/*
* \brief Generic file encryption program using generic wrappers for configured
* security.
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
/* Enable definition of fileno() even when compiling with -std=c99. Must be
* set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
* Harmless on other platforms. */
#define _POSIX_C_SOURCE 200112L
#include "mbedtls/build_info.h"
#include "mbedtls/platform.h"
#if defined(MBEDTLS_CIPHER_C) && defined(MBEDTLS_MD_C) && \
defined(MBEDTLS_FS_IO)
#include "mbedtls/cipher.h"
#include "mbedtls/md.h"
#include "mbedtls/platform_util.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#endif
#if defined(_WIN32)
#include <windows.h>
#if !defined(_WIN32_WCE)
#include <io.h>
#endif
#else
#include <sys/types.h>
#include <unistd.h>
#endif
#define MODE_ENCRYPT 0
#define MODE_DECRYPT 1
#define USAGE \
"\n crypt_and_hash <mode> <input filename> <output filename> <cipher> <mbedtls_md> <key>\n" \
"\n <mode>: 0 = encrypt, 1 = decrypt\n" \
"\n example: crypt_and_hash 0 file file.aes AES-128-CBC SHA1 hex:E76B2413958B00E193\n" \
"\n"
#if !defined(MBEDTLS_CIPHER_C) || !defined(MBEDTLS_MD_C) || \
!defined(MBEDTLS_FS_IO)
int main(void)
{
mbedtls_printf("MBEDTLS_CIPHER_C and/or MBEDTLS_MD_C and/or MBEDTLS_FS_IO not defined.\n");
mbedtls_exit(0);
}
#else
int main(int argc, char *argv[])
{
int ret = 1, i;
unsigned n;
int exit_code = MBEDTLS_EXIT_FAILURE;
int mode;
size_t keylen, ilen, olen;
FILE *fkey, *fin = NULL, *fout = NULL;
char *p;
unsigned char IV[16];
unsigned char key[512];
unsigned char digest[MBEDTLS_MD_MAX_SIZE];
unsigned char buffer[1024];
unsigned char output[1024];
unsigned char diff;
const mbedtls_cipher_info_t *cipher_info;
const mbedtls_md_info_t *md_info;
mbedtls_cipher_context_t cipher_ctx;
mbedtls_md_context_t md_ctx;
mbedtls_cipher_mode_t cipher_mode;
unsigned int cipher_block_size;
unsigned char md_size;
#if defined(_WIN32_WCE)
long filesize, offset;
#elif defined(_WIN32)
LARGE_INTEGER li_size;
__int64 filesize, offset;
#else
off_t filesize, offset;
#endif
mbedtls_cipher_init(&cipher_ctx);
mbedtls_md_init(&md_ctx);
/*
* Parse the command-line arguments.
*/
if (argc != 7) {
const int *list;
mbedtls_printf(USAGE);
mbedtls_printf("Available ciphers:\n");
list = mbedtls_cipher_list();
while (*list) {
cipher_info = mbedtls_cipher_info_from_type(*list);
const char *name = mbedtls_cipher_info_get_name(cipher_info);
if (name) {
mbedtls_printf(" %s\n", mbedtls_cipher_info_get_name(cipher_info));
}
list++;
}
mbedtls_printf("\nAvailable message digests:\n");
list = mbedtls_md_list();
while (*list) {
md_info = mbedtls_md_info_from_type(*list);
mbedtls_printf(" %s\n", mbedtls_md_get_name(md_info));
list++;
}
goto exit;
}
mode = atoi(argv[1]);
if (mode != MODE_ENCRYPT && mode != MODE_DECRYPT) {
mbedtls_fprintf(stderr, "invalid operation mode\n");
goto exit;
}
if (strcmp(argv[2], argv[3]) == 0) {
mbedtls_fprintf(stderr, "input and output filenames must differ\n");
goto exit;
}
if ((fin = fopen(argv[2], "rb")) == NULL) {
mbedtls_fprintf(stderr, "fopen(%s,rb) failed\n", argv[2]);
goto exit;
}
if ((fout = fopen(argv[3], "wb+")) == NULL) {
mbedtls_fprintf(stderr, "fopen(%s,wb+) failed\n", argv[3]);
goto exit;
}
/* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
mbedtls_setbuf(fin, NULL);
mbedtls_setbuf(fout, NULL);
/*
* Read the Cipher and MD from the command line
*/
cipher_info = mbedtls_cipher_info_from_string(argv[4]);
if (cipher_info == NULL) {
mbedtls_fprintf(stderr, "Cipher '%s' not found\n", argv[4]);
goto exit;
}
if ((ret = mbedtls_cipher_setup(&cipher_ctx, cipher_info)) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_setup failed\n");
goto exit;
}
md_info = mbedtls_md_info_from_string(argv[5]);
if (md_info == NULL) {
mbedtls_fprintf(stderr, "Message Digest '%s' not found\n", argv[5]);
goto exit;
}
if (mbedtls_md_setup(&md_ctx, md_info, 1) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_setup failed\n");
goto exit;
}
/*
* Read the secret key from file or command line
*/
if ((fkey = fopen(argv[6], "rb")) != NULL) {
keylen = fread(key, 1, sizeof(key), fkey);
fclose(fkey);
} else {
if (memcmp(argv[6], "hex:", 4) == 0) {
p = &argv[6][4];
keylen = 0;
while (sscanf(p, "%02X", (unsigned int *) &n) > 0 &&
keylen < (int) sizeof(key)) {
key[keylen++] = (unsigned char) n;
p += 2;
}
} else {
keylen = strlen(argv[6]);
if (keylen > (int) sizeof(key)) {
keylen = (int) sizeof(key);
}
memcpy(key, argv[6], keylen);
}
}
#if defined(_WIN32_WCE)
filesize = fseek(fin, 0L, SEEK_END);
#else
#if defined(_WIN32)
/*
* Support large files (> 2Gb) on Win32
*/
li_size.QuadPart = 0;
li_size.LowPart =
SetFilePointer((HANDLE) _get_osfhandle(_fileno(fin)),
li_size.LowPart, &li_size.HighPart, FILE_END);
if (li_size.LowPart == 0xFFFFFFFF && GetLastError() != NO_ERROR) {
mbedtls_fprintf(stderr, "SetFilePointer(0,FILE_END) failed\n");
goto exit;
}
filesize = li_size.QuadPart;
#else
if ((filesize = lseek(fileno(fin), 0, SEEK_END)) < 0) {
perror("lseek");
goto exit;
}
#endif
#endif
if (fseek(fin, 0, SEEK_SET) < 0) {
mbedtls_fprintf(stderr, "fseek(0,SEEK_SET) failed\n");
goto exit;
}
md_size = mbedtls_md_get_size(md_info);
cipher_block_size = mbedtls_cipher_get_block_size(&cipher_ctx);
if (mode == MODE_ENCRYPT) {
/*
* Generate the initialization vector as:
* IV = MD( filesize || filename )[0..15]
*/
for (i = 0; i < 8; i++) {
buffer[i] = (unsigned char) (filesize >> (i << 3));
}
p = argv[2];
if (mbedtls_md_starts(&md_ctx) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_starts() returned error\n");
goto exit;
}
if (mbedtls_md_update(&md_ctx, buffer, 8) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
goto exit;
}
if (mbedtls_md_update(&md_ctx, (unsigned char *) p, strlen(p))
!= 0) {
mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
goto exit;
}
if (mbedtls_md_finish(&md_ctx, digest) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_finish() returned error\n");
goto exit;
}
memcpy(IV, digest, 16);
/*
* Append the IV at the beginning of the output.
*/
if (fwrite(IV, 1, 16, fout) != 16) {
mbedtls_fprintf(stderr, "fwrite(%d bytes) failed\n", 16);
goto exit;
}
/*
* Hash the IV and the secret key together 8192 times
* using the result to setup the AES context and HMAC.
*/
memset(digest, 0, 32);
memcpy(digest, IV, 16);
for (i = 0; i < 8192; i++) {
if (mbedtls_md_starts(&md_ctx) != 0) {
mbedtls_fprintf(stderr,
"mbedtls_md_starts() returned error\n");
goto exit;
}
if (mbedtls_md_update(&md_ctx, digest, 32) != 0) {
mbedtls_fprintf(stderr,
"mbedtls_md_update() returned error\n");
goto exit;
}
if (mbedtls_md_update(&md_ctx, key, keylen) != 0) {
mbedtls_fprintf(stderr,
"mbedtls_md_update() returned error\n");
goto exit;
}
if (mbedtls_md_finish(&md_ctx, digest) != 0) {
mbedtls_fprintf(stderr,
"mbedtls_md_finish() returned error\n");
goto exit;
}
}
if (mbedtls_cipher_setkey(&cipher_ctx,
digest,
(int) mbedtls_cipher_info_get_key_bitlen(cipher_info),
MBEDTLS_ENCRYPT) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_setkey() returned error\n");
goto exit;
}
if (mbedtls_cipher_set_iv(&cipher_ctx, IV, 16) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_set_iv() returned error\n");
goto exit;
}
if (mbedtls_cipher_reset(&cipher_ctx) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_reset() returned error\n");
goto exit;
}
if (mbedtls_md_hmac_starts(&md_ctx, digest, 32) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_starts() returned error\n");
goto exit;
}
/*
* Encrypt and write the ciphertext.
*/
for (offset = 0; offset < filesize; offset += cipher_block_size) {
ilen = ((unsigned int) filesize - offset > cipher_block_size) ?
cipher_block_size : (unsigned int) (filesize - offset);
if (fread(buffer, 1, ilen, fin) != ilen) {
mbedtls_fprintf(stderr, "fread(%ld bytes) failed\n", (long) ilen);
goto exit;
}
if (mbedtls_cipher_update(&cipher_ctx, buffer, ilen, output, &olen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_update() returned error\n");
goto exit;
}
if (mbedtls_md_hmac_update(&md_ctx, output, olen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_update() returned error\n");
goto exit;
}
if (fwrite(output, 1, olen, fout) != olen) {
mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
goto exit;
}
}
if (mbedtls_cipher_finish(&cipher_ctx, output, &olen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_finish() returned error\n");
goto exit;
}
if (mbedtls_md_hmac_update(&md_ctx, output, olen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_update() returned error\n");
goto exit;
}
if (fwrite(output, 1, olen, fout) != olen) {
mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
goto exit;
}
/*
* Finally write the HMAC.
*/
if (mbedtls_md_hmac_finish(&md_ctx, digest) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_finish() returned error\n");
goto exit;
}
if (fwrite(digest, 1, md_size, fout) != md_size) {
mbedtls_fprintf(stderr, "fwrite(%d bytes) failed\n", md_size);
goto exit;
}
}
if (mode == MODE_DECRYPT) {
/*
* The encrypted file must be structured as follows:
*
* 00 .. 15 Initialization Vector
* 16 .. 31 Encrypted Block #1
* ..
* N*16 .. (N+1)*16 - 1 Encrypted Block #N
* (N+1)*16 .. (N+1)*16 + n Hash(ciphertext)
*/
if (filesize < 16 + md_size) {
mbedtls_fprintf(stderr, "File too short to be encrypted.\n");
goto exit;
}
if (cipher_block_size == 0) {
mbedtls_fprintf(stderr, "Invalid cipher block size: 0. \n");
goto exit;
}
/*
* Check the file size.
*/
cipher_mode = mbedtls_cipher_info_get_mode(cipher_info);
if (cipher_mode != MBEDTLS_MODE_GCM &&
cipher_mode != MBEDTLS_MODE_CTR &&
cipher_mode != MBEDTLS_MODE_CFB &&
cipher_mode != MBEDTLS_MODE_OFB &&
((filesize - md_size) % cipher_block_size) != 0) {
mbedtls_fprintf(stderr, "File content not a multiple of the block size (%u).\n",
cipher_block_size);
goto exit;
}
/*
* Subtract the IV + HMAC length.
*/
filesize -= (16 + md_size);
/*
* Read the IV and original filesize modulo 16.
*/
if (fread(buffer, 1, 16, fin) != 16) {
mbedtls_fprintf(stderr, "fread(%d bytes) failed\n", 16);
goto exit;
}
memcpy(IV, buffer, 16);
/*
* Hash the IV and the secret key together 8192 times
* using the result to setup the AES context and HMAC.
*/
memset(digest, 0, 32);
memcpy(digest, IV, 16);
for (i = 0; i < 8192; i++) {
if (mbedtls_md_starts(&md_ctx) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_starts() returned error\n");
goto exit;
}
if (mbedtls_md_update(&md_ctx, digest, 32) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
goto exit;
}
if (mbedtls_md_update(&md_ctx, key, keylen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_update() returned error\n");
goto exit;
}
if (mbedtls_md_finish(&md_ctx, digest) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_finish() returned error\n");
goto exit;
}
}
if (mbedtls_cipher_setkey(&cipher_ctx,
digest,
(int) mbedtls_cipher_info_get_key_bitlen(cipher_info),
MBEDTLS_DECRYPT) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_setkey() returned error\n");
goto exit;
}
if (mbedtls_cipher_set_iv(&cipher_ctx, IV, 16) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_set_iv() returned error\n");
goto exit;
}
if (mbedtls_cipher_reset(&cipher_ctx) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_reset() returned error\n");
goto exit;
}
if (mbedtls_md_hmac_starts(&md_ctx, digest, 32) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_starts() returned error\n");
goto exit;
}
/*
* Decrypt and write the plaintext.
*/
for (offset = 0; offset < filesize; offset += cipher_block_size) {
ilen = ((unsigned int) filesize - offset > cipher_block_size) ?
cipher_block_size : (unsigned int) (filesize - offset);
if (fread(buffer, 1, ilen, fin) != ilen) {
mbedtls_fprintf(stderr, "fread(%u bytes) failed\n",
cipher_block_size);
goto exit;
}
if (mbedtls_md_hmac_update(&md_ctx, buffer, ilen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_update() returned error\n");
goto exit;
}
if (mbedtls_cipher_update(&cipher_ctx, buffer, ilen, output,
&olen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_update() returned error\n");
goto exit;
}
if (fwrite(output, 1, olen, fout) != olen) {
mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
goto exit;
}
}
/*
* Verify the message authentication code.
*/
if (mbedtls_md_hmac_finish(&md_ctx, digest) != 0) {
mbedtls_fprintf(stderr, "mbedtls_md_hmac_finish() returned error\n");
goto exit;
}
if (fread(buffer, 1, md_size, fin) != md_size) {
mbedtls_fprintf(stderr, "fread(%d bytes) failed\n", md_size);
goto exit;
}
/* Use constant-time buffer comparison */
diff = 0;
for (i = 0; i < md_size; i++) {
diff |= digest[i] ^ buffer[i];
}
if (diff != 0) {
mbedtls_fprintf(stderr, "HMAC check failed: wrong key, "
"or file corrupted.\n");
goto exit;
}
/*
* Write the final block of data
*/
if (mbedtls_cipher_finish(&cipher_ctx, output, &olen) != 0) {
mbedtls_fprintf(stderr, "mbedtls_cipher_finish() returned error\n");
goto exit;
}
if (fwrite(output, 1, olen, fout) != olen) {
mbedtls_fprintf(stderr, "fwrite(%ld bytes) failed\n", (long) olen);
goto exit;
}
}
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
if (fin) {
fclose(fin);
}
if (fout) {
fclose(fout);
}
/* Zeroize all command line arguments to also cover
the case when the user has missed or reordered some,
in which case the key might not be in argv[6]. */
for (i = 0; i < argc; i++) {
mbedtls_platform_zeroize(argv[i], strlen(argv[i]));
}
mbedtls_platform_zeroize(IV, sizeof(IV));
mbedtls_platform_zeroize(key, sizeof(key));
mbedtls_platform_zeroize(buffer, sizeof(buffer));
mbedtls_platform_zeroize(output, sizeof(output));
mbedtls_platform_zeroize(digest, sizeof(digest));
mbedtls_cipher_free(&cipher_ctx);
mbedtls_md_free(&md_ctx);
mbedtls_exit(exit_code);
}
#endif /* MBEDTLS_CIPHER_C && MBEDTLS_MD_C && MBEDTLS_FS_IO */