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 rsa_export.c
  Export RSA PKCS keys, Tom St Denis
*/

#ifdef LTC_MRSA

/**
    This will export either an RSAPublicKey or RSAPrivateKey [defined in PKCS #1 v2.1]
    @param out       [out] Destination of the packet
    @param outlen    [in/out] The max size and resulting size of the packet
    @param type      The type of exported key (PK_PRIVATE or PK_PUBLIC)
    @param key       The RSA key to export
    @return CRYPT_OK if successful
*/
int rsa_export(unsigned char *out, unsigned long *outlen, int type, rsa_key *key)
{
   unsigned long zero=0;
   int err;
   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);
   LTC_ARGCHK(key    != NULL);

   /* type valid? */
   if (!(key->type == PK_PRIVATE) && (type == PK_PRIVATE)) {
      return CRYPT_PK_INVALID_TYPE;
   }

   if (type == PK_PRIVATE) {
      /* private key */
      /* output is
            Version, n, e, d, p, q, d mod (p-1), d mod (q - 1), 1/q mod p
       */
      return der_encode_sequence_multi(out, outlen,
                          LTC_ASN1_SHORT_INTEGER, 1UL, &zero,
                          LTC_ASN1_INTEGER, 1UL,  key->N,
                          LTC_ASN1_INTEGER, 1UL,  key->e,
                          LTC_ASN1_INTEGER, 1UL,  key->d,
                          LTC_ASN1_INTEGER, 1UL,  key->p,
                          LTC_ASN1_INTEGER, 1UL,  key->q,
                          LTC_ASN1_INTEGER, 1UL,  key->dP,
                          LTC_ASN1_INTEGER, 1UL,  key->dQ,
                          LTC_ASN1_INTEGER, 1UL,  key->qP,
                          LTC_ASN1_EOL,     0UL, NULL);
   } else {
      /* public key */
      unsigned long tmplen, *ptmplen;
      unsigned char* tmp = NULL;

      if (type & PK_STD) {
          tmplen = (mp_count_bits(key->N)/8)*2+8;
          tmp = XMALLOC(tmplen);
          ptmplen = &tmplen;
          if (tmp == NULL) {
              return CRYPT_MEM;
          }
      }
      else {
          tmp = out;
          ptmplen = outlen;
      }

      err = der_encode_sequence_multi(tmp, ptmplen,
                                 LTC_ASN1_INTEGER, 1UL,  key->N,
                                 LTC_ASN1_INTEGER, 1UL,  key->e,
                                 LTC_ASN1_EOL,     0UL, NULL);

      if ((err != CRYPT_OK) || !(type & PK_STD)) {
          goto finish;
      }

      err = der_encode_subject_public_key_info(out, outlen,
        PKA_RSA, tmp, tmplen, LTC_ASN1_NULL, NULL, 0);

finish:
      if (tmp != out)
        XFREE(tmp);
      return err;

   }
}

#endif /* LTC_MRSA */

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