Fix SEED cryptography algorithm

Fix SEED cryptography algorithm

WelsonJS.Toolkit/WelsonJS.Cryptography.Test/Program.vb

@@ -23,6 +23,9 @@ Module Program
     Public Sub RunTest(cipher As SymmetricAlgorithm)
         Dim inputBytes As Byte() = {&H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0, &HFE}
 
+        Console.WriteLine("Key (HEX):")
+        PrintHex(cipher.Key)
+
         Console.WriteLine("Original bytes (HEX):")
         PrintHex(inputBytes)
 

WelsonJS.Toolkit/WelsonJS.Cryptography/SeedCore.vb

@@ -156,11 +156,21 @@ Public Class SeedCore
         KeySchedule(key)
     End Sub
 
-    ' Extract a byte (0 = LSB, 3 = MSB)
     Private Shared Function GetByte(n As UInteger, index As Integer) As Byte
         Return CByte((n >> (index * 8)) And &HFF)
     End Function
 
+    Private Shared Function ToUInt32BE(data() As Byte, offset As Integer) As UInteger
+        Return (CUInt(data(offset)) << 24) Or (CUInt(data(offset + 1)) << 16) Or (CUInt(data(offset + 2)) << 8) Or CUInt(data(offset + 3))
+    End Function
+
+    Private Shared Sub WriteUInt32BE(value As UInteger, output() As Byte, offset As Integer)
+        output(offset) = CByte((value >> 24) And &HFF)
+        output(offset + 1) = CByte((value >> 16) And &HFF)
+        output(offset + 2) = CByte((value >> 8) And &HFF)
+        output(offset + 3) = CByte(value And &HFF)
+    End Sub
+
     Private Shared Function RoundFunction(T0 As UInteger, T1 As UInteger) As Tuple(Of UInteger, UInteger)
         T1 = T1 Xor T0
         T1 = SS0(GetByte(T1, 0)) Xor SS1(GetByte(T1, 1)) Xor SS2(GetByte(T1, 2)) Xor SS3(GetByte(T1, 3))
@@ -173,10 +183,10 @@ Public Class SeedCore
     End Function
 
     Private Sub KeySchedule(userKey As Byte())
-        Dim A As UInteger = BitConverter.ToUInt32(userKey, 0)
+        Dim A As UInteger = ToUInt32BE(userKey, 0)
-        Dim B As UInteger = BitConverter.ToUInt32(userKey, 4)
+        Dim B As UInteger = ToUInt32BE(userKey, 4)
-        Dim C As UInteger = BitConverter.ToUInt32(userKey, 8)
+        Dim C As UInteger = ToUInt32BE(userKey, 8)
-        Dim D As UInteger = BitConverter.ToUInt32(userKey, 12)
+        Dim D As UInteger = ToUInt32BE(userKey, 12)
 
         For i As Integer = 0 To 15
             Dim T0 As UInteger = (A + C - KC(i)) And &HFFFFFFFFUI
@@ -185,66 +195,62 @@ Public Class SeedCore
             roundKey(2 * i + 1) = SS0(GetByte(T1, 0)) Xor SS1(GetByte(T1, 1)) Xor SS2(GetByte(T1, 2)) Xor SS3(GetByte(T1, 3))
 
             If i Mod 2 = 0 Then
-                Dim tmpA = A
+                Dim AB As ULong = (CLng(A) << 32) Or B
-                A = (A >> 8) Or (B << 24)
+                AB = ((AB >> 8) Or (AB << 56)) And &HFFFFFFFFFFFFFFFFUL
-                B = (B >> 8) Or (tmpA << 24)
+                A = CUInt(AB >> 32)
+                B = CUInt(AB And &HFFFFFFFFUL)
             Else
-                Dim tmpC = C
+                Dim CD As ULong = (CLng(C) << 32) Or D
-                C = (C << 8) Or (D >> 24)
+                CD = ((CD << 8) Or (CD >> 56)) And &HFFFFFFFFFFFFFFFFUL
-                D = (D << 8) Or (tmpC >> 24)
+                C = CUInt(CD >> 32)
+                D = CUInt(CD And &HFFFFFFFFUL)
             End If
         Next
     End Sub
 
     Public Sub EncryptBlock(input() As Byte, inOffset As Integer, output() As Byte, outOffset As Integer)
-        Dim L0 = BitConverter.ToUInt32(input, inOffset)
+        Dim L0 = ToUInt32BE(input, inOffset)
-        Dim L1 = BitConverter.ToUInt32(input, inOffset + 4)
+        Dim L1 = ToUInt32BE(input, inOffset + 4)
-        Dim R0 = BitConverter.ToUInt32(input, inOffset + 8)
+        Dim R0 = ToUInt32BE(input, inOffset + 8)
-        Dim R1 = BitConverter.ToUInt32(input, inOffset + 12)
+        Dim R1 = ToUInt32BE(input, inOffset + 12)
 
         For i As Integer = 0 To 15
             Dim t = RoundFunction(R0 Xor roundKey(2 * i), R1 Xor roundKey(2 * i + 1))
             Dim T0 = t.Item1
             Dim T1 = t.Item2
 
-            L0 = L0 Xor T0
+            Dim temp0 = L0 Xor T0
-            L1 = L1 Xor T1
+            Dim temp1 = L1 Xor T1
-
-            ' swap
-            Dim tmp0 = L0 : Dim tmp1 = L1
             L0 = R0 : L1 = R1
-            R0 = tmp0 : R1 = tmp1
+            R0 = temp0 : R1 = temp1
         Next
 
-        Array.Copy(BitConverter.GetBytes(R0), 0, output, outOffset, 4)
+        WriteUInt32BE(R0, output, outOffset)
-        Array.Copy(BitConverter.GetBytes(R1), 0, output, outOffset + 4, 4)
+        WriteUInt32BE(R1, output, outOffset + 4)
-        Array.Copy(BitConverter.GetBytes(L0), 0, output, outOffset + 8, 4)
+        WriteUInt32BE(L0, output, outOffset + 8)
-        Array.Copy(BitConverter.GetBytes(L1), 0, output, outOffset + 12, 4)
+        WriteUInt32BE(L1, output, outOffset + 12)
     End Sub
 
     Public Sub DecryptBlock(input() As Byte, inOffset As Integer, output() As Byte, outOffset As Integer)
-        Dim L0 = BitConverter.ToUInt32(input, inOffset)
+        Dim L0 = ToUInt32BE(input, inOffset)
-        Dim L1 = BitConverter.ToUInt32(input, inOffset + 4)
+        Dim L1 = ToUInt32BE(input, inOffset + 4)
-        Dim R0 = BitConverter.ToUInt32(input, inOffset + 8)
+        Dim R0 = ToUInt32BE(input, inOffset + 8)
-        Dim R1 = BitConverter.ToUInt32(input, inOffset + 12)
+        Dim R1 = ToUInt32BE(input, inOffset + 12)
 
         For i As Integer = 0 To 15
             Dim t = RoundFunction(R0 Xor roundKey(30 - 2 * i), R1 Xor roundKey(31 - 2 * i))
             Dim T0 = t.Item1
             Dim T1 = t.Item2
 
-            L0 = L0 Xor T0
+            Dim temp0 = L0 Xor T0
-            L1 = L1 Xor T1
+            Dim temp1 = L1 Xor T1
-
-            ' swap
-            Dim tmp0 = L0 : Dim tmp1 = L1
             L0 = R0 : L1 = R1
-            R0 = tmp0 : R1 = tmp1
+            R0 = temp0 : R1 = temp1
         Next
 
-        Array.Copy(BitConverter.GetBytes(R0), 0, output, outOffset, 4)
+        WriteUInt32BE(R0, output, outOffset)
-        Array.Copy(BitConverter.GetBytes(R1), 0, output, outOffset + 4, 4)
+        WriteUInt32BE(R1, output, outOffset + 4)
-        Array.Copy(BitConverter.GetBytes(L0), 0, output, outOffset + 8, 4)
+        WriteUInt32BE(L0, output, outOffset + 8)
-        Array.Copy(BitConverter.GetBytes(L1), 0, output, outOffset + 12, 4)
+        WriteUInt32BE(L1, output, outOffset + 12)
     End Sub
 End Class

WelsonJS.Toolkit/WelsonJS.Cryptography/SeedEcbTransform.vb

@@ -2,7 +2,7 @@
 ' SPDX-License-Identifier: MIT
 ' SPDX-FileCopyrightText: 2025 Namhyeon Go <gnh1201@catswords.re.kr>, Catswords OSS And WelsonJS Contributors
 ' https://github.com/gnh1201/welsonjs
-' 
+
 Imports System.Security.Cryptography
 
 Public Class SeedEcbTransform
@@ -45,55 +45,47 @@ Public Class SeedEcbTransform
 
     Public Function TransformBlock(input() As Byte, inputOffset As Integer, inputCount As Integer,
                                    output() As Byte, outputOffset As Integer) As Integer Implements ICryptoTransform.TransformBlock
-        If inputCount <= 0 Then
+        If inputCount <= 0 Then Return 0
-            Return 0
-        End If
 
         Dim blockSize = InputBlockSize
+        Dim remaining = inputCount
+        Dim inPtr = inputOffset
+        Dim outPtr = outputOffset
 
-        For i As Integer = 0 To inputCount - 1 Step blockSize
+        While remaining >= blockSize
             If encrypt Then
-                seedCore.EncryptBlock(input, inputOffset + i, output, outputOffset + i)
+                seedCore.EncryptBlock(input, inPtr, output, outPtr)
             Else
-                seedCore.DecryptBlock(input, inputOffset + i, output, outputOffset + i)
+                seedCore.DecryptBlock(input, inPtr, output, outPtr)
             End If
-        Next
+            inPtr += blockSize
+            outPtr += blockSize
+            remaining -= blockSize
+        End While
 
-        Return inputCount
+        Return inputCount - remaining
     End Function
 
     Public Function TransformFinalBlock(input() As Byte, inputOffset As Integer, inputCount As Integer) As Byte() Implements ICryptoTransform.TransformFinalBlock
-        If inputCount = 0 Then
+        Dim blockSize = InputBlockSize
-            Return Array.Empty(Of Byte)()
-        End If
-
-        Dim blockSize As Integer = InputBlockSize
-        Dim paddedLength As Integer
         Dim buffer() As Byte
 
         If encrypt Then
+            Dim paddedLength As Integer
             Select Case paddingMode
                 Case PaddingMode.None
                     If (inputCount Mod blockSize) <> 0 Then
                         Throw New CryptographicException("Input data is not a multiple of block size and PaddingMode is None.")
                     End If
-                    ' None 패딩은 추가 블록 없음
                     paddedLength = inputCount
 
                 Case PaddingMode.Zeros
-                    ' Zeros 패딩은 추가 블록 필요 없음
                     paddedLength = ((inputCount + blockSize - 1) \ blockSize) * blockSize
 
                 Case PaddingMode.PKCS7, PaddingMode.ANSIX923, PaddingMode.ISO10126
-                    ' PKCS7. ANSIX923, ISO10126 패딩은 입력이 블록 배수면 +1 블록 추가
+                    Dim padLen = blockSize - (inputCount Mod blockSize)
-                    ' (설명) 블록암호에서 블록 길이와 같은 길이의 원문을 넣으면, 암호화문 길이가 원문 길이의 2배가 되는 원인은 여기에 기인한다.
+                    If padLen = 0 Then padLen = blockSize
-                    Dim fullBlocks As Integer = inputCount \ blockSize
+                    paddedLength = inputCount + padLen
-                    Dim remainder As Integer = inputCount Mod blockSize
-                    If remainder = 0 Then
-                        paddedLength = (fullBlocks + 1) * blockSize ' 추가 블록 붙임
-                    Else
-                        paddedLength = (fullBlocks + 1) * blockSize
-                    End If
 
                 Case Else
                     Throw New NotSupportedException("Unsupported padding mode: " & paddingMode.ToString())
@@ -102,32 +94,30 @@ Public Class SeedEcbTransform
             buffer = New Byte(paddedLength - 1) {}
             Array.Copy(input, inputOffset, buffer, 0, inputCount)
 
-            If paddingMode = PaddingMode.PKCS7 Then
+            Dim padVal As Byte = CByte(paddedLength - inputCount)
-                Dim padValue As Byte = CByte(paddedLength - inputCount)
+            Select Case paddingMode
-                For i As Integer = inputCount To paddedLength - 1
+                Case PaddingMode.PKCS7
-                    buffer(i) = padValue
+                    For i = inputCount To paddedLength - 1
+                        buffer(i) = padVal
                     Next
-
+                Case PaddingMode.ANSIX923
-            ElseIf paddingMode = PaddingMode.ANSIX923 Then
+                    For i = inputCount To paddedLength - 2
-                Dim padValue As Byte = CByte(paddedLength - inputCount)
-                For i As Integer = inputCount To paddedLength - 2
                         buffer(i) = 0
                     Next
-                buffer(paddedLength - 1) = padValue
+                    buffer(paddedLength - 1) = padVal
-
+                Case PaddingMode.ISO10126
-            ElseIf paddingMode = PaddingMode.ISO10126 Then
+                    For i = inputCount To paddedLength - 2
-                Dim padValue As Byte = CByte(paddedLength - inputCount)
-                For i As Integer = inputCount To paddedLength - 2
                         buffer(i) = CByte(rnd.Next(0, 256))
                     Next
-                buffer(paddedLength - 1) = padValue
+                    buffer(paddedLength - 1) = padVal
-            End If
+            End Select
 
-            TransformBlock(buffer, 0, paddedLength, buffer, 0)
+            For i = 0 To buffer.Length - 1 Step blockSize
+                seedCore.EncryptBlock(buffer, i, buffer, i)
+            Next
             Return buffer
 
         Else
-            ' Decryption
             If (inputCount Mod blockSize) <> 0 Then
                 Throw New CryptographicException("Encrypted data is not a multiple of block size.")
             End If
@@ -135,76 +125,37 @@ Public Class SeedEcbTransform
             buffer = New Byte(inputCount - 1) {}
             TransformBlock(input, inputOffset, inputCount, buffer, 0)
 
-            Select Case paddingMode
+            Dim padVal As Integer = buffer(buffer.Length - 1)
-                Case PaddingMode.None
+            If padVal <= 0 OrElse padVal > blockSize Then
-                    Return buffer
+                Throw New CryptographicException("Invalid padding.")
-
-                Case PaddingMode.Zeros
-                    Dim trimLength As Integer = buffer.Length
-                    While trimLength > 0 AndAlso buffer(trimLength - 1) = 0
-                        trimLength -= 1
-                    End While
-                    Dim result(trimLength - 1) As Byte
-                    Array.Copy(buffer, 0, result, 0, trimLength)
-                    Return result
-
-                Case PaddingMode.PKCS7
-                    Dim padValue As Integer = buffer(buffer.Length - 1)
-                    If padValue <= 0 OrElse padValue > blockSize Then
-                        Throw New CryptographicException("Invalid PKCS7 padding.")
             End If
-                    For i As Integer = buffer.Length - padValue To buffer.Length - 1
+
-                        If buffer(i) <> padValue Then
+            Select Case paddingMode
+                Case PaddingMode.PKCS7
+                    For i = buffer.Length - padVal To buffer.Length - 1
+                        If buffer(i) <> padVal Then
                             Throw New CryptographicException("Invalid PKCS7 padding value.")
                         End If
                     Next
-                    Dim unpaddedLength As Integer = buffer.Length - padValue
-                    If unpaddedLength < 0 Then
-                        Throw New CryptographicException("Invalid unpadded length.")
-                    End If
-                    Dim result(unpaddedLength - 1) As Byte
-                    Array.Copy(buffer, 0, result, 0, unpaddedLength)
-                    Return result
-
                 Case PaddingMode.ANSIX923
-                    Dim padValue As Integer = buffer(buffer.Length - 1)
+                    For i = buffer.Length - padVal To buffer.Length - 2
-                    If padValue <= 0 OrElse padValue > blockSize Then
-                        Throw New CryptographicException("Invalid ANSIX923 padding.")
-                    End If
-                    For i As Integer = buffer.Length - padValue To buffer.Length - 2
                         If buffer(i) <> 0 Then
                             Throw New CryptographicException("Invalid ANSIX923 padding value.")
                         End If
                     Next
-                    Dim unpaddedLengthAnsix As Integer = buffer.Length - padValue
-                    If unpaddedLengthAnsix < 0 Then
-                        Throw New CryptographicException("Invalid unpadded length.")
-                    End If
-                    Dim resultAnsix(unpaddedLengthAnsix - 1) As Byte
-                    Array.Copy(buffer, 0, resultAnsix, 0, unpaddedLengthAnsix)
-                    Return resultAnsix
-
                 Case PaddingMode.ISO10126
-                    Dim padValue As Integer = buffer(buffer.Length - 1)
+                    ' no need to check random bytes, only length byte matters
-                    If padValue <= 0 OrElse padValue > blockSize Then
-                        Throw New CryptographicException("Invalid ISO10126 padding.")
-                    End If
-                    ' Check the last byte (length)
-                    Dim unpaddedLengthIso As Integer = buffer.Length - padValue
-                    If unpaddedLengthIso < 0 Then
-                        Throw New CryptographicException("Invalid unpadded length.")
-                    End If
-                    Dim resultIso(unpaddedLengthIso - 1) As Byte
-                    Array.Copy(buffer, 0, resultIso, 0, unpaddedLengthIso)
-                    Return resultIso
-
                 Case Else
                     Throw New NotSupportedException("Unsupported padding mode: " & paddingMode.ToString())
             End Select
+
+            Dim result(buffer.Length - padVal - 1) As Byte
+            Array.Copy(buffer, 0, result, 0, result.Length)
+            Return result
         End If
     End Function
 
     Public Sub Dispose() Implements IDisposable.Dispose
-        ' Nothing
+        ' No resources to dispose
     End Sub
 End Class