openssl库中BIGNUM的使用

最新推荐文章于 2023-11-21 15:25:03 发布

转载最新推荐文章于 2023-11-21 15:25:03 发布 · 2.8k 阅读

openssl 专栏收录该内容

6 篇文章

订阅专栏

本文演示了如何使用OpenSSL库中的BIGNUM类型执行基本的数学运算，包括随机数生成、加减乘除、取模、指数运算等，并展示了生成素数的方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

随机数

加减乘除

取模

指数

[cpp] view plain copy

print ?

#include <stdio.h>
#include <openssl/bn.h>
#include <openssl/rand.h>
#include <openssl/err.h>
void bn_printf(BIGNUM * a, int n)
{
printf(”0x”);
BN_print_fp(stdout, a);
if (n)
printf(”\n”);
}
void bn_hex_printf(BIGNUM * a)
{
char *p = BN_bn2hex(a);
printf(”0x%s\n”, p);
OPENSSL_free(p);
}
void bn_dec_printf(BIGNUM * a)
{
char *p = BN_bn2dec(a);
printf(”%s\n”, p);
OPENSSL_free(p);
}
int main(int argc, char *argv[])
{
int bits = 3;
if (argc > 1) {
bits = atoi(argv[1]);
}
if (bits <= 0) {
bits = 8;
}
printf(”bits: %d\n”, bits);
BN_CTX *ctx;
BIGNUM a, b, c, d;
ctx = BN_CTX_new();
if (ctx == NULL)
exit(1);
BN_init(&a);
BN_init(&b);
BN_init(&c);
BN_init(&d);
BN_rand(&a, bits, 1, 1);
printf(”BN_rand a: ”);
bn_printf(&a, 1);
bn_hex_printf(&a);
bn_dec_printf(&a);
BN_add_word(&a, 1);
printf(”BN_add_word a + 1\n”);
bn_printf(&a, 1);
BN_free(&a);
BN_init(&a);
BN_rand(&a, bits, 1, 0);
printf(”BN_rand a: ”);
bn_printf(&a, 1);
BN_rand(&b, bits, 0, 1);
printf(”BN_rand b: ”);
bn_printf(&b, 1);
BN_add(&c, &a, &b);
printf(”BN_add a + b\n”);
bn_printf(&a, 0);
printf(” + ”);
bn_printf(&b, 0);
printf(” = ”);
bn_printf(&c, 1);
BN_sub(&c, &a, &b);
printf(”BN_sub a - b\n”);
bn_printf(&a, 0);
printf(” - ”);
bn_printf(&b, 0);
printf(” = ”);
bn_printf(&c, 1);
BN_mul(&c, &a, &b, ctx);
printf(”BN_mul a * b\n”);
bn_printf(&a, 0);
printf(” * ”);
bn_printf(&b, 0);
printf(” = ”);
bn_printf(&c, 1);
BN_div(&d, &c, &a, &b, ctx);
printf(”BN_div a / b\n”);
bn_printf(&a, 0);
printf(” / ”);
bn_printf(&b, 0);
printf(” = ”);
bn_printf(&d, 1);
printf(”remainder ”);
bn_printf(&c, 1);
BN_mod(&c, &a, &b, ctx);
printf(”BN_mod a %% b\n”);
bn_printf(&a, 0);
printf(” %% ”);
bn_printf(&b, 0);
printf(” = ”);
bn_printf(&c, 1);
BN_exp(&c, &a, &b, ctx);
printf(”BN_exp a ^ b\n”);
bn_printf(&a, 0);
printf(” ^ ”);
bn_printf(&b, 0);
printf(” = ”);
if (BN_num_bits(&c) < 64 * 8) {
bn_printf(&c, 1);
} else {
printf(”BN_num_bits(c) %d too long, not print\n”,
BN_num_bits(&c));
}
BN_set_word(&a, 100);
printf(”BN_set_word a: ”);
bn_printf(&a, 1);
bn_printf(&a, 0);
if (BN_is_word(&a, 100)) {
printf(” is 100\n”);
} else {
printf(” is not 100\n”);
}
BN_set_negative(&a, 1);
printf(”BN_set_negative a: ”);
bn_dec_printf(&a);
BN_free(&a);
BN_init(&a);
BN_generate_prime_ex(&a, bits, 1, NULL, NULL, NULL);
printf(”BN_generate_prime_ex a: ”);
bn_printf(&a, 1);
bn_printf(&a, 0);
if (1 == BN_is_prime_ex(&a, BN_prime_checks, NULL, NULL)) {
printf(” is prime\n”);
} else {
printf(” is not prime\n”);
}
BN_add_word(&a, 2);
bn_printf(&a, 0);
if (1 == BN_is_prime_ex(&a, BN_prime_checks, NULL, NULL)) {
printf(” is prime\n”);
} else {
printf(” is not prime\n”);
}
BN_free(&a);
BN_free(&b);
BN_free(&c);
BN_free(&d);
BN_CTX_free(ctx);
return 0;
}

#include <stdio.h>

include <openssl/bn.h>

include <openssl/rand.h>

include <openssl/err.h>

void bn_printf(BIGNUM * a, int n)
{
printf("0x");
BN_print_fp(stdout, a);
if (n)
printf("\n");
}

void bn_hex_printf(BIGNUM * a)
{
char *p = BN_bn2hex(a);
printf("0x%s\n", p);
OPENSSL_free(p);
}

void bn_dec_printf(BIGNUM * a)
{
char *p = BN_bn2dec(a);
printf("%s\n", p);
OPENSSL_free(p);
}

int main(int argc, char *argv[])
{
int bits = 3;

if (argc &gt; 1) {
    bits = atoi(argv[1]);
}
if (bits &lt;= 0) {
    bits = 8;
}
printf("bits: %d\n", bits);

BN_CTX *ctx;
BIGNUM a, b, c, d;

ctx = BN_CTX_new();
if (ctx == NULL)
    exit(1);

BN_init(&amp;a);
BN_init(&amp;b);
BN_init(&amp;c);
BN_init(&amp;d);

BN_rand(&amp;a, bits, 1, 1);
printf("BN_rand a: ");
bn_printf(&amp;a, 1);
bn_hex_printf(&amp;a);
bn_dec_printf(&amp;a);

BN_add_word(&amp;a, 1);
printf("BN_add_word a + 1\n");
bn_printf(&amp;a, 1);

BN_free(&amp;a);
BN_init(&amp;a);

BN_rand(&amp;a, bits, 1, 0);
printf("BN_rand a: ");
bn_printf(&amp;a, 1);

BN_rand(&amp;b, bits, 0, 1);
printf("BN_rand b: ");
bn_printf(&amp;b, 1);

BN_add(&amp;c, &amp;a, &amp;b);
printf("BN_add a + b\n");
bn_printf(&amp;a, 0);
printf(" + ");
bn_printf(&amp;b, 0);
printf(" = ");
bn_printf(&amp;c, 1);

BN_sub(&amp;c, &amp;a, &amp;b);
printf("BN_sub a - b\n");
bn_printf(&amp;a, 0);
printf(" - ");
bn_printf(&amp;b, 0);
printf(" = ");
bn_printf(&amp;c, 1);

BN_mul(&amp;c, &amp;a, &amp;b, ctx);
printf("BN_mul a * b\n");
bn_printf(&amp;a, 0);
printf(" * ");
bn_printf(&amp;b, 0);
printf(" = ");
bn_printf(&amp;c, 1);

BN_div(&amp;d, &amp;c, &amp;a, &amp;b, ctx);
printf("BN_div a / b\n");
bn_printf(&amp;a, 0);
printf(" / ");
bn_printf(&amp;b, 0);
printf(" = ");
bn_printf(&amp;d, 1);
printf("remainder ");
bn_printf(&amp;c, 1);

BN_mod(&amp;c, &amp;a, &amp;b, ctx);
printf("BN_mod a %% b\n");
bn_printf(&amp;a, 0);
printf(" %% ");
bn_printf(&amp;b, 0);
printf(" = ");
bn_printf(&amp;c, 1);

BN_exp(&amp;c, &amp;a, &amp;b, ctx);
printf("BN_exp a ^ b\n");
bn_printf(&amp;a, 0);
printf(" ^ ");
bn_printf(&amp;b, 0);
printf(" = ");
if (BN_num_bits(&amp;c) &lt; 64 * 8) {
    bn_printf(&amp;c, 1);
} else {
    printf("BN_num_bits(c) %d too long, not print\n",
           BN_num_bits(&amp;c));
}

BN_set_word(&amp;a, 100);
printf("BN_set_word a: ");
bn_printf(&amp;a, 1);

bn_printf(&amp;a, 0);
if (BN_is_word(&amp;a, 100)) {
    printf(" is 100\n");
} else {
    printf(" is not 100\n");
}

BN_set_negative(&amp;a, 1);
printf("BN_set_negative a: ");
bn_dec_printf(&amp;a);

BN_free(&amp;a);
BN_init(&amp;a);

BN_generate_prime_ex(&amp;a, bits, 1, NULL, NULL, NULL);
printf("BN_generate_prime_ex a: ");
bn_printf(&amp;a, 1);

bn_printf(&amp;a, 0);
if (1 == BN_is_prime_ex(&amp;a, BN_prime_checks, NULL, NULL)) {
    printf(" is prime\n");
} else {
    printf(" is not prime\n");
}

BN_add_word(&amp;a, 2);
bn_printf(&amp;a, 0);
if (1 == BN_is_prime_ex(&amp;a, BN_prime_checks, NULL, NULL)) {
    printf(" is prime\n");
} else {
    printf(" is not prime\n");
}

BN_free(&amp;a);
BN_free(&amp;b);
BN_free(&amp;c);
BN_free(&amp;d);

BN_CTX_free(ctx);

return 0;

}

运行结果

[plain] view plain copy

print ?

$ gcc -Wall -lcrypto bn.c  </li><li class="">  </li><li class="alt">  </li><li class="">$ ./a.out 5
bits: 5
BN_rand a: 0x19
0x19
25
BN_add_word a + 1
0x1A
BN_rand a: 0x1E
BN_rand b: 0x1D
BN_add a + b
0x1E + 0x1D = 0x3B
BN_sub a - b
0x1E - 0x1D = 0x1
BN_mul a * b
0x1E * 0x1D = 0x366
BN_div a / b
0x1E / 0x1D = 0x1
remainder 0x1
BN_mod a % b
0x1E % 0x1D = 0x1
BN_exp a ^ b
0x1E ^ 0x1D = 0x4EC8A7BC9DC1FCCECDF11AC97979E0000000
BN_set_word a: 0x64
0x64 is 100
BN_set_negative a: -100
BN_generate_prime_ex a: 0x8C27
0x8C27 is prime
0x8C29 is not prime
$ ./a.out 16  </li><li class="alt">bits: 16  </li><li class="">BN_rand a: 0xD3C5  </li><li class="alt">0xD3C5  </li><li class="">54213  </li><li class="alt">BN_add_word a + 1  </li><li class="">0xD3C6  </li><li class="alt">BN_rand a: 0xCDE5  </li><li class="">BN_rand b: 0xB79B  </li><li class="alt">BN_add a + b  </li><li class="">0xCDE5 + 0xB79B = 0x18580  </li><li class="alt">BN_sub a - b  </li><li class="">0xCDE5 - 0xB79B = 0x164A  </li><li class="alt">BN_mul a * b  </li><li class="">0xCDE5 * 0xB79B = 0x93AB5CA7  </li><li class="alt">BN_div a / b  </li><li class="">0xCDE5 / 0xB79B = 0x1  </li><li class="alt">remainder 0x164A  </li><li class="">BN_mod a % b  </li><li class="alt">0xCDE5 % 0xB79B = 0x164A  </li><li class="">BN_exp a ^ b  </li><li class="alt">0xCDE5 ^ 0xB79B = BN_num_bits(c) 737278 too long, not print  </li><li class="">BN_set_word a: 0x64  </li><li class="alt">0x64 is 100  </li><li class="">BN_set_negative a: -100  </li><li class="alt">BN_generate_prime_ex a: 0xDEA7  </li><li class="">0xDEA7 is prime  </li><li class="alt">0xDEA9 is not prime  </li></ol></div><pre class="plain" name="code" style="display: none;">$ gcc -Wall -lcrypto bn.c $./a.out 5 bits: 5 BN_rand a: 0x19 0x19 25 BN_add_word a + 1 0x1A BN_rand a: 0x1E BN_rand b: 0x1D BN_add a + b 0x1E + 0x1D = 0x3B BN_sub a - b 0x1E - 0x1D = 0x1 BN_mul a * b 0x1E * 0x1D = 0x366 BN_div a / b 0x1E / 0x1D = 0x1 remainder 0x1 BN_mod a % b 0x1E % 0x1D = 0x1 BN_exp a ^ b 0x1E ^ 0x1D = 0x4EC8A7BC9DC1FCCECDF11AC97979E0000000 BN_set_word a: 0x64 0x64 is 100 BN_set_negative a: -100 BN_generate_prime_ex a: 0x8C27 0x8C27 is prime 0x8C29 is not prime$ ./a.out 16 bits: 16 BN_rand a: 0xD3C5 0xD3C5 54213 BN_add_word a + 1 0xD3C6 BN_rand a: 0xCDE5 BN_rand b: 0xB79B BN_add a + b 0xCDE5 + 0xB79B = 0x18580 BN_sub a - b 0xCDE5 - 0xB79B = 0x164A BN_mul a * b 0xCDE5 * 0xB79B = 0x93AB5CA7 BN_div a / b 0xCDE5 / 0xB79B = 0x1 remainder 0x164A BN_mod a % b 0xCDE5 % 0xB79B = 0x164A BN_exp a ^ b 0xCDE5 ^ 0xB79B = BN_num_bits(c) 737278 too long, not print BN_set_word a: 0x64 0x64 is 100 BN_set_negative a: -100 BN_generate_prime_ex a: 0xDEA7 0xDEA7 is prime 0xDEA9 is not prime