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.
 */

/* Defines the LTC_ARGCHK macro used within the library */
/* ARGTYPE is defined in tomcrypt_cfg.h */
#if ARGTYPE == 0

#include <signal.h>

/* portability macros for compiler-specific code attributes */
#ifdef __GNUC__
#define ATTRIB_NORETURN __attribute__((noreturn))
#else
#define ATTRIB_NORETURN
#endif


/* this is the default LibTomCrypt macro  */
#if defined(__clang__) || defined(__GNUC_MINOR__)
#define NORETURN __attribute__ ((noreturn))
#else
#define NORETURN
#endif

void crypt_argchk(const char *v, const char *s, int d) NORETURN;
#define LTC_ARGCHK(x) do { if (!(x)) { crypt_argchk(#x, __FILE__, __LINE__); } }while(0)
#define LTC_ARGCHKVD(x) do { if (!(x)) { crypt_argchk(#x, __FILE__, __LINE__); } }while(0)

#elif ARGTYPE == 1

/* fatal type of error */
#define LTC_ARGCHK(x) assert((x))
#define LTC_ARGCHKVD(x) LTC_ARGCHK(x)

#elif ARGTYPE == 2

#define LTC_ARGCHK(x) if (!(x)) { fprintf(stderr, "\nwarning: ARGCHK failed at %s:%d\n", __FILE__, __LINE__); }
#define LTC_ARGCHKVD(x) LTC_ARGCHK(x)

#elif ARGTYPE == 3

#define LTC_ARGCHK(x) 
#define LTC_ARGCHKVD(x) LTC_ARGCHK(x)

#elif ARGTYPE == 4

#define LTC_ARGCHK(x)   if (!(x)) return CRYPT_INVALID_ARG;
#define LTC_ARGCHKVD(x) if (!(x)) return;

#endif


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