Ejemplo n.º 1
0
        public void AES_ECB_decrypt(ref AES_ctx ctx, ref uint[] buf)
        {
            // The next function call decrypts the PlainText with the Key using AES algorithm.
            uint k = 0;

            Array.Clear(state_t.state_t, 0, 16);

            for (int j = 0; j < 4 && k < buf.Length; j++)
            {
                for (int i = 0; i < 4 && k < buf.Length; i++, k++)
                {
                    state_t.state_t[j, i] = buf[k];
                }
            }
            InvCipher(ref state_t, ref ctx.RoundKey);
        }
Ejemplo n.º 2
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 void AES_ctx_set_iv(ref AES_ctx ctx, ref uint[] iv)
 {
     Array.Copy(ctx.Iv, iv, AES_BLOCKLEN);
 }
Ejemplo n.º 3
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 void AES_init_ctx_iv(ref AES_ctx ctx, ref uint[] key, ref uint[] iv)
 {
     KeyExpansion(ref ctx, ref key);
     Array.Copy(iv, ctx.Iv, AES_BLOCKLEN);
 }
Ejemplo n.º 4
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 public void AES_init_ctx(ref AES_ctx ctx, ref uint[] key)
 {
     KeyExpansion(ref ctx, ref key);
 }
Ejemplo n.º 5
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        // This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
        private void KeyExpansion(ref AES_ctx RoundKey, ref uint[] Key)
        {
            uint i, j, k;

            uint[] tempa = new uint[4]; // Used for the column/row operations

            // The first round key is the key itself.
            for (i = 0; i < Nk; ++i)
            {
                RoundKey.RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
                RoundKey.RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
                RoundKey.RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
                RoundKey.RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
            }

            // All other round keys are found from the previous round keys.
            for (i = Nk; i < Nb * (Nr + 1); ++i)
            {
                {
                    k        = (i - 1) * 4;
                    tempa[0] = RoundKey.RoundKey[k + 0];
                    tempa[1] = RoundKey.RoundKey[k + 1];
                    tempa[2] = RoundKey.RoundKey[k + 2];
                    tempa[3] = RoundKey.RoundKey[k + 3];
                }

                if (i % Nk == 0)
                {
                    // This function shifts the 4 bytes in a word to the left once.
                    // [a0,a1,a2,a3] becomes [a1,a2,a3,a0]

                    // Function RotWord()
                    {
                        k        = tempa[0];
                        tempa[0] = tempa[1];
                        tempa[1] = tempa[2];
                        tempa[2] = tempa[3];
                        tempa[3] = k;
                    }

                    // SubWord() is a function that takes a four-byte input word and
                    // applies the S-box to each of the four bytes to produce an output word.

                    // Function Subword()
                    {
                        tempa[0] = getSBoxValue(tempa[0]);
                        tempa[1] = getSBoxValue(tempa[1]);
                        tempa[2] = getSBoxValue(tempa[2]);
                        tempa[3] = getSBoxValue(tempa[3]);
                    }

                    tempa[0] = tempa[0] ^ Rcon[i / Nk];
                }

#if AES256
                if (i % Nk == 4)
                {
                    // Function Subword()
                    {
                        tempa[0] = getSBoxValue(tempa[0]);
                        tempa[1] = getSBoxValue(tempa[1]);
                        tempa[2] = getSBoxValue(tempa[2]);
                        tempa[3] = getSBoxValue(tempa[3]);
                    }
                }
#endif

                j = i * 4; k = (i - Nk) * 4;
                RoundKey.RoundKey[j + 0] = RoundKey.RoundKey[k + 0] ^ tempa[0];
                RoundKey.RoundKey[j + 1] = RoundKey.RoundKey[k + 1] ^ tempa[1];
                RoundKey.RoundKey[j + 2] = RoundKey.RoundKey[k + 2] ^ tempa[2];
                RoundKey.RoundKey[j + 3] = RoundKey.RoundKey[k + 3] ^ tempa[3];
            }
        }
Ejemplo n.º 6
0
        public void EncryptFile(string inputFilename, string outputFilename, string firmwareRevisionFilename, string newKey)
        {
            Aes aes = new Aes();

            if (!File.Exists(inputFilename))
            {
                Console.WriteLine("{0} {1}", inputFilename, " file does not exist!");
                return;
            }
            if (File.Exists(outputFilename))
            {
                File.Delete(outputFilename);
            }

            if (firmwareRevisionFilename != "")
            {
                string revisionName = "";
                revisionName = GetVersionNumberFromFile(firmwareRevisionFilename);
                if (outputFilename.Contains(".crx"))
                {
                    outputFilename = outputFilename.Insert(outputFilename.IndexOf(".crx"), "_" + revisionName + "_");
                }
                else
                {
                    Console.WriteLine("The output file name extension is not valid. The extension should end in \".crx\"");
                    return;
                }
            }

            FileStream   fsOut    = File.Create(outputFilename);
            FileStream   fsIn     = File.OpenRead(inputFilename);
            StreamReader sr       = new StreamReader(fsIn);
            ulong        fileSize = (ulong)fsIn.Length;

            // todo: final filesize. Needs to be in increments of 16 bytes.
            ulong finalRemainder = (16 - (fileSize % 16)); // find how many bytes left then subtract from 16 to get value to add to current file size.

            fileSize += finalRemainder;                    // add how many bytes to current file size
            UInt16 lastKeys = (UInt16)(fileSize);          // now get the low 2 byte value from fize size.

            // Create your own 128 bit key. This should be the same key as the decryption key
            uint[] key = new uint[16] {
                0xA4, 0xDD, 0xE2, 0x16, 0x63, 0x51, 0x4A, 0x4D, 0xB1, 0xAB, 0x0E, 0x5D, 0x2C, 0xE2, 0xD7, 0xB7
            };                                    // new guid (A4DDE216-6351-4A4D-B1AB-0E5D2CE2D7B7)

            if (!newKey.Equals(""))               // if a GUID was included then replace default GUID. Also I do not have error checking implemeted so an invalid GUID will more than likely cause a crash.
            {
                newKey = newKey.Replace("-", ""); // some GUId may have dashes, so this will remove them.
                byte[] aKey = StrToByteArray(newKey);
                Array.Copy(aKey, key, key.Length);
            }

            // changing last two bytes of key depending on file size. Doing this will make the encryption key random for each hex file.
            key[14] = (uint)lastKeys >> 8;
            key[15] = (uint)lastKeys & 0xff;

            string getLine   = string.Empty;
            string temp_line = string.Empty;

            AES_ctx ctx = new AES_ctx();

            aes.AES_init_ctx(ref ctx, ref key);

            char[] charArray = new char[fileSize];
            //read all chars from file into array
            for (ulong i = 0; i < fileSize; i++)
            {
                charArray[i] = (char)sr.Read();
            }

            uint[] tempArray = new uint[16]; // new array

            ulong charCounter = 0;

            while (charCounter < fileSize)
            {
                Array.Clear(tempArray, 0, tempArray.Length);
                Array.Copy(charArray, (int)charCounter, tempArray, 0, 16);

                aes.AES_ECB_encrypt(ref ctx, ref tempArray);

                byte[] byteArray = new byte[16];
                uint   k         = 0;
                for (int j = 0; j < 4; j++)
                {
                    for (uint i = 0; i < 4; i++, k++)
                    {
                        byteArray[k] = (byte)aes.state_t.state_t[j, i];
                    }
                }

                // write to the new file
                fsOut.Write(byteArray, 0, byteArray.Length);
                charCounter += 16;
            }

            fsIn.Close();
            fsOut.Close();
            Console.WriteLine(Path.GetFileName(inputFilename) + " has been encrypted successfully! New filename: " + Path.GetFileName(outputFilename));
        }
Ejemplo n.º 7
0
        public void DecryptFile(string inputFilename, string outputFilename, string newKey)
        {
            Aes aes = new Aes();

            if (!File.Exists(inputFilename))
            {
                Console.WriteLine("{0} {1}", inputFilename, " file does not exist!");
                return;
            }
            if (File.Exists(outputFilename))
            {
                File.Delete(outputFilename);
            }

            FileStream   fsOut    = File.Create(outputFilename);
            FileStream   fsIn     = File.OpenRead(inputFilename);
            StreamReader sr       = new StreamReader(fsIn);
            ulong        fileSize = (ulong)fsIn.Length;

            string myFile = string.Empty;

            // Create your own 128 bit key. This should be the same as the encryption key
            uint[] key = new uint[16] {
                0xA4, 0xDD, 0xE2, 0x16, 0x63, 0x51, 0x4A, 0x4D, 0xB1, 0xAB, 0x0E, 0x5D, 0x2C, 0xE2, 0xD7, 0xB7
            };                                                                                                                            // new guid (A4DDE216-6351-4A4D-B1AB-0E5D2CE2D7B7)

            if (!newKey.Equals(""))
            {
                newKey = newKey.Replace("-", "");
                byte[] aKey = StrToByteArray(newKey);
                Array.Copy(aKey, key, key.Length);
            }

            UInt16 lastKeys = (UInt16)(fileSize);

            key[14] = (uint)lastKeys >> 8;
            key[15] = (uint)lastKeys & 0xff; // changing last two bytes of key depending on file size.

            //aes.Phex(ref key, 0);

            byte[] fileBytes      = new byte[fsIn.Length];
            int    numBytesToRead = (int)fsIn.Length;

            int numBytesRead = 0;

            while (numBytesToRead > 0)
            {
                // Read may return anything from 0 to numBytesToRead.
                int n = fsIn.Read(fileBytes, numBytesRead, numBytesToRead);

                // Break when the end of the file is reached.
                if (n == 0)
                {
                    break;
                }

                numBytesRead   += n;
                numBytesToRead -= n;
            }
            numBytesToRead = fileBytes.Length; // reload size

            fsIn.Close();                      // done with file

            AES_ctx ctx = new AES_ctx();

            aes.AES_init_ctx(ref ctx, ref key);

            numBytesRead = 0;
            while (numBytesRead < numBytesToRead)
            {
                uint[] tempArray = new uint[16];                       // new temp array

                Array.Copy(fileBytes, numBytesRead, tempArray, 0, 16); // copy 16 bytes at a time
                aes.AES_ECB_decrypt(ref ctx, ref tempArray);           // decrypt 16 bytes

                byte[] byteArray = new byte[16];
                Array.Clear(byteArray, 0, byteArray.Length);
                uint k = 0;
                for (int j = 0; j < 4; j++)
                {
                    for (uint i = 0; i < 4; i++, k++)
                    {
                        byteArray[k] = (byte)((char)aes.state_t.state_t[j, i]);
                    }
                }
                myFile       += Encoding.Default.GetString(byteArray); // keep adding to string
                numBytesRead += 16;                                    // inc the read pointer
            }

            byte myByte = 0;

            numBytesRead = 0; // the counter for the file size
            foreach (char c in myFile)
            {
                myByte = (byte)Convert.ToByte(c);

                if (myByte <= 127)           // check if ascii char 0-127
                {
                    fsOut.WriteByte(myByte); // write whole string to file
                    numBytesRead += 1;
                }

                if (numBytesRead == numBytesToRead)
                {
                    break;
                }
            }

            Console.WriteLine("The filesize: " + numBytesRead); // this is what we need to do for the Firmware updater app to send to bootloader.

            fsOut.Close();                                      // close file
            Console.WriteLine(Path.GetFileName(inputFilename) + " has been decrypted successfully! New filename: " + Path.GetFileName(outputFilename));
        }