Question

I have two strings as below
Str1: 1234\099
Str2: 123499

If I calculate MD5 on these string using unsigned char *MD5(const unsigned char *d, unsigned long n, unsigned char *md);

Will the function MD5 calculate the hash for first 4 bytes of Str1 or would it take the complete string “1234\099”.

Will the MD5 of Str1 and Str2 be same or different????

Thanks

Answer 1

Yes, Michael is right. I executed the below program and it seems that MD5 calculation takes place on second argument irrespective of what is in the string.

#include <stdio.h>
#include <openssl/md5.h>

int main() { <br>
    char *p = NULL;<br>
    char *c = NULL;<br>
    char *q = NULL;<br>

    p = malloc(10*(sizeof(char)));
    strncpy(p, "ABCDEDFGO", 9);
    c = malloc(200*(sizeof(char)));
    memset(c,0, 200);

    p[3] = '\0';

    q = MD5(p, 9, c);
    printf("\n For 9 bytes hash %x", *c);
    q = MD5(p, 4, c);
    printf("\n For 4 bytes hash %x", *c);
    q = MD5(p, 3, c);
    printf("\n For 3 bytes hash %x", *c);

    free(c);
    return (0);
}

For 9 bytes hash ffffffc9
For 4 bytes hash ffffffe5
For 3 bytes hash ffffff90