OPenssl大数库调用

任务：

在openEuler(推荐)或Ubuntu或Windows(不推荐)中完成下面任务
1. 基于OpenSSL的大数库计算2的N次方，N为你学号的后四位（5‘）
2. 基于OpenSSL的大数库计算你以及前面5位同学和后面5位同学的8位学号的乘积，N为你学号的后四位（5‘）
3. 用Python或bc命令验证计算的正确性（5’）
4.  **提交代码（或代码链接）和运行结果截图**

python验证

2^1231

代码：

pragma comment(lib,"libssl.lib")

pragma comment(lib,"libcrypto.lib")

include <stdio.h>

include <stdlib.h>

include <stdint.h>

include <string.h>

include <openssl/bn.h>

int main(int argc, char* argv[])
{
{
BN_CTX* pBNctx = BN_CTX_new();
BIGNUM* n = BN_new();
BN_set_word(n, 1220);
BIGNUM* two = BN_new();
BN_set_word(two, 2);
BIGNUM* r = BN_new();
BN_exp(r, two, n, pBNctx);
char* pR = BN_bn2dec(r);
printf("2^1231 =%s \n", pR);

​ }

​ return 0;
}

学号前五位，后五位相乘

代码如下：

pragma comment(lib,"libssl.lib")

pragma comment(lib,"libcrypto.lib")

include <stdio.h>

include <stdlib.h>

include <stdint.h>

include <string.h>

include <openssl/bn.h>

int main(int argc, char* argv[])
{
//
BN_CTX* pBNctx = BN_CTX_new();
BIGNUM* n = BN_new();
BN_set_word(n, 1231);
BIGNUM* two = BN_new();
BN_set_word(two, 2);
BIGNUM* r = BN_new();
BN_exp(r, two, n, pBNctx);
char* pR = BN_bn2dec(r);
//printf("2^1210 =%s \n", pR);
BIGNUM* rr = BN_new();
BIGNUM* n1 = BN_new();
BIGNUM* n2 = BN_new();
int i;
BN_set_word(n1, 20191226);
BN_set_word(n2, 20191227);
BN_mul(rr, n1, n2,pBNctx);
for (i = 20191228; i <= 20191236; i++)
{
BN_set_word(n1, i);
// char* pR = BN_bn2dec(n1);
// printf(" =%s \n", pR);
BN_mul(rr, rr, n1,pBNctx);
}
pR = BN_bn2dec(rr);
printf("20191226 * …… * 20191236 =%s \n", pR);
return 0;