dsa算法c语言
时间: 2023-12-15 07:03:45 浏览: 36
DSA(Digital Signature Algorithm)是一种数字签名算法,用于对数字文件进行签名和验证。在C语言中,可以使用以下步骤实现DSA算法:
1. 生成公钥和私钥
```
#include <openssl/dsa.h>
DSA *dsa = DSA_new();
int bits = 1024;
unsigned char seed[20];
DSA_generate_parameters_ex(dsa, bits, seed, 20, NULL, NULL, NULL);
DSA_generate_key(dsa);
```
2. 对数据进行签名
```
unsigned char data[] = "hello world";
unsigned int data_len = strlen(data);
unsigned char *sig = (unsigned char *)malloc(DSA_size(dsa));
unsigned int sig_len;
DSA_sign(0, data, data_len, sig, &sig_len, dsa);
```
3. 对签名进行验证
```
int ret = DSA_verify(0, data, data_len, sig, sig_len, dsa);
if (ret == 1) {
printf("signature is valid\n");
} else {
printf("signature is invalid\n");
}
```
以上代码使用了OpenSSL库来实现DSA算法。需要在编译时链接OpenSSL库,例如使用以下命令进行编译:
```
gcc dsa.c -o dsa -lssl -lcrypto
```