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53 lines
987 B
Go
53 lines
987 B
Go
package shadowstream
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import (
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"crypto/cipher"
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"io"
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"github.com/nadoo/glider/pkg/pool"
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)
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const bufSize = 32 * 1024
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type writer struct {
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io.Writer
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cipher.Stream
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}
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// NewWriter wraps an io.Writer with stream cipher encryption.
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func NewWriter(w io.Writer, s cipher.Stream) io.Writer {
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return &writer{Writer: w, Stream: s}
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}
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func (w *writer) Write(p []byte) (n int, err error) {
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buf := pool.GetBuffer(bufSize)
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defer pool.PutBuffer(buf)
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for nw := 0; n < len(p) && err == nil; n += nw {
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end := min(n+len(buf), len(p))
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w.XORKeyStream(buf, p[n:end])
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nw, err = w.Writer.Write(buf[:end-n])
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}
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return
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}
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type reader struct {
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io.Reader
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cipher.Stream
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}
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// NewReader wraps an io.Reader with stream cipher decryption.
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func NewReader(r io.Reader, s cipher.Stream) io.Reader {
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return &reader{Reader: r, Stream: s}
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}
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func (r *reader) Read(p []byte) (int, error) {
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n, err := r.Reader.Read(p)
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if err != nil {
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return 0, err
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}
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p = p[:n]
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r.XORKeyStream(p, p)
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return n, nil
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}
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