The Amazon Signature must be url encoded in a slightly different way to what VBSCript encodes. The following function will encode the result correctly:
JScript Version:
function amazonEncode(s)
{
return Server.UrlEncode(s).replace(/\+/g,"%20").replace(/\%2E/g,".").replace(/\%2D/g,"-").replace(/\%7E/g,"~").replace(/\%5F/g,"_");
}
VBScript Version:
function amazonEncode(s)
dim retval
retval = Server.UrlEncode(s)
retval = replace(retval,"+","%20")
retval = replace(retval,"%2E",".")
retval = replace(retval,"%2D","-")
retval = replace(retval,"%7E","~")
retval = replace(retval,"%5F","_")
amazonEncode = retval
end function
As for base64, I used .NET's already built functionality for it. I had to create a DLL to wrap it, so that I could use it from JScript (or VBScript).
Here's how to create that dll:
Download the free C# 2010 Express and install it.
You also need to use two other tools that you won’t have a path to, so you will need to add the path to your PATH environment variable, so at a cmd prompt search for regasm.exe, guidgen.exe and sn.exe (you might find several versions – select the one with the latest date).
• cd\
• dir/s regasm.exe
• dir/s sn.exe
• dir/s guidgen.exe
So as an example, a COM object that has just one method which just returns “Hello”:
Our eventual aim is to use it like this:
<%@Language=JScript%>
<%
var x = Server.CreateObject("blah.whatever");
Response.Write(x.someMethod());
%>
or
<%@Language=VBScript%>
<%
dim x
set x = Server.CreateObject("blah.whatever")
Response.Write x.someMethod()
%>
• Start C# and create a new project
• Select “Empty Project”
• Give it a name – this becomes the namespace by default (the blah in the sample above)
• Next save the project (so you know where to go for the next bit). This will create a folder structure like so:
o blah this contains your solution files that the editor needs (blah.sln etc)
blah this contains your source code and project files
• bin
o Debug the compiled output ends up here
• Next, using the cmd console, navigate to the root blah folder and create a key pair file:
sn –k key.snk
• Next you need a unique guid (enter guidgen at the cmd prompt)
o Select registry format
o Click “New Guid”
o Click “Copy”
• Back to C# editor – from the menu, select Project – Add Class
• Give it a name – this is the whatever in the sample above
• After the opening brace just after the namespace line type:
[GuidAttribute(“paste your guid here”)]
remove the curly brackets from your pasted guid
• You will need to add another “using” at the top
using System.Runtime.InteropServices;
• Finally you need to create someMethod
The final C# code looks like this (the bits in red may be different in your version):
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
namespace blah
{
[GuidAttribute("AEF4F27F-9E97-4189-9AD5-64386A1699A7")]
public class whatever
{
public string someMethod()
{
return "Hello";
}
}
}
• Next, from the menu, select Project – Properties
o On the left, select Application and, for the Output type dropdown, select “Class Library”
o On the left, select Signing and tick the “Sign the assembly” box, then browse to the key.snk file you made earlier
o Save the properties (CTRL-S)
• Next build the dll (Press F6) – This will create a dll in the Debug folder
• Open a cmd window as administrator (right click cmd.exe and select “Run as Administrator”)
• Navigate to the Debug folder and enter the following to register the assembly:
regasm blah.dll /tlb:blah.tlb /codebase blah
That’s it – the above is a genuine COM component and will work in other applications, the example below allows for event handling and only really works in ASP due to the default property mechanism of ASP:
The code for the base64 stuff would be:
// returns a base 64 encoded string that has been encrypted with SHA256
// parameters:
// s string to encrypt
// k key to use during encryption
public string getBase64SHA256(string s, string k)
{
HMACSHA256 sha = new HMACSHA256();
System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
sha.Key = encoding.GetBytes(k);
byte[] hashBytes = sha.ComputeHash(encoding.GetBytes(s));
return System.Convert.ToBase64String(hashBytes);
}
// returns a base 64 encoded string that has been encrypted with SHA1
// parameters:
// s string to encrypt
// k key to use during encryption
public string getBase64SHA1(string s, string k)
{
HMACSHA1 sha = new HMACSHA1();
System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
sha.Key = encoding.GetBytes(k);
byte[] hashBytes = sha.ComputeHash(encoding.GetBytes(s));
return System.Convert.ToBase64String(hashBytes);
}
You would need the relevant usings:
using System.Security.Cryptography;
The signature in full must have all the query string name-value pairs in alphabetical order before computing the SHA and base64. Here is my version of the signature creator function:
function buildAmazonSignature(host,req,qstring)
{
var str="", i, arr = String(qstring).split("&");
for (i=0; i<arr.length; i++)
arr[i] = arr[i].split("=");
arr.sort(amazonSortFunc);
for (i=0; i<arr.length; i++)
{
if (str != "")
str += "&";
str += arr[i][0] + "=" + arr[i][1];
}
str = "GET\n"+host+"\n"+req+"\n"+str;
var utils = Server.CreateObject("FMAG.Utils");
var b64 = utils.getBase64SHA256(str, "xxxxxxxxxx");
utils = null;
return amazonEncode(b64);
}
function amazonSortFunc(a,b)
{
return (a[0]<b[0])?-1:((a[0]>b[0])?1:0);
}
VBScript doesn't have a very good array sort facility, so you'll have to work that one out yourself - sorry
Also I have the timestamp in this format:
YYYY-MM-DDTHH:MM:SSZ
Also the stuff in the query string included the following:
AWSAccessKeyId
SignatureMethod
SignatureVersion
Version
Expires
Action
Hope that helps
sRemoteFilePathas/files/test.jpg.GetByteshas been modified incorrect. It must return bytes of file not size of bytes. I'll update my answer with these improvements as you need current. As starting, just copy and use after modifying S3 credentials. – Chichihaerh"The requested header was not found"Problem code is.send GetBytes(LocalFile)– HaloThe HTTP redirect request failedsame line of code. – Halo