69 lines
1.7 KiB
Go
69 lines
1.7 KiB
Go
package server
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import (
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"crypto/cipher"
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"crypto/rand"
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"fmt"
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"net"
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"github.com/ProtonMail/gopenpgp/v3/crypto"
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)
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func (bismuth BismuthServer) encryptMessage(aead cipher.AEAD, msg []byte) ([]byte, error) {
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nonce := make([]byte, aead.NonceSize(), aead.NonceSize()+len(msg)+aead.Overhead())
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if _, err := rand.Read(nonce); err != nil {
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return []byte{}, err
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}
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encryptedMsg := aead.Seal(nonce, nonce, msg, nil)
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return encryptedMsg, nil
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}
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func (bismuth BismuthServer) decryptMessage(aead cipher.AEAD, encMsg []byte) ([]byte, error) {
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if len(encMsg) < aead.NonceSize() {
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return []byte{}, fmt.Errorf("ciphertext too short")
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}
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// Split nonce and ciphertext.
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nonce, ciphertext := encMsg[:aead.NonceSize()], encMsg[aead.NonceSize():]
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// Decrypt the message and check it wasn't tampered with.
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decryptedData, err := aead.Open(nil, nonce, ciphertext, nil)
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if err != nil {
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return []byte{}, err
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}
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return decryptedData, nil
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}
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// Initializes a Bismuth server.
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//
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// Both `pubKey` and `privKey` are armored PGP public and private keys respectively.
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func NewBismuthServer(pubKey string, privKey string, signServers []string, encryptionAlgo int, connHandler func(conn net.Conn) error) (*BismuthServer, error) {
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publicKey, err := crypto.NewKeyFromArmored(pubKey)
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if err != nil {
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return nil, err
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}
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privateKey, err := crypto.NewKeyFromArmored(privKey)
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if err != nil {
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return nil, err
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}
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pgp := crypto.PGP()
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bismuth := BismuthServer{
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PublicKey: publicKey,
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PrivateKey: privateKey,
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HandleConnection: connHandler,
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SigningServers: signServers,
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SymmetricEncryptionAlgorithm: encryptionAlgo,
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pgp: pgp,
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}
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return &bismuth, nil
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}
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