public static byte[] EncryptMessage(byte[] key, byte[] nonce, byte[] message, ulong sessionID, out byte[] signature)
{
SMB2TransformHeader transformHeader = CreateTransformHeader(nonce, message.Length, sessionID);
byte[] associatedata = transformHeader.GetAssociatedData();
return(AesCcm.Encrypt(key, nonce, message, associatedata, SMB2TransformHeader.SignatureLength, out signature));
}
// Based on #1 test vector from https://docs.microsoft.com/en-us/archive/blogs/openspecification/encryption-in-smb-3-0-a-protocol-perspective
public void TestEncryption()
{
byte[] key = new byte[] { 0x26, 0x1B, 0x72, 0x35, 0x05, 0x58, 0xF2, 0xE9, 0xDC, 0xF6, 0x13, 0x07, 0x03, 0x83, 0xED, 0xBF };
byte[] nonce = new byte[] { 0x66, 0xE6, 0x9A, 0x11, 0x18, 0x92, 0x58, 0x4F, 0xB5, 0xED, 0x52 };
byte[] data = new byte[] { 0xFE, 0x53, 0x4D, 0x42, 0x40, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x09, 0x00, 0x40, 0x00,
0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0xFF, 0xFE, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x11, 0x00, 0x00, 0x14, 0x00, 0xE4, 0x08, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x31, 0x00, 0x70, 0x00, 0x17, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x15, 0x01, 0x00, 0x00, 0x39, 0x00, 0x00, 0x02, 0x01, 0x00, 0x00, 0x00, 0x39, 0x02, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x53, 0x6D, 0x62, 0x33, 0x20, 0x65, 0x6E, 0x63, 0x72, 0x79, 0x70, 0x74, 0x69, 0x6F, 0x6E, 0x20,
0x74, 0x65, 0x73, 0x74, 0x69, 0x6E, 0x67 };
byte[] associatedData = new byte[] { 0x66, 0xE6, 0x9A, 0x11, 0x18, 0x92, 0x58, 0x4F, 0xB5, 0xED, 0x52, 0x4A, 0x74, 0x4D, 0xA3, 0xEE,
0x87, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x11, 0x00, 0x00, 0x14, 0x00, 0xE4, 0x08, 0x00 };
byte[] expectedEncrypted = new byte[] { 0x25, 0xC8, 0xFE, 0xE1, 0x66, 0x05, 0xA4, 0x37, 0x83, 0x2D, 0x1C, 0xD5, 0x2D, 0xA9, 0xF4, 0x64,
0x53, 0x33, 0x48, 0x2A, 0x17, 0x5F, 0xE5, 0x38, 0x45, 0x63, 0xF4, 0x5F, 0xCD, 0xAF, 0xAE, 0xF3,
0x8B, 0xC6, 0x2B, 0xA4, 0xD5, 0xC6, 0x28, 0x97, 0x99, 0x66, 0x25, 0xA4, 0x4C, 0x29, 0xBE, 0x56,
0x58, 0xDE, 0x2E, 0x61, 0x17, 0x58, 0x57, 0x79, 0xE7, 0xB5, 0x9F, 0xFD, 0x97, 0x12, 0x78, 0xD0,
0x85, 0x80, 0xD7, 0xFA, 0x89, 0x9E, 0x41, 0x0E, 0x91, 0x0E, 0xAB, 0xF5, 0xAA, 0x1D, 0xB4, 0x30,
0x50, 0xB3, 0x3B, 0x49, 0x18, 0x26, 0x37, 0x75, 0x9A, 0xC1, 0x5D, 0x84, 0xBF, 0xCD, 0xF5, 0xB6,
0xB2, 0x38, 0x99, 0x3C, 0x0F, 0x4C, 0xF4, 0xD6, 0x01, 0x20, 0x23, 0xF6, 0xC6, 0x27, 0x29, 0x70,
0x75, 0xD8, 0x4B, 0x78, 0x03, 0x91, 0x2D, 0x0A, 0x96, 0x39, 0x63, 0x44, 0x53, 0x59, 0x5E, 0xF3,
0xE3, 0x3F, 0xFE, 0x4E, 0x7A, 0xC2, 0xAB };
byte[] expectedSignature = new byte[] { 0x81, 0xA2, 0x86, 0x53, 0x54, 0x15, 0x44, 0x5D, 0xAE, 0x39, 0x39, 0x21, 0xE4, 0x4F, 0xA4, 0x2E };
byte[] calculatedSignature;
byte[] encrypted = AesCcm.Encrypt(key, nonce, data, associatedData, 16, out calculatedSignature);
Assert.True(ByteUtils.AreByteArraysEqual(expectedEncrypted, encrypted));
Assert.True(ByteUtils.AreByteArraysEqual(expectedSignature, calculatedSignature));
}
static (byte[] CipherText, byte[] Tag) EncryptCCM(string text, byte[] key, byte[] nonce, byte[] associatedData = null)
{
var byteText = Encoding.ASCII.GetBytes(text);
var tag = new byte[16];
var cipherText = new byte[byteText.Length];
using var gcm = new AesCcm(key);
gcm.Encrypt(nonce, byteText, cipherText, tag, associatedData);
return(cipherText, tag);
}
public static void TwoEncryptionsAndDecryptionsUsingOneInstance()
{
byte[] key = "d5a194ed90cfe08abecd4691997ceb2c".HexToByteArray();
byte[] originalData1 = Enumerable.Range(1, 15).Select((x) => (byte)x).ToArray();
byte[] originalData2 = Enumerable.Range(14, 97).Select((x) => (byte)x).ToArray();
byte[] associatedData2 = Enumerable.Range(100, 109).Select((x) => (byte)x).ToArray();
byte[] nonce1 = "b41329dd64af2c3036661b46".HexToByteArray();
byte[] nonce2 = "8ba10892e8b87d031196".HexToByteArray();
byte[] expectedCiphertext1 = "58457f5939e029b99637c9aef266aa".HexToByteArray();
byte[] expectedTag1 = "ac5ccedc".HexToByteArray();
byte[] expectedCiphertext2 = (
"be4a5174fc244002d8614652d75cad9b464d86709cd9e8c58061add9a7546a1d" +
"8165b375011bd4d8e188d4d2782ae890aa7ddf335c9759267f813148903c47d1" +
"de0278c772dc2295bef9bba3bbfde319edbb54b71288c1fd1ddefb4a9b12534d" +
"15").HexToByteArray();
byte[] expectedTag2 = "f564b8439dc79ddf7aa1a497bc1f780e".HexToByteArray();
using (var aesCcm = new AesCcm(key))
{
byte[] ciphertext1 = new byte[originalData1.Length];
byte[] tag1 = new byte[expectedTag1.Length];
aesCcm.Encrypt(nonce1, originalData1, ciphertext1, tag1);
Assert.Equal(expectedCiphertext1, ciphertext1);
Assert.Equal(expectedTag1, tag1);
byte[] ciphertext2 = new byte[originalData2.Length];
byte[] tag2 = new byte[expectedTag2.Length];
aesCcm.Encrypt(nonce2, originalData2, ciphertext2, tag2, associatedData2);
Assert.Equal(expectedCiphertext2, ciphertext2);
Assert.Equal(expectedTag2, tag2);
byte[] plaintext1 = new byte[originalData1.Length];
aesCcm.Decrypt(nonce1, ciphertext1, tag1, plaintext1);
Assert.Equal(originalData1, plaintext1);
byte[] plaintext2 = new byte[originalData2.Length];
aesCcm.Decrypt(nonce2, ciphertext2, tag2, plaintext2, associatedData2);
Assert.Equal(originalData2, plaintext2);
}
}
public void Encrypt_throws_on_too_short_iv(int ivLength)
{
var key = new byte[16];
Exceptions.AssertThrowsInternalError(() => AesCcm.Encrypt(key: key,
plaintext: new byte[1],
iv: new byte[ivLength],
adata: new byte[0],
tagLength: 8),
"IV must be at least 7 bytes long");
}
public void Encrypt_throws_on_invalid_tag_length(int tagLength)
{
var key = new byte[16];
Exceptions.AssertThrowsInternalError(() => AesCcm.Encrypt(key: key,
plaintext: new byte[1],
iv: new byte[16],
adata: new byte[0],
tagLength: tagLength),
"Tag must be 4, 8, 10, 12, 14 or 16 bytes long");
}
/// <summary>
/// Encrypts or decrypts a byte array with the AES Counter with Cbc-Mac (CCM) mode.
/// Note that for this algorithm, encryption and decryption are identical. Decryption
/// consists of encrypting the encrypted byte array again with the same nonce
/// and key used during encryption.
/// </summary>
/// <param name="bytesToEncrypt">
/// The byte array that will get encrypted.
/// </param>
/// <param name="nonce">
/// The "number used only once" used during encryption.
/// </param>
/// <param name="key">The key used during encryption.</param>
/// <param name="tag">The tag generated during encryption.</param>
public static void AESCCMEncryptBytes(
byte[] bytesToEncrypt,
byte[] nonce,
byte[] key,
byte[] tag)
{
// Note that this passes the bytesToEncrypt as both the input and output array.
// This works, since AES-CTR XOR-s the input array with the encrypted counters,
// so this is equivalent to saying bytesToEncrypt[i + j] ^= encryptedCounter[j]
using AesCcm ccm = new AesCcm(key);
ccm.Encrypt(nonce, bytesToEncrypt, bytesToEncrypt, tag);
}
public static void EncryptDecryptNullTag()
{
byte[] key = "d5a194ed90cfe08abecd4691997ceb2c".HexToByteArray();
byte[] nonce = new byte[12];
byte[] plaintext = new byte[0];
byte[] ciphertext = new byte[0];
using (var aesCcm = new AesCcm(key))
{
Assert.Throws <ArgumentNullException>("tag", () => aesCcm.Encrypt(nonce, plaintext, ciphertext, (byte[])null));
Assert.Throws <ArgumentNullException>("tag", () => aesCcm.Decrypt(nonce, ciphertext, (byte[])null, plaintext));
}
}
public void Test_03_Encrypt_Example3_C3()
{
// §C.3
using (AesCcm AesCcm = new AesCcm(128, 64 / 8, 96 / 8))
{
byte[] Ciphertext = AesCcm.Encrypt(
new byte[] { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37 }, // P
new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13 }, // A
new byte[] { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b }, // N
new byte[] { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f }); // K
AssertEqual(new byte[] { 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a, 0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b, 0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5, 0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }, Ciphertext);
}
}
public void Test_02_Encrypt_Example2_C2()
{
// §C.2
using (AesCcm AesCcm = new AesCcm(128, 48 / 8, 64 / 8))
{
byte[] Ciphertext = AesCcm.Encrypt(
new byte[] { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f }, // P
new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }, // A
new byte[] { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 }, // N
new byte[] { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f }); // K
AssertEqual(new byte[] { 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62, 0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d, 0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd }, Ciphertext);
}
}
public void Test_01_Encrypt_Example1_C1()
{
// §C.1
using (AesCcm AesCcm = new AesCcm(128, 32 / 8, 56 / 8))
{
byte[] Ciphertext = AesCcm.Encrypt(
new byte[] { 0x20, 0x21, 0x22, 0x23 }, // P
new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 }, // A
new byte[] { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16 }, // N
new byte[] { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f }); // K
AssertEqual(new byte[] { 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d }, Ciphertext);
}
}
public static void PlaintextAndCiphertextSizeDiffer(int ptLen, int ctLen)
{
byte[] key = new byte[16];
byte[] nonce = new byte[12];
byte[] plaintext = new byte[ptLen];
byte[] ciphertext = new byte[ctLen];
byte[] tag = new byte[16];
using (var aesCcm = new AesCcm(key))
{
Assert.Throws <ArgumentException>(() => aesCcm.Encrypt(nonce, plaintext, ciphertext, tag));
Assert.Throws <ArgumentException>(() => aesCcm.Decrypt(nonce, ciphertext, tag, plaintext));
}
}
public static void AesCcmNistTests(AEADTest testCase)
{
using (var aesCcm = new AesCcm(testCase.Key))
{
byte[] ciphertext = new byte[testCase.Plaintext.Length];
byte[] tag = new byte[testCase.Tag.Length];
aesCcm.Encrypt(testCase.Nonce, testCase.Plaintext, ciphertext, tag, testCase.AssociatedData);
Assert.Equal(testCase.Ciphertext, ciphertext);
Assert.Equal(testCase.Tag, tag);
byte[] plaintext = new byte[testCase.Plaintext.Length];
aesCcm.Decrypt(testCase.Nonce, ciphertext, tag, plaintext, testCase.AssociatedData);
Assert.Equal(testCase.Plaintext, plaintext);
}
}
public static void InvalidNonceSize(int nonceSize)
{
int dataLength = 30;
byte[] plaintext = Enumerable.Range(1, dataLength).Select((x) => (byte)x).ToArray();
byte[] ciphertext = new byte[dataLength];
byte[] key = new byte[16];
byte[] nonce = new byte[nonceSize];
byte[] tag = new byte[AesCcm.TagByteSizes.MinSize];
RandomNumberGenerator.Fill(key);
RandomNumberGenerator.Fill(nonce);
using (var aesCcm = new AesCcm(key))
{
Assert.Throws<ArgumentException>("nonce", () => aesCcm.Encrypt(nonce, plaintext, ciphertext, tag));
}
}
public static void InplaceEncryptDecrypt()
{
byte[] key = "d5a194ed90cfe08abecd4691997ceb2c".HexToByteArray();
byte[] nonce = new byte[12];
byte[] originalPlaintext = new byte[] { 1, 2, 8, 12, 16, 99, 0 };
byte[] data = (byte[])originalPlaintext.Clone();
byte[] tag = new byte[16];
RandomNumberGenerator.Fill(nonce);
using (var aesCcm = new AesCcm(key))
{
aesCcm.Encrypt(nonce, data, data, tag);
Assert.NotEqual(originalPlaintext, data);
aesCcm.Decrypt(nonce, data, tag, data);
Assert.Equal(originalPlaintext, data);
}
}
public static void AesCcmNistTestsTamperCiphertext(AEADTest testCase)
{
using (var aesCcm = new AesCcm(testCase.Key))
{
byte[] ciphertext = new byte[testCase.Plaintext.Length];
byte[] tag = new byte[testCase.Tag.Length];
aesCcm.Encrypt(testCase.Nonce, testCase.Plaintext, ciphertext, tag, testCase.AssociatedData);
Assert.Equal(testCase.Ciphertext, ciphertext);
Assert.Equal(testCase.Tag, tag);
ciphertext[0] ^= 1;
byte[] plaintext = new byte[testCase.Plaintext.Length];
RandomNumberGenerator.Fill(plaintext);
Assert.Throws <CryptographicException>(
() => aesCcm.Decrypt(testCase.Nonce, ciphertext, tag, plaintext, testCase.AssociatedData));
Assert.Equal(new byte[plaintext.Length], plaintext);
}
}
public void TestEncryption_Rfc3610_Packet_Vector1()
{
byte[] key = { 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF };
byte[] nonce = { 0x00, 0x00, 0x00, 0x03, 0x02, 0x01, 0x00, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5 };
byte[] data = { 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E };
byte[] associatedData = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
byte[] expectedEncrypted = { 0x58, 0x8C, 0x97, 0x9A, 0x61, 0xC6, 0x63, 0xD2, 0xF0, 0x66, 0xD0, 0xC2, 0xC0, 0xF9, 0x89, 0x80,
0x6D, 0x5F, 0x6B, 0x61, 0xDA, 0xC3, 0x84 };
byte[] expectedSignature = { 0x17, 0xE8, 0xD1, 0x2C, 0xFD, 0xF9, 0x26, 0xE0 };
byte[] encrypted = AesCcm.Encrypt(key, nonce, data, associatedData, 8, out byte[] calculatedSignature);
Assert.True(ByteUtils.AreByteArraysEqual(expectedEncrypted, encrypted));
Assert.True(ByteUtils.AreByteArraysEqual(expectedSignature, calculatedSignature));
}
public static void ValidNonceSize(int nonceSize)
{
const int dataLength = 35;
byte[] plaintext = Enumerable.Range(1, dataLength).Select((x) => (byte)x).ToArray();
byte[] ciphertext = new byte[dataLength];
byte[] key = new byte[16];
byte[] nonce = new byte[nonceSize];
byte[] tag = new byte[AesCcm.TagByteSizes.MinSize];
RandomNumberGenerator.Fill(key);
RandomNumberGenerator.Fill(nonce);
using (var aesCcm = new AesCcm(key))
{
aesCcm.Encrypt(nonce, plaintext, ciphertext, tag);
byte[] decrypted = new byte[dataLength];
aesCcm.Decrypt(nonce, ciphertext, tag, decrypted);
Assert.Equal(plaintext, decrypted);
}
}
public static void InplaceEncryptTamperTagDecrypt()
{
byte[] key = "d5a194ed90cfe08abecd4691997ceb2c".HexToByteArray();
byte[] nonce = new byte[12];
byte[] originalPlaintext = new byte[] { 1, 2, 8, 12, 16, 99, 0 };
byte[] data = (byte[])originalPlaintext.Clone();
byte[] tag = new byte[16];
RandomNumberGenerator.Fill(nonce);
using (var aesCcm = new AesCcm(key))
{
aesCcm.Encrypt(nonce, data, data, tag);
Assert.NotEqual(originalPlaintext, data);
tag[0] ^= 1;
Assert.Throws <CryptographicException>(
() => aesCcm.Decrypt(nonce, data, tag, data));
Assert.Equal(new byte[data.Length], data);
}
}
public void Test_04_Encrypt_Example4_C4()
{
// §C.4
using (AesCcm AesCcm = new AesCcm(128, 112 / 8, 104 / 8))
{
byte[] AD = new byte[65536];
int i;
for (i = 0; i < 65536; i++)
{
AD[i] = (byte)i;
}
byte[] Ciphertext = AesCcm.Encrypt(
new byte[] { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f }, // P
AD, // A
new byte[] { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c }, // N
new byte[] { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f }); // K
AssertEqual(new byte[] { 0x69, 0x91, 0x5d, 0xad, 0x1e, 0x84, 0xc6, 0x37, 0x6a, 0x68, 0xc2, 0x96, 0x7e, 0x4d, 0xab, 0x61, 0x5a, 0xe0, 0xfd, 0x1f, 0xae, 0xc4, 0x4c, 0xc4, 0x84, 0x82, 0x85, 0x29, 0x46, 0x3c, 0xcf, 0x72, 0xb4, 0xac, 0x6b, 0xec, 0x93, 0xe8, 0x59, 0x8e, 0x7f, 0x0d, 0xad, 0xbc, 0xea, 0x5b }, Ciphertext);
}
}
public static void EncryptTamperAADDecrypt(int dataLength, int additionalDataLength)
{
byte[] additionalData = new byte[additionalDataLength];
RandomNumberGenerator.Fill(additionalData);
byte[] plaintext = Enumerable.Range(1, dataLength).Select((x) => (byte)x).ToArray();
byte[] ciphertext = new byte[dataLength];
byte[] key = new byte[16];
byte[] nonce = new byte[AesCcm.NonceByteSizes.MinSize];
byte[] tag = new byte[AesCcm.TagByteSizes.MinSize];
RandomNumberGenerator.Fill(key);
RandomNumberGenerator.Fill(nonce);
using (var aesCcm = new AesCcm(key))
{
aesCcm.Encrypt(nonce, plaintext, ciphertext, tag, additionalData);
additionalData[0] ^= 1;
byte[] decrypted = new byte[dataLength];
Assert.Throws <CryptographicException>(
() => aesCcm.Decrypt(nonce, ciphertext, tag, decrypted, additionalData));
}
}
private static Smb2EncryptedPacket Encrypt(ulong sessionId, Smb2CryptoInfo cryptoInfo, Smb2Role role, Smb2Packet packet, Smb2Packet packetBeforCompression)
{
Packet_Header header;
if (packetBeforCompression is Smb2SinglePacket)
{
header = (packetBeforCompression as Smb2SinglePacket).Header;
}
else if (packetBeforCompression is Smb2CompoundPacket)
{
header = (packetBeforCompression as Smb2CompoundPacket).Packets[0].Header;
}
else
{
throw new InvalidOperationException("Unsupported SMB2 packet type!");
}
// Encrypt all messages after session setup if global encryption enabled.
// Encrypt all messages after tree connect if global encryption disabled but share encryption enabled.
if ((cryptoInfo.EnableSessionEncryption ||
(cryptoInfo.EnableTreeEncryption.Contains(header.TreeId) &&
header.Command != Smb2Command.TREE_CONNECT
)
)
)
{
byte[] originalBinary = packet.ToBytes();
Transform_Header transformHeader = new Transform_Header
{
ProtocolId = Smb2Consts.ProtocolIdInTransformHeader,
OriginalMessageSize = (uint)originalBinary.Length,
SessionId = sessionId,
Signature = new byte[16]
};
if (cryptoInfo.Dialect == DialectRevision.Smb311)
{
transformHeader.Flags = TransformHeaderFlags.Encrypted;
}
else
{
transformHeader.EncryptionAlgorithm = EncryptionAlgorithm.ENCRYPTION_AES128_CCM;
}
byte[] encrypted = new byte[originalBinary.Length];
byte[] tag = new byte[16];
byte[] key = role == Smb2Role.Server ? cryptoInfo.ServerOutKey : cryptoInfo.ServerInKey;
// The reserved field (5 bytes for CCM, 4 bytes for GCM) must be set to zero.
byte[] nonce = new byte[16];
if (cryptoInfo.CipherId == EncryptionAlgorithm.ENCRYPTION_AES128_CCM)
{
int nonceLength = Smb2Consts.AES128CCM_Nonce_Length;
Buffer.BlockCopy(Guid.NewGuid().ToByteArray(), 0, nonce, 0, nonceLength);
transformHeader.Nonce = new Guid(nonce);
using (var cipher = new AesCcm(key))
{
cipher.Encrypt(
transformHeader.Nonce.ToByteArray().Take(nonceLength).ToArray(),
originalBinary,
encrypted,
tag,
// Use the fields including and after Nonce field as auth data
Smb2Utility.MarshalStructure(transformHeader).Skip(20).ToArray());
}
}
else if (cryptoInfo.CipherId == EncryptionAlgorithm.ENCRYPTION_AES128_GCM)
{
int nonceLength = Smb2Consts.AES128GCM_Nonce_Length;
Buffer.BlockCopy(Guid.NewGuid().ToByteArray(), 0, nonce, 0, nonceLength);
transformHeader.Nonce = new Guid(nonce);
using (var cipher = new AesGcm(key))
{
cipher.Encrypt(
transformHeader.Nonce.ToByteArray().Take(nonceLength).ToArray(),
originalBinary,
encrypted,
tag,
// Use the fields including and after Nonce field as auth data
Smb2Utility.MarshalStructure(transformHeader).Skip(20).ToArray());
}
}
else
{
throw new InvalidOperationException(String.Format(
"Invalid encryption algorithm is set in Smb2CryptoInfo when encrypting: {0}", cryptoInfo.CipherId));
}
transformHeader.Signature = tag;
var encryptedPacket = new Smb2EncryptedPacket();
encryptedPacket.Header = transformHeader;
encryptedPacket.EncryptdData = encrypted;
return(encryptedPacket);
}
// Return null if the message is not required to be encrypted.
return(null);
}
public void Encrypt_returns_correct_value(CcmTestCase tc)
{
var ciphertext = AesCcm.Encrypt(tc.Key, tc.Plaintext, tc.Iv, tc.Adata, tc.TagLength);
Assert.Equal(tc.Ciphertext, ciphertext);
}