demos/maurice/example4.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
  20 static const char *usage = "Usage: example4 [-d]\n";
  21
  22 void do_encode(void);
  23 void do_decode(void);
  24
  25 int main(int argc, char *argv[])
  26 {
  27         if ((argc == 1))
  28         {
  29                 do_encode();
  30         }
  31         else if ((argc == 2) && !strcmp(argv[1],"-d"))
  32         {
  33                 do_decode();
  34         }
  35         else
  36         {
  37                 fprintf(stderr,"%s", usage);
  38                 exit(1);
  39         }
  40
  41         return 0;
  42 }
  43
  44 void do_encode()
  45 {
  46         char buf[BUFLEN];
  47         char ebuf[BUFLEN+24];
  48         unsigned int ebuflen;
  49         EVP_ENCODE_CTX ectx;
  50
  51         EVP_EncodeInit(&ectx);
  52
  53         while(1)
  54         {
  55                 int readlen = read(STDIN, buf, sizeof(buf));
  56
  57                 if (readlen <= 0)
  58                 {
  59                         if (!readlen)
  60                            break;
  61                         else
  62                         {
  63                                 perror("read");
  64                                 exit(1);
  65                         }
  66                 }
  67
  68                 EVP_EncodeUpdate(&ectx, ebuf, &ebuflen, buf, readlen);
  69
  70                 write(STDOUT, ebuf, ebuflen);
  71         }
  72
  73         EVP_EncodeFinal(&ectx, ebuf, &ebuflen);
  74
  75         write(STDOUT, ebuf, ebuflen);
  76 }
  77
  78 void do_decode()
  79 {
  80         char buf[BUFLEN];
  81         char ebuf[BUFLEN+24];
  82         unsigned int ebuflen;
  83         EVP_ENCODE_CTX ectx;
  84
  85         EVP_DecodeInit(&ectx);
  86
  87         while(1)
  88         {
  89                 int readlen = read(STDIN, buf, sizeof(buf));
  90                 int rc;
  91
  92                 if (readlen <= 0)
  93                 {
  94                         if (!readlen)
  95                            break;
  96                         else
  97                         {
  98                                 perror("read");
  99                                 exit(1);
 100                         }
 101                 }
 102
 103                 rc = EVP_DecodeUpdate(&ectx, ebuf, &ebuflen, buf, readlen);
 104                 if (rc <= 0)
 105                 {
 106                         if (!rc)
 107                         {
 108                                 write(STDOUT, ebuf, ebuflen);
 109                                 break;
 110                         }
 111
 112                         fprintf(stderr, "Error: decoding message\n");
 113                         return;
 114                 }
 115
 116                 write(STDOUT, ebuf, ebuflen);
 117         }
 118
 119         EVP_DecodeFinal(&ectx, ebuf, &ebuflen);
 120
 121         write(STDOUT, ebuf, ebuflen);
 122 }
 123