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Diffstat (limited to 'src/lib/libcrypto/bn/bn_recp.c')
-rw-r--r--src/lib/libcrypto/bn/bn_recp.c223
1 files changed, 123 insertions, 100 deletions
diff --git a/src/lib/libcrypto/bn/bn_recp.c b/src/lib/libcrypto/bn/bn_recp.c
index 0f808fca64..31fe4eb897 100644
--- a/src/lib/libcrypto/bn/bn_recp.c
+++ b/src/lib/libcrypto/bn/bn_recp.c
@@ -5,21 +5,21 @@
5 * This package is an SSL implementation written 5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com). 6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL. 7 * The implementation was written so as to conform with Netscapes SSL.
8 * 8 *
9 * This library is free for commercial and non-commercial use as long as 9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions 10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA, 11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms 13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 * 15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed. 17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution 18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used. 19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or 20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package. 21 * in documentation (online or textual) provided with the package.
22 * 22 *
23 * Redistribution and use in source and binary forms, with or without 23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions 24 * modification, are permitted provided that the following conditions
25 * are met: 25 * are met:
@@ -34,10 +34,10 @@
34 * Eric Young (eay@cryptsoft.com)" 34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library 35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-). 36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement: 38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 * 40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
@@ -49,7 +49,7 @@
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE. 51 * SUCH DAMAGE.
52 * 52 *
53 * The licence and distribution terms for any publically available version or 53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence 55 * copied and put under another distribution licence
@@ -60,99 +60,110 @@
60#include "cryptlib.h" 60#include "cryptlib.h"
61#include "bn_lcl.h" 61#include "bn_lcl.h"
62 62
63void BN_RECP_CTX_init(BN_RECP_CTX *recp) 63void
64 { 64BN_RECP_CTX_init(BN_RECP_CTX *recp)
65{
65 BN_init(&(recp->N)); 66 BN_init(&(recp->N));
66 BN_init(&(recp->Nr)); 67 BN_init(&(recp->Nr));
67 recp->num_bits=0; 68 recp->num_bits = 0;
68 recp->flags=0; 69 recp->flags = 0;
69 } 70}
70 71
71BN_RECP_CTX *BN_RECP_CTX_new(void) 72BN_RECP_CTX *
72 { 73BN_RECP_CTX_new(void)
74{
73 BN_RECP_CTX *ret; 75 BN_RECP_CTX *ret;
74 76
75 if ((ret=(BN_RECP_CTX *)malloc(sizeof(BN_RECP_CTX))) == NULL) 77 if ((ret = (BN_RECP_CTX *)malloc(sizeof(BN_RECP_CTX))) == NULL)
76 return(NULL); 78 return (NULL);
77 79
78 BN_RECP_CTX_init(ret); 80 BN_RECP_CTX_init(ret);
79 ret->flags=BN_FLG_MALLOCED; 81 ret->flags = BN_FLG_MALLOCED;
80 return(ret); 82 return (ret);
81 } 83}
82 84
83void BN_RECP_CTX_free(BN_RECP_CTX *recp) 85void
84 { 86BN_RECP_CTX_free(BN_RECP_CTX *recp)
85 if(recp == NULL) 87{
86 return; 88 if (recp == NULL)
89 return;
87 90
88 BN_free(&(recp->N)); 91 BN_free(&(recp->N));
89 BN_free(&(recp->Nr)); 92 BN_free(&(recp->Nr));
90 if (recp->flags & BN_FLG_MALLOCED) 93 if (recp->flags & BN_FLG_MALLOCED)
91 free(recp); 94 free(recp);
92 } 95}
93 96
94int BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx) 97int
95 { 98BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx)
96 if (!BN_copy(&(recp->N),d)) return 0; 99{
100 if (!BN_copy(&(recp->N), d))
101 return 0;
97 BN_zero(&(recp->Nr)); 102 BN_zero(&(recp->Nr));
98 recp->num_bits=BN_num_bits(d); 103 recp->num_bits = BN_num_bits(d);
99 recp->shift=0; 104 recp->shift = 0;
100 return(1); 105 return (1);
101 } 106}
102 107
103int BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y, 108int
104 BN_RECP_CTX *recp, BN_CTX *ctx) 109BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
105 { 110 BN_RECP_CTX *recp, BN_CTX *ctx)
106 int ret=0; 111{
112 int ret = 0;
107 BIGNUM *a; 113 BIGNUM *a;
108 const BIGNUM *ca; 114 const BIGNUM *ca;
109 115
110 BN_CTX_start(ctx); 116 BN_CTX_start(ctx);
111 if ((a = BN_CTX_get(ctx)) == NULL) goto err; 117 if ((a = BN_CTX_get(ctx)) == NULL)
112 if (y != NULL) 118 goto err;
113 { 119 if (y != NULL) {
114 if (x == y) 120 if (x == y) {
115 { if (!BN_sqr(a,x,ctx)) goto err; } 121 if (!BN_sqr(a, x, ctx))
116 else 122 goto err;
117 { if (!BN_mul(a,x,y,ctx)) goto err; } 123 } else {
118 ca = a; 124 if (!BN_mul(a, x, y, ctx))
125 goto err;
119 } 126 }
120 else 127 ca = a;
121 ca=x; /* Just do the mod */ 128 } else
129 ca = x; /* Just do the mod */
130
131 ret = BN_div_recp(NULL, r, ca, recp, ctx);
122 132
123 ret = BN_div_recp(NULL,r,ca,recp,ctx);
124err: 133err:
125 BN_CTX_end(ctx); 134 BN_CTX_end(ctx);
126 bn_check_top(r); 135 bn_check_top(r);
127 return(ret); 136 return (ret);
128 } 137}
129 138
130int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, 139int
131 BN_RECP_CTX *recp, BN_CTX *ctx) 140BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, BN_RECP_CTX *recp,
132 { 141 BN_CTX *ctx)
133 int i,j,ret=0; 142{
134 BIGNUM *a,*b,*d,*r; 143 int i, j, ret = 0;
144 BIGNUM *a, *b, *d, *r;
135 145
136 BN_CTX_start(ctx); 146 BN_CTX_start(ctx);
137 a=BN_CTX_get(ctx); 147 a = BN_CTX_get(ctx);
138 b=BN_CTX_get(ctx); 148 b = BN_CTX_get(ctx);
139 if (dv != NULL) 149 if (dv != NULL)
140 d=dv; 150 d = dv;
141 else 151 else
142 d=BN_CTX_get(ctx); 152 d = BN_CTX_get(ctx);
143 if (rem != NULL) 153 if (rem != NULL)
144 r=rem; 154 r = rem;
145 else 155 else
146 r=BN_CTX_get(ctx); 156 r = BN_CTX_get(ctx);
147 if (a == NULL || b == NULL || d == NULL || r == NULL) goto err; 157 if (a == NULL || b == NULL || d == NULL || r == NULL)
158 goto err;
148 159
149 if (BN_ucmp(m,&(recp->N)) < 0) 160 if (BN_ucmp(m, &(recp->N)) < 0) {
150 {
151 BN_zero(d); 161 BN_zero(d);
152 if (!BN_copy(r,m)) return 0; 162 if (!BN_copy(r, m))
163 return 0;
153 BN_CTX_end(ctx); 164 BN_CTX_end(ctx);
154 return(1); 165 return (1);
155 } 166 }
156 167
157 /* We want the remainder 168 /* We want the remainder
158 * Given input of ABCDEF / ab 169 * Given input of ABCDEF / ab
@@ -161,74 +172,86 @@ int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
161 */ 172 */
162 173
163 /* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */ 174 /* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */
164 i=BN_num_bits(m); 175 i = BN_num_bits(m);
165 j=recp->num_bits<<1; 176 j = recp->num_bits << 1;
166 if (j>i) i=j; 177 if (j > i)
178 i = j;
167 179
168 /* Nr := round(2^i / N) */ 180 /* Nr := round(2^i / N) */
169 if (i != recp->shift) 181 if (i != recp->shift)
170 recp->shift=BN_reciprocal(&(recp->Nr),&(recp->N), 182 recp->shift = BN_reciprocal(&(recp->Nr), &(recp->N), i, ctx); /* BN_reciprocal returns i, or -1 for an error */
171 i,ctx); /* BN_reciprocal returns i, or -1 for an error */ 183 if (recp->shift == -1)
172 if (recp->shift == -1) goto err; 184 goto err;
173 185
174 /* d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))| 186 /* d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
175 * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))| 187 * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
176 * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)| 188 * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
177 * = |m/N| 189 * = |m/N|
178 */ 190 */
179 if (!BN_rshift(a,m,recp->num_bits)) goto err; 191 if (!BN_rshift(a, m, recp->num_bits))
180 if (!BN_mul(b,a,&(recp->Nr),ctx)) goto err; 192 goto err;
181 if (!BN_rshift(d,b,i-recp->num_bits)) goto err; 193 if (!BN_mul(b, a,&(recp->Nr), ctx))
182 d->neg=0; 194 goto err;
195 if (!BN_rshift(d, b, i - recp->num_bits))
196 goto err;
197 d->neg = 0;
183 198
184 if (!BN_mul(b,&(recp->N),d,ctx)) goto err; 199 if (!BN_mul(b, &(recp->N), d, ctx))
185 if (!BN_usub(r,m,b)) goto err; 200 goto err;
186 r->neg=0; 201 if (!BN_usub(r, m, b))
202 goto err;
203 r->neg = 0;
187 204
188#if 1 205#if 1
189 j=0; 206 j = 0;
190 while (BN_ucmp(r,&(recp->N)) >= 0) 207 while (BN_ucmp(r, &(recp->N)) >= 0) {
191 { 208 if (j++ > 2) {
192 if (j++ > 2) 209 BNerr(BN_F_BN_DIV_RECP, BN_R_BAD_RECIPROCAL);
193 {
194 BNerr(BN_F_BN_DIV_RECP,BN_R_BAD_RECIPROCAL);
195 goto err; 210 goto err;
196 }
197 if (!BN_usub(r,r,&(recp->N))) goto err;
198 if (!BN_add_word(d,1)) goto err;
199 } 211 }
212 if (!BN_usub(r, r, &(recp->N)))
213 goto err;
214 if (!BN_add_word(d, 1))
215 goto err;
216 }
200#endif 217#endif
201 218
202 r->neg=BN_is_zero(r)?0:m->neg; 219 r->neg = BN_is_zero(r) ? 0 : m->neg;
203 d->neg=m->neg^recp->N.neg; 220 d->neg = m->neg^recp->N.neg;
204 ret=1; 221 ret = 1;
222
205err: 223err:
206 BN_CTX_end(ctx); 224 BN_CTX_end(ctx);
207 bn_check_top(dv); 225 bn_check_top(dv);
208 bn_check_top(rem); 226 bn_check_top(rem);
209 return(ret); 227 return (ret);
210 } 228}
211 229
212/* len is the expected size of the result 230/* len is the expected size of the result
213 * We actually calculate with an extra word of precision, so 231 * We actually calculate with an extra word of precision, so
214 * we can do faster division if the remainder is not required. 232 * we can do faster division if the remainder is not required.
215 */ 233 */
216/* r := 2^len / m */ 234/* r := 2^len / m */
217int BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx) 235int
218 { 236BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx)
219 int ret= -1; 237{
238 int ret = -1;
220 BIGNUM *t; 239 BIGNUM *t;
221 240
222 BN_CTX_start(ctx); 241 BN_CTX_start(ctx);
223 if((t = BN_CTX_get(ctx)) == NULL) goto err; 242 if ((t = BN_CTX_get(ctx)) == NULL)
243 goto err;
224 244
225 if (!BN_set_bit(t,len)) goto err; 245 if (!BN_set_bit(t, len))
246 goto err;
226 247
227 if (!BN_div(r,NULL,t,m,ctx)) goto err; 248 if (!BN_div(r, NULL, t,m, ctx))
249 goto err;
250
251 ret = len;
228 252
229 ret=len;
230err: 253err:
231 bn_check_top(r); 254 bn_check_top(r);
232 BN_CTX_end(ctx); 255 BN_CTX_end(ctx);
233 return(ret); 256 return (ret);
234 } 257}