45 lines
1.5 KiB
C#
45 lines
1.5 KiB
C#
using System.Collections.Generic;
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using Sodium;
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namespace chestcrypto{
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namespace symmetric{
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public class Symmetric{
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public static byte[] encrypt(byte[] plaintext, byte[] key){
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if (key.Length != 32){
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throw new exceptions.InvalidKeyLength();
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}
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List<byte> encrypted = new List<byte>();
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byte[] nonce = SecretBox.GenerateNonce();
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encrypted.AddRange(nonce);
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byte[] ciphertext = SecretBox.Create(plaintext, nonce, key);
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encrypted.AddRange(ciphertext);
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return encrypted.ToArray();
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}
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public static (byte[] ciphertext, byte[] key) encrypt(byte[] plaintext){
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byte[] key = SecretBox.GenerateKey();
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return (encrypt(plaintext, key), key);
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}
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public static byte[] decrypt(byte[] ciphertext, byte[] key){
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// Nonce is first 24 bytes of ciphertext, unencrypted (this is safe according to libsodium docs)
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int nonceSize = 24;
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byte[] nonce = new byte[nonceSize];
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List<byte> message = new List<byte>();
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for (int i = 0; i < ciphertext.Length; i++){
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if (i < nonceSize){
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nonce[i] = ciphertext[i];
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continue;
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}
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message.Add(ciphertext[i]);
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}
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return SecretBox.Open(message.ToArray(), nonce, key);
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}
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}
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}
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} |