function fnSignedQuery( strQuery, strKey ) {
    strQuery += "&Timestamp=" + timestamp();
    var strSignedQuery;
    var strToSign = strQuery.replace( /(https?:\/\/)([^\/]*)(\/.*)\?(.*)/i,
        function( strMatch, strScheme, strHost, strUri, strParams ) {
            var aParams = strParams.split("&").sort();
            for ( var i in aParams ) {
                var aKV = aParams[i].split("=");
                for ( var j in aKV )
                    aKV[j] = encodeURIComponentAWS( aKV[j] );
                aParams[i] = aKV.join("=");
            }
            strParams = aParams.join("&");
            strHost = strHost.toLowerCase();
            strSignedQuery = strScheme + strHost + strUri + "?" + strParams;
            return (new Array( "GET", strHost, strUri, strParams )).join("\n");
        })
    strSignature = encodeURIComponentAWS( Base64.encode( HMAC_SHA256_MAC( strKey, strToSign ) ) );
    strSignedQuery += "&Signature=" + strSignature;
    return strSignedQuery;
}
 
function encodeURIComponentAWS( str ) {
    // developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Global_Functions/EncodeURIComponent
    // "... encodeURIComponent escapes all characters except the following: alphabetic, decimal digits, - _ . ! ~ * ' ( )  ..."
    // same for MS JScript ?  seems to be.
    return fnTranslate( encodeURIComponent( str ),
        [ ["!", "%21"], ["'", "%27"], ["(", "%28"], [")", "%29"], ["*", "%2A"] ] );
}
 
function fnTranslate( str, aTranslate ) {
    for ( var i in aTranslate )
        str = str.replace( aTranslate[i][0], aTranslate[i][1] );
    return str;
}
 
function timestamp() { return toZString( new Date() ) }
 
function toZString( dt ) {
    // "Sun, 10 May 2009 18:45:50 UTC" to "2009-05-10T18:45:50Z":
    return dt.toUTCString().replace( /.{3}, (\d{2}) .{3} (\d{4}) (\d{2}:\d{2}:\d{2}) UTC/,
        function(strMatch, strDay, strYear, strTime) {
            strMonth = (dt.getUTCMonth()+1).toString().replace( /^(\d)$/, "0$1" );
            return strYear + "-" + strMonth + "-" + strDay + "T" + strTime + "Z";
        });
}

GET
ecs.amazonaws.com
/onca/xml
AWSAccessKeyId=XXXXXXXXXXXXXXXXXXXX&AssociateTag=XXXXXXXXXXXXXXXX&ListId=XXXXXXXXXXXXX&ListType=WishList&Operation=ListLookup&ProductPage=1&ResponseGroup=ListInfo&Service=AWSECommerceService&Sort=DateAdded&Timestamp=2009-05-11T00%3A12%3A46Z&Version=2007-10-29