Xcode C++ MD5 hash

Question

I would like to hash a simple string using MD5 in Xcode c++. I searched a lot but I couldn't find a tutorial. I have to #import <CommonCrypto/CommonDigest.h>. Is that all? How can I call MD5 after that? I have found this code but it gives me an error. How will I get my hashed value is it updated in the string variable?

 unsigned char digest[16];
 const char* string = "Hello World";
 struct MD5Context context;     **(error: variable has incomplete type
 MD5Init(&context);
 MD5Update(&context, string, strlen(string));
 MD5Final(digest, &context);

I'm just using a simple command line application no headers inside just the basic main.cpp. I really appreciate any help!!!!

Answer 1

You're using the wrong API. I'm not sure where you're getting those from (they look like OpenSSL calls), but it should look like this:

#include <stdio.h>
#include <string.h>

#include <CommonCrypto/CommonDigest.h>

int main()
{
    unsigned char digest[CC_MD5_DIGEST_LENGTH];
    const char string[] = "Hello World";

    CC_MD5_CTX context;
    CC_MD5_Init(&context);
    CC_MD5_Update(&context, string, (CC_LONG)strlen(string));
    CC_MD5_Final(digest, &context);

    for (size_t i=0; i<CC_MD5_DIGEST_LENGTH; ++i)
        printf("%.2x", digest[i]);
    fputc('\n', stdout);
    return 0;
}

Output

b10a8db164e0754105b7a99be72e3fe5

Validated here.