fix some gcc warnings (#73) * tweak string size fix gcc8 warnings ``` svr-agentfwd.c: In function 'bindagent': svr-agentfwd.c:254:53: warning: '%s' directive output may be truncated writing up to 107 bytes into a region of size between 0 and 107 [-Wformat-truncation=] snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile); ^~ ~~~~~~~~ svr-agentfwd.c:254:2: note: 'snprintf' output between 2 and 216 bytes into a destination of size 108 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``` * cleanup signed/unsigned comparison fix gcc8 warnings ``` scp.c: In function 'do_local_cmd': scp.c:132:17: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare] for (i = 0; i < a->num; i++) ^ scpmisc.c: In function 'addargs': scpmisc.c:161:25: warning: comparison of integer expressions of different signedness: 'int' and 'u_int' {aka 'unsigned int'} [-Wsign-compare] } else if (args->num+2 >= nalloc) ^~ scpmisc.c: In function 'replacearg': scpmisc.c:183:12: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare] if (which >= args->num) ^~ scpmisc.c: In function 'freeargs': scpmisc.c:196:17: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare] for (i = 0; i < args->num; i++) ^ ``` see https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/misc.h.diff?r1=1.16&r2=1.17

/* 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"

#ifdef LTC_CHACHA20POLY1305_MODE

/**
   Encrypt bytes of ciphertext with ChaCha20Poly1305
   @param st      The ChaCha20Poly1305 state
   @param in      The plaintext
   @param inlen   The length of the input (octets)
   @param out     [out] The ciphertext (length inlen)
   @return CRYPT_OK if successful
*/
int chacha20poly1305_encrypt(chacha20poly1305_state *st, const unsigned char *in, unsigned long inlen, unsigned char *out)
{
   unsigned char padzero[16] = { 0 };
   unsigned long padlen;
   int err;

   if (inlen == 0) return CRYPT_OK; /* nothing to do */
   LTC_ARGCHK(st != NULL);

   if ((err = chacha_crypt(&st->chacha, in, inlen, out)) != CRYPT_OK)         return err;
   if (st->aadflg) {
      padlen = 16 - (unsigned long)(st->aadlen % 16);
      if (padlen < 16) {
        if ((err = poly1305_process(&st->poly, padzero, padlen)) != CRYPT_OK) return err;
      }
      st->aadflg = 0; /* no more AAD */
   }
   if ((err = poly1305_process(&st->poly, out, inlen)) != CRYPT_OK)           return err;
   st->ctlen += (ulong64)inlen;
   return CRYPT_OK;
}

#endif

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