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.
 */
#include "tomcrypt.h"

/**
   @file pmac_process.c
   PMAC implementation, process data, by Tom St Denis
*/


#ifdef LTC_PMAC

/**
  Process data in a PMAC stream
  @param pmac     The PMAC state
  @param in       The data to send through PMAC
  @param inlen    The length of the data to send through PMAC
  @return CRYPT_OK if successful
*/
int pmac_process(pmac_state *pmac, const unsigned char *in, unsigned long inlen)
{
   int err, n;
   unsigned long x;
   unsigned char Z[MAXBLOCKSIZE];

   LTC_ARGCHK(pmac != NULL);
   LTC_ARGCHK(in   != NULL);
   if ((err = cipher_is_valid(pmac->cipher_idx)) != CRYPT_OK) {
      return err;
   }

   if ((pmac->buflen > (int)sizeof(pmac->block)) || (pmac->buflen < 0) ||
       (pmac->block_len > (int)sizeof(pmac->block)) || (pmac->buflen > pmac->block_len)) {
      return CRYPT_INVALID_ARG;
   }

#ifdef LTC_FAST
   if (pmac->buflen == 0 && inlen > 16) {
      unsigned long y;
      for (x = 0; x < (inlen - 16); x += 16) {
          pmac_shift_xor(pmac);
          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
              *(LTC_FAST_TYPE_PTR_CAST(&Z[y])) = *(LTC_FAST_TYPE_PTR_CAST(&in[y])) ^ *(LTC_FAST_TYPE_PTR_CAST(&pmac->Li[y]));
          }
          if ((err = cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key)) != CRYPT_OK) {
             return err;
          }
          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
              *(LTC_FAST_TYPE_PTR_CAST(&pmac->checksum[y])) ^= *(LTC_FAST_TYPE_PTR_CAST(&Z[y]));
          }
          in += 16;
      }
      inlen -= x;
   }
#endif

   while (inlen != 0) {
       /* ok if the block is full we xor in prev, encrypt and replace prev */
       if (pmac->buflen == pmac->block_len) {
          pmac_shift_xor(pmac);
          for (x = 0; x < (unsigned long)pmac->block_len; x++) {
               Z[x] = pmac->Li[x] ^ pmac->block[x];
          }
          if ((err = cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key)) != CRYPT_OK) {
             return err;
           }
          for (x = 0; x < (unsigned long)pmac->block_len; x++) {
              pmac->checksum[x] ^= Z[x];
          }
          pmac->buflen = 0;
       }

       /* add bytes */
       n = MIN(inlen, (unsigned long)(pmac->block_len - pmac->buflen));
       XMEMCPY(pmac->block + pmac->buflen, in, n);
       pmac->buflen  += n;
       inlen         -= n;
       in            += n;
   }

#ifdef LTC_CLEAN_STACK
   zeromem(Z, sizeof(Z));
#endif

   return CRYPT_OK;
}

#endif

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