Decrypting a string in c#

ToArray ; memoryStream. Close ; cryptoStream. Close ; return Convert. Read plainTextBytes, 0, plainTextBytes. Length ; memoryStream. Close ; return Encoding. See Also The example project and source code: encrypt-string.

Archived Comments Sam on June 28, at am said: Thanks for this code it looks like what I was in need of for a simple application with a little bit of sensitive data.

Sam on June 28, at am said: System. IO is also required in the name space for the memory stream. Kochav on August 24, at pm said: Thanks for this code it is exactly what I was in need of for encrypt a string in a batch file. Kyle on December 7, at am said: I tried this, encryption works but when I go to decrypt, I get an error when it tries to figure out the decrypted byte count. Any ideas?

ZVey on January 28, at am said: This example is perfect for my usecase but there is only one problem. Thanks in advance. ZVey on January 28, at am said: Anyways. UrlEncode Convert. Very useful. Lino on April 22, at am said: Hello, excuse my ignorance. Thank you! Joe on August 13, at pm said: Awesome, thanks for sharing!

Encryption was good. WriteLine "Press any key to exit The password derivation is now properly salted whereas previously it wasn't salted at all another silly bug squished. Kolappan N 2, 2 2 gold badges 30 30 silver badges 36 36 bronze badges. Your comments about IV are incorrect, a 16 character UTF8 is 16 bytes, it works anyway because IV size is actually based on block size, not key size. Also IV is being ascii decoded instead of utf8 decoded in decrypt. Ur answer talks about abstracting away salts and IVs but really u just removed them -- not modern or secure — jbtule.

This is unauthenticated encryption. An attacker can change the message without you being able to notice. He cannot learn the message but he can change it. CraigTP Good explanation but iterations is very low. When the PBKDF2 standard was written in , the recommended minimum number of iterations was , but the parameter is intended to be increased over time as CPU speeds increase.

As of a Kerberos standard recommended iterations, Apple iOS 3 used , iOS 4 used , while in LastPass used iterations for JavaScript clients and iterations for server-side hashing. Any chance for a. I am not allowed to answer the question, so I just comment here. As far as. NET Standard 2 goes, the block size must be Here's how it changes your code: github.

Show 45 more comments. GetBytes 32 ; encryptor. CreateEncryptor , CryptoStreamMode. Write clearBytes, 0, clearBytes. Length ; cs. ToBase64String ms. CreateDecryptor , CryptoStreamMode. Write cipherBytes, 0, cipherBytes. GetString ms. A Ghazal A Ghazal 2, 1 1 gold badge 16 16 silver badges 11 11 bronze badges. You probably shouldn't hard code the encryption key into the methods.

This is very useful and simple for the numerous cases where we do not need the complexities of salt. I just made the encryption key a parameter and was able to use the code successfully as is. FrenkyB to make the method portable, you can always pass the key as a method parameter. For example: public static string Encrypt string clearText, string encryptionKey This way you can have unique keys for each method call. My Code Analyzer warned that variable cs is being disposed twice. We do not need redundant statements cs.

Close in both Encrypt and Decrypt methods, since both will be disposed once control exists the using block. Show 7 more comments. CreateProtector Purpose ; return protector.

Sergey Kolodiy Sergey Kolodiy 5, 1 1 gold badge 35 35 silver badges 57 57 bronze badges. A quick note about the article you provided is that it states: " Encryption requires a key, which is created and managed by the data protection system. Keys are created with a default lifetime of 90 days, and stored in a suitable location according to the environment.

The following class is one I wrote a while ago to perform exactly the kind of thing you're after, a simple single method call to allow some string-based plaintext to be encrypted with a string-based password, with the resulting encrypted string also being represented as a string.

Of course, there's an equivalent method to decrypt the encrypted string with the same password. Unlike the first version of this code, which used the exact same salt and IV values every time, this newer version will generate random salt and IV values each time.

Since salt and IV must be the same between the encryption and decryption of a given string, the salt and IV is prepended to the cipher text upon encryption and extracted from it again in order to perform the decryption. The result of this is that encrypting the exact same plaintext with the exact same password gives and entirely different ciphertext result each time.

The "strength" of using this comes from using the RijndaelManaged class to perform the encryption for you, along with using the RfcDeriveBytes function of the System.

Cryptography namespace which will generate your encryption key using a standard and secure algorithm specifically, PBKDF2 based upon the string-based password you supply. Finally, it's important to note that this is still unauthenticated encryption. Encryption alone provides only privacy i.

Without knowing your exact requirements, it's difficult to say whether the code here is sufficiently secure for your needs, however, it has been produced to deliver a good balance between relative simplicity of implementation vs "quality".

For example, if your "receiver" of an encrypted string is receiving the string directly from a trusted "sender", then authentication may not even be necessary. If you require something more complex, and which offers authenticated encryption, check out this post for an implementation.

You can download a simple VS sample solution which includes a few unit tests here. If you are targeting ASP. See this article for more details.

If you need to store a password in memory and would like to have it encrypted you should use SecureString :. See this page for an implementation example:. HOW TO? Now, we are going to write the following code in the Main method that is inside the Program. In the given code, we are using a hardcoded value as a key but in real time, we can get a key at runtime and also, we can use the optional initialization vector IV as per the complexity we need.

In this article, we learned how to use a symmetric key for encryption and decryption in C. As per our requirement, we can also use different types of methods present inside the Aes Class. View All. Vivek Kumar Updated date Mar 11,