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 der_encode_utf8_string.c
  ASN.1 DER, encode a UTF8 STRING, Tom St Denis
*/


#ifdef LTC_DER

/**
  Store an UTF8 STRING
  @param in       The array of UTF8 to store (one per wchar_t)
  @param inlen    The number of UTF8 to store
  @param out      [out] The destination for the DER encoded UTF8 STRING
  @param outlen   [in/out] The max size and resulting size of the DER UTF8 STRING
  @return CRYPT_OK if successful
*/
int der_encode_utf8_string(const wchar_t *in,  unsigned long inlen,
                           unsigned char *out, unsigned long *outlen)
{
   unsigned long x, y, len;

   LTC_ARGCHK(in     != NULL);
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);

   /* get the size */
   for (x = len = 0; x < inlen; x++) {
       if (!der_utf8_valid_char(in[x])) return CRYPT_INVALID_ARG;
       len += der_utf8_charsize(in[x]);
   }

   if (len < 128) {
      y = 2 + len;
   } else if (len < 256) {
      y = 3 + len;
   } else if (len < 65536UL) {
      y = 4 + len;
   } else if (len < 16777216UL) {
      y = 5 + len;
   } else {
      return CRYPT_INVALID_ARG;
   }

   /* too big? */
   if (y > *outlen) {
      *outlen = y;
      return CRYPT_BUFFER_OVERFLOW;
   }

   /* encode the header+len */
   x = 0;
   out[x++] = 0x0C;
   if (len < 128) {
      out[x++] = (unsigned char)len;
   } else if (len < 256) {
      out[x++] = 0x81;
      out[x++] = (unsigned char)len;
   } else if (len < 65536UL) {
      out[x++] = 0x82;
      out[x++] = (unsigned char)((len>>8)&255);
      out[x++] = (unsigned char)(len&255);
   } else if (len < 16777216UL) {
      out[x++] = 0x83;
      out[x++] = (unsigned char)((len>>16)&255);
      out[x++] = (unsigned char)((len>>8)&255);
      out[x++] = (unsigned char)(len&255);
   } else {
       /* coverity[dead_error_line] */
      return CRYPT_INVALID_ARG;
   }

   /* store UTF8 */
   for (y = 0; y < inlen; y++) {
       switch (der_utf8_charsize(in[y])) {
          case 1: out[x++] = (unsigned char)in[y]; break;
          case 2: out[x++] = 0xC0 | ((in[y] >> 6) & 0x1F);  out[x++] = 0x80 | (in[y] & 0x3F); break;
          case 3: out[x++] = 0xE0 | ((in[y] >> 12) & 0x0F); out[x++] = 0x80 | ((in[y] >> 6) & 0x3F); out[x++] = 0x80 | (in[y] & 0x3F); break;
#if !defined(LTC_WCHAR_MAX) || LTC_WCHAR_MAX > 0xFFFF
          case 4: out[x++] = 0xF0 | ((in[y] >> 18) & 0x07); out[x++] = 0x80 | ((in[y] >> 12) & 0x3F); out[x++] = 0x80 | ((in[y] >> 6) & 0x3F); out[x++] = 0x80 | (in[y] & 0x3F); break;
#endif
       }
   }

   /* retun length */
   *outlen = x;

   return CRYPT_OK;
}

#endif

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