Курнат Андрей
63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
package jwe
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import (
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"bytes"
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"compress/flate"
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"fmt"
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"io"
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"github.com/lestrrat-go/jwx/v3/internal/pool"
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)
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func uncompress(src []byte, maxBufferSize int64) ([]byte, error) {
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var dst bytes.Buffer
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r := flate.NewReader(bytes.NewReader(src))
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defer r.Close()
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var buf [16384]byte
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var sofar int64
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for {
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n, readErr := r.Read(buf[:])
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sofar += int64(n)
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if sofar > maxBufferSize {
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return nil, fmt.Errorf(`compressed payload exceeds maximum allowed size`)
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}
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if readErr != nil {
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// if we have a read error, and it's not EOF, then we need to stop
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if readErr != io.EOF {
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return nil, fmt.Errorf(`failed to read inflated data: %w`, readErr)
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}
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}
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if _, err := dst.Write(buf[:n]); err != nil {
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return nil, fmt.Errorf(`failed to write inflated data: %w`, err)
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}
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if readErr != nil {
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// if it got here, then readErr == io.EOF, we're done
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return dst.Bytes(), nil
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}
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}
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}
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func compress(plaintext []byte) ([]byte, error) {
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buf := pool.BytesBuffer().Get()
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defer pool.BytesBuffer().Put(buf)
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w, _ := flate.NewWriter(buf, 1)
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in := plaintext
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for len(in) > 0 {
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n, err := w.Write(in)
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if err != nil {
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return nil, fmt.Errorf(`failed to write to compression writer: %w`, err)
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}
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in = in[n:]
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}
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if err := w.Close(); err != nil {
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return nil, fmt.Errorf(`failed to close compression writer: %w`, err)
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}
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ret := make([]byte, buf.Len())
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copy(ret, buf.Bytes())
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return ret, nil
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}
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