diff options
Diffstat (limited to 'openssl/crypto/bn/bn_word.c')
| -rw-r--r-- | openssl/crypto/bn/bn_word.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/openssl/crypto/bn/bn_word.c b/openssl/crypto/bn/bn_word.c new file mode 100644 index 00000000..ee7b87c4 --- /dev/null +++ b/openssl/crypto/bn/bn_word.c @@ -0,0 +1,247 @@ +/* crypto/bn/bn_word.c */ +/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) + * All rights reserved. + * + * This package is an SSL implementation written + * by Eric Young (eay@cryptsoft.com). + * The implementation was written so as to conform with Netscapes SSL. + * + * This library is free for commercial and non-commercial use as long as + * the following conditions are aheared to. The following conditions + * apply to all code found in this distribution, be it the RC4, RSA, + * lhash, DES, etc., code; not just the SSL code. The SSL documentation + * included with this distribution is covered by the same copyright terms + * except that the holder is Tim Hudson (tjh@cryptsoft.com). + * + * Copyright remains Eric Young's, and as such any Copyright notices in + * the code are not to be removed. + * If this package is used in a product, Eric Young should be given attribution + * as the author of the parts of the library used. + * This can be in the form of a textual message at program startup or + * in documentation (online or textual) provided with the package. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * "This product includes cryptographic software written by + * Eric Young (eay@cryptsoft.com)" + * The word 'cryptographic' can be left out if the rouines from the library + * being used are not cryptographic related :-). + * 4. If you include any Windows specific code (or a derivative thereof) from + * the apps directory (application code) you must include an acknowledgement: + * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" + * + * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * The licence and distribution terms for any publically available version or + * derivative of this code cannot be changed. i.e. this code cannot simply be + * copied and put under another distribution licence + * [including the GNU Public Licence.] + */ + +#include <stdio.h> +#include "cryptlib.h" +#include "bn_lcl.h" + +BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w) + { +#ifndef BN_LLONG + BN_ULONG ret=0; +#else + BN_ULLONG ret=0; +#endif + int i; + + if (w == 0) + return (BN_ULONG)-1; + + bn_check_top(a); + w&=BN_MASK2; + for (i=a->top-1; i>=0; i--) + { +#ifndef BN_LLONG + ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%w; + ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%w; +#else + ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])% + (BN_ULLONG)w); +#endif + } + return((BN_ULONG)ret); + } + +BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w) + { + BN_ULONG ret = 0; + int i, j; + + bn_check_top(a); + w &= BN_MASK2; + + if (!w) + /* actually this an error (division by zero) */ + return (BN_ULONG)-1; + if (a->top == 0) + return 0; + + /* normalize input (so bn_div_words doesn't complain) */ + j = BN_BITS2 - BN_num_bits_word(w); + w <<= j; + if (!BN_lshift(a, a, j)) + return (BN_ULONG)-1; + + for (i=a->top-1; i>=0; i--) + { + BN_ULONG l,d; + + l=a->d[i]; + d=bn_div_words(ret,l,w); + ret=(l-((d*w)&BN_MASK2))&BN_MASK2; + a->d[i]=d; + } + if ((a->top > 0) && (a->d[a->top-1] == 0)) + a->top--; + ret >>= j; + bn_check_top(a); + return(ret); + } + +int BN_add_word(BIGNUM *a, BN_ULONG w) + { + BN_ULONG l; + int i; + + bn_check_top(a); + w &= BN_MASK2; + + /* degenerate case: w is zero */ + if (!w) return 1; + /* degenerate case: a is zero */ + if(BN_is_zero(a)) return BN_set_word(a, w); + /* handle 'a' when negative */ + if (a->neg) + { + a->neg=0; + i=BN_sub_word(a,w); + if (!BN_is_zero(a)) + a->neg=!(a->neg); + return(i); + } + /* Only expand (and risk failing) if it's possibly necessary */ + if (((BN_ULONG)(a->d[a->top - 1] + 1) == 0) && + (bn_wexpand(a,a->top+1) == NULL)) + return(0); + i=0; + for (;;) + { + if (i >= a->top) + l=w; + else + l=(a->d[i]+w)&BN_MASK2; + a->d[i]=l; + if (w > l) + w=1; + else + break; + i++; + } + if (i >= a->top) + a->top++; + bn_check_top(a); + return(1); + } + +int BN_sub_word(BIGNUM *a, BN_ULONG w) + { + int i; + + bn_check_top(a); + w &= BN_MASK2; + + /* degenerate case: w is zero */ + if (!w) return 1; + /* degenerate case: a is zero */ + if(BN_is_zero(a)) + { + i = BN_set_word(a,w); + if (i != 0) + BN_set_negative(a, 1); + return i; + } + /* handle 'a' when negative */ + if (a->neg) + { + a->neg=0; + i=BN_add_word(a,w); + a->neg=1; + return(i); + } + + if ((a->top == 1) && (a->d[0] < w)) + { + a->d[0]=w-a->d[0]; + a->neg=1; + return(1); + } + i=0; + for (;;) + { + if (a->d[i] >= w) + { + a->d[i]-=w; + break; + } + else + { + a->d[i]=(a->d[i]-w)&BN_MASK2; + i++; + w=1; + } + } + if ((a->d[i] == 0) && (i == (a->top-1))) + a->top--; + bn_check_top(a); + return(1); + } + +int BN_mul_word(BIGNUM *a, BN_ULONG w) + { + BN_ULONG ll; + + bn_check_top(a); + w&=BN_MASK2; + if (a->top) + { + if (w == 0) + BN_zero(a); + else + { + ll=bn_mul_words(a->d,a->d,a->top,w); + if (ll) + { + if (bn_wexpand(a,a->top+1) == NULL) return(0); + a->d[a->top++]=ll; + } + } + } + bn_check_top(a); + return(1); + } + |