[C] Using MD5 in C language

#include <openssl/md5.h>

/*Encode str to str_enc using md5 algorithm*/
void md5(char *str, char *str_enc) {

    int i = 0;
    unsigned char d[16];
    MD5_CTX ctx;

    MD5_Init(&ctx);
    MD5_Update (&ctx, (char *) str, strlen(str));
    MD5_Final(d, &ctx);

    for (i = 0; i < 16; i++) {
        sprintf(str_enc + (i*2), "%02X", d[i]);
    }
    str_enc[32] = 0;
}

Reference Link:
http://blog.roodo.com/rocksaying/archives/3873017.html