openwrt/package/utils/uencrypt/src/uencrypt.c

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/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright (C) 2022 Eneas Ulir de Queiroz
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef USE_WOLFSSL
# include <wolfssl/options.h>
# include <wolfssl/openssl/evp.h>
#else
# include <openssl/evp.h>
#endif
int do_crypt(FILE *infile, FILE *outfile, const EVP_CIPHER *cipher, const char *key, const char *iv,
int enc, int padding)
{
EVP_CIPHER_CTX *ctx;
unsigned char inbuf[1024], outbuf[1024 + EVP_MAX_BLOCK_LENGTH];
int inlen, outlen;
ctx = EVP_CIPHER_CTX_new();
EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
EVP_CIPHER_CTX_set_padding(ctx, padding);
for (;;) {
inlen = fread(inbuf, 1, 1024, infile);
if (inlen <= 0)
break;
if (!EVP_CipherUpdate(ctx, outbuf, &outlen, inbuf, inlen)) {
EVP_CIPHER_CTX_free(ctx);
return -1;
}
fwrite(outbuf, 1, outlen, outfile);
}
if (!EVP_CipherFinal_ex(ctx, outbuf, &outlen)) {
EVP_CIPHER_CTX_free(ctx);
return -1;
}
fwrite(outbuf, 1, outlen, outfile);
EVP_CIPHER_CTX_free(ctx);
return 0;
}
static void check_enc_dec(const int enc)
{
if (enc == -1)
return;
fprintf(stderr, "Error: both -d and -e were specified.\n");
exit(EXIT_FAILURE);
}
#ifndef USE_WOLFSSL
static void print_ciphers(const OBJ_NAME *name,void *arg) {
fprintf(arg, "\t%s\n", name->name);
}
#endif
static void check_cipher(const EVP_CIPHER *cipher)
{
if (cipher == NULL) {
fprintf(stderr, "Error: invalid cipher: %s.\n", optarg);
#ifndef USE_WOLFSSL
fprintf(stderr, "Supported ciphers: \n", optarg);
OBJ_NAME_do_all_sorted(OBJ_NAME_TYPE_CIPHER_METH, print_ciphers, stderr);
#endif
exit(EXIT_FAILURE);
}
}
static void show_usage(const char* name)
{
fprintf(stderr, "Usage: %s: [-d | -e] [-n] -k key [-i iv] [-c cipher]\n"
"-d = decrypt; -e = encrypt; -n = no padding\n", name);
}
int main(int argc, char *argv[])
{
int enc = -1;
unsigned char *iv = NULL;
unsigned char *key = NULL;
long len;
int opt;
int padding = 1;
int need_iv = 1;
const EVP_CIPHER *cipher = EVP_aes_128_cbc();
int ret;
while ((opt = getopt(argc, argv, "c:dei:k:n")) != -1) {
switch (opt) {
case 'c':
cipher = EVP_get_cipherbyname(optarg);
check_cipher(cipher);
int arglen = strlen(optarg);
if (arglen > 3 && strncmp(optarg+arglen-3, "ecb", 3) == 0) //if ends with "ecb"
need_iv = 0;
break;
case 'd':
check_enc_dec(enc);
enc = 0;
break;
case 'e':
check_enc_dec(enc);
enc = 1;
break;
case 'i':
iv = OPENSSL_hexstr2buf((const char *)optarg, &len);
if (iv == NULL) {
fprintf(stderr, "Error setting IV to %s. The IV should be encoded in hex.\n",
optarg);
exit(EINVAL);
}
break;
case 'k':
key = OPENSSL_hexstr2buf((const char *)optarg, &len);
if (key == NULL) {
fprintf(stderr, "Error setting key to %s. The key should be encoded in hex.\n",
optarg);
exit(EINVAL);
}
break;
case 'n':
padding = 0;
break;
default:
show_usage(argv[0]);
exit(EINVAL);
}
}
if (need_iv && iv == NULL) {
fprintf(stderr, "Error: iv not set.\n");
show_usage(argv[0]);
exit(EXIT_FAILURE);
}
if (key == NULL) {
fprintf(stderr, "Error: key not set.\n");
show_usage(argv[0]);
exit(EXIT_FAILURE);
}
ret = do_crypt(stdin, stdout, cipher, key, iv, !!enc, padding);
if (ret)
fprintf(stderr, "Error during crypt operation.\n");
OPENSSL_free(iv);
OPENSSL_free(key);
return ret;
}