Mercurial > dropbear
view libtommath/bn_mp_prime_random_ex.c @ 1306:34e6127ef02e
merge fixes from PuTTY import.c
toint() from misc.c
(revids are from hggit conversion)
changeset: 4620:60a336a6c85c
user: Simon Tatham <[email protected]>
date: Thu Feb 25 20:26:33 2016 +0000
files: import.c
description:
Fix potential segfaults in reading OpenSSH's ASN.1 key format.
The length coming back from ber_read_id_len might have overflowed, so
treat it as potentially negative. Also, while I'm here, accumulate it
inside ber_read_id_len as an unsigned, so as to avoid undefined
behaviour on integer overflow, and toint() it before return.
Thanks to Hanno Böck for spotting this, with the aid of AFL.
(cherry picked from commit 5b7833cd474a24ec098654dcba8cb9509f3bf2c1)
Conflicts:
import.c
(cherry-picker's note: resolving the conflict involved removing an
entire section of the original commit which fixed ECDSA code not
present on this branch)
changeset: 4619:9c6c638d98d8
user: Simon Tatham <[email protected]>
date: Sun Jul 14 10:45:54 2013 +0000
files: import.c ssh.c sshdss.c sshpubk.c sshrsa.c
description:
Tighten up a lot of casts from unsigned to int which are read by one
of the GET_32BIT macros and then used as length fields. Missing bounds
checks against zero have been added, and also I've introduced a helper
function toint() which casts from unsigned to int in such a way as to
avoid C undefined behaviour, since I'm not sure I trust compilers any
more to do the obviously sensible thing.
[originally from svn r9918]
changeset: 4618:3957829f24d3
user: Simon Tatham <[email protected]>
date: Mon Jul 08 22:36:04 2013 +0000
files: import.c sshdss.c sshrsa.c
description:
Add an assortment of extra safety checks.
[originally from svn r9896]
changeset: 4617:2cddee0bce12
user: Jacob Nevins <[email protected]>
date: Wed Dec 07 00:24:45 2005 +0000
files: import.c
description:
Institutional failure to memset() things pointed at rather than pointers.
Things should now be zeroed and memory not leaked. Spotted by Brant Thomsen.
[originally from svn r6476]
changeset: 4616:24ac78a9c71d
user: Simon Tatham <[email protected]>
date: Wed Feb 11 13:58:27 2004 +0000
files: import.c
description:
Jacob's last-minute testing found a couple of trivial bugs in
import.c, and my attempts to reproduce them in cmdgen found another
one there :-)
[originally from svn r3847]
changeset: 4615:088d39a73db0
user: Simon Tatham <[email protected]>
date: Thu Jan 22 18:52:49 2004 +0000
files: import.c
description:
Placate some gcc warnings.
[originally from svn r3761]
changeset: 4614:e4288bad4d93
parent: 1758:108b8924593d
user: Simon Tatham <[email protected]>
date: Fri Oct 03 21:21:23 2003 +0000
files: import.c
description:
My ASN.1 decoder returned wrong IDs for anything above 0x1E! Good
job it's never had to yet. Ahem.
[originally from svn r3479]
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Tue, 12 Jul 2016 23:00:01 +0800 |
parents | 5ff8218bcee9 |
children | 60fc6476e044 |
line wrap: on
line source
#include <tommath.h> #ifdef BN_MP_PRIME_RANDOM_EX_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.com */ /* makes a truly random prime of a given size (bits), * * Flags are as follows: * * LTM_PRIME_BBS - make prime congruent to 3 mod 4 * LTM_PRIME_SAFE - make sure (p-1)/2 is prime as well (implies LTM_PRIME_BBS) * LTM_PRIME_2MSB_OFF - make the 2nd highest bit zero * LTM_PRIME_2MSB_ON - make the 2nd highest bit one * * You have to supply a callback which fills in a buffer with random bytes. "dat" is a parameter you can * have passed to the callback (e.g. a state or something). This function doesn't use "dat" itself * so it can be NULL * */ /* This is possibly the mother of all prime generation functions, muahahahahaha! */ int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback cb, void *dat) { unsigned char *tmp, maskAND, maskOR_msb, maskOR_lsb; int res, err, bsize, maskOR_msb_offset; /* sanity check the input */ if (size <= 1 || t <= 0) { return MP_VAL; } /* LTM_PRIME_SAFE implies LTM_PRIME_BBS */ if (flags & LTM_PRIME_SAFE) { flags |= LTM_PRIME_BBS; } /* calc the byte size */ bsize = (size>>3) + ((size&7)?1:0); /* we need a buffer of bsize bytes */ tmp = OPT_CAST(unsigned char) XMALLOC(bsize); if (tmp == NULL) { return MP_MEM; } /* calc the maskAND value for the MSbyte*/ maskAND = ((size&7) == 0) ? 0xFF : (0xFF >> (8 - (size & 7))); /* calc the maskOR_msb */ maskOR_msb = 0; maskOR_msb_offset = ((size & 7) == 1) ? 1 : 0; if (flags & LTM_PRIME_2MSB_ON) { maskOR_msb |= 0x80 >> ((9 - size) & 7); } /* get the maskOR_lsb */ maskOR_lsb = 1; if (flags & LTM_PRIME_BBS) { maskOR_lsb |= 3; } do { /* read the bytes */ if (cb(tmp, bsize, dat) != bsize) { err = MP_VAL; goto error; } /* work over the MSbyte */ tmp[0] &= maskAND; tmp[0] |= 1 << ((size - 1) & 7); /* mix in the maskORs */ tmp[maskOR_msb_offset] |= maskOR_msb; tmp[bsize-1] |= maskOR_lsb; /* read it in */ if ((err = mp_read_unsigned_bin(a, tmp, bsize)) != MP_OKAY) { goto error; } /* is it prime? */ if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { goto error; } if (res == MP_NO) { continue; } if (flags & LTM_PRIME_SAFE) { /* see if (a-1)/2 is prime */ if ((err = mp_sub_d(a, 1, a)) != MP_OKAY) { goto error; } if ((err = mp_div_2(a, a)) != MP_OKAY) { goto error; } /* is it prime? */ if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { goto error; } } } while (res == MP_NO); if (flags & LTM_PRIME_SAFE) { /* restore a to the original value */ if ((err = mp_mul_2(a, a)) != MP_OKAY) { goto error; } if ((err = mp_add_d(a, 1, a)) != MP_OKAY) { goto error; } } err = MP_OKAY; error: XFREE(tmp); return err; } #endif /* $Source: /cvs/libtom/libtommath/bn_mp_prime_random_ex.c,v $ */ /* $Revision: 1.4 $ */ /* $Date: 2006/03/31 14:18:44 $ */