/* test CFB/OFB/CBC modes */#include "test.h"int modes_test(void){   unsigned char pt[64], ct[64], tmp[64], key[16], iv[16], iv2[16];   int x, cipher_idx;   symmetric_CBC cbc;   symmetric_CFB cfb;   symmetric_OFB ofb;   symmetric_CTR ctr;   unsigned long l;      /* make a random pt, key and iv */   yarrow_read(pt,  64, &test_yarrow);   yarrow_read(key, 16, &test_yarrow);   yarrow_read(iv,  16, &test_yarrow);      /* get idx of AES handy */   cipher_idx = find_cipher("aes");   if (cipher_idx == -1) {      printf("test requires AES");      return 1;   }      /* test CBC mode */   /* encode the block */   DO(cbc_start(cipher_idx, iv, key, 16, 0, &cbc));   l = sizeof(iv2);   DO(cbc_getiv(iv2, &l, &cbc));   if (l != 16 || memcmp(iv2, iv, 16)) {      printf("cbc_getiv failed");      return 1;   }   for (x = 0; x < 4; x++) {      DO(cbc_encrypt(pt+x*16, ct+x*16, &cbc));   }      /* decode the block */   DO(cbc_setiv(iv2, l, &cbc));   zeromem(tmp, sizeof(tmp));   for (x = 0; x < 4; x++) {      DO(cbc_decrypt(ct+x*16, tmp+x*16, &cbc));   }   if (memcmp(tmp, pt, 64) != 0) {      printf("CBC failed");      return 1;   }      /* test CFB mode */   /* encode the block */   DO(cfb_start(cipher_idx, iv, key, 16, 0, &cfb));   l = sizeof(iv2);   DO(cfb_getiv(iv2, &l, &cfb));   /* note we don't memcmp iv2/iv since cfb_start processes the IV for the first block */   if (l != 16) {      printf("cfb_getiv failed");      return 1;   }   DO(cfb_encrypt(pt, ct, 64, &cfb));      /* decode the block */   DO(cfb_setiv(iv, l, &cfb));   zeromem(tmp, sizeof(tmp));   DO(cfb_decrypt(ct, tmp, 64, &cfb));   if (memcmp(tmp, pt, 64) != 0) {      printf("CFB failed");      return 1;   }      /* test OFB mode */   /* encode the block */   DO(ofb_start(cipher_idx, iv, key, 16, 0, &ofb));   l = sizeof(iv2);   DO(ofb_getiv(iv2, &l, &ofb));   if (l != 16 || memcmp(iv2, iv, 16)) {      printf("ofb_getiv failed");      return 1;   }   DO(ofb_encrypt(pt, ct, 64, &ofb));      /* decode the block */   DO(ofb_setiv(iv2, l, &ofb));   zeromem(tmp, sizeof(tmp));   DO(ofb_decrypt(ct, tmp, 64, &ofb));   if (memcmp(tmp, pt, 64) != 0) {      printf("OFB failed");      return 1;   }      /* test CTR mode */   /* encode the block */   DO(ctr_start(cipher_idx, iv, key, 16, 0, &ctr));   l = sizeof(iv2);   DO(ctr_getiv(iv2, &l, &ctr));   if (l != 16 || memcmp(iv2, iv, 16)) {      printf("ctr_getiv failed");      return 1;   }   DO(ctr_encrypt(pt, ct, 64, &ctr));      /* decode the block */   DO(ctr_setiv(iv2, l, &ctr));   zeromem(tmp, sizeof(tmp));   DO(ctr_decrypt(ct, tmp, 64, &ctr));   if (memcmp(tmp, pt, 64) != 0) {      printf("CTR failed");      return 1;   }            return 0;}