Esempio n. 1
0
        private Node TryParseEPasaInternal(TokenType expectedToken, TextReader reader, ref EPasaErrorCode error, string prefix = null, string postFix = null)
        {
            Node result = null;

            if (error != EPasaErrorCode.Success)
            {
                return(null);
            }

            if (prefix != null)
            {
                foreach (var prefixChar in prefix)
                {
                    if (!reader.MatchChar(prefixChar))
                    {
                        error = EPasaErrorCode.BadFormat;
                        return(null);
                    }
                }
            }

            switch (expectedToken)
            {
            case TokenType.EPASA:
                result = new EPasaNode {
                    Type             = TokenType.EPASA,
                    Account          = TryParseEPasaInternal(TokenType.PASA, reader, ref error) as AccountNode,
                    Payload          = TryParseEPasaInternal(TokenType.Payload, reader, ref error) as PayloadNode,
                    ExtendedChecksum = TryParseEPasaInternal(TokenType.ExtendedChecksum, reader, ref error) as ValueNode
                };
                if (!reader.MatchChar(null as char?))
                {
                    // match end-of-string
                    error = EPasaErrorCode.BadFormat;
                    return(null);
                }
                break;

            case TokenType.PASA:
                if (IsStartChar(TokenType.AccountNumber, reader.PeekChar()))
                {
                    result = TryParseEPasaInternal(TokenType.AccountNumber, reader, ref error);
                }
                else if (IsStartChar(TokenType.AccountName, reader.PeekChar()))
                {
                    result = TryParseEPasaInternal(TokenType.AccountName, reader, ref error);
                }
                else
                {
                    error = EPasaErrorCode.InvalidAccountNumber;
                }
                break;

            case TokenType.AccountName:
                result = new AccountNode {
                    Type = TokenType.AccountName,
                    Name = TryParseEPasaInternal(TokenType.Pascal64String, reader, ref error) as ValueNode
                };
                break;

            case TokenType.AccountNumber:
                result = new AccountNode {
                    Type      = TokenType.AccountNumber,
                    AccountNo = TryParseEPasaInternal(TokenType.Number, reader, ref error) as ValueNode,
                    Checksum  = TryParseEPasaInternal(TokenType.Checksum, reader, ref error) as ValueNode
                };
                break;

            case TokenType.Checksum:
                if (IsStartChar(TokenType.Checksum, reader.PeekChar()))
                {
                    result = TryParseEPasaInternal(TokenType.Number, reader, ref error, prefix: "-") as ValueNode;
                }
                break;

            case TokenType.Payload:
                if (IsStartChar(TokenType.Payload, reader.PeekChar()))
                {
                    result = new PayloadNode {
                        Type = TokenType.Payload
                    };
                    var payloadOpenChar = reader.ReadChar();
                    ((PayloadNode)result).Content = TryParseEPasaInternal(TokenType.PayloadContent, reader, ref error) as ValueNode;
                    if (reader.PeekChar() == ':')
                    {
                        if (payloadOpenChar != '{')
                        {
                            error = EPasaErrorCode.UnusedPassword;
                            return(result);
                        }
                        ((PayloadNode)result).Password = TryParseEPasaInternal(TokenType.PascalAsciiString, reader, ref error, prefix: ":") as ValueNode;
                    }
                    else if (payloadOpenChar == '{')
                    {
                        error = EPasaErrorCode.MissingPassword;
                        return(null);
                    }
                    var payloadEndChar = reader.PeekChar();
                    if (!payloadEndChar.IsIn(']', ')', '>', '}'))
                    {
                        error = EPasaErrorCode.BadFormat;
                        return(null);
                    }
                    char?expectedEndChar = null;
                    switch (payloadOpenChar)
                    {
                    case '[':
                        ((PayloadNode)result).Encryption = PayloadType.Public;
                        expectedEndChar = ']';
                        break;

                    case '(':
                        ((PayloadNode)result).Encryption = PayloadType.RecipientKeyEncrypted;
                        expectedEndChar = ')';
                        break;

                    case '<':
                        ((PayloadNode)result).Encryption = PayloadType.SenderKeyEncrypted;
                        expectedEndChar = '>';
                        break;

                    case '{':
                        ((PayloadNode)result).Encryption = PayloadType.PasswordEncrypted;
                        expectedEndChar = '}';
                        break;

                    default:
                        throw new InternalErrorException("Implementation Error");
                    }
                    if (reader.PeekChar() != expectedEndChar)
                    {
                        error = EPasaErrorCode.MismatchedPayloadEncoding;
                        return(null);
                    }

                    if (!reader.MatchChar(']', ')', '>', '}'))
                    {
                        error = EPasaErrorCode.BadFormat;
                        return(null);
                    }
                }
                break;

            case TokenType.PayloadContent:
                var contentStartChar = reader.PeekChar();
                if (contentStartChar == '"')
                {
                    result = TryParseEPasaInternal(TokenType.PascalAsciiString, reader, ref error, prefix: "\"", postFix: "\"") as ValueNode;
                }
                else if (IsStartChar(TokenType.HexString, contentStartChar))
                {
                    result = TryParseEPasaInternal(TokenType.HexString, reader, ref error, prefix: "0x") as ValueNode;
                }
                else if (IsStartChar(TokenType.Base58String, contentStartChar))
                {
                    result = TryParseEPasaInternal(TokenType.Base58String, reader, ref error) as ValueNode;
                }
                else
                {
                    // unrecognized content, assume empty
                }
                break;

            case TokenType.ExtendedChecksum:
                if (reader.PeekChar() == ':')
                {
                    result = TryParseEPasaInternal(TokenType.HexString, reader, ref error, prefix: ":") as ValueNode;
                }
                break;

            case TokenType.PascalAsciiString:
            case TokenType.Pascal64String:
                result = new ValueNode {
                    Type  = expectedToken,
                    Value = string.Empty
                };
                if (!IsStartChar(expectedToken, reader.PeekChar()))
                {
                    // first character is a non-character, assume empty string
                    return(result);
                }
                var escapedValue = string.Empty;
                do
                {
                    if (reader.PeekChar() == GetEscapeChar(expectedToken))
                    {
                        escapedValue += reader.ReadChar();
                        if (!IsEscapedChar(expectedToken, reader.PeekChar()))
                        {
                            error = EPasaErrorCode.BadFormat;                                     // illegal escape sequence
                            return(result);
                        }
                    }
                    else if (IsEscapedChar(expectedToken, reader.PeekChar()))
                    {
                        // encountered a character that needs escaping
                        // assume end of token
                        break;
                    }
                    escapedValue += reader.ReadChar();
                } while (IsValidValueChar(expectedToken, reader.PeekChar()));
                ((ValueNode)result).Value = escapedValue;
                break;

            case TokenType.HexString:
            case TokenType.Base58String:
            case TokenType.Number:
                result = new ValueNode {
                    Type  = expectedToken,
                    Value = string.Empty
                };
                while (IsValidValueChar(expectedToken, reader.PeekChar()))
                {
                    ((ValueNode)result).Value = ((ValueNode)result).Value + reader.ReadChar();
                }
                break;

            default:
                throw new ArgumentOutOfRangeException(nameof(expectedToken), expectedToken, null);
            }
            if (error == EPasaErrorCode.Success && postFix != null)
            {
                foreach (var postfixChar in postFix)
                {
                    if (!reader.MatchChar(postfixChar))
                    {
                        error = EPasaErrorCode.BadFormat;
                        return(null);
                    }
                }
            }
            return(result);
        }
Esempio n. 2
0
        private EPasaErrorCode TryCompile(EPasaNode epasaNode, EPasa epasa)
        {
            EPasaErrorCode TryCompileAccount(AccountNode accountNode)
            {
                switch (accountNode.Type)
                {
                case TokenType.AccountName:
                    if (!Pascal64Encoding.IsValidEscaped(accountNode.Name.Value))
                    {
                        return(EPasaErrorCode.InvalidAccountName);
                    }
                    epasa.AccountName = Pascal64Encoding.Unescape(accountNode.Name.Value);
                    epasa.PayloadType = epasa.PayloadType.SetFlags(PayloadType.AddressedByName);
                    break;

                case TokenType.AccountNumber:
                    if (!uint.TryParse(accountNode.AccountNo.Value, out var accNo))
                    {
                        return(EPasaErrorCode.BadFormat);
                    }
                    if (accountNode.AccountNo.Value.StartsWith("0") && accNo != 0)
                    {
                        return(EPasaErrorCode.BadFormat);
                    }
                    epasa.Account = accNo;
                    var actualChecksum = AccountHelper.CalculateAccountChecksum(accNo);
                    if (accountNode.Checksum != null)
                    {
                        if (!uint.TryParse(accountNode.Checksum.Value, out var checksum))
                        {
                            return(EPasaErrorCode.BadFormat);
                        }
                        if (checksum != actualChecksum)
                        {
                            return(EPasaErrorCode.AccountChecksumInvalid);
                        }
                    }
                    epasa.AccountChecksum = actualChecksum;
                    break;

                default:
                    throw new ArgumentOutOfRangeException(nameof(accountNode));
                }
                return(EPasaErrorCode.Success);
            }

            EPasaErrorCode TryCompilePayload(PayloadNode payloadNode)
            {
                epasa.PayloadType = epasa.PayloadType | payloadNode.Encryption;
                if (payloadNode.Content != null)
                {
                    switch (payloadNode.Content.Type)
                    {
                    case TokenType.PascalAsciiString:
                        epasa.PayloadType = epasa.PayloadType | PayloadType.AsciiFormatted;
                        epasa.Payload     = PascalAsciiEncoding.Unescape(payloadNode.Content.Value);
                        break;

                    case TokenType.Base58String:
                        epasa.PayloadType = epasa.PayloadType | PayloadType.Base58Formatted;
                        epasa.Payload     = payloadNode.Content.Value;
                        break;

                    case TokenType.HexString:
                        epasa.PayloadType = epasa.PayloadType | PayloadType.HexFormatted;
                        epasa.Payload     = payloadNode.Content.Value;
                        break;

                    default:
                        throw new ArgumentOutOfRangeException(nameof(payloadNode.Content.Type));
                    }
                    if (!EPasaHelper.IsValidPayloadLength(epasa.PayloadType, epasa.Payload))
                    {
                        return(EPasaErrorCode.PayloadTooLarge);
                    }
                }
                if (payloadNode.Password != null)
                {
                    if (!EPasaHelper.IsValidPasswordLength(payloadNode.Password.Value))
                    {
                        return(EPasaErrorCode.InvalidPassword);
                    }
                    epasa.Password = PascalAsciiEncoding.Unescape(payloadNode.Password.Value);
                }
                return(EPasaErrorCode.Success);
            }

            EPasaErrorCode TryCompileExtendedChecksum(ValueNode extendedChecksumNode)
            {
                var actualExtendedChecksum = EPasaHelper.ComputeExtendedChecksum(epasa.ToString(true));

                if (extendedChecksumNode != null && extendedChecksumNode.Value != actualExtendedChecksum)
                {
                    return(EPasaErrorCode.AccountChecksumInvalid);
                }
                epasa.ExtendedChecksum = actualExtendedChecksum;
                return(EPasaErrorCode.Success);
            }

            var result = TryCompileAccount(epasaNode.Account);

            if (result != EPasaErrorCode.Success)
            {
                return(result);
            }
            if (epasaNode.Payload != null)
            {
                result = TryCompilePayload(epasaNode.Payload);
                if (result != EPasaErrorCode.Success)
                {
                    return(result);
                }
            }
            result = TryCompileExtendedChecksum(epasaNode.ExtendedChecksum);
            if (result != EPasaErrorCode.Success)
            {
                return(result);
            }

            return(result);
        }