl);
if (ret) {
if (soutl > INT_MAX) {
EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_UPDATE_ERROR);
return 0;
}
*outl = soutl;
}
return ret;
/* TODO(3.0): Remove legacy code below */
legacy:
b = ctx->cipher->block_size;
if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
cmpl = (cmpl + 7) / 8;
if (inl <= 0) {
*outl = 0;
return inl == 0;
}
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
return 0;
}
fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
if (fix_len < 0) {
*outl = 0;
return 0;
} else
*outl = fix_len;
return 1;
}
if (ctx->flags & EVP_CIPH_NO_PADDING)
return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
OPENSSL_assert(b <= sizeof(ctx->final));
if (ctx->final_used) {
/* see comment about PTRDIFF_T comparison above */
if (((PTRDIFF_T)out == (PTRDIFF_T)in)
|| is_partially_overlapping(out, in, b)) {
EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
return 0;
}
memcpy(out, ctx->final, b);
out += b;
fix_len = 1;
} else
fix_len = 0;
if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
return 0;
/*
* if we have 'decrypted' a multiple of block size, make sure we have a
* copy of this last block
*/
if (b > 1 && !ctx->buf_len) {
*outl -= b;
ctx->final_used = 1;
memcpy(ctx->final, &out[*outl], b);
} else
ctx->final_used = 0;
if (fix_len)
*outl += b;
return 1;
}
int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int ret;
ret = EVP_DecryptFinal_ex(ctx, out, outl);
return ret;
}
int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int i, n;
unsigned int b;
size_t soutl;
int ret;
int blocksize;
/* Prevent accidental use of encryption context when decrypting */
if (ctx->encrypt) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
return 0;
}
if (ctx->cipher == NULL || ctx->cipher->prov == NULL)
goto legacy;
blocksize = EVP_CIPHER_CTX_block_size(ctx);
if (blocksize < 1 || ctx->cipher->cfinal == NULL) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
return 0;
}
ret = ctx->cipher->cfinal(ctx->provctx, out, &soutl,
blocksize == 1 ? 0 : blocksize);
if (ret) {
if (soutl > INT_MAX) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_FINAL_ERROR);
return 0;
}
*outl = soutl;
}
return ret;
/* TODO(3.0): Remove legacy code below */
legacy:
*outl = 0;
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
if (i < 0)
return 0;
else
*outl = i;
return 1;
}
b = ctx->cipher->block_size;
if (ctx->flags & EVP_CIPH_NO_PADDING) {
if (ctx->buf_len) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
return 0;
}
*outl = 0;
return 1;
}
if (b > 1) {
if (ctx->buf_len || !ctx->final_used) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
return 0;
}
OPENSSL_assert(b <= sizeof(ctx->final));
/*
* The following assumes that the ciphertext has been authenticated.
* Otherwise it provides a padding oracle.
*/
n = ctx->final[b - 1];
if (n == 0 || n > (int)b) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
return 0;
}
for (i = 0; i < n; i++) {
if (ctx->final[--b] != n) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
return 0;
}
}
n = ctx->cipher->block_size - n;
for (i = 0; i < n; i++)
out[i] = ctx->final[i];
*outl = n;
} else
*outl = 0;
return 1;
}
int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
{
if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
if (EVP_CIPHER_CTX_key_length(c) == keylen)
return 1;
if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
c->key_len = keylen;
return 1;
}
EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
return 0;
}
int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
{
if (pad)
ctx->flags &= ~EVP_CIPH_NO_PADDING;
else
ctx->flags |= EVP_CIPH_NO_PADDING;
if (ctx->cipher != NULL && ctx->cipher->prov != NULL) {
OSSL_PARAM params[] = {
OSSL_PARAM_int(OSSL_CIPHER_PARAM_PADDING, NULL),
OSSL_PARAM_END
};
params[0].data = &pad;
if (ctx->cipher->ctx_set_params == NULL) {
EVPerr(EVP_F_EVP_CIPHER_CTX_SET_PADDING, EVP_R_CTRL_NOT_IMPLEMENTED);
return 0;
}
if (!ctx->cipher->ctx_set_params(ctx->provctx, params))
return 0;
}
return 1;
}
int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
{
int ret;
if (!ctx->cipher) {
EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
return 0;
}
if (!ctx->cipher->ctrl) {
EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
return 0;
}
ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
if (ret == -1) {
EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
return 0;
}
return ret;
}
int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
{
if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
if (RAND_priv_bytes(key, ctx->key_len) <= 0)
return 0;
return 1;
}
int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
{
if ((in == NULL) || (in->cipher == NULL)) {
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
return 0;
}
if (in->cipher->prov == NULL)
goto legacy;
if (in->cipher->dupctx == NULL) {
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
return 0;
}
EVP_CIPHER_CTX_reset(out);
*out = *in;
out->provctx = NULL;
if (in->fetched_cipher != NULL && !EVP_CIPHER_upref(in->fetched_cipher)) {
out->fetched_cipher = NULL;
return 0;
}
out->provctx = in->cipher->dupctx(in->provctx);
if (out->provctx == NULL) {
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_NOT_ABLE_TO_COPY_CTX);
return 0;
}
return 1;
/* TODO(3.0): Remove legacy code below */
legacy:
#ifndef OPENSSL_NO_ENGINE
/* Make sure it's safe to copy a cipher context using an ENGINE */
if (in->engine && !ENGINE_init(in->engine)) {
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
return 0;
}
#endif
EVP_CIPHER_CTX_reset(out);
memcpy(out, in, sizeof(*out));
if (in->cipher_data && in->cipher->ctx_size) {
out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
if (out->cipher_data == NULL) {
out->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
return 0;
}
memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
}
if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
out->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
return 0;
}
return 1;
}
static void *evp_cipher_from_dispatch(int nid, const OSSL_DISPATCH *fns,
OSSL_PROVIDER *prov)
{
EVP_CIPHER *cipher = NULL;
int fnciphcnt = 0, fnctxcnt = 0;
if ((cipher = EVP_CIPHER_meth_new(nid, 0, 0)) == NULL)
return NULL;
for (; fns->function_id != 0; fns++) {
switch (fns->function_id) {
case OSSL_FUNC_CIPHER_NEWCTX:
if (cipher->newctx != NULL)
break;
cipher->newctx = OSSL_get_OP_cipher_newctx(fns);
fnctxcnt++;
break;
case OSSL_FUNC_CIPHER_ENCRYPT_INIT:
if (cipher->einit != NULL)
break;
cipher->einit = OSSL_get_OP_cipher_encrypt_init(fns);
fnciphcnt++;
break;
case OSSL_FUNC_CIPHER_DECRYPT_INIT:
if (cipher->dinit != NULL)
break;
cipher->dinit = OSSL_get_OP_cipher_decrypt_init(fns);
fnciphcnt++;
break;
case OSSL_FUNC_CIPHER_UPDATE:
if (cipher->cupdate != NULL)
break;
cipher->cupdate = OSSL_get_OP_cipher_update(fns);
fnciphcnt++;
break;
case OSSL_FUNC_CIPHER_FINAL:
if (cipher->cfinal != NULL)
break;
cipher->cfinal = OSSL_get_OP_cipher_final(fns);
fnciphcnt++;
break;
case OSSL_FUNC_CIPHER_CIPHER:
if (cipher->ccipher != NULL)
break;
cipher->ccipher = OSSL_get_OP_cipher_cipher(fns);
break;
case OSSL_FUNC_CIPHER_FREECTX:
if (cipher->freectx != NULL)
break;
cipher->freectx = OSSL_get_OP_cipher_freectx(fns);
fnctxcnt++;
break;
case OSSL_FUNC_CIPHER_DUPCTX:
if (cipher->dupctx != NULL)
break;
cipher->dupctx = OSSL_get_OP_cipher_dupctx(fns);
break;
case OSSL_FUNC_CIPHER_KEY_LENGTH:
if (cipher->key_length != NULL)
break;
cipher->key_length = OSSL_get_OP_cipher_key_length(fns);
break;
case OSSL_FUNC_CIPHER_IV_LENGTH:
if (cipher->iv_length != NULL)
break;
cipher->iv_length = OSSL_get_OP_cipher_iv_length(fns);
break;
case OSSL_FUNC_CIPHER_BLOCK_SIZE:
if (cipher->blocksize != NULL)
break;
cipher->blocksize = OSSL_get_OP_cipher_block_size(fns);
break;
case OSSL_FUNC_CIPHER_GET_PARAMS:
if (cipher->get_params != NULL)
break;
cipher->get_params = OSSL_get_OP_cipher_get_params(fns);
break;
case OSSL_FUNC_CIPHER_CTX_GET_PARAMS:
if (cipher->ctx_get_params != NULL)
break;
cipher->ctx_get_params = OSSL_get_OP_cipher_ctx_get_params(fns);
break;
case OSSL_FUNC_CIPHER_CTX_SET_PARAMS:
if (cipher->ctx_set_params != NULL)
break;
cipher->ctx_set_params = OSSL_get_OP_cipher_ctx_set_params(fns);
break;
}
}
if ((fnciphcnt != 0 && fnciphcnt != 3 && fnciphcnt != 4)
|| (fnciphcnt == 0 && cipher->ccipher == NULL)
|| fnctxcnt != 2) {
/*
* In order to be a consistent set of functions we must have at least
* a complete set of "encrypt" functions, or a complete set of "decrypt"
* functions, or a single "cipher" function. In all cases we need a
* complete set of context management functions
*/
EVP_CIPHER_meth_free(cipher);
EVPerr(EVP_F_EVP_CIPHER_FROM_DISPATCH, EVP_R_INVALID_PROVIDER_FUNCTIONS);
return NULL;
}
cipher->prov = prov;
if (prov != NULL)
ossl_provider_upref(prov);
return cipher;
}
static int evp_cipher_upref(void *cipher)
{
return EVP_CIPHER_upref(cipher);
}
static void evp_cipher_free(void *cipher)
{
EVP_CIPHER_meth_free(cipher);
}
static int evp_cipher_nid(void *vcipher)
{
EVP_CIPHER *cipher = vcipher;
return cipher->nid;
}
EVP_CIPHER *EVP_CIPHER_fetch(OPENSSL_CTX *ctx, const char *algorithm,
const char *properties)
{
return evp_generic_fetch(ctx, OSSL_OP_CIPHER, algorithm, properties,
evp_cipher_from_dispatch, evp_cipher_upref,
evp_cipher_free, evp_cipher_nid);
}
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