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