KeysFromAddress(string address, ulong prefix)
{
/* Split into chunks of 11 */
List <List <char> > chunks = address.ToList().ChunkBy(11);
List <byte> decoded = new List <byte>();
foreach (List <char> chunk in chunks)
{
List <byte> decodedChunk;
try
{
/* Convert char list to string, and decode from base58 */
decodedChunk = new List <byte>(
Base58.Decode(string.Concat(chunk))
);
}
/* Contains non base58 characters */
catch (FormatException)
{
return(Either.Left <Error, PublicKeys>(
Error.AddressNotBase58()
));
}
/* Only take last 8 bytes, any more in a chunk are padding
* from the base58 convert. Remember we pad the beginning
* of a chunk, so we need to take the last 8 bytes, not the
* first 8 bytes. */
decoded.AddRange(decodedChunk.TakeLast(8));
}
byte[] expectedPrefix = PackPrefixAsByteList(prefix).ToArray();
/* Prefix length + spend key length + view key length
+ checksum length */
int expectedLength = expectedPrefix.Length + 32 + 32 + 4;
if (decoded.Count != expectedLength)
{
return(Either.Left <Error, PublicKeys>(
Error.AddressWrongLength()
));
}
byte[] actualPrefix = new byte[expectedPrefix.Length];
byte[] spendKeyData = new byte[32];
byte[] viewKeyData = new byte[32];
byte[] actualChecksum = new byte[4];
int i = 0;
for (int j = 0; j < expectedPrefix.Length; j++)
{
actualPrefix[j] = decoded[i++];
}
for (int j = 0; j < spendKeyData.Length; j++)
{
spendKeyData[j] = decoded[i++];
}
for (int j = 0; j < viewKeyData.Length; j++)
{
viewKeyData[j] = decoded[i++];
}
for (int j = 0; j < actualChecksum.Length; j++)
{
actualChecksum[j] = decoded[i++];
}
/* Sanity checking */
for (int j = 0; j < expectedPrefix.Length; j++)
{
/* We already know the lengths are the same so won't go out
* of bounds */
if (actualPrefix[j] != expectedPrefix[j])
{
return(Either.Left <Error, PublicKeys>(
Error.AddressWrongPrefix()
));
}
}
List <byte> addressNoChecksum = new List <byte>();
addressNoChecksum.AddRange(actualPrefix);
addressNoChecksum.AddRange(spendKeyData);
addressNoChecksum.AddRange(viewKeyData);
byte[] expectedChecksum = GetAddressChecksum(addressNoChecksum);
for (int j = 0; j < expectedChecksum.Length; j++)
{
if (actualChecksum[j] != expectedChecksum[j])
{
return(Either.Left <Error, PublicKeys>(
Error.AddressWrongChecksum()
));
}
}
var spendKey = new PublicKey(spendKeyData);
var viewKey = new PublicKey(viewKeyData);
if (!KeyOps.IsValidKey(spendKey) || !KeyOps.IsValidKey(viewKey))
{
return(Either.Left <Error, PublicKeys>(
Error.InvalidPublicKey()
));
}
return(Either.Right <Error, PublicKeys>(
new PublicKeys(spendKey, viewKey)
));
}