HMACSHA1 Constructor (Byte[])
Silverlight
Initializes a new instance of the HMACSHA1 class with the specified key data.
Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)
Parameters
- key
- Type: System.Byte[]
The secret key for HMACSHA1 encryption. The key can be any length, but if it is more than 64 bytes long it will be hashed (using SHA-1) to derive a 64-byte key. Therefore, the recommended size of the secret key is 64 bytes.
| Exception | Condition |
|---|---|
| ArgumentNullException | The key parameter is null. |
HMACSHA1 is a type of keyed hash algorithm that is constructed from the SHA1 hash function and used as an HMAC, or hash-based message authentication code. The HMAC process mixes a secret key with the message data, hashes the result with the hash function, mixes that hash value with the secret key again, then applies the hash function a second time. The output hash will be 160 bits (20 bytes) in length.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
