Fixed N4 calculation issue - see BJA-655

2 files changed, 50 insertions, 3 deletions

diff --git a/crypto/src/crypto/modes/GOFBBlockCipher.cs b/crypto/src/crypto/modes/GOFBBlockCipher.cs
index a91562549..4299f11a9 100644
--- a/crypto/src/crypto/modes/GOFBBlockCipher.cs
+++ b/crypto/src/crypto/modes/GOFBBlockCipher.cs
@@ -169,7 +169,11 @@ namespace Org.BouncyCastle.Crypto.Modes
 			}
 			N3 += C2;
 			N4 += C1;
-			intTobytes(N3, ofbV, 0);
+            if (N4 < C1)  // addition is mod (2**32 - 1)
+            {
+                N4++;
+            }
+            intTobytes(N3, ofbV, 0);
 			intTobytes(N4, ofbV, 4);
 
 			cipher.ProcessBlock(ofbV, 0, ofbOutV, 0);
diff --git a/crypto/test/src/crypto/test/GOST28147Test.cs b/crypto/test/src/crypto/test/GOST28147Test.cs
index 5b6753517..865dcc2a7 100644
--- a/crypto/test/src/crypto/test/GOST28147Test.cs
+++ b/crypto/test/src/crypto/test/GOST28147Test.cs
@@ -37,7 +37,19 @@ namespace Org.BouncyCastle.Crypto.Tests
 				0xF,0xE,0xD,0xC,0xB,0xA,0x9,0x8,0x7,0x6,0x5,0x4,0x3,0x2,0x1,0x0
 		};
 
-		static SimpleTest[] tests =
+        static byte[] TestSBox_1 =
+        {
+            0xE, 0x3, 0xC, 0xD, 0x1, 0xF, 0xA, 0x9, 0xB, 0x6, 0x2, 0x7, 0x5, 0x0, 0x8, 0x4,
+            0xD, 0x9, 0x0, 0x4, 0x7, 0x1, 0x3, 0xB, 0x6, 0xC, 0x2, 0xA, 0xF, 0xE, 0x5, 0x8,
+            0x8, 0xB, 0xA, 0x7, 0x1, 0xD, 0x5, 0xC, 0x6, 0x3, 0x9, 0x0, 0xF, 0xE, 0x2, 0x4,
+            0xD, 0x7, 0xC, 0x9, 0xF, 0x0, 0x5, 0x8, 0xA, 0x2, 0xB, 0x6, 0x4, 0x3, 0x1, 0xE,
+            0xB, 0x4, 0x6, 0x5, 0x0, 0xF, 0x1, 0xC, 0x9, 0xE, 0xD, 0x8, 0x3, 0x7, 0xA, 0x2,
+            0xD, 0xF, 0x9, 0x4, 0x2, 0xC, 0x5, 0xA, 0x6, 0x0, 0x3, 0x8, 0x7, 0xE, 0x1, 0xB,
+            0xF, 0xE, 0x9, 0x5, 0xB, 0x2, 0x1, 0x8, 0x6, 0x0, 0xD, 0x3, 0x4, 0x7, 0xC, 0xA,
+            0xA, 0x3, 0xE, 0x2, 0x0, 0x1, 0x4, 0x6, 0xB, 0x8, 0xC, 0x7, 0xD, 0x5, 0xF, 0x9
+        };
+
+        static SimpleTest[] tests =
 		{   new BlockCipherVectorTest(1, new Gost28147Engine(),
 				new KeyParameter(Hex.Decode("546d203368656c326973652073736e62206167796967747473656865202c3d73")),
 					input1, output1),
@@ -128,7 +140,38 @@ namespace Org.BouncyCastle.Crypto.Tests
 					Hex.Decode("1234567890abcdef")), //IV
 					"bc350e71aa11345709acde",  //input message
 					"1bcc2282707c676fb656dc"), //encrypt message
-
+            new BlockCipherVectorTest(15, new GOfbBlockCipher(new Gost28147Engine()),
+                new ParametersWithIV(
+                    new ParametersWithSBox(
+                        new KeyParameter(Hex.Decode("0A43145BA8B9E9FF0AEA67D3F26AD87854CED8D9017B3D33ED81301F90FDF993")), //key
+                        TestSBox_1), //type, IV, S-box
+                    Hex.Decode("8001069080010690")),
+                "094C912C5EFDD703D42118971694580B", //input message
+                "2707B58DF039D1A64460735FFE76D55F"), //encrypt message
+            new BlockCipherVectorTest(16, new GOfbBlockCipher(new Gost28147Engine()),
+                new ParametersWithIV(
+                    new ParametersWithSBox(
+                        new KeyParameter(Hex.Decode("0A43145BA8B9E9FF0AEA67D3F26AD87854CED8D9017B3D33ED81301F90FDF993")), //key
+                        TestSBox_1), //type, S-box
+                        Hex.Decode("800107A0800107A0")),
+                "FE780800E0690083F20C010CF00C0329", //input message
+                "9AF623DFF948B413B53171E8D546188D"), //encrypt message
+            new BlockCipherVectorTest(17, new GOfbBlockCipher(new Gost28147Engine()),
+                new ParametersWithIV(
+                    new ParametersWithSBox(
+                        new KeyParameter(Hex.Decode("0A43145BA8B9E9FF0AEA67D3F26AD87854CED8D9017B3D33ED81301F90FDF993")), //key
+                        TestSBox_1), //type, S-box
+                        Hex.Decode("8001114080011140")),
+                "D1088FD8C0A86EE8F1DCD1088FE8C058", //input message
+                "62A6B64D12253BCD8241A4BB0CFD3E7C"), //encrypt message
+            new BlockCipherVectorTest(18, new GOfbBlockCipher(new Gost28147Engine()),
+                new ParametersWithIV(
+                    new ParametersWithSBox(
+                        new KeyParameter(Hex.Decode("0A43145BA8B9E9FF0AEA67D3F26AD87854CED8D9017B3D33ED81301F90FDF993")), //key
+                        TestSBox_1), //type, IV, S-box
+                        Hex.Decode("80011A3080011A30")),
+                "D431FACD011C502C501B500A12921090", //input message
+                "07313C89D302FF73234B4A0506AB00F3"), //encrypt message
 		};
 
 		private const int Gost28147_KEY_LENGTH = 32;