diff options
author | Geoff Thorpe <geoff@openssl.org> | 2004-03-17 17:36:54 +0000 |
---|---|---|
committer | Geoff Thorpe <geoff@openssl.org> | 2004-03-17 17:36:54 +0000 |
commit | e042540f6bb0ebd8acf5c2ab0ccd1f14b5fc0f77 (patch) | |
tree | 45cc4498f4011adb6d3a20a608f131b01bcc2c7a /crypto/bn/bn_lib.c | |
parent | 4e8172d6dafec18c4512267b80879de7f0a9fff9 (diff) |
Variety of belt-tightenings in the bignum code. (Please help test this!)
- Remove some unnecessary "+1"-like fudges. Sizes should be handled
exactly, as enlarging size parameters causes needless bloat and may just
make bugs less likely rather than fixing them: bn_expand() macro,
bn_expand_internal(), and BN_sqr().
- Deprecate bn_dup_expand() - it's new since 0.9.7, unused, and not that
useful.
- Remove unnecessary zeroing of unused bytes in bn_expand2().
- Rewrite BN_set_word() - it should be much simpler, the previous
complexities probably date from old mismatched type issues.
- Add missing bn_check_top() macros in bn_word.c
- Improve some degenerate case handling in BN_[add|sub]_word(), add
comments, and avoid a bignum expansion if an overflow isn't possible.
Diffstat (limited to 'crypto/bn/bn_lib.c')
-rw-r--r-- | crypto/bn/bn_lib.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index 3f607cd532..0cc20d9239 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -330,7 +330,7 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); return(NULL); } - a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1)); + a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*words); if (A == NULL) { BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE); @@ -369,7 +369,7 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) } #else - memset(A,0,sizeof(BN_ULONG)*(words+1)); + memset(A,0,sizeof(BN_ULONG)*words); memcpy(A,b->d,sizeof(b->d[0])*b->top); #endif @@ -387,6 +387,7 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) * while bn_dup_expand() makes sure allocation is made only once. */ +#ifndef OPENSSL_NO_DEPRECATED BIGNUM *bn_dup_expand(const BIGNUM *b, int words) { BIGNUM *r = NULL; @@ -430,6 +431,7 @@ BIGNUM *bn_dup_expand(const BIGNUM *b, int words) bn_check_top(r); return r; } +#endif /* This is an internal function that should not be used in applications. * It ensures that 'b' has enough room for a 'words' word number @@ -439,9 +441,6 @@ BIGNUM *bn_dup_expand(const BIGNUM *b, int words) BIGNUM *bn_expand2(BIGNUM *b, int words) { - BN_ULONG *A; - int i; - bn_check_top(b); if (words > b->dmax) @@ -453,10 +452,13 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) b->dmax=words; } +/* None of this should be necessary because of what b->top means! */ +#if 0 /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */ if (b->top < b->dmax) { - A = &(b->d[b->top]); + int i; + BN_ULONG *A = &(b->d[b->top]); for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8) { A[0]=0; A[1]=0; A[2]=0; A[3]=0; @@ -466,6 +468,7 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) A[0]=0; assert(A == &(b->d[b->dmax])); } +#endif bn_check_top(b); return b; } @@ -632,6 +635,7 @@ BN_ULONG BN_get_word(const BIGNUM *a) return(ret); } +#if 0 /* a->d[0] is a BN_ULONG, w is a BN_ULONG, what's the big deal? */ int BN_set_word(BIGNUM *a, BN_ULONG w) { int i,n; @@ -660,6 +664,18 @@ int BN_set_word(BIGNUM *a, BN_ULONG w) bn_check_top(a); return(1); } +#else +int BN_set_word(BIGNUM *a, BN_ULONG w) + { + bn_check_top(a); + if (bn_expand(a,(int)sizeof(BN_ULONG)*8) == NULL) return(0); + a->neg = 0; + a->d[0] = w; + a->top = (w ? 1 : 0); + bn_check_top(a); + return(1); + } +#endif BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) { |