OpenCoverage

bn_kron.c

Absolute File Name:/home/opencoverage/opencoverage/guest-scripts/openssl/src/crypto/bn/bn_kron.c
Source codeSwitch to Preprocessed file
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1/*-
2 * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.-
3 *-
4 * Licensed under the OpenSSL license (the "License"). You may not use-
5 * this file except in compliance with the License. You can obtain a copy-
6 * in the file LICENSE in the source distribution or at-
7 * https://www.openssl.org/source/license.html-
8 */-
9-
10#include "internal/cryptlib.h"-
11#include "bn_lcl.h"-
12-
13/* least significant word */-
14#define BN_lsw(n) (((n)->top == 0) ? (BN_ULONG) 0 : (n)->d[0])-
15-
16/* Returns -2 for errors because both -1 and 0 are valid results. */-
17int BN_kronecker(const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)-
18{-
19 int i;-
20 int ret = -2; /* avoid 'uninitialized' warning */-
21 int err = 0;-
22 BIGNUM *A, *B, *tmp;-
23 /*--
24 * In 'tab', only odd-indexed entries are relevant:-
25 * For any odd BIGNUM n,-
26 * tab[BN_lsw(n) & 7]-
27 * is $(-1)^{(n^2-1)/8}$ (using TeX notation).-
28 * Note that the sign of n does not matter.-
29 */-
30 static const int tab[8] = { 0, 1, 0, -1, 0, -1, 0, 1 };-
31-
32 bn_check_top(a);-
33 bn_check_top(b);-
34-
35 BN_CTX_start(ctx);-
36 A = BN_CTX_get(ctx);-
37 B = BN_CTX_get(ctx);-
38 if (B == NULL)
B == ((void *)0)Description
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
39 goto end;
never executed: goto end;
0
40-
41 err = !BN_copy(A, a);-
42 if (err)
errDescription
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
43 goto end;
never executed: goto end;
0
44 err = !BN_copy(B, b);-
45 if (err)
errDescription
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
46 goto end;
never executed: goto end;
0
47-
48 /*-
49 * Kronecker symbol, implemented according to Henri Cohen,-
50 * "A Course in Computational Algebraic Number Theory"-
51 * (algorithm 1.4.10).-
52 */-
53-
54 /* Cohen's step 1: */-
55-
56 if (BN_is_zero(B)) {
BN_is_zero(B)Description
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
57 ret = BN_abs_is_word(A, 1);-
58 goto end;
never executed: goto end;
0
59 }-
60-
61 /* Cohen's step 2: */-
62-
63 if (!BN_is_odd(A) && !BN_is_odd(B)) {
!BN_is_odd(A)Description
TRUEevaluated 10723 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 10401 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
!BN_is_odd(B)Description
TRUEnever evaluated
FALSEevaluated 10723 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-10723
64 ret = 0;-
65 goto end;
never executed: goto end;
0
66 }-
67-
68 /* now B is non-zero */-
69 i = 0;-
70 while (!BN_is_bit_set(B, i))
!BN_is_bit_set(B, i)Description
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
71 i++;
never executed: i++;
0
72 err = !BN_rshift(B, B, i);-
73 if (err)
errDescription
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
74 goto end;
never executed: goto end;
0
75 if (i & 1) {
i & 1Description
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
76 /* i is odd */-
77 /* (thus B was even, thus A must be odd!) */-
78-
79 /* set 'ret' to $(-1)^{(A^2-1)/8}$ */-
80 ret = tab[BN_lsw(A) & 7];-
81 } else {
never executed: end of block
0
82 /* i is even */-
83 ret = 1;-
84 }
executed 21124 times by 1 test: end of block
Executed by:
  • libcrypto.so.1.1
21124
85-
86 if (B->neg) {
B->negDescription
TRUEevaluated 100 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 21024 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
100-21024
87 B->neg = 0;-
88 if (A->neg)
A->negDescription
TRUEevaluated 50 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 50 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
50
89 ret = -ret;
executed 50 times by 1 test: ret = -ret;
Executed by:
  • libcrypto.so.1.1
50
90 }
executed 100 times by 1 test: end of block
Executed by:
  • libcrypto.so.1.1
100
91-
92 /*-
93 * now B is positive and odd, so what remains to be done is to compute-
94 * the Jacobi symbol (A/B) and multiply it by 'ret'-
95 */-
96-
97 while (1) {-
98 /* Cohen's step 3: */-
99-
100 /* B is positive and odd */-
101-
102 if (BN_is_zero(A)) {
BN_is_zero(A)Description
TRUEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 101152 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
21124-101152
103 ret = BN_is_one(B) ? ret : 0;
BN_is_one(B)Description
TRUEevaluated 21119 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 5 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
5-21119
104 goto end;
executed 21124 times by 1 test: goto end;
Executed by:
  • libcrypto.so.1.1
21124
105 }-
106-
107 /* now A is non-zero */-
108 i = 0;-
109 while (!BN_is_bit_set(A, i))
!BN_is_bit_set(A, i)Description
TRUEevaluated 100720 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 101152 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
100720-101152
110 i++;
executed 100720 times by 1 test: i++;
Executed by:
  • libcrypto.so.1.1
100720
111 err = !BN_rshift(A, A, i);-
112 if (err)
errDescription
TRUEnever evaluated
FALSEevaluated 101152 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-101152
113 goto end;
never executed: goto end;
0
114 if (i & 1) {
i & 1Description
TRUEevaluated 33446 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 67706 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
33446-67706
115 /* i is odd */-
116 /* multiply 'ret' by $(-1)^{(B^2-1)/8}$ */-
117 ret = ret * tab[BN_lsw(B) & 7];-
118 }
executed 33446 times by 1 test: end of block
Executed by:
  • libcrypto.so.1.1
33446
119-
120 /* Cohen's step 4: */-
121 /* multiply 'ret' by $(-1)^{(A-1)(B-1)/4}$ */-
122 if ((A->neg ? ~BN_lsw(A) : BN_lsw(A)) & BN_lsw(B) & 2)
(A->neg ? ~(((...(B)->d[0]) & 2Description
TRUEevaluated 16549 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 84603 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
A->negDescription
TRUEevaluated 50 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
FALSEevaluated 101102 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
((A)->top == 0)Description
TRUEnever evaluated
FALSEevaluated 101102 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-101102
123 ret = -ret;
executed 16549 times by 1 test: ret = -ret;
Executed by:
  • libcrypto.so.1.1
16549
124-
125 /* (A, B) := (B mod |A|, |A|) */-
126 err = !BN_nnmod(B, B, A, ctx);-
127 if (err)
errDescription
TRUEnever evaluated
FALSEevaluated 101152 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-101152
128 goto end;
never executed: goto end;
0
129 tmp = A;-
130 A = B;-
131 B = tmp;-
132 tmp->neg = 0;-
133 }
executed 101152 times by 1 test: end of block
Executed by:
  • libcrypto.so.1.1
101152
134 end:
code before this statement never executed: end:
0
135 BN_CTX_end(ctx);-
136 if (err)
errDescription
TRUEnever evaluated
FALSEevaluated 21124 times by 1 test
Evaluated by:
  • libcrypto.so.1.1
0-21124
137 return -2;
never executed: return -2;
0
138 else-
139 return ret;
executed 21124 times by 1 test: return ret;
Executed by:
  • libcrypto.so.1.1
21124
140}-
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