Question

Here is C code:

#include <openssl/sha.h>
#include <stdio.h>
char *hash_sha512(char *data){
    SHA512_CTX ctx;
    char *md=malloc(sizeof(char)*(SHA512_DIGEST_LENGTH+1));

    SHA512_Init(&ctx);
    SHA512_Update(&ctx, data, strlen(data));
    SHA512_Final(md, &ctx);
    md[SHA512_DIGEST_LENGTH]='\0';

    return md;
}
int main(int argc, char *argv[]){
    str=hash_sha512("GFLOuJnR19881218");
    printf("%s\n", str);
    free(str);
    return 1;
}

The output:

�<�4����IIA[r�� Η#� 6π�8jD����J�b9��ږ��^X�

Here is PHP code:

$hash=hash('sha512', 'GFLOuJnR19881218', TRUE);

The output:

�<��>4��ǰ��II�-A[r�?�� �Η#��D6π�8jD���?���J�b9��ږ��^X�

The results of C code and PHP code are different, what is wrong with my code?

Answer 1

The output is garbled because the output is a binary string which the browser is trying to display as ASCII or UTF-8 and can’t. You need to encode both as hexidecimal, decimal, base32, or some other normal human representation and then compare them.

$binary = hash('sha512', 'GFLOuJnR19881218', TRUE);
$hex = hash('sha512', 'GFLOuJnR19881218');

string hash ( string $algo , string $data [, bool $raw_output = false ] )  

When set to TRUE, outputs raw binary data. FALSE outputs lowercase hexits.

• https://www.php.net/manual/en/function.hash.php