Add Chacha20-Poly1305, AES128-GCM and AES256-GCM support (#93) * Add Chacha20-Poly1305 authenticated encryption * Add general AEAD approach. * Add [email protected] algo using LibTomCrypt chacha and poly1305 routines. Chacha20-Poly1305 is generally faster than AES256 on CPU w/o dedicated AES instructions, having the same key size. Compiling in will add ~5,5kB to binary size on x86-64. function old new delta chacha_crypt - 1397 +1397 _poly1305_block - 608 +608 poly1305_done - 595 +595 dropbear_chachapoly_crypt - 457 +457 .rodata 26976 27392 +416 poly1305_process - 290 +290 poly1305_init - 221 +221 chacha_setup - 218 +218 encrypt_packet 1068 1270 +202 dropbear_chachapoly_getlength - 147 +147 decrypt_packet 756 897 +141 chacha_ivctr64 - 137 +137 read_packet 543 637 +94 dropbear_chachapoly_start - 94 +94 read_kex_algos 792 880 +88 chacha_keystream - 69 +69 dropbear_mode_chachapoly - 48 +48 sshciphers 280 320 +40 dropbear_mode_none 24 48 +24 dropbear_mode_ctr 24 48 +24 dropbear_mode_cbc 24 48 +24 dropbear_chachapoly_mac - 24 +24 dropbear_chachapoly - 24 +24 gen_new_keys 848 854 +6 ------------------------------------------------------------------------------ (add/remove: 14/0 grow/shrink: 10/0 up/down: 5388/0) Total: 5388 bytes * Add AES128-GCM and AES256-GCM authenticated encryption * Add general AES-GCM mode. * Add [email protected] and [email protected] algo using LibTomCrypt gcm routines. AES-GCM is combination of AES CTR mode and GHASH, slower than AES-CTR on CPU w/o dedicated AES/GHASH instructions therefore disabled by default. Compiling in will add ~6kB to binary size on x86-64. function old new delta gcm_process - 1060 +1060 .rodata 26976 27808 +832 gcm_gf_mult - 820 +820 gcm_add_aad - 660 +660 gcm_shift_table - 512 +512 gcm_done - 471 +471 gcm_add_iv - 384 +384 gcm_init - 347 +347 dropbear_gcm_crypt - 309 +309 encrypt_packet 1068 1270 +202 decrypt_packet 756 897 +141 gcm_reset - 118 +118 read_packet 543 637 +94 read_kex_algos 792 880 +88 sshciphers 280 360 +80 gcm_mult_h - 80 +80 dropbear_gcm_start - 62 +62 dropbear_mode_gcm - 48 +48 dropbear_mode_none 24 48 +24 dropbear_mode_ctr 24 48 +24 dropbear_mode_cbc 24 48 +24 dropbear_ghash - 24 +24 dropbear_gcm_getlength - 24 +24 gen_new_keys 848 854 +6 ------------------------------------------------------------------------------ (add/remove: 14/0 grow/shrink: 10/0 up/down: 6434/0) Total: 6434 bytes

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 */
/* test CFB/OFB/CBC modes */
#include <tomcrypt_test.h>

int modes_test(void)
{
   int ret = CRYPT_NOP;
#ifdef LTC_CBC_MODE
   symmetric_CBC cbc;
#endif
#ifdef LTC_CFB_MODE
   symmetric_CFB cfb;
#endif
#ifdef LTC_OFB_MODE
   symmetric_OFB ofb;
#endif
#if defined(LTC_CBC_MODE) || defined(LTC_CFB_MODE) || defined(LTC_OFB_MODE)
   unsigned char pt[64], ct[64], tmp[64], key[16], iv[16], iv2[16];
   int cipher_idx;
   unsigned long l;

   /* make a random pt, key and iv */
   yarrow_read(pt,  64, &yarrow_prng);
   yarrow_read(key, 16, &yarrow_prng);
   yarrow_read(iv,  16, &yarrow_prng);

   /* get idx of AES handy */
   cipher_idx = find_cipher("aes");
   if (cipher_idx == -1) {
      fprintf(stderr, "test requires AES");
      return 1;
   }
#endif

#ifdef LTC_F8_MODE
   DO(ret = f8_test_mode());
#endif

#ifdef LTC_LRW_MODE
   DO(ret = lrw_test());
#endif

#ifdef LTC_CBC_MODE
   /* test CBC mode */
   /* encode the block */
   DO(ret = cbc_start(cipher_idx, iv, key, 16, 0, &cbc));
   l = sizeof(iv2);
   DO(ret = cbc_getiv(iv2, &l, &cbc));
   if (l != 16 || memcmp(iv2, iv, 16)) {
      fprintf(stderr, "cbc_getiv failed");
      return 1;
   }
   DO(ret = cbc_encrypt(pt, ct, 64, &cbc));

   /* decode the block */
   DO(ret = cbc_setiv(iv2, l, &cbc));
   zeromem(tmp, sizeof(tmp));
   DO(ret = cbc_decrypt(ct, tmp, 64, &cbc));
   if (memcmp(tmp, pt, 64) != 0) {
      fprintf(stderr, "CBC failed");
      return 1;
   }
#endif

#ifdef LTC_CFB_MODE
   /* test CFB mode */
   /* encode the block */
   DO(ret = cfb_start(cipher_idx, iv, key, 16, 0, &cfb));
   l = sizeof(iv2);
   DO(ret = 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) {
      fprintf(stderr, "cfb_getiv failed");
      return 1;
   }
   DO(ret = cfb_encrypt(pt, ct, 64, &cfb));

   /* decode the block */
   DO(ret = cfb_setiv(iv, l, &cfb));
   zeromem(tmp, sizeof(tmp));
   DO(ret = cfb_decrypt(ct, tmp, 64, &cfb));
   if (memcmp(tmp, pt, 64) != 0) {
      fprintf(stderr, "CFB failed");
      return 1;
   }
#endif

#ifdef LTC_OFB_MODE
   /* test OFB mode */
   /* encode the block */
   DO(ret = ofb_start(cipher_idx, iv, key, 16, 0, &ofb));
   l = sizeof(iv2);
   DO(ret = ofb_getiv(iv2, &l, &ofb));
   if (l != 16 || memcmp(iv2, iv, 16)) {
      fprintf(stderr, "ofb_getiv failed");
      return 1;
   }
   DO(ret = ofb_encrypt(pt, ct, 64, &ofb));

   /* decode the block */
   DO(ret = ofb_setiv(iv2, l, &ofb));
   zeromem(tmp, sizeof(tmp));
   DO(ret = ofb_decrypt(ct, tmp, 64, &ofb));
   if (memcmp(tmp, pt, 64) != 0) {
      fprintf(stderr, "OFB failed");
      return 1;
   }
#endif

#if defined(LTC_CTR_MODE) && defined(LTC_RIJNDAEL)
   DO(ret = ctr_test());
#endif

#ifdef LTC_XTS_MODE
   DO(ret = xts_test());
#endif

   return 0;
}

/* ref:         $Format:%D$ */
/* git commit:  $Format:%H$ */
/* commit time: $Format:%ai$ */