Embed the data files needed for the ssh kitten into the Go binary

tools/utils/embed.go

@@ -0,0 +1,43 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package utils
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+var _ = fmt.Print
+
+func ReadAll(r io.Reader, expected_size int) ([]byte, error) {
+	b := make([]byte, 0, expected_size)
+	for {
+		if len(b) == cap(b) {
+			// Add more capacity (let append pick how much).
+			b = append(b, 0)[:len(b)]
+		}
+		n, err := r.Read(b[len(b):cap(b)])
+		b = b[:len(b)+n]
+		if err != nil {
+			if err == io.EOF {
+				err = nil
+			}
+			return b, err
+		}
+	}
+}
+
+func ReadCompressedEmbeddedData(raw string) []byte {
+	compressed := UnsafeStringToBytes(raw)
+	uncompressed_size := binary.LittleEndian.Uint32(compressed)
+	r, _ := zlib.NewReader(bytes.NewReader(compressed[4:]))
+	defer r.Close()
+	ans, err := ReadAll(r, int(uncompressed_size))
+	if err != nil {
+		panic(err)
+	}
+	return ans
+}