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• Optimizing AES modes on Solaris for Intel Westmere

  - by danx

  Optimizing AES modes on Solaris for Intel Westmere Review AES is a strong method of symmetric (secret-key) encryption. It is a U.S. FIPS-approved cryptographic algorithm (FIPS 197) that operates on 16-byte blocks. AES has been available since 2001 and is widely used. However, AES by itself has a weakness. AES encryption isn't usually used by itself because identical blocks of plaintext are always encrypted into identical blocks of ciphertext. This encryption can be easily attacked with "dictionaries" of common blocks of text and allows one to more-easily discern the content of the unknown cryptotext. This mode of encryption is called "Electronic Code Book" (ECB), because one in theory can keep a "code book" of all known cryptotext and plaintext results to cipher and decipher AES. In practice, a complete "code book" is not practical, even in electronic form, but large dictionaries of common plaintext blocks is still possible. Here's a diagram of encrypting input data using AES ECB mode: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ AESKey-->(AES Encryption) AESKey-->(AES Encryption) | | | | \/ \/ CipherTextOutput CipherTextOutput Block 1 Block 2 What's the solution to the same cleartext input producing the same ciphertext output? The solution is to further process the encrypted or decrypted text in such a way that the same text produces different output. This usually involves an Initialization Vector (IV) and XORing the decrypted or encrypted text. As an example, I'll illustrate CBC mode encryption: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ IV >----->(XOR) +------------->(XOR) +---> . . . . | | | | | | | | \/ | \/ | AESKey-->(AES Encryption) | AESKey-->(AES Encryption) | | | | | | | | | \/ | \/ | CipherTextOutput ------+ CipherTextOutput -------+ Block 1 Block 2 The steps for CBC encryption are: Start with a 16-byte Initialization Vector (IV), choosen randomly. XOR the IV with the first block of input plaintext Encrypt the result with AES using a user-provided key. The result is the first 16-bytes of output cryptotext. Use the cryptotext (instead of the IV) of the previous block to XOR with the next input block of plaintext Another mode besides CBC is Counter Mode (CTR). As with CBC mode, it also starts with a 16-byte IV. However, for subsequent blocks, the IV is just incremented by one. Also, the IV ix XORed with the AES encryption result (not the plain text input). Here's an illustration: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ AESKey-->(AES Encryption) AESKey-->(AES Encryption) | | | | \/ \/ IV >----->(XOR) IV + 1 >---->(XOR) IV + 2 ---> . . . . | | | | \/ \/ CipherTextOutput CipherTextOutput Block 1 Block 2 Optimization Which of these modes can be parallelized? ECB encryption/decryption can be parallelized because it does more than plain AES encryption and decryption, as mentioned above. CBC encryption can't be parallelized because it depends on the output of the previous block. However, CBC decryption can be parallelized because all the encrypted blocks are known at the beginning. CTR encryption and decryption can be parallelized because the input to each block is known--it's just the IV incremented by one for each subsequent block. So, in summary, for ECB, CBC, and CTR modes, encryption and decryption can be parallelized with the exception of CBC encryption. How do we parallelize encryption? By interleaving. Usually when reading and writing data there are pipeline "stalls" (idle processor cycles) that result from waiting for memory to be loaded or stored to or from CPU registers. Since the software is written to encrypt/decrypt the next data block where pipeline stalls usually occurs, we can avoid stalls and crypt with fewer cycles. This software processes 4 blocks at a time, which ensures virtually no waiting ("stalling") for reading or writing data in memory. Other Optimizations Besides interleaving, other optimizations performed are Loading the entire key schedule into the 128-bit %xmm registers. This is done once for per 4-block of data (since 4 blocks of data is processed, when present). The following is loaded: the entire "key schedule" (user input key preprocessed for encryption and decryption). This takes 11, 13, or 15 registers, for AES-128, AES-192, and AES-256, respectively The input data is loaded into another %xmm register The same register contains the output result after encrypting/decrypting Using SSSE 4 instructions (AESNI). Besides the aesenc, aesenclast, aesdec, aesdeclast, aeskeygenassist, and aesimc AESNI instructions, Intel has several other instructions that operate on the 128-bit %xmm registers. Some common instructions for encryption are: pxor exclusive or (very useful), movdqu load/store a %xmm register from/to memory, pshufb shuffle bytes for byte swapping, pclmulqdq carry-less multiply for GCM mode Combining AES encryption/decryption with CBC or CTR modes processing. Instead of loading input data twice (once for AES encryption/decryption, and again for modes (CTR or CBC, for example) processing, the input data is loaded once as both AES and modes operations occur at in the same function Performance Everyone likes pretty color charts, so here they are. I ran these on Solaris 11 running on a Piketon Platform system with a 4-core Intel Clarkdale processor @3.20GHz. Clarkdale which is part of the Westmere processor architecture family. The "before" case is Solaris 11, unmodified. Keep in mind that the "before" case already has been optimized with hand-coded Intel AESNI assembly. The "after" case has combined AES-NI and mode instructions, interleaved 4 blocks at-a-time. « For the first table, lower is better (milliseconds). The first table shows the performance improvement using the Solaris encrypt(1) and decrypt(1) CLI commands. I encrypted and decrypted a 1/2 GByte file on /tmp (swap tmpfs). Encryption improved by about 40% and decryption improved by about 80%. AES-128 is slighty faster than AES-256, as expected. The second table shows more detail timings for CBC, CTR, and ECB modes for the 3 AES key sizes and different data lengths. » The results shown are the percentage improvement as shown by an internal PKCS#11 microbenchmark. And keep in mind the previous baseline code already had optimized AESNI assembly! The keysize (AES-128, 192, or 256) makes little difference in relative percentage improvement (although, of course, AES-128 is faster than AES-256). Larger data sizes show better improvement than 128-byte data. Availability This software is in Solaris 11 FCS. It is available in the 64-bit libcrypto library and the "aes" Solaris kernel module. You must be running hardware that supports AESNI (for example, Intel Westmere and Sandy Bridge, microprocessor architectures). The easiest way to determine if AES-NI is available is with the isainfo(1) command. For example, $ isainfo -v 64-bit amd64 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu 32-bit i386 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov sep cx8 tsc fpu No special configuration or setup is needed to take advantage of this software. Solaris libraries and kernel automatically determine if it's running on AESNI-capable machines and execute the correctly-tuned software for the current microprocessor. Summary Maximum throughput of AES cipher modes can be achieved by combining AES encryption with modes processing, interleaving encryption of 4 blocks at a time, and using Intel's wide 128-bit %xmm registers and instructions. References "Block cipher modes of operation", Wikipedia Good overview of AES modes (ECB, CBC, CTR, etc.) "Advanced Encryption Standard", Wikipedia "Current Modes" describes NIST-approved block cipher modes (ECB,CBC, CFB, OFB, CCM, GCM)

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• Encrypted AES key too large to Decrypt with RSA (Java)

  - by Petey B

  Hello, I am trying to make a program that Encrypts data using AES, then encrypts the AES key with RSA, and then decrypt. However, once i encrypt the AES key it comes out to 128 bytes. RSA will only allow me to decrypt 117 bytes or less, so when i go to decrypt the AES key it throws an error. Relavent code: KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA"); kpg.initialize(1024); KeyPair kpa = kpg.genKeyPair(); pubKey = kpa.getPublic(); privKey = kpa.getPrivate(); updateText("Private Key: " +privKey +"\n\nPublic Key: " +pubKey); updateText("Encrypting " +infile); //Genereate aes key KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128); // 192/256 SecretKey aeskey = kgen.generateKey(); byte[] raw = aeskey.getEncoded(); SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); updateText("Encrypting data with AES"); //encrypt data with AES key Cipher aesCipher = Cipher.getInstance("AES"); aesCipher.init(Cipher.ENCRYPT_MODE, skeySpec); SealedObject aesEncryptedData = new SealedObject(infile, aesCipher); updateText("Encrypting AES key with RSA"); //encrypt AES key with RSA Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, pubKey); byte[] encryptedAesKey = cipher.doFinal(raw); updateText("Decrypting AES key with RSA. Encrypted AES key length: " +encryptedAesKey.length); //decrypt AES key with RSA Cipher decipher = Cipher.getInstance("RSA"); decipher.init(Cipher.DECRYPT_MODE, privKey); byte[] decryptedRaw = cipher.doFinal(encryptedAesKey); //error thrown here because encryptedAesKey is 128 bytes SecretKeySpec decryptedSecKey = new SecretKeySpec(decryptedRaw, "AES"); updateText("Decrypting data with AES"); //decrypt data with AES key Cipher decipherAES = Cipher.getInstance("AES"); decipherAES.init(Cipher.DECRYPT_MODE, decryptedSecKey); String decryptedText = (String) aesEncryptedData.getObject(decipherAES); updateText("Decrypted Text: " +decryptedText); Any idea on how to get around this?

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• Aes key length significance/implications

  - by cppdev

  Hi, I am using a AES algorithm in my application for encrypting plain text. I am trying to use a key which is a six digit number. But as per the AES spec, the key should be minimum sixteen bytes in length. I am planning to append leading zeros to my six digit number to make it a 16 byte and then use this as a key. Would it have any security implications ? I mean will it make my ciphertext more prone to attacks. Please help.

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• Converting AES encryption token code in C# to php

  - by joey

  Hello, I have the following .Net code which takes two inputs. 1) A 128 bit base 64 encoded key and 2) the userid. It outputs the AES encrypted token. I need the php equivalent of the same code, but dont know which corresponding php classes are to be used for RNGCryptoServiceProvider,RijndaelManaged,ICryptoTransform,MemoryStream and CryptoStream. Im stuck so any help regarding this would be really appreciated. using System; using System.Text; using System.IO; using System.Security.Cryptography; class AESToken { [STAThread] static int Main(string[] args) { if (args.Length != 2) { Console.WriteLine("Usage: AESToken key userId\n"); Console.WriteLine("key Specifies 128-bit AES key base64 encoded supplied by MediaNet to the partner"); Console.WriteLine("userId specifies the unique id"); return -1; } string key = args[0]; string userId = args[1]; StringBuilder sb = new StringBuilder(); // This example code uses the magic string “CAMB2B”. The implementer // must use the appropriate magic string for the web services API. sb.Append("CAMB2B"); sb.Append(args[1]); // userId sb.Append('|'); // pipe char sb.Append(System.DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ssUTC")); //timestamp Byte[] payload = Encoding.ASCII.GetBytes(sb.ToString()); byte[] salt = new Byte[16]; // 16 bytes of random salt RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); rng.GetBytes(salt); // the plaintext is 16 bytes of salt followed by the payload. byte[] plaintext = new byte[salt.Length + payload.Length]; salt.CopyTo(plaintext, 0); payload.CopyTo(plaintext, salt.Length); // the AES cryptor: 128-bit key, 128-bit block size, CBC mode RijndaelManaged cryptor = new RijndaelManaged(); cryptor.KeySize = 128; cryptor.BlockSize = 128; cryptor.Mode = CipherMode.CBC; cryptor.GenerateIV(); cryptor.Key = Convert.FromBase64String(args[0]); // the key byte[] iv = cryptor.IV; // the IV. // do the encryption ICryptoTransform encryptor = cryptor.CreateEncryptor(cryptor.Key, iv); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write); cs.Write(plaintext, 0, plaintext.Length); cs.FlushFinalBlock(); byte[] ciphertext = ms.ToArray(); ms.Close(); cs.Close(); // build the token byte[] tokenBytes = new byte[iv.Length + ciphertext.Length]; iv.CopyTo(tokenBytes, 0); ciphertext.CopyTo(tokenBytes, iv.Length); string token = Convert.ToBase64String(tokenBytes); Console.WriteLine(token); return 0; } } Please help. Thank You.

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• encrypt- decrypt with AES using C/C++

  - by iassael

  Hi! How can I encrypt decrypt a file with a 256 key AES in c or c++? Which library do you suggest? Thank you!

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• C#, AES encryption check!

  - by Data-Base

  I have this code for AES encryption, can some one verify that this code is good and not wrong? it works fine, but I'm more concern about the implementation of the algorithm // Plaintext value to be encrypted. //Passphrase from which a pseudo-random password will be derived. //The derived password will be used to generate the encryption key. //Password can be any string. In this example we assume that this passphrase is an ASCII string. //Salt value used along with passphrase to generate password. //Salt can be any string. In this example we assume that salt is an ASCII string. //HashAlgorithm used to generate password. Allowed values are: "MD5" and "SHA1". //SHA1 hashes are a bit slower, but more secure than MD5 hashes. //PasswordIterations used to generate password. One or two iterations should be enough. //InitialVector (or IV). This value is required to encrypt the first block of plaintext data. //For RijndaelManaged class IV must be exactly 16 ASCII characters long. //KeySize. Allowed values are: 128, 192, and 256. //Longer keys are more secure than shorter keys. //Encrypted value formatted as a base64-encoded string. public static string Encrypt(string PlainText, string Password, string Salt, string HashAlgorithm, int PasswordIterations, string InitialVector, int KeySize) { byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector); byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt); byte[] PlainTextBytes = Encoding.UTF8.GetBytes(PlainText); PasswordDeriveBytes DerivedPassword = new PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations); byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8); RijndaelManaged SymmetricKey = new RijndaelManaged(); SymmetricKey.Mode = CipherMode.CBC; ICryptoTransform Encryptor = SymmetricKey.CreateEncryptor(KeyBytes, InitialVectorBytes); MemoryStream MemStream = new MemoryStream(); CryptoStream CryptoStream = new CryptoStream(MemStream, Encryptor, CryptoStreamMode.Write); CryptoStream.Write(PlainTextBytes, 0, PlainTextBytes.Length); CryptoStream.FlushFinalBlock(); byte[] CipherTextBytes = MemStream.ToArray(); MemStream.Close(); CryptoStream.Close(); return Convert.ToBase64String(CipherTextBytes); } public static string Decrypt(string CipherText, string Password, string Salt, string HashAlgorithm, int PasswordIterations, string InitialVector, int KeySize) { byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector); byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt); byte[] CipherTextBytes = Convert.FromBase64String(CipherText); PasswordDeriveBytes DerivedPassword = new PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations); byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8); RijndaelManaged SymmetricKey = new RijndaelManaged(); SymmetricKey.Mode = CipherMode.CBC; ICryptoTransform Decryptor = SymmetricKey.CreateDecryptor(KeyBytes, InitialVectorBytes); MemoryStream MemStream = new MemoryStream(CipherTextBytes); CryptoStream cryptoStream = new CryptoStream(MemStream, Decryptor, CryptoStreamMode.Read); byte[] PlainTextBytes = new byte[CipherTextBytes.Length]; int ByteCount = cryptoStream.Read(PlainTextBytes, 0, PlainTextBytes.Length); MemStream.Close(); cryptoStream.Close(); return Encoding.UTF8.GetString(PlainTextBytes, 0, ByteCount); } Thank you

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• Using AES encryption in .NET - CryptographicException saying the padding is invalid and cannot be removed

  - by Jake Petroules

  I wrote some AES encryption code in C# and I am having trouble getting it to encrypt and decrypt properly. If I enter "test" as the passphrase and "This data must be kept secret from everyone!" I receive the following exception: System.Security.Cryptography.CryptographicException: Padding is invalid and cannot be removed. at System.Security.Cryptography.RijndaelManagedTransform.DecryptData(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount, Byte[]& outputBuffer, Int32 outputOffset, PaddingMode paddingMode, Boolean fLast) at System.Security.Cryptography.RijndaelManagedTransform.TransformFinalBlock(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount) at System.Security.Cryptography.CryptoStream.FlushFinalBlock() at System.Security.Cryptography.CryptoStream.Dispose(Boolean disposing) at System.IO.Stream.Close() at System.IO.Stream.Dispose() ... And if I enter something less than 16 characters I get no output. I believe I need some special handling in the encryption since AES is a block cipher, but I'm not sure exactly what that is, and I wasn't able to find any examples on the web showing how. Here is my code: using System; using System.IO; using System.Security.Cryptography; using System.Text; public static class DatabaseCrypto { public static EncryptedData Encrypt(string password, string data) { return DatabaseCrypto.Transform(true, password, data, null, null) as EncryptedData; } public static string Decrypt(string password, EncryptedData data) { return DatabaseCrypto.Transform(false, password, data.DataString, data.SaltString, data.MACString) as string; } private static object Transform(bool encrypt, string password, string data, string saltString, string macString) { using (AesManaged aes = new AesManaged()) { aes.Mode = CipherMode.CBC; aes.Padding = PaddingMode.PKCS7; int key_len = aes.KeySize / 8; int iv_len = aes.BlockSize / 8; const int salt_size = 8; const int iterations = 8192; byte[] salt = encrypt ? new Rfc2898DeriveBytes(string.Empty, salt_size).Salt : Convert.FromBase64String(saltString); byte[] bc_key = new Rfc2898DeriveBytes("BLK" + password, salt, iterations).GetBytes(key_len); byte[] iv = new Rfc2898DeriveBytes("IV" + password, salt, iterations).GetBytes(iv_len); byte[] mac_key = new Rfc2898DeriveBytes("MAC" + password, salt, iterations).GetBytes(16); aes.Key = bc_key; aes.IV = iv; byte[] rawData = encrypt ? Encoding.UTF8.GetBytes(data) : Convert.FromBase64String(data); using (ICryptoTransform transform = encrypt ? aes.CreateEncryptor() : aes.CreateDecryptor()) using (MemoryStream memoryStream = encrypt ? new MemoryStream() : new MemoryStream(rawData)) using (CryptoStream cryptoStream = new CryptoStream(memoryStream, transform, encrypt ? CryptoStreamMode.Write : CryptoStreamMode.Read)) { if (encrypt) { cryptoStream.Write(rawData, 0, rawData.Length); return new EncryptedData(salt, mac_key, memoryStream.ToArray()); } else { byte[] originalData = new byte[rawData.Length]; int count = cryptoStream.Read(originalData, 0, originalData.Length); return Encoding.UTF8.GetString(originalData, 0, count); } } } } } public class EncryptedData { public EncryptedData() { } public EncryptedData(byte[] salt, byte[] mac, byte[] data) { this.Salt = salt; this.MAC = mac; this.Data = data; } public EncryptedData(string salt, string mac, string data) { this.SaltString = salt; this.MACString = mac; this.DataString = data; } public byte[] Salt { get; set; } public string SaltString { get { return Convert.ToBase64String(this.Salt); } set { this.Salt = Convert.FromBase64String(value); } } public byte[] MAC { get; set; } public string MACString { get { return Convert.ToBase64String(this.MAC); } set { this.MAC = Convert.FromBase64String(value); } } public byte[] Data { get; set; } public string DataString { get { return Convert.ToBase64String(this.Data); } set { this.Data = Convert.FromBase64String(value); } } } static void ReadTest() { Console.WriteLine("Enter password: "); string password = Console.ReadLine(); using (StreamReader reader = new StreamReader("aes.cs.txt")) { EncryptedData enc = new EncryptedData(); enc.SaltString = reader.ReadLine(); enc.MACString = reader.ReadLine(); enc.DataString = reader.ReadLine(); Console.WriteLine("The decrypted data was: " + DatabaseCrypto.Decrypt(password, enc)); } } static void WriteTest() { Console.WriteLine("Enter data: "); string data = Console.ReadLine(); Console.WriteLine("Enter password: "); string password = Console.ReadLine(); EncryptedData enc = DatabaseCrypto.Encrypt(password, data); using (StreamWriter stream = new StreamWriter("aes.cs.txt")) { stream.WriteLine(enc.SaltString); stream.WriteLine(enc.MACString); stream.WriteLine(enc.DataString); Console.WriteLine("The encrypted data was: " + enc.DataString); } }

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• Using AesCryptoServiceProvider in VB.NET

  - by Collegeman

  My problem is actually a bit more complicated than just how to use AES in VB.NET, since what I'm really trying to do is use AES in VB.NET from within a Java application across JACOB. But for now, what I need to focus on is the AES implementation itself. Here's my encryption code Public Function EncryptAES(ByVal toEncrypt As String, ByVal key As String) As Byte() Dim keyArray = Convert.FromBase64String(key) Dim toEncryptArray = Encoding.Unicode.GetBytes(toEncrypt) Dim aes = New AesCryptoServiceProvider aes.Key = keyArray aes.Mode = CipherMode.ECB aes.Padding = PaddingMode.ISO10126 Dim encryptor = aes.CreateEncryptor() Dim encrypted = encryptor.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length) aes.Clear() Return encrypted End Function Once back in the Java code, I turn the byte array into a hexadecimal String. Now, to reverse the process, here's my decryption code Public Function DecryptAES(ByVal toDecrypt As String, ByVal key As String) As Byte() Dim keyArray = Convert.FromBase64String(key) Dim toDecryptArray = Convert.FromBase64String(toDecrypt) Dim aes = New AesCryptoServiceProvider aes.Key = keyArray aes.Mode = CipherMode.ECB aes.Padding = PaddingMode.ISO10126 Dim decryptor = aes.CreateDecryptor() Dim decrypted = decryptor.TransformFinalBlock(toDecryptArray, 0, toDecryptArray.Length) aes.Clear() Return decrypted End Function When I run the decryption code, I get the following error message Padding is invalid and cannot be removed.

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• Android AES and init vector

  - by Donald_W

  I have an issue with AES encryptio and decryption: I can change my IV entirely and still I'm able to decode my data. public static final byte[] IV = { 65, 1, 2, 23, 4, 5, 6, 7, 32, 21, 10, 11, 12, 13, 84, 45 }; public static final byte[] IV2 = { 65, 1, 2, 23, 45, 54, 61, 81, 32, 21, 10, 121, 12, 13, 84, 45 }; public static final byte[] KEY = { 0, 42, 2, 54, 4, 45, 6, 7, 65, 9, 54, 11, 12, 13, 60, 15 }; public static final byte[] KEY2 = { 0, 42, 2, 54, 43, 45, 16, 17, 65, 9, 54, 11, 12, 13, 60, 15 }; //public static final int BITS = 256; public static void test() { try { // encryption Cipher c = Cipher.getInstance("AES"); SecretKeySpec keySpec = new SecretKeySpec(KEY, "AES"); c.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(IV)); String s = "Secret message"; byte[] data = s.getBytes(); byte[] encrypted = c.doFinal(data); String encryptedStr = ""; for (int i = 0; i < encrypted.length; i++) encryptedStr += (char) encrypted[i]; //decryoption Cipher d_c = Cipher.getInstance("AES"); SecretKeySpec d_keySpec = new SecretKeySpec(KEY, "AES"); d_c.init(Cipher.DECRYPT_MODE, d_keySpec, new IvParameterSpec(IV2)); byte[] decrypted = d_c.doFinal(encrypted); String decryptedStr = ""; for (int i = 0; i < decrypted.length; i++) decryptedStr += (char) decrypted[i]; Log.d("", decryptedStr); } catch (Exception ex) { Log.d("", ex.getMessage()); } } Any ideas what I'm doing wrong? How can I get 256 bit AES encryption (only change key to 32-byte long array?) Encryption is a new topic for me so please for newbie friendly answers.

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• AES Cipher Key Strength in BlackBerry

  - by Basilio

  Hi All, I need to create an application that decrypts data that is encrypted using AES with a 512-bit key. What I need to know is whether we can create an AES key of length 512-bits? The documentation says we can create a key of length up to 256-bits. If that is the case, is there any way that I can add my own implementation for 512-bit AES key, or will I have to reduce the key strength used to encrypt the data originally? Thanks, Basilio

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• How to encrypt/decrypt multiple strings in AES encryption??

  - by sebby_zml

  hello again everyone, i would like to know if i could encrypt two or more strings in AES encryption. let say, i want to encrypt username, password and nonce_value, can i use the following code? try{ String codeWord = username, password, nonceInString; String encryptedData = aseEncryptDecrypt.encrypt(codeWord); String decryptedData = aseEncryptDecrypt.decrypt(encryptedData); System.out.println("Encrypted : " + encryptedData); System.out.println("Decrypted : " + decryptedData); }catch (Throwable e) { // TODO Auto-generated catch block e.printStackTrace(); } thanks in advance. your suggestions and guidance will be very helpful for me.

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• decrypting AES files in an apache module?

  - by Tom H

  I have a client with a security policy compliance requirement to encrypt certain files on disk. The obvious way to do this is with Device-mapper and an AES crypto module However the current system is setup to generate individual files that are encrypted. What are my options for decrypting files on-the-fly in apache? I see that mod_ssl and mod_session_crypto do encryption/decryption or something similar but not exactly what I am after. I could imagine that a PerlSetOutputFilter would work with a suitable Perl script configured, and I also see mod_ext_filter so I could just fork a unix command and decrypt the file, but they both feel like a hack. I am kind of surprised that there is no mod_crypto available...or am I missing something obvious here? Presumably resource-wise the perl filter is the way to go?

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• what is wrong in java AES decrypt function?

  - by rohit

  hi, i modified the code available on http://java.sun.com/developer/technicalArticles/Security/AES/AES_v1.html and made encrypt and decrypt methods in program. but i am getting BadpaddingException.. also the function is returning null.. why it is happing?? whats going wrong? please help me.. these are variables i am using: kgen = KeyGenerator.getInstance("AES"); kgen.init(128); raw = new byte[]{(byte)0x00,(byte)0x11,(byte)0x22,(byte)0x33,(byte)0x44,(byte)0x55,(byte)0x66,(byte)0x77,(byte)0x88,(byte)0x99,(byte)0xaa,(byte)0xbb,(byte)0xcc,(byte)0xdd,(byte)0xee,(byte)0xff}; skeySpec = new SecretKeySpec(raw, "AES"); cipher = Cipher.getInstance("AES"); plainText=null; cipherText=null; following is decrypt function.. public String decrypt(String cipherText) { try { cipher.init(Cipher.DECRYPT_MODE, skeySpec); byte[] original = cipher.doFinal(cipherText.getBytes()); plainText = new String(original); } catch(BadPaddingException e) { } return plainText; }

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• Detecting incorrect key using AES/GCM in JAVA

  - by 4r1y4n

  I'm using AES to encrypt/decrypt some files in GCM mode using BouncyCastle. While I'm proving wrong key for decryption there is no exception. How should I check that the key is incorrect? my code is this: SecretKeySpec incorrectKey = new SecretKeySpec(keyBytes, "AES"); IvParameterSpec ivSpec = new IvParameterSpec(ivBytes); Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding", "BC"); byte[] block = new byte[1048576]; int i; cipher.init(Cipher.DECRYPT_MODE, incorrectKey, ivSpec); BufferedInputStream fis=new BufferedInputStream(new ProgressMonitorInputStream(null,"Decrypting ...",new FileInputStream("file.enc"))); BufferedOutputStream ro=new BufferedOutputStream(new FileOutputStream("file_org")); CipherOutputStream dcOut = new CipherOutputStream(ro, cipher); while ((i = fis.read(block)) != -1) { dcOut.write(block, 0, i); } dcOut.close(); fis.close(); thanks

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• openssl hmac using aes-256-cbc

  - by Ryan

  Hello, I am trying to take an AES HMAC of a file using the openssl command line program on Linux. I have been looking at the man pages but can't quite figure out how successfully make a HMAC. I can encrypt a file using the enc command with openssl however I can't seem to create a HMAC. The encryption looks like the following: openssl enc -aes-256-cbc -in plaintext -out ciphertext Any advice or tutorials would be wonderful

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• AES code throwing NoSuchPaddingException: Padding NoPaddin unknown

  - by Tom Brito

  The following code is a try to encrypt data using AES with asymmetric key: import java.io.OutputStream; import java.math.BigInteger; import java.security.Key; import java.security.KeyFactory; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.RSAPrivateKeySpec; import java.security.spec.RSAPublicKeySpec; import javax.crypto.Cipher; public class AsyncronousKeyTest { private final Cipher cipher; private final KeyFactory keyFactory; private final RSAPrivateKey privKey; private AsyncronousKeyTest() throws Exception { cipher = Cipher.getInstance("AES/CBC/NoPaddin", "BC"); keyFactory = KeyFactory.getInstance("AES", "BC"); // create the keys // TODO should this numbers be random? RSAPrivateKeySpec privKeySpec = new RSAPrivateKeySpec(new BigInteger( "d46f473a2d746537de2056ae3092c451", 16), new BigInteger("57791d5430d593164082036ad8b29fb1", 16)); privKey = (RSAPrivateKey) keyFactory.generatePrivate(privKeySpec); } public void generateAuthorizationAct(OutputStream outputStream) throws Exception { // TODO Ticket #14 - GenerateAuthorization action KeyFactory keyFactory = KeyFactory.getInstance("AES", "BC"); // TODO should this numbers be random? RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger("d46f473a2d746537de2056ae3092c451", 16), new BigInteger("11", 16)); RSAPublicKey pubKey = (RSAPublicKey) keyFactory.generatePublic(pubKeySpec); byte[] data = new byte[] {0x01}; byte[] encrypted = encryptAO(pubKey, data); outputStream.write(encrypted); } /** Encrypt the AuthorizationObject. */ public byte[] encryptAO(Key pubKey, byte[] data) throws Exception { cipher.init(Cipher.ENCRYPT_MODE, pubKey); byte[] cipherText = cipher.doFinal(data); return cipherText; } public byte[] decrypt(byte[] cipherText) throws Exception { cipher.init(Cipher.DECRYPT_MODE, privKey); byte[] decyptedData = cipher.doFinal(cipherText); return decyptedData; } public static void main(String[] args) throws Exception { System.out.println("start"); AsyncronousKeyTest auth = new AsyncronousKeyTest(); auth.generateAuthorizationAct(System.out); System.out.println("done"); } } but at line cipher = Cipher.getInstance(AesEncrypter.getTransformation(), "BC"); it throws NoSuchPaddingException: Padding NoPaddin unknown. What is this? And how to solve?

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• Solaris X86 AESNI OpenSSL Engine

  - by danx

  Solaris X86 AESNI OpenSSL Engine Cryptography is a major component of secure e-commerce. Since cryptography is compute intensive and adds a significant load to applications, such as SSL web servers (https), crypto performance is an important factor. Providing accelerated crypto hardware greatly helps these applications and will help lead to a wider adoption of cryptography, and lower cost, in e-commerce and other applications. The Intel Westmere microprocessor has six new instructions to acclerate AES encryption. They are called "AESNI" for "AES New Instructions". These are unprivileged instructions, so no "root", other elevated access, or context switch is required to execute these instructions. These instructions are used in a new built-in OpenSSL 1.0 engine available in Solaris 11, the aesni engine. Previous Work Previously, AESNI instructions were introduced into the Solaris x86 kernel and libraries. That is, the "aes" kernel module (used by IPsec and other kernel modules) and the Solaris pkcs11 library (for user applications). These are available in Solaris 10 10/09 (update 8) and above, and Solaris 11. The work here is to add the aesni engine to OpenSSL. X86 AESNI Instructions Intel's Xeon 5600 is one of the processors that support AESNI. This processor is used in the Sun Fire X4170 M2 As mentioned above, six new instructions acclerate AES encryption in processor silicon. The new instructions are: aesenc performs one round of AES encryption. One encryption round is composed of these steps: substitute bytes, shift rows, mix columns, and xor the round key. aesenclast performs the final encryption round, which is the same as above, except omitting the mix columns (which is only needed for the next encryption round). aesdec performs one round of AES decryption aesdeclast performs the final AES decryption round aeskeygenassist Helps expand the user-provided key into a "key schedule" of keys, one per round aesimc performs an "inverse mixed columns" operation to convert the encryption key schedule into a decryption key schedule pclmulqdq Not a AESNI instruction, but performs "carryless multiply" operations to acclerate AES GCM mode. Since the AESNI instructions are implemented in hardware, they take a constant number of cycles and are not vulnerable to side-channel timing attacks that attempt to discern some bits of data from the time taken to encrypt or decrypt the data. Solaris x86 and OpenSSL Software Optimizations Having X86 AESNI hardware crypto instructions is all well and good, but how do we access it? The software is available with Solaris 11 and is used automatically if you are running Solaris x86 on a AESNI-capable processor. AESNI is used internally in the kernel through kernel crypto modules and is available in user space through the PKCS#11 library. For OpenSSL on Solaris 11, AESNI crypto is available directly with a new built-in OpenSSL 1.0 engine, called the "aesni engine." This is in lieu of the extra overhead of going through the Solaris OpenSSL pkcs11 engine, which accesses Solaris crypto and digest operations. Instead, AESNI assembly is included directly in the new aesni engine. Instead of including the aesni engine in a separate library in /lib/openssl/engines/, the aesni engine is "built-in", meaning it is included directly in OpenSSL's libcrypto.so.1.0.0 library. This reduces overhead and the need to manually specify the aesni engine. Since the engine is built-in (that is, in libcrypto.so.1.0.0), the openssl -engine command line flag or API call is not needed to access the engine—the aesni engine is used automatically on AESNI hardware. Ciphers and Digests supported by OpenSSL aesni engine The Openssl aesni engine auto-detects if it's running on AESNI hardware and uses AESNI encryption instructions for these ciphers: AES-128-CBC, AES-192-CBC, AES-256-CBC, AES-128-CFB128, AES-192-CFB128, AES-256-CFB128, AES-128-CTR, AES-192-CTR, AES-256-CTR, AES-128-ECB, AES-192-ECB, AES-256-ECB, AES-128-OFB, AES-192-OFB, and AES-256-OFB. Implementation of the OpenSSL aesni engine The AESNI assembly language routines are not a part of the regular Openssl 1.0.0 release. AESNI is a part of the "HEAD" ("development" or "unstable") branch of OpenSSL, for future release. But AESNI is also available as a separate patch provided by Intel to the OpenSSL project for OpenSSL 1.0.0. A minimal amount of "glue" code in the aesni engine works between the OpenSSL libcrypto.so.1.0.0 library and the assembly functions. The aesni engine code is separate from the base OpenSSL code and requires patching only a few source files to use it. That means OpenSSL can be more easily updated to future versions without losing the performance from the built-in aesni engine. OpenSSL aesni engine Performance Here's some graphs of aesni engine performance I measured by running openssl speed -evp $algorithm where $algorithm is aes-128-cbc, aes-192-cbc, and aes-256-cbc. These are using the 64-bit version of openssl on the same AESNI hardware, a Sun Fire X4170 M2 with a Intel Xeon E5620 @2.40GHz, running Solaris 11 FCS. "Before" is openssl without the aesni engine and "after" is openssl with the aesni engine. The numbers are MBytes/second. OpenSSL aesni engine performance on Sun Fire X4170 M2 (Xeon E5620 @2.40GHz) (Higher is better; "before"=OpenSSL on AESNI without AESNI engine software, "after"=OpenSSL AESNI engine) As you can see the speedup is dramatic for all 3 key lengths and for data sizes from 16 bytes to 8 Kbytes—AESNI is about 7.5-8x faster over hand-coded amd64 assembly (without aesni instructions). Verifying the OpenSSL aesni engine is present The easiest way to determine if you are running the aesni engine is to type "openssl engine" on the command line. No configuration, API, or command line options are needed to use the OpenSSL aesni engine. If you are running on Intel AESNI hardware with Solaris 11 FCS, you'll see this output indicating you are using the aesni engine: intel-westmere $ openssl engine (aesni) Intel AES-NI engine (no-aesni) (dynamic) Dynamic engine loading support (pkcs11) PKCS #11 engine support If you are running on Intel without AESNI hardware you'll see this output indicating the hardware can't support the aesni engine: intel-nehalem $ openssl engine (aesni) Intel AES-NI engine (no-aesni) (dynamic) Dynamic engine loading support (pkcs11) PKCS #11 engine support For Solaris on SPARC or older Solaris OpenSSL software, you won't see any aesni engine line at all. Third-party OpenSSL software (built yourself or from outside Oracle) will not have the aesni engine either. Solaris 11 FCS comes with OpenSSL version 1.0.0e. The output of typing "openssl version" should be "OpenSSL 1.0.0e 6 Sep 2011". 64- and 32-bit OpenSSL OpenSSL comes in both 32- and 64-bit binaries. 64-bit executable is now the default, at /usr/bin/openssl, and OpenSSL 64-bit libraries at /lib/amd64/libcrypto.so.1.0.0 and libssl.so.1.0.0 The 32-bit executable is at /usr/bin/i86/openssl and the libraries are at /lib/libcrytpo.so.1.0.0 and libssl.so.1.0.0. Availability The OpenSSL AESNI engine is available in Solaris 11 x86 for both the 64- and 32-bit versions of OpenSSL. It is not available with Solaris 10. You must have a processor that supports AESNI instructions, otherwise OpenSSL will fallback to the older, slower AES implementation without AESNI. Processors that support AESNI include most Westmere and Sandy Bridge class processor architectures. Some low-end processors (such as for mobile/laptop platforms) do not support AESNI. The easiest way to determine if the processor supports AESNI is with the isainfo -v command—look for "amd64" and "aes" in the output: $ isainfo -v 64-bit amd64 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu Conclusion The Solaris 11 OpenSSL aesni engine provides easy access to powerful Intel AESNI hardware cryptography, in addition to Solaris userland PKCS#11 libraries and Solaris crypto kernel modules.

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• Solaris X86 AESNI OpenSSL Engine

  - by danx

  Solaris X86 AESNI OpenSSL Engine Cryptography is a major component of secure e-commerce. Since cryptography is compute intensive and adds a significant load to applications, such as SSL web servers (https), crypto performance is an important factor. Providing accelerated crypto hardware greatly helps these applications and will help lead to a wider adoption of cryptography, and lower cost, in e-commerce and other applications. The Intel Westmere microprocessor has six new instructions to acclerate AES encryption. They are called "AESNI" for "AES New Instructions". These are unprivileged instructions, so no "root", other elevated access, or context switch is required to execute these instructions. These instructions are used in a new built-in OpenSSL 1.0 engine available in Solaris 11, the aesni engine. Previous Work Previously, AESNI instructions were introduced into the Solaris x86 kernel and libraries. That is, the "aes" kernel module (used by IPsec and other kernel modules) and the Solaris pkcs11 library (for user applications). These are available in Solaris 10 10/09 (update 8) and above, and Solaris 11. The work here is to add the aesni engine to OpenSSL. X86 AESNI Instructions Intel's Xeon 5600 is one of the processors that support AESNI. This processor is used in the Sun Fire X4170 M2 As mentioned above, six new instructions acclerate AES encryption in processor silicon. The new instructions are: aesenc performs one round of AES encryption. One encryption round is composed of these steps: substitute bytes, shift rows, mix columns, and xor the round key. aesenclast performs the final encryption round, which is the same as above, except omitting the mix columns (which is only needed for the next encryption round). aesdec performs one round of AES decryption aesdeclast performs the final AES decryption round aeskeygenassist Helps expand the user-provided key into a "key schedule" of keys, one per round aesimc performs an "inverse mixed columns" operation to convert the encryption key schedule into a decryption key schedule pclmulqdq Not a AESNI instruction, but performs "carryless multiply" operations to acclerate AES GCM mode. Since the AESNI instructions are implemented in hardware, they take a constant number of cycles and are not vulnerable to side-channel timing attacks that attempt to discern some bits of data from the time taken to encrypt or decrypt the data. Solaris x86 and OpenSSL Software Optimizations Having X86 AESNI hardware crypto instructions is all well and good, but how do we access it? The software is available with Solaris 11 and is used automatically if you are running Solaris x86 on a AESNI-capable processor. AESNI is used internally in the kernel through kernel crypto modules and is available in user space through the PKCS#11 library. For OpenSSL on Solaris 11, AESNI crypto is available directly with a new built-in OpenSSL 1.0 engine, called the "aesni engine." This is in lieu of the extra overhead of going through the Solaris OpenSSL pkcs11 engine, which accesses Solaris crypto and digest operations. Instead, AESNI assembly is included directly in the new aesni engine. Instead of including the aesni engine in a separate library in /lib/openssl/engines/, the aesni engine is "built-in", meaning it is included directly in OpenSSL's libcrypto.so.1.0.0 library. This reduces overhead and the need to manually specify the aesni engine. Since the engine is built-in (that is, in libcrypto.so.1.0.0), the openssl -engine command line flag or API call is not needed to access the engine—the aesni engine is used automatically on AESNI hardware. Ciphers and Digests supported by OpenSSL aesni engine The Openssl aesni engine auto-detects if it's running on AESNI hardware and uses AESNI encryption instructions for these ciphers: AES-128-CBC, AES-192-CBC, AES-256-CBC, AES-128-CFB128, AES-192-CFB128, AES-256-CFB128, AES-128-CTR, AES-192-CTR, AES-256-CTR, AES-128-ECB, AES-192-ECB, AES-256-ECB, AES-128-OFB, AES-192-OFB, and AES-256-OFB. Implementation of the OpenSSL aesni engine The AESNI assembly language routines are not a part of the regular Openssl 1.0.0 release. AESNI is a part of the "HEAD" ("development" or "unstable") branch of OpenSSL, for future release. But AESNI is also available as a separate patch provided by Intel to the OpenSSL project for OpenSSL 1.0.0. A minimal amount of "glue" code in the aesni engine works between the OpenSSL libcrypto.so.1.0.0 library and the assembly functions. The aesni engine code is separate from the base OpenSSL code and requires patching only a few source files to use it. That means OpenSSL can be more easily updated to future versions without losing the performance from the built-in aesni engine. OpenSSL aesni engine Performance Here's some graphs of aesni engine performance I measured by running openssl speed -evp $algorithm where $algorithm is aes-128-cbc, aes-192-cbc, and aes-256-cbc. These are using the 64-bit version of openssl on the same AESNI hardware, a Sun Fire X4170 M2 with a Intel Xeon E5620 @2.40GHz, running Solaris 11 FCS. "Before" is openssl without the aesni engine and "after" is openssl with the aesni engine. The numbers are MBytes/second. OpenSSL aesni engine performance on Sun Fire X4170 M2 (Xeon E5620 @2.40GHz) (Higher is better; "before"=OpenSSL on AESNI without AESNI engine software, "after"=OpenSSL AESNI engine) As you can see the speedup is dramatic for all 3 key lengths and for data sizes from 16 bytes to 8 Kbytes—AESNI is about 7.5-8x faster over hand-coded amd64 assembly (without aesni instructions). Verifying the OpenSSL aesni engine is present The easiest way to determine if you are running the aesni engine is to type "openssl engine" on the command line. No configuration, API, or command line options are needed to use the OpenSSL aesni engine. If you are running on Intel AESNI hardware with Solaris 11 FCS, you'll see this output indicating you are using the aesni engine: intel-westmere $ openssl engine (aesni) Intel AES-NI engine (no-aesni) (dynamic) Dynamic engine loading support (pkcs11) PKCS #11 engine support If you are running on Intel without AESNI hardware you'll see this output indicating the hardware can't support the aesni engine: intel-nehalem $ openssl engine (aesni) Intel AES-NI engine (no-aesni) (dynamic) Dynamic engine loading support (pkcs11) PKCS #11 engine support For Solaris on SPARC or older Solaris OpenSSL software, you won't see any aesni engine line at all. Third-party OpenSSL software (built yourself or from outside Oracle) will not have the aesni engine either. Solaris 11 FCS comes with OpenSSL version 1.0.0e. The output of typing "openssl version" should be "OpenSSL 1.0.0e 6 Sep 2011". 64- and 32-bit OpenSSL OpenSSL comes in both 32- and 64-bit binaries. 64-bit executable is now the default, at /usr/bin/openssl, and OpenSSL 64-bit libraries at /lib/amd64/libcrypto.so.1.0.0 and libssl.so.1.0.0 The 32-bit executable is at /usr/bin/i86/openssl and the libraries are at /lib/libcrytpo.so.1.0.0 and libssl.so.1.0.0. Availability The OpenSSL AESNI engine is available in Solaris 11 x86 for both the 64- and 32-bit versions of OpenSSL. It is not available with Solaris 10. You must have a processor that supports AESNI instructions, otherwise OpenSSL will fallback to the older, slower AES implementation without AESNI. Processors that support AESNI include most Westmere and Sandy Bridge class processor architectures. Some low-end processors (such as for mobile/laptop platforms) do not support AESNI. The easiest way to determine if the processor supports AESNI is with the isainfo -v command—look for "amd64" and "aes" in the output: $ isainfo -v 64-bit amd64 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu Conclusion The Solaris 11 OpenSSL aesni engine provides easy access to powerful Intel AESNI hardware cryptography, in addition to Solaris userland PKCS#11 libraries and Solaris crypto kernel modules.

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• AES Encryption Java Invalid Key length

  - by wuntee

  I am trying to create an AES encryption method, but for some reason I keep getting a 'java.security.InvalidKeyException: Key length not 128/192/256 bits'. Here is the code: public static SecretKey getSecretKey(char[] password, byte[] salt) throws NoSuchAlgorithmException, InvalidKeySpecException{ SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWithMD5AndDES"); // NOTE: last argument is the key length, and it is 256 KeySpec spec = new PBEKeySpec(password, salt, 1024, 256); SecretKey tmp = factory.generateSecret(spec); SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES"); return(secret); } public static byte[] encrypt(char[] password, byte[] salt, String text) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, InvalidKeyException, InvalidParameterSpecException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException{ SecretKey secret = getSecretKey(password, salt); Cipher cipher = Cipher.getInstance("AES"); // NOTE: This is where the Exception is being thrown cipher.init(Cipher.ENCRYPT_MODE, secret); byte[] ciphertext = cipher.doFinal(text.getBytes("UTF-8")); return(ciphertext); } Can anyone see what I am doing wrong? I am thinking it may have something to do with the SecretKeyFactory algorithm, but that is the only one I can find that is supported on the end system I am developing against. Any help would be appreciated. Thanks.

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• AES/Rijndael implementation for SQL Server 2000?

  - by Victor Rodrigues

  Do you know any function implementation I could use for decrypting data encrypted by AES/Rijndael in SQLSERVER2000?

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• AES Encryption. From Python (pyCrypto) to .NET

  - by Why

  I am currently trying to port a legacy Python app over to .NET which contains AES encrpytion using from what I can tell pyCrpyto. I have very limited Python and Crypto experience. The code uses the snippet from the following page. http://www.djangosnippets.org/snippets/1095/ So far I believe I have managed to work out that it that it calls Crypto.Cipher with AES and the first 32 character of our secret key as the password, but no mode or IV. It also puts a prefix on the encrpyed text when it is added to database. What I can't work out is how I can decrypt the existing ecrypted database records in .NET. I have been looking at RijndaelManaged but it requires an IV and can't see any reference to one in python. Can anyone point me in the dirrection to what method could be used in .NET to get the desired result.

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• AES decryption in Java - IvParameterSpec to big

  - by user1277269

  Im going to decrypt a plaintext with two keys. As you see in the picture were have one encrypted file wich contains KEY1(128 bytes),KEYIV(128 bytes),key2(128bytes) wich is not used in this case then we have the ciphertext. The error I get here is "Exception in thread "main" java.security.InvalidAlgorithmParameterException: Wrong IV length: must be 16 bytes long. but it is 64 bytes." Picture: http://i264.photobucket.com/albums/ii200/XeniuM05/bg_zps0a523659.png public class AES { public static void main(String[] args) throws Exception { byte[] encKey1 = new byte[128]; byte[] EncIV = new byte[256]; byte[] UnEncIV = new byte[128]; byte[] unCrypKey = new byte[128]; byte[] unCrypText = new byte[1424]; File f = new File("C://ftp//ciphertext.enc"); FileInputStream fis = new FileInputStream(F); byte[] EncText = new byte[(int) f.length()]; fis.read(encKey1); fis.read(EncIV); fis.read(EncText); EncIV = Arrays.copyOfRange(EncIV, 128, 256); EncText = Arrays.copyOfRange(EncText, 384, EncText.length); System.out.println(EncText.length); KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType()); char[] password = "lab1StorePass".toCharArray(); java.io.FileInputStream fos = new java.io.FileInputStream( "C://ftp//lab1Store"); ks.load(fos, password); char[] passwordkey1 = "lab1KeyPass".toCharArray(); PrivateKey Lab1EncKey = (PrivateKey) ks.getKey("lab1EncKeys", passwordkey1); Cipher rsaDec = Cipher.getInstance("RSA"); // set cipher to RSA decryption rsaDec.init(Cipher.DECRYPT_MODE, Lab1EncKey); // initalize cipher ti lab1key unCrypKey = rsaDec.doFinal(encKey1); // Decryps first key UnEncIV = rsaDec.doFinal(EncIV); //decryps encive byte array to undecrypted bytearray---- OBS! Error this is 64 BYTES big, we want 16? System.out.println("lab1key "+ unCrypKey +" IV " + UnEncIV); //-------CIPHERTEXT decryption--------- Cipher AESDec = Cipher.getInstance("AES/CBC/PKCS5Padding"); //---------convert decrypted bytearrays to acctual keys SecretKeySpec unCrypKey1 = new SecretKeySpec(unCrypKey, "AES"); IvParameterSpec ivSpec = new IvParameterSpec(UnEncIV); AESDec.init(Cipher.DECRYPT_MODE, unCrypKey1, ivSpec ); unCrypText = AESDec.doFinal(EncText); // Convert decrypted cipher bytearray to string String deCryptedString = new String(unCrypKey); System.out.println(deCryptedString); }

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• C# Libraries to encrypt/decrypt using AES

  - by nabo

  I couldn't find aes libraries in .net framework. Is there any external libraries? thanks

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• My AES encryption/decryption functions don't work with random ivecs

  - by Brendan Long

  I was bored and wrote a wrapper around openSSL to do AES encryption with less work. If I do it like this: http://pastebin.com/V1eqz4jp (ivec = 0) Everything works fine, but the default ivec is all 0's, which has some security problems. Since I'm passing the data back as a string anyway, I figured, why not generate a random ivec and stick it to the front, the take it back off when I decrypt the string? For some reason it doesn't work though. With random ivec: http://pastebin.com/MkDBFcn6 Well actually, it almost works. It seems to decrypt the middle of the string, but not the beginning or end: String is: 0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF Encrypting.. ???l%%1u???B! ?????`pN)?????[l????{?Q???2?/?H??y"?=Z?Cu????l%%1u???B! Decrypting.. String is: ?%???G*?5J?0??0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF!-e????V?5 I honestly have no idea what's going wrong. Maybe some stupid mistake, or maybe I'm missing something about AES?

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• AES encryption/decryption java bouncy castle explanation?

  - by Programmer0

  Can someone please explain what this program is doing pointing out some of the major points? I'm looking at the code and I'm completely lost. I just need explanation on the encryption/decryption phases. I think it generates an AES 192 key at one point but I'm not 100% sure. I'm not sure what the byte/ivBytes are used for either. import java.security.Key; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.spec.IvParameterSpec; public class RandomKey { public static void main(String[] args) throws Exception { byte[] input = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 }; byte[] ivBytes = new byte[] { 0x00, 0x00, 0x00, 0x01, 0x04, 0x05, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }; //initializing a new initialization vector IvParameterSpec ivSpec = new IvParameterSpec(ivBytes); //what does this actually do? Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC"); //what does this do? KeyGenerator generator = KeyGenerator.getInstance("AES","BC"); //I assume this generates a key size of 192 bits generator.init(192); //does this generate a random key? Key encryptKey = generator.generateKey(); System.out.println("input: " +toHex(input)); //encryption phase cipher.init(Cipher.ENCRYPT_MODE, encryptKey, ivSpec); //what is this doing? byte[] cipherText = new byte[cipher.getOutputSize(input.length)]; //what is this doing? int ctLength = cipher.update(input, 0, input.length, cipherText,0); //getting the cipher text length i assume? ctLength += cipher.doFinal (cipherText, ctLength ); System.out.println ("Cipher: " +toHex(cipherText) + " bytes: " + ctLength); //decryption phase cipher.init(Cipher.DECRYPT_MODE, encryptKey, ivSpec); //storing the ciphertext in plaintext i'm assuming? byte[] plainText = new byte[cipher.getOutputSize(ctLength)]; int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0); //getting plaintextLength i think? ptLength= cipher.doFinal (plainText, ptLength); System.out.println("plain: " + toHex(plainText, ptLength)); } private static String digits = "0123456789abcdef"; public static String toHex(byte[] data, int length) { StringBuffer buf = new StringBuffer(); for (int i=0; i!= length; i++) { int v = data[i] & 0xff; buf.append(digits.charAt(v >>4)); buf.append(digits.charAt(v & 0xf)); } return buf.toString(); } public static String toHex(byte[] data) { return toHex(data, data.length); } }

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