Java 解密TLS 1.2 AES-GCM数据包
我正在开发一个Java程序来解密一个TLS1.2会话,该会话使用Java 解密TLS 1.2 AES-GCM数据包,java,ssl,encryption,bouncycastle,aes-gcm,Java,Ssl,Encryption,Bouncycastle,Aes Gcm,我正在开发一个Java程序来解密一个TLS1.2会话,该会话使用TLS\u RSA\u和\u AES\u 128\u GCM\u SHA256密码。我用wireshark录制了一个测试会话。主秘密已为人所知 No. Time Protocol Length Info 4 0.000124000 TLSv1.2 166 Client Hello 6 0.000202000 TLSv1.2 1074 Server Hell
TLS\u RSA\u和\u AES\u 128\u GCM\u SHA256
密码。我用wireshark录制了一个测试会话。主秘密已为人所知
No. Time Protocol Length Info
4 0.000124000 TLSv1.2 166 Client Hello
6 0.000202000 TLSv1.2 1074 Server Hello, Certificate, Server Hello Done
8 0.001071000 TLSv1.2 393 Client Key Exchange, Change Cipher Spec, Finished
9 0.003714000 TLSv1.2 301 New Session Ticket, Change Cipher Spec, Finished
11 6.443056000 TLSv1.2 116 Application Data
12 6.443245000 TLSv1.2 765 Application Data
15 6.443390000 TLSv1.2 103 Alert (Level: Warning, Description: Close Notify)
数据包11
包含一个我正试图解密的HTTP GET请求
握手数据:
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
数据包11数据:
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
到目前为止我所做的:
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
密钥派生:
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
这里我只需要客户端密钥,因为我想解密一个Client->Server包。我根据RFC扩展了服务器和客户端密钥和IVs。
客户端写入密钥:4B119DFBFC930ABE1300BD53C3BF78
客户写入IV:2029CAE2
Nonce:
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
我从salt(=客户端写入IV)和显式nonce(=加密数据的前8字节)创建AES-GCM nonce。
盐:2029CAE2
明确一次:C91DE005E2AE50A8
暂时:2029CAE2C91DE005E2AE50A8
附加身份验证数据(AAD):
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
这就是我被卡住的地方。RFC5246说明:
附加数据=序号+TLSCompressed.type+
TLSCompressed.version+TLSCompressed.length;
其中“+”表示串联
所以我做了这个:
byte[] aad = {0, 0, 0, 0, 0, 0, 0, 1, // seq_no uint64
0x17, // type 0x17 = Application Data
0x03, 0x03, // TLS Version 1.2
0, 45}; // 45 Bytes of encrypted data
我认为序号是1。当发送Change Cipher Spec
记录时,它被重置为零。(Packet#8
)则加密的完成的记录具有序号=0
。下一个客户端数据包是我们的数据包#11
,带有序号=1
代码:
Cipher: TLS_RSA_WITH_AES_128_GCM_SHA256
Client Random: 375f5632ba9075b88dd83eeeed4adb427d4011298efb79fb2bf78f4a4b7d9d95
Server Random: 5a1b3957e3bd1644e7083e25c64f137ed2803b680e43395a82e5b302b64ba763
Master Secret: 2FB179AB70CD4CA2C1285B4B1E294F8F44B7E8DA26B62D00EE35181575EAB04C
4FA11C0DA3ABABB4AF8D09ACB4CCC3CD
Direction is Client -> Server.
Secure Sockets Layer
TLSv1.2 Record Layer: Application Data Protocol: Application Data
Content Type: Application Data (23)
Version: TLS 1.2 (0x0303)
Length: 45
Encrypted Application Data: c91de005e2ae50a8a57abee55c183667b136343feef4a387cb7cf83030a47e230af268378c4f33c8b5bab3d26d
现在我把所有东西都放进BouncyCastle:
AEADParameters parameters = new AEADParameters(new KeyParameter(clientWriteKey), 128, nonce, aad);
GCMBlockCipher gcmBlockCipher = new GCMBlockCipher(new AESFastEngine());
gcmBlockCipher.init(false, parameters);
byte[] plainText = new byte[gcmBlockCipher.getOutputSize(cipherText.length)];
try {
int decLen = gcmBlockCipher.processBytes(cipherText, 0, cipherText.length, plainText, 0);
decLen += gcmBlockCipher.doFinal(plainText, decLen);
} catch (InvalidCipherTextException e) {
System.out.println("MAC failed: " + e.getMessage());
}
这总是抛出MAC失败:GCM中的MAC检查失败但是解密的输出是正确的:
byte[] decomp = decompress(plainText);
System.out.println(new String(decomp, "UTF-8"));
这将打印GET/HTTP/1.0\n
解压缩帮助程序:
public static byte[] decompress(byte[] data) throws IOException, DataFormatException {
Inflater inflater = new Inflater(true);
inflater.setInput(data);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream(data.length);
byte[] buffer = new byte[1024];
while (inflater.getRemaining() > 0) {
int count = inflater.inflate(buffer);
outputStream.write(buffer, 0, count);
}
outputStream.close();
byte[] output = outputStream.toByteArray();
inflater.end();
return output;
}
结论:
由于解密的输出是正确的,我可以安全地假设密钥派生和解密工作正常。只有身份验证失败。所以我想我可能在附加身份验证数据(AAD)方面做错了什么。
所以这个问题可以归结为:
附加身份验证数据(AAD)是如何正确组装的?
谢谢大家! GCM模式根据消息、相关数据和公共时态计算MAC,您已经很好地介绍了它
我认为您使用了错误的长度,在加密和附加MAC之前应该是明文长度。尝试45-8(显式nonce)-16(MAC)=21