package/utils/uencrypt/src/uencrypt.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later
   2  * Copyright (C) 2022 Eneas Ulir de Queiroz
   3  */
   4
   5 #include <errno.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9
  10 #ifdef USE_WOLFSSL
  11 # include <wolfssl/options.h>
  12 # include <wolfssl/openssl/evp.h>
  13 #else
  14 # include <openssl/evp.h>
  15 #endif
  16
  17 int do_crypt(FILE *infile, FILE *outfile, const char *key, const char *iv,
  18              int enc, int padding)
  19 {
  20     EVP_CIPHER_CTX *ctx;
  21     unsigned char inbuf[1024], outbuf[1024 + EVP_MAX_BLOCK_LENGTH];
  22     int inlen, outlen;
  23
  24     ctx = EVP_CIPHER_CTX_new();
  25     EVP_CipherInit_ex(ctx, EVP_aes_128_cbc(), NULL, key, iv, enc);
  26     EVP_CIPHER_CTX_set_padding(ctx, padding);
  27
  28     for (;;) {
  29         inlen = fread(inbuf, 1, 1024, infile);
  30         if (inlen <= 0)
  31             break;
  32         if (!EVP_CipherUpdate(ctx, outbuf, &outlen, inbuf, inlen)) {
  33             EVP_CIPHER_CTX_free(ctx);
  34             return -1;
  35         }
  36         fwrite(outbuf, 1, outlen, outfile);
  37     }
  38     if (!EVP_CipherFinal_ex(ctx, outbuf, &outlen)) {
  39         EVP_CIPHER_CTX_free(ctx);
  40         return -1;
  41     }
  42     fwrite(outbuf, 1, outlen, outfile);
  43
  44     EVP_CIPHER_CTX_free(ctx);
  45     return 0;
  46 }
  47
  48 static void check_enc_dec(const int enc)
  49 {
  50     if (enc == -1)
  51         return;
  52     fprintf(stderr, "Error: both -d and -e were specified.\n");
  53     exit(EXIT_FAILURE);
  54 }
  55
  56 static void show_usage(const char* name)
  57 {
  58     fprintf(stderr, "Usage: %s: [-d | -e] [-n] -k key -i iv\n"
  59                     "-d = decrypt; -e = encrypt; -n = no padding\n", name);
  60 }
  61
  62 int main(int argc, char *argv[])
  63 {
  64     int enc = -1;
  65     unsigned char *iv = NULL;
  66     unsigned char *key = NULL;
  67     long len;
  68     int opt;
  69     int padding = 1;
  70     int ret;
  71
  72     while ((opt = getopt(argc, argv, "dei:k:n")) != -1) {
  73         switch (opt) {
  74         case 'd':
  75             check_enc_dec(enc);
  76             enc = 0;
  77             break;
  78         case 'e':
  79             check_enc_dec(enc);
  80             enc = 1;
  81             break;
  82         case 'i':
  83             iv = OPENSSL_hexstr2buf((const char *)optarg, &len);
  84             if (iv == NULL || len != 16) {
  85                 fprintf(stderr, "Error setting IV to %s. The IV should be 16 bytes, encoded in hex.\n",
  86                         optarg);
  87                 exit(EINVAL);
  88             }
  89             break;
  90         case 'k':
  91             key = OPENSSL_hexstr2buf((const char *)optarg, &len);
  92             if (key == NULL || len != 16) {
  93                 fprintf(stderr, "Error setting key to %s. The key should be 16 bytes, encoded in hex.\n",
  94                         optarg);
  95                 exit(EINVAL);
  96             }
  97             break;
  98         case 'n':
  99             padding = 0;
 100             break;
 101         default:
 102             show_usage(argv[0]);
 103             exit(EINVAL);
 104         }
 105     }
 106     if (iv == NULL || key == NULL) {
 107         fprintf(stderr, "Error: %s not set.\n", key ? "iv" : (iv ? "key" : "key and iv"));
 108         show_usage(argv[0]);
 109         exit(EXIT_FAILURE);
 110     }
 111     ret = do_crypt(stdin, stdout, key, iv, !!enc, padding);
 112     if (ret)
 113         fprintf(stderr, "Error during crypt operation.\n");
 114     OPENSSL_free(iv);
 115     OPENSSL_free(key);
 116     return ret;
 117 }