Mercurial > dropbear
view libtommath/bn_mp_div_3.c @ 340:454a34b2dfd1
Fixes from Erik Hovland:
cli-authpubkey.c:
fix leak of keybuf
cli-kex.c:
fix leak of fingerprint fp
cli-service.c:
remove commented out code
dropbearkey.c:
don't attepmt to free NULL key on failure
common-kex.c:
only free key if it is initialised
keyimport.c:
remove dead encrypted-key code
don't leak a FILE* loading OpenSSH keys
rsa.c, dss.c:
check return values for some libtommath functions
svr-kex.c:
check return value retrieving DH kex mpint
svr-tcpfwd.c:
fix null-dereference if remote tcp forward request fails
tcp-accept.c:
don't incorrectly free the tcpinfo var
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Fri, 07 Jul 2006 09:17:18 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
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#include <tommath.h> #ifdef BN_MP_DIV_3_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * * LibTomMath is a library that provides multiple-precision * integer arithmetic as well as number theoretic functionality. * * The library was designed directly after the MPI library by * Michael Fromberger but has been written from scratch with * additional optimizations in place. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://math.libtomcrypt.org */ /* divide by three (based on routine from MPI and the GMP manual) */ int mp_div_3 (mp_int * a, mp_int *c, mp_digit * d) { mp_int q; mp_word w, t; mp_digit b; int res, ix; /* b = 2**DIGIT_BIT / 3 */ b = (((mp_word)1) << ((mp_word)DIGIT_BIT)) / ((mp_word)3); if ((res = mp_init_size(&q, a->used)) != MP_OKAY) { return res; } q.used = a->used; q.sign = a->sign; w = 0; for (ix = a->used - 1; ix >= 0; ix--) { w = (w << ((mp_word)DIGIT_BIT)) | ((mp_word)a->dp[ix]); if (w >= 3) { /* multiply w by [1/3] */ t = (w * ((mp_word)b)) >> ((mp_word)DIGIT_BIT); /* now subtract 3 * [w/3] from w, to get the remainder */ w -= t+t+t; /* fixup the remainder as required since * the optimization is not exact. */ while (w >= 3) { t += 1; w -= 3; } } else { t = 0; } q.dp[ix] = (mp_digit)t; } /* [optional] store the remainder */ if (d != NULL) { *d = (mp_digit)w; } /* [optional] store the quotient */ if (c != NULL) { mp_clamp(&q); mp_exch(&q, c); } mp_clear(&q); return res; } #endif