git-secure-export

 1package cmd
 2
 3import (
 4	"bufio"
 5	"bytes"
 6	"fmt"
 7	"io"
 8)
 9
10type CryptFn func(in io.Reader, inLen int64, out io.Writer) (int, error)
11
12func Handle(in io.Reader, out io.Writer, fn CryptFn) error {
13	reader := bufio.NewReader(in)
14	for {
15		line, err := reader.ReadString('\n')
16		if err != nil {
17			if err == io.EOF {
18				break
19			}
20			return err
21		}
22
23		var numBytes uint
24		n, _ := fmt.Sscanf(line, "data %d\n", &numBytes)
25		if n != 1 || numBytes == 0 {
26			fmt.Fprint(out, line)
27			continue
28		}
29
30		writer := bytes.NewBuffer(nil)
31		n, err = fn(reader, int64(numBytes), writer)
32		if err != nil {
33			return err
34		}
35
36		fmt.Fprintf(out, "data %d\n", n)
37		_, err = writer.WriteTo(out)
38		if err != nil {
39			return err
40		}
41	}
42
43	return nil
44}