Initial commit

application/commands/string.go

@@ -0,0 +1,103 @@
+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package commands
+
+import (
+	"errors"
+
+	"github.com/niruix/sshwifty/application/rw"
+)
+
+// Errors
+var (
+	ErrStringParseBufferTooSmall = errors.New(
+		"Not enough buffer space to parse given string")
+
+	ErrStringMarshalBufferTooSmall = errors.New(
+		"Not enough buffer space to marshal given string")
+)
+
+// String data
+type String struct {
+	len  Integer
+	data []byte
+}
+
+// ParseString build the String according to readed data
+func ParseString(reader rw.ReaderFunc, b []byte) (String, error) {
+	lenData := Integer(0)
+
+	mErr := lenData.Unmarshal(reader)
+
+	if mErr != nil {
+		return String{}, mErr
+	}
+
+	bLen := len(b)
+
+	if bLen < lenData.Int() {
+		return String{}, ErrStringParseBufferTooSmall
+	}
+
+	_, rErr := rw.ReadFull(reader, b[:lenData])
+
+	if rErr != nil {
+		return String{}, rErr
+	}
+
+	return String{
+		len:  lenData,
+		data: b[:lenData],
+	}, nil
+}
+
+// NewString create a new String
+func NewString(d []byte) String {
+	dLen := len(d)
+
+	if dLen > MaxInteger {
+		panic("Data was too long for a String")
+	}
+
+	return String{
+		len:  Integer(dLen),
+		data: d,
+	}
+}
+
+// Data returns the data of the string
+func (s String) Data() []byte {
+	return s.data
+}
+
+// Marshal the string to give buffer
+func (s String) Marshal(b []byte) (int, error) {
+	bLen := len(b)
+
+	if bLen < s.len.ByteSize()+len(s.data) {
+		return 0, ErrStringMarshalBufferTooSmall
+	}
+
+	mLen, mErr := s.len.Marshal(b)
+
+	if mErr != nil {
+		return 0, mErr
+	}
+
+	return copy(b[mLen:], s.data) + mLen, nil
+}