/// <summary>
/// Converte a Base32 string to byte array.
/// </summary>
/// <param name="base32">
/// Base32 formated string.
/// </param>
/// <param name="format">
/// Specify the Base32 encoding format.
/// </param>
/// <returns>
/// byte array with value of Base32 encoding.
/// </returns>
public static byte[] Decode(string base32, Base32Format format = Base32Format.RFC4648)
{
if (base32.Length == 0)
{
return(new byte[0]);
}
var mapping = Base32Mapping.GetMapping(format);
base32 = RemovePadding(base32, mapping.PaddingChar);
byte[] result = new byte[base32.Length * 5 / 8];
int buffer = 0;
int next = 0;
int bitsLeft = 0;
foreach (var c in base32.ToCharArray())
{
if (!mapping.CharValues.ContainsKey(c))
{
throw new Base32DecodingException($"Character was illigal: {c}");
}
buffer <<= 5;
buffer |= mapping.CharValues[c] & 31;
bitsLeft += 5;
if (bitsLeft >= 8)
{
result[next++] = (byte)(buffer >> (bitsLeft - 8));
bitsLeft -= 8;
}
}
return(result);
}
public static byte[] Decode(this Base32Mapping mapping, string data)
{
IMapping map = mappings[mapping];
int dataIndex = 0;
int bufferIndex = 0;
int buffer = 0;
int mask = 0b11111111;
if (map.Padding != null)
{
data = data.Replace(map.Padding, "");
}
MemoryStream result = new MemoryStream();
while (dataIndex < data.Length)
{
for (int i = 0; i < 5 && dataIndex < data.Length; i++)
{
buffer = buffer << 5;
buffer += map[data.Substring(dataIndex++, 1)];
bufferIndex += 5;
}
while (bufferIndex >= 8)
{
int offset = bufferIndex - 8;
result.WriteByte((byte)((buffer & (mask << offset)) >> offset));
buffer = buffer & (~(mask << offset));
bufferIndex -= 8;
}
}
return(result.ToArray());
}
public static string Encode(this Base32Mapping mapping, byte[] data)
{
IMapping map = mappings[mapping];
int dataIndex = 0;
int bufferIndex = 0;
int buffer = 0;
int mask = 0b11111;
string result = "";
while (dataIndex < data.Length)
{
for (int i = 0; i < 3 && dataIndex < data.Length; i++)
{
buffer = buffer << 8;
buffer += data[dataIndex++];
bufferIndex += 8;
}
while (bufferIndex >= 5)
{
int offset = bufferIndex - 5;
result += map[(buffer & (mask << offset)) >> offset];
buffer = buffer & (~(mask << offset));
bufferIndex -= 5;
}
}
if (bufferIndex != 0)
{
int d = 5 - bufferIndex;
result += map[(buffer << d) & mask];
}
if (map.Padding != null)
{
while (result.Length % map.Quantum != 0)
{
result += map.Padding;
}
}
return(result);
}
public static byte[] Base32Decode(this string data, Base32Mapping mapping = Base32Mapping.NS6316)
{
return(mapping.Decode(data));
}
public static string Base32Encode(this byte[] data, Base32Mapping mapping = Base32Mapping.NS6316)
{
return(mapping.Encode(data));
}
