hi, I'm back again with another openssl related question.

given this program

--------------

  import std.stdio;
  import deimos.openssl.hmac;
  import deimos.openssl.evp;

  void main() {
      HMAC_CTX *ctx = new HMAC_CTX;
      HMAC_CTX_init(ctx);
      auto key = "123456";
      auto s = "hello";

      auto digest = HMAC(EVP_sha1(),
                         cast(void *) key,
                         cast(int) key.length,
                         cast(ubyte*) s,
                         cast(int) s.length,
                         null,null);
  }

--------------

"digest" should be of type ubyte*

does anyone know how to print this out as ascii?

thanks!
brad

brad clawsie:

>       auto digest = HMAC(EVP_sha1(),
>                          cast(void *) key,

Better to attach the * to void.


>                          cast(int) key.length,
>                          cast(ubyte*) s,

Here you are casting a struct of pointer to immutable plus length to a mutable ubyte pointer.


>                          cast(int) s.length,
>                          null,null);

This whole function call is quite bug-prone.


> "digest" should be of type ubyte*
>
> does anyone know how to print this out as ascii?

Do you mean in hex? Perhaps something like this? But hardcodes the hash function output length:

writefln("%-(%02x%)", digest[0 .. 40])

Bye,
bearophile

On Wed, 30 Apr 2014 07:27:23 +0000
brad clawsie via Digitalmars-d-learn
<digitalmars-d-learn@puremagic.com> wrote:

> hi, I'm back again with another openssl related question.
> 
> given this program
> 
> --------------
> 
>    import std.stdio;
>    import deimos.openssl.hmac;
>    import deimos.openssl.evp;
> 
>    void main() {
>        HMAC_CTX *ctx = new HMAC_CTX;
>        HMAC_CTX_init(ctx);
>        auto key = "123456";
>        auto s = "hello";
> 
>        auto digest = HMAC(EVP_sha1(),
>                           cast(void *) key,
>                           cast(int) key.length,
>                           cast(ubyte*) s,
>                           cast(int) s.length,
>                           null,null);
>    }
> 
> --------------
> 
> "digest" should be of type ubyte*
> 
> does anyone know how to print this out as ascii?

If you want to print a ubyte*, then you can do something like

auto str = cast(char[])digest[0 .. lengthOfDigest];
writeln(str);

Slicing the pointer results in an array, and you can cast ubyte[] to char[], which will print as characters rather than their integral values.

- Jonathan M Davis