Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All

Rfc2898DeriveBytes Constructor (String, Byte[])

Initializes a new instance of the Rfc2898DeriveBytes class using a password and salt to derive the key.

Namespace:  System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)

public Rfc2898DeriveBytes(
	string password,
	byte[] salt
)

Parameters

password
Type: System.String
The password used to derive the key.
salt
Type: System.Byte[]
The key salt used to derive the key.

ExceptionCondition
ArgumentException

The specified salt size is smaller than 8 bytes or the iteration count is less than 1.

ArgumentNullException

The password or salt is null.

The salt size must be 8 bytes or larger.

RFC 2898 includes methods for creating a key and initialization vector (IV) from a password and salt. You can use PBKDF2, a password-based key derivation function, to derive keys using a pseudo-random function that allows keys of virtually unlimited length to be generated. The Rfc2898DeriveBytes class can be used to produce a derived key from a base key and other parameters. In a password-based key derivation function, the base key is a password and the other parameters are a salt value and an iteration count.

For more information about PBKDF2, see RFC 2898, "PKCS #5: Password-Based Cryptography Specification Version 2.0," available on the Request for Comment Web site. See section 5.2, "PBKDF2," for complete details.

Security noteSecurity Note:

Never hard-code a password within your source code. Hard-coded passwords can be retrieved from an assembly by using the Microsoft Intermediate Language Disassembler (Ildasm.exe), by using a hexadecimal editor, or by simply opening up the assembly in a text editor such as Notepad.exe.

The following example demonstrates how to use the Rfc2898DeriveBytes constructor to encrypt an isolated storage file. This code example is part of a larger example provided for the AesManaged class.

AesManaged#3

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Community Additions

ADD
Show:
© 2015 Microsoft