EZ-SSL library

 #include "ezs.h"

 static char *hw = "Hello, world.";

main()
{
   EZS *E;
   char *mycn;
   int r;
   char resp[4096];

   /* allocate an ezs struct */
   E = ezs_new(NULL);

   /* add the CA info */
   if (!ezs_add_ca(CA's certificate file)) {
      fprintf(stderr, "set ca: %d\n", ezs_errno(E));
      exit (1);
   }

   /* add our cert */
   if (!ezs_add_cert(my cert and key file, NULL, &mycn)) {
      fprintf(stderr, "set cert: %d\n", ezs_errno(E));
      exit (1);
   }

   /* connect to server */
   if (!ezs_connect(E, server host:port, mycn)) {
      fprintf(stderr,">> Connect error, err = %d\n",
              ezs_errno(E));
      exit (1);
   }

   /* send message */

   if ((r=ezs_write(E, hw, strlen(hw)<0) {
       fprintf(stderr, ">> write failed, %d\n",
              ezs_errno(E));
       exit (1);
   }

   /* read reply */

   if ((r=ezs_read(E, resp, 4095))<=0) {
      fprintf(stderr, ">> read failed, %d\n",
              ezs_errno(E));
      exit (1);
   }

   resp[r] = '\0';
   printf("Received: %s\n", resp);

   ezs_disconnect(E);

}

 #include "ezs.h"

 static char *hw = "Hello, world.";
 static key = "my key string";

 #define UC (unsigned char*)

main()
{
   EZS *E;
   unsigned char *e_hw;
   int e_len;
   unsigned char *mac;
   int mac_len;
   unsigned char *iv = NULL;
   char *mac64, *e64;

   /* alloc an ezs struct */
   ezs_init(NULL);
   E = ezs_new(NULL);
   
   /* Initialize */
   ezs_crypt_init(E, key, strlen(key), &iv);

   /* encrypt */
   e_hw = UC malloc(strlen(hw)+EZS_BLOCKSIZE(E));
   
   ezs_crypt(E, EZS_ENCRYPT, e_hw, &e_len, UC hw, strlen(hw));

   /* get mac */
   ezs_hmac(&mac, &mac_len, e_hw, e_len, UC key, strlen(key));

   ezs_data_to_base64(&mac64, NULL, (void*)mac, mac_len);
   ezs_data_to_base64(&e64, NULL, (void*)e_hw, e_len);

   printf("%s encoded = %s\n", hw, e64);
   printf("mac = %s\n", mac64);
}