/// <summary>
/// Given a Hash of parameters, normalize them (flatten and convert to a
/// string), then generate the HMAC-SHA-256 signature using the provided key.
/// </summary>
/// <param name="params">the parameters to sign</param>
/// <param name="key">the key to sign the params with</param>
/// <returns>the resulting signature</returns>
internal static string GetSignatureForParams(HashParams @params, string key)
{
byte[] keybytes = Encoding.UTF8.GetBytes(key);
byte[] paramsbytes = Encoding.UTF8.GetBytes(@params.ToQueryString());
byte[] hashedbytes = new HMACSHA256(keybytes).ComputeHash(paramsbytes);
return(BitConverter.ToString(hashedbytes).Replace("-", string.Empty).ToLower());
}
/// <summary>
/// Toes the hash params.
/// </summary>
/// <param name="queryStringable">The query stringable.</param>
/// <param name="hash">The hash.</param>
/// <param name="prefix">The prefix.</param>
/// <returns>HashParams object</returns>
internal static HashParams ToHashParams(
this object queryStringable, HashParams hash = null, string prefix = null)
{
Func <object, bool> isOfSimpleType = o =>
{
var type = o.GetType();
return(type.IsPrimitive ||
type == typeof(string) ||
type == typeof(decimal) ||
type == typeof(DateTimeOffset));
};
PropertyInfo[] propertyInfos = queryStringable.GetType().GetProperties(
BindingFlags.Public | BindingFlags.Instance);
hash = hash ?? new HashParams();
foreach (PropertyInfo propertyInfo in propertyInfos)
{
if (propertyInfo.GetSetMethod(true) == null)
{
continue;
}
var value = propertyInfo.GetValue(queryStringable, null);
if (value != null)
{
var propertyName = (prefix != null)
? prefix + "[" + propertyInfo.Name.ToUnderscoreCase() + "]"
: propertyInfo.Name.ToUnderscoreCase();
if (value is Array)
{
foreach (var innerValue in (Array)value)
{
if (isOfSimpleType(innerValue))
{
hash.Add(propertyName + "[]", innerValue);
}
else
{
innerValue.ToHashParams(hash, propertyName + "[]");
}
}
}
else if (isOfSimpleType(value))
{
hash.Add(propertyName, value);
}
else
{
value.ToHashParams(hash, propertyName);
}
}
}
return(hash);
}
/// <summary>
/// Toes the query string.
/// </summary>
/// <param name="hash">The hash.</param>
/// <returns>Query String</returns>
internal static string ToQueryString(this HashParams hash)
{
var s = new StringBuilder();
foreach (string key in hash.Select(x => x.Key).Distinct().OrderBy(x => x))
{
string key1 = key;
foreach (var value in hash[key1].OrderBy(x => x.ToString()))
{
s.Append("&");
s.Append(key.ToUrlString());
s.Append("=");
s.Append(value.ToUrlString());
}
}
// TODO: percent_encoding
// cut off the first &
return(s.ToString().Substring(1));
}
