aes

AES/CBC/PKCS5Padding vs AES/CBC/PKCS7Padding with 256 key size performance java

The block size is a property of the used cipher algorithm. For AES it is always 16 bytes. So strictly speaking, PKCS5Padding cannot be used with AES since it is defined only for a block size of 8 bytes. I assume, AES/CBC/PKCS5Padding is interpreted as AES/CBC/PKCS7Padding internally. The only difference between these padding schemes is … Read more

AES string encryption in Objective-C

This line near the top says you’re adding AES functionality to NSMutableData: @implementation NSMutableData(AES) In Objective-C, this is called a category; categories let you extend an existing class. This code would typically go in a file named NSMutableData-AES.m. Create a header file too, NSMutableData-AES.h. It should contain: @interface NSMutableData(AES) – (NSMutableData*) EncryptAES: (NSString *) key; … Read more

Is it possible to encrypt data with AES (256 bit) GCM mode in .net framework 4.7?

This answer reflects the comments from Luke Park, bartonjs, Timo, aand Maarten Bodewes above. One option is to use the Bouncycastle C# library, which has its own self-contained implementation of AES as well as the GCM mode. Look at the source code for the classes GCMBlockCipher, AesEngine, and AEADParameters. Another option is to use P/Invoke … Read more

PyCrypto problem using AES+CTR

The counter must return the same on decryption as it did on encryption, as you intuit, so, one (NOT SECURE AT ALL) way to do it is: >>> secret = os.urandom(16) >>> crypto = AES.new(os.urandom(32), AES.MODE_CTR, counter=lambda: secret) >>> encrypted = crypto.encrypt(“aaaaaaaaaaaaaaaa”) >>> print crypto.decrypt(encrypted) aaaaaaaaaaaaaaaa CTR is a block cipher, so the “16-at-a-time” constraint … Read more

Getting SlowAES and RijndaelManaged class in .NET to play together

maybe I can help. I took your C# code and modified it slightly. The C# code I use, in its entirety, is: using System; using System.Security.Cryptography; public class Bob { internal static string FormatByteArray(byte[] b) { System.Text.StringBuilder sb1 = new System.Text.StringBuilder(); int i = 0; for (i = 0; i < b.Length; i++) { if … Read more

How to encrypt in VBScript using AES?

One way is to declare encryption classes within vbscript, without needing external added COM objects or wrapper. The following example takes a string, encrypts and decrypts using Rijndael managed class: ‘—————————————————– Dim obj,arr,i,r,str,enc,asc dim bytes,bytesd,s,sc,sd set obj=WScript.CreateObject(“System.Security.Cryptography.RijndaelManaged”) Set asc = CreateObject(“System.Text.UTF8Encoding”) s=”This is a private message” bytes=asc.GetBytes_4(s) obj.GenerateKey() obj.GenerateIV() set enc=obj.CreateEncryptor() set dec=obj.CreateDecryptor() bytec=enc.TransformFinalBlock((bytes),0,lenb(bytes)) sc=asc.GetString((bytec)) … Read more

How to append to AES encrypted file

If you’re using AES in CBC mode, you can use the second to last block as the IV to decrypt the last block, which may be only partially full, then again to encrypt the plaintext of the last block followed by the new plaintext. Here’s a proof of concept: import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; … Read more

Encrypt in java and Decrypt in C# For AES 256 bit

After I got very helpful suggestions from @deathismyfriend and other, I found out what I am missing in my C# Decrypt function.So I change my function as below. /// C# Error Fixed Version – CipherMode.ECB public static string keyStr = “xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx”; private static string Encrypt(string PlainText) { RijndaelManaged aes = new RijndaelManaged(); aes.BlockSize = 128; … Read more