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crypto.go
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crypto.go
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package ecc
import (
"fmt"
"io"
"dev.shib.me/xipher/internal/xcp"
"golang.org/x/crypto/curve25519"
)
// NewEncryptingWriter returns a new WriteCloser that encrypts data with the public key and writes to dst.
func (publicKey *PublicKey) NewEncryptingWriter(dst io.Writer, compression bool) (io.WriteCloser, error) {
encrypter, err := publicKey.getEncrypter()
if err != nil {
return nil, err
}
if _, err = dst.Write(encrypter.ephPubKey); err != nil {
return nil, fmt.Errorf("%s: encrypter failed to write ephemeral public key: %w", "xipher", err)
}
return (*encrypter.cipher).NewEncryptingWriter(dst, compression)
}
// NewDecryptingReader returns a new ReadCloser that reads and decrypts data with the private key from src.
func (privateKey *PrivateKey) NewDecryptingReader(src io.Reader) (io.ReadCloser, error) {
ephPubKey := make([]byte, KeyLength)
if _, err := io.ReadFull(src, ephPubKey); err != nil {
return nil, fmt.Errorf("%s: decrypter failed to read ephemeral public key: %w", "xipher", err)
}
sharedKey, err := curve25519.X25519(*privateKey.key, ephPubKey)
if err != nil {
return nil, fmt.Errorf("%s: decrypter failed to generate shared key: %w", "xipher", err)
}
decrypter, err := xcp.New(sharedKey)
if err != nil {
return nil, err
}
return decrypter.NewDecryptingReader(src)
}