diff options
author | Bodo Möller <bodo@openssl.org> | 2002-10-28 13:23:24 +0000 |
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committer | Bodo Möller <bodo@openssl.org> | 2002-10-28 13:23:24 +0000 |
commit | 5c6bf03117a26942327f43d02e9113e9870f7aba (patch) | |
tree | 69fe35ae1e549a9b68c2e6fbb0d209a19dc8856f /crypto/bn/bn_lib.c | |
parent | f72ed6153b2b54c2129354187a2f50193b68f0a1 (diff) |
fast reduction for NIST curves
Submitted by: Nils Larsch
Diffstat (limited to 'crypto/bn/bn_lib.c')
-rw-r--r-- | crypto/bn/bn_lib.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index 20f851cc66..fc610e0438 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -522,6 +522,51 @@ BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) return(a); } +BIGNUM *BN_ncopy(BIGNUM *a, const BIGNUM *b, size_t n) + { + int i, min; + BN_ULONG *A; + const BN_ULONG *B; + + bn_check_top(b); + + if (a == b) + return a; + + min = (b->top < (int)n)? b->top: (int)n; + + if (!min) + { + BN_zero(a); + return a; + } + + if (bn_wexpand(a, min) == NULL) + return NULL; + + A=a->d; + B=b->d; + for (i=min>>2; i>0; i--, A+=4, B+=4) + { + BN_ULONG a0,a1,a2,a3; + a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; + A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; + } + switch (min&3) + { + case 3: A[2]=B[2]; + case 2: A[1]=B[1]; + case 1: A[0]=B[0]; + case 0: ; + } + a->top = min; + + a->neg = b->neg; + bn_fix_top(a); + + return(a); + } + void BN_swap(BIGNUM *a, BIGNUM *b) { int flags_old_a, flags_old_b; |