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 hmac_memory.c
  HMAC support, process a block of memory, Tom St Denis/Dobes Vandermeer
*/

#ifdef LTC_HMAC

/**
   HMAC a block of memory to produce the authentication tag
   @param hash      The index of the hash to use
   @param key       The secret key
   @param keylen    The length of the secret key (octets)
   @param in        The data to HMAC
   @param inlen     The length of the data to HMAC (octets)
   @param out       [out] Destination of the authentication tag
   @param outlen    [in/out] Max size and resulting size of authentication tag
   @return CRYPT_OK if successful
*/
int hmac_memory(int hash,
                const unsigned char *key,  unsigned long keylen,
                const unsigned char *in,   unsigned long inlen,
                      unsigned char *out,  unsigned long *outlen)
{
    hmac_state *hmac;
    int         err;

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

    /* make sure hash descriptor is valid */
    if ((err = hash_is_valid(hash)) != CRYPT_OK) {
       return err;
    }

    /* is there a descriptor? */
    if (hash_descriptor[hash].hmac_block != NULL) {
        return hash_descriptor[hash].hmac_block(key, keylen, in, inlen, out, outlen);
    }

    /* nope, so call the hmac functions */
    /* allocate ram for hmac state */
    hmac = XMALLOC(sizeof(hmac_state));
    if (hmac == NULL) {
       return CRYPT_MEM;
    }

    if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) {
       goto LBL_ERR;
    }

    if ((err = hmac_process(hmac, in, inlen)) != CRYPT_OK) {
       goto LBL_ERR;
    }

    if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) {
       goto LBL_ERR;
    }

   err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
   zeromem(hmac, sizeof(hmac_state));
#endif

   XFREE(hmac);
   return err;
}

#endif


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/* commit time: $Format:%ai$ */