88 lines
1.8 KiB
Go
88 lines
1.8 KiB
Go
package accessbox
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import (
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"bufio"
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"bytes"
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"encoding/binary"
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"fmt"
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"io"
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"github.com/nspcc-dev/neofs-s3-gw/creds/hcs"
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"golang.org/x/crypto/chacha20poly1305"
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"golang.org/x/crypto/curve25519"
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)
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type decoder struct {
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*bufio.Reader
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key hcs.PrivateKey
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}
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// NewDecoder returns new private key decoder.
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func NewDecoder(r io.Reader, key hcs.PrivateKey) Decoder {
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return &decoder{Reader: bufio.NewReader(r), key: key}
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}
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func decrypt(owner hcs.PrivateKey, sender hcs.PublicKey, data []byte) ([]byte, error) {
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sb := sender.Bytes()
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key, err := curve25519.X25519(owner.Bytes(), sb)
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if err != nil {
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return nil, err
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}
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dec, err := chacha20poly1305.NewX(key)
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if err != nil {
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return nil, err
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}
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if ld, ns := len(data), dec.NonceSize(); ld < ns {
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return nil, fmt.Errorf("wrong data size (%d), should be greater than %d", ld, ns)
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}
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nonce, cypher := data[:dec.NonceSize()], data[dec.NonceSize():]
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return dec.Open(nil, nonce, cypher, nil)
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}
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func (d *decoder) Decode(box Box) error {
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sender, err := hcs.NewPublicKeyFromReader(d)
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if err != nil {
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return err
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}
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var lastErr error
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for {
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size, err := binary.ReadVarint(d)
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if err == io.EOF {
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break
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} else if err != nil {
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return err
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}
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data := make([]byte, size)
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if ln, err := d.Read(data); err != nil {
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lastErr = err
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continue
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} else if ln != int(size) {
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lastErr = fmt.Errorf("expect %d bytes, but read only %d bytes", size, ln)
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continue
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} else if decoded, err := decrypt(d.key, sender, data); err != nil {
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lastErr = err
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continue
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} else if err = box.Unmarshal(decoded); err != nil {
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lastErr = err
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continue
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}
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return nil
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}
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return lastErr
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}
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// Decode unwraps serialized bearer token from data into box using owner key.
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func Decode(data []byte, box Box, owner hcs.PrivateKey) error {
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return NewDecoder(bytes.NewBuffer(data), owner).Decode(box)
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}
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