demos/maurice/example3.c

   1 /* NOCW */
   2 /*
   3         Please read the README file for condition of use, before
   4         using this software.
   5
   6         Maurice Gittens  <mgittens@gits.nl>   January 1997
   7
   8 */
   9
  10 #include <stdio.h>
  11 #include <fcntl.h>
  12 #include <sys/stat.h>
  13 #include <evp.h>
  14
  15 #define STDIN           0
  16 #define STDOUT          1
  17 #define BUFLEN          512
  18 #define INIT_VECTOR     "12345678"
  19 #define ENCRYPT         1
  20 #define DECRYPT         0
  21 #define ALG             EVP_des_ede3_cbc()
  22
  23 static const char *usage = "Usage: example3 [-d] password\n";
  24
  25 void do_cipher(char *,int);
  26
  27 int main(int argc, char *argv[])
  28 {
  29         if ((argc == 2))
  30         {
  31                 do_cipher(argv[1],ENCRYPT);
  32         }
  33         else if ((argc == 3) && !strcmp(argv[1],"-d"))
  34         {
  35                 do_cipher(argv[2],DECRYPT);
  36         }
  37         else
  38         {
  39                 fprintf(stderr,"%s", usage);
  40                 exit(1);
  41         }
  42
  43         return 0;
  44 }
  45
  46 void do_cipher(char *pw, int operation)
  47 {
  48         char buf[BUFLEN];
  49         char ebuf[BUFLEN + 8];
  50         unsigned int ebuflen, rc;
  51         unsigned char iv[EVP_MAX_IV_LENGTH], key[EVP_MAX_KEY_LENGTH];
  52         unsigned int ekeylen, net_ekeylen;
  53         EVP_CIPHER_CTX ectx;
  54
  55         memcpy(iv, INIT_VECTOR, sizeof(iv));
  56
  57         EVP_BytesToKey(ALG, EVP_md5(), "salu", pw, strlen(pw), 1, key, iv);
  58
  59         EVP_CipherInit(&ectx, ALG, key, iv, operation);
  60
  61         while(1)
  62         {
  63                 int readlen = read(STDIN, buf, sizeof(buf));
  64
  65                 if (readlen <= 0)
  66                 {
  67                         if (!readlen)
  68                            break;
  69                         else
  70                         {
  71                                 perror("read");
  72                                 exit(1);
  73                         }
  74                 }
  75
  76                 EVP_CipherUpdate(&ectx, ebuf, &ebuflen, buf, readlen);
  77
  78                 write(STDOUT, ebuf, ebuflen);
  79         }
  80
  81         EVP_CipherFinal(&ectx, ebuf, &ebuflen);
  82
  83         write(STDOUT, ebuf, ebuflen);
  84 }
  85
  86