42 lines
931 B
Go
42 lines
931 B
Go
package crypto
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import (
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"crypto/rc4"
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"encoding/binary"
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)
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type Ciphers struct {
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client *rc4.Cipher // For decryption (client->server)
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server *rc4.Cipher // For encryption (server->client)
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}
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// NewCiphers creates a new pair of RC4 ciphers for the client and server
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func NewCiphers(key int64) (*Ciphers, error) {
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keyBytes := make([]byte, 8)
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binary.LittleEndian.PutUint64(keyBytes, uint64(key))
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// Client cipher uses NOT of key
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clientKeyBytes := make([]byte, 8)
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binary.LittleEndian.PutUint64(clientKeyBytes, uint64(^key))
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clientCipher, err := rc4.NewCipher(keyBytes)
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if err != nil {
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return nil, err
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}
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serverCipher, err := rc4.NewCipher(clientKeyBytes)
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if err != nil {
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return nil, err
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}
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// Drop first 20 bytes from both ciphers
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drop := make([]byte, 20)
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clientCipher.XORKeyStream(drop, drop)
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serverCipher.XORKeyStream(drop, drop)
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return &Ciphers{
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client: clientCipher,
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server: serverCipher,
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}, nil
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}
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