String to Byte array

kpaxian25 has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying to write the below C# code in perl, what is the C# equivalent for Convert.ToByte(key.Text.Substring(i * 2, 2), 16); in perl.
Any insight is much appreciated.
Thanks.

C# code

// convert key to a byte array
                int len = key.Text.Length / 2;
                if (len == 0)
                    throw new ApplicationException("key must be provid
+ed");
                byte[] k = new byte[len];
                for (int i = 0; i < len; i++)
                {
                    k[i] = Convert.ToByte(key.Text.Substring(i * 2, 2)
+, 16);
                }
                summaryText += "key=" + key.Text.Trim() + "\r\n\r\n";
[download]

Perl code I got so far # convert key to a byte array

$key="AJDAHSDJ213718327DSFSDJFHSDKFJ87348171837"; #example
$len=length($key) / 2;
if($len == 0)
 {     print"Key must be provided";}
else  {
     for($i=0;$i<$len;$i++)      {
        $k[$i]= ?
      }
[download]

Also how do you pass the byte array as a key value to sha256 hash, Join the array values ? $key_value=@k; $digest=hmac_sha256_base64($data,$key_value);

Comment on String to Byte array Select or Download Code

Replies are listed 'Best First'.
Re: String to Byte array by BrowserUk (Patriarch) on Sep 19, 2013 at 16:42 UTC
That usage of Convert.ToByte( string, 16 ) converts a 2-digit hex string to an unsigned 8-bit integer. The direct equivalent in Perl would be `unpack 'H2', substr $key, $i*2, 2;`. But then you'll need to convert that integer into a character and pack it back into a string. But, you have a bigger problem if your example `"AJDAHSDJ213718327DSFSDJFHSDKFJ87348171837"` is obtained from somewhere rather than just made up? J, K, H & S are not hex digits. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^2: String to Byte array by toolic (Bishop) on Sep 19, 2013 at 16:51 UTC
J, K, H & S are not hex digits. Maybe they're kpaxadecimal :) </lame>	[reply]
Re^3: String to Byte array by kpaxian25 (Novice) on Sep 20, 2013 at 21:29 UTC
:)	[reply]
Re^2: String to Byte array by kpaxian25 (Novice) on Sep 20, 2013 at 21:12 UTC
Yes that was just made up text. Didn't realize about the J,K,H&S.	[reply]
Re: String to Byte array by hdb (Monsignor) on Sep 19, 2013 at 19:03 UTC
Assuming the key contains valid 2digit hex numbers: `use strict; use warnings; my $key = "A21B12C212AD12FF"; my @key = map hex, $key =~ /../g; print "@key\n";` [download] HELP: How to do this with unpack? All my attempts are failing...	[reply] [d/l]
Re^2: String to Byte array by BrowserUk (Patriarch) on Sep 19, 2013 at 20:50 UTC
What the OP probably needs, rather than an array of integers, is a binary string of unsigned chars derived from the hex string input. That is done using pack, not unpack: `print pack 'H*', "A21B12C212AD12FF";; ó←↕┬↕¡↕` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^3: String to Byte array by kpaxian25 (Novice) on Sep 20, 2013 at 21:11 UTC
Thanks that helped me to get the same output as C# code. Perl Rules :)	[reply]
Re: String to Byte array by Tux (Canon) on Sep 19, 2013 at 16:34 UTC
I'd suggest using unpack. Enjoy, Have FUN! H.Merijn	[reply]
Re^2: String to Byte array by erictrarner (Initiate) on Oct 11, 2014 at 08:01 UTC
Using UTF8 conversion byte[] bArray = Encoding.UTF8.GetBytes (inputString); Using ASCII conversion byte[] bArray = Encoding.ASCII.GetBytes (inputString); Full Source: http://net-informations.com/q/faq/stringtobyte.html Eric	[reply]