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Diffstat (limited to 'package/ead/src/tinysrp/bn_exp.c')
| -rw-r--r-- | package/ead/src/tinysrp/bn_exp.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/package/ead/src/tinysrp/bn_exp.c b/package/ead/src/tinysrp/bn_exp.c new file mode 100644 index 0000000000..09afb79f6d --- /dev/null +++ b/package/ead/src/tinysrp/bn_exp.c @@ -0,0 +1,395 @@ +/* crypto/bn/bn_exp.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.] + */ +/* ==================================================================== + * Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved. + * + * 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 above 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 acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@openssl.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.openssl.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED 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 OpenSSL PROJECT OR + * ITS 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. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ + + +#include <stdio.h> +#include "bn_lcl.h" + +#define TABLE_SIZE 32 + +/* slow but works */ +int BN_mod_mul(BIGNUM *ret, BIGNUM *a, BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) + { + BIGNUM *t; + int r=0; + + bn_check_top(a); + bn_check_top(b); + bn_check_top(m); + + BN_CTX_start(ctx); + if ((t = BN_CTX_get(ctx)) == NULL) goto err; + if (a == b) + { if (!BN_sqr(t,a,ctx)) goto err; } + else + { if (!BN_mul(t,a,b,ctx)) goto err; } + if (!BN_mod(ret,t,m,ctx)) goto err; + r=1; +err: + BN_CTX_end(ctx); + return(r); + } + +int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m, + BN_CTX *ctx) + { + int ret; + + bn_check_top(a); + bn_check_top(p); + bn_check_top(m); + +#ifdef MONT_MUL_MOD + /* I have finally been able to take out this pre-condition of + * the top bit being set. It was caused by an error in BN_div + * with negatives. There was also another problem when for a^b%m + * a >= m. eay 07-May-97 */ +/* if ((m->d[m->top-1]&BN_TBIT) && BN_is_odd(m)) */ + + if (BN_is_odd(m)) + { + if (a->top == 1) + { + BN_ULONG A = a->d[0]; + ret=BN_mod_exp_mont_word(r,A,p,m,ctx,NULL); + } + else + ret=BN_mod_exp_mont(r,a,p,m,ctx,NULL); + } + else +#endif +#ifdef RECP_MUL_MOD + { ret=BN_mod_exp_recp(r,a,p,m,ctx); } +#else + { ret=BN_mod_exp_simple(r,a,p,m,ctx); } +#endif + + return(ret); + } + + +#ifdef RECP_MUL_MOD +int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, + const BIGNUM *m, BN_CTX *ctx) + { + int i,j,bits,ret=0,wstart,wend,window,wvalue; + int start=1,ts=0; + BIGNUM *aa; + BIGNUM val[TABLE_SIZE]; + BN_RECP_CTX recp; + + bits=BN_num_bits(p); + + if (bits == 0) + { + BN_one(r); + return(1); + } + + BN_CTX_start(ctx); + if ((aa = BN_CTX_get(ctx)) == NULL) goto err; + + BN_RECP_CTX_init(&recp); + if (BN_RECP_CTX_set(&recp,m,ctx) <= 0) goto err; + + BN_init(&(val[0])); + ts=1; + + if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */ + + window = BN_window_bits_for_exponent_size(bits); + if (window > 1) + { + if (!BN_mod_mul_reciprocal(aa,&(val[0]),&(val[0]),&recp,ctx)) + goto err; /* 2 */ + j=1<<(window-1); + for (i=1; i<j; i++) + { + BN_init(&val[i]); + if (!BN_mod_mul_reciprocal(&(val[i]),&(val[i-1]),aa,&recp,ctx)) + goto err; + } + ts=i; + } + + start=1; /* This is used to avoid multiplication etc + * when there is only the value '1' in the + * buffer. */ + wvalue=0; /* The 'value' of the window */ + wstart=bits-1; /* The top bit of the window */ + wend=0; /* The bottom bit of the window */ + + if (!BN_one(r)) goto err; + + for (;;) + { + if (BN_is_bit_set(p,wstart) == 0) + { + if (!start) + if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx)) + goto err; + if (wstart == 0) break; + wstart--; + continue; + } + /* We now have wstart on a 'set' bit, we now need to work out + * how bit a window to do. To do this we need to scan + * forward until the last set bit before the end of the + * window */ + j=wstart; + wvalue=1; + wend=0; + for (i=1; i<window; i++) + { + if (wstart-i < 0) break; + if (BN_is_bit_set(p,wstart-i)) + { + wvalue<<=(i-wend); + wvalue|=1; + wend=i; + } + } + + /* wend is the size of the current window */ + j=wend+1; + /* add the 'bytes above' */ + if (!start) + for (i=0; i<j; i++) + { + if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx)) + goto err; + } + + /* wvalue will be an odd number < 2^window */ + if (!BN_mod_mul_reciprocal(r,r,&(val[wvalue>>1]),&recp,ctx)) + goto err; + + /* move the 'window' down further */ + wstart-=wend+1; + wvalue=0; + start=0; + if (wstart < 0) break; + } + ret=1; +err: + BN_CTX_end(ctx); + for (i=0; i<ts; i++) + BN_clear_free(&(val[i])); + BN_RECP_CTX_free(&recp); + return(ret); + } +#else + +/* The old fallback, simple version :-) */ +int BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, + const BIGNUM *m, BN_CTX *ctx) + { + int i,j,bits,ret=0,wstart,wend,window,wvalue,ts=0; + int start=1; + BIGNUM *d; + BIGNUM val[TABLE_SIZE]; + + bits=BN_num_bits(p); + + if (bits == 0) + { + BN_one(r); + return(1); + } + + BN_CTX_start(ctx); + if ((d = BN_CTX_get(ctx)) == NULL) goto err; + + BN_init(&(val[0])); + ts=1; + if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */ + + window = BN_window_bits_for_exponent_size(bits); + if (window > 1) + { + if (!BN_mod_mul(d,&(val[0]),&(val[0]),m,ctx)) + goto err; /* 2 */ + j=1<<(window-1); + for (i=1; i<j; i++) + { + BN_init(&(val[i])); + if (!BN_mod_mul(&(val[i]),&(val[i-1]),d,m,ctx)) + goto err; + } + ts=i; + } + + start=1; /* This is used to avoid multiplication etc + * when there is only the value '1' in the + * buffer. */ + wvalue=0; /* The 'value' of the window */ + wstart=bits-1; /* The top bit of the window */ + wend=0; /* The bottom bit of the window */ + + if (!BN_one(r)) goto err; + + for (;;) + { + if (BN_is_bit_set(p,wstart) == 0) + { + if (!start) + if (!BN_mod_mul(r,r,r,m,ctx)) + goto err; + if (wstart == 0) break; + wstart--; + continue; + } + /* We now have wstart on a 'set' bit, we now need to work out + * how bit a window to do. To do this we need to scan + * forward until the last set bit before the end of the + * window */ + j=wstart; + wvalue=1; + wend=0; + for (i=1; i<window; i++) + { + if (wstart-i < 0) break; + if (BN_is_bit_set(p,wstart-i)) + { + wvalue<<=(i-wend); + wvalue|=1; + wend=i; + } + } + + /* wend is the size of the current window */ + j=wend+1; + /* add the 'bytes above' */ + if (!start) + for (i=0; i<j; i++) + { + if (!BN_mod_mul(r,r,r,m,ctx)) + goto err; + } + + /* wvalue will be an odd number < 2^window */ + if (!BN_mod_mul(r,r,&(val[wvalue>>1]),m,ctx)) + goto err; + + /* move the 'window' down further */ + wstart-=wend+1; + wvalue=0; + start=0; + if (wstart < 0) break; + } + ret=1; +err: + BN_CTX_end(ctx); + for (i=0; i<ts; i++) + BN_clear_free(&(val[i])); + return(ret); + } +#endif |