怎么用c语言获取文件MD5的值

???C???????MD5?,?????????:

1. ????????:

```c

#include

#include

#include

#include

```

2. ????????????MD5?:

```c

void compute_md5(const char* filepath, unsigned char* md5_hash) {

FILE* file = fopen(filepath, "rb");

if(file == NULL) {

printf("??????\n");

return;

}

MD5_CTX md5_ctx;

MD5_Init(&md5_ctx);

unsigned char buffer[1024];

int bytes;

while((bytes = fread(buffer, 1, sizeof(buffer), file)) != 0) {

MD5_Update(&md5_ctx, buffer, bytes);

}

MD5_Final(md5_hash, &md5_ctx);

fclose(file);

}

```

3. ???????compute_md5????????MD5?:

```c

int main() {

const char* filepath = "????";

unsigned char md5_hash[MD5_DIGEST_LENGTH];

compute_md5(filepath, md5_hash);

// ?MD5??16????????

for(int i = 0; i < MD5_DIGEST_LENGTH; i++) {

printf("x", md5_hash[i]);

}

printf("\n");

return 0;

}

```

???,?????????OpenSSL????,??????????:

```bash

gcc -o ??? ????.c -lcrypto

```

??"????"???????MD5??????????