Microsoft.Data.SqlClient.SqlAeadAes256CbcHmac256Algorithm

class SqlAeadAes256CbcHmac256Algorithm : SqlClientEncryptionAlgorithm

This class implements authenticated encryption algorithm with associated data as described in http://tools.ietf.org/html/draft-mcgrew-aead-aes-cbc-hmac-sha2-05. More specifically this implements AEAD_AES_256_CBC_HMAC_SHA256 algorithm.

Documentation
Code

protected byte[] DecryptData(byte[] cipherText, bool hasAuthenticationTag)

Decryption steps 1. Validate version byte 2. (optional) Validate Authentication tag 3. Decrypt the message

protected byte[] EncryptData(byte[] plainText, bool hasAuthenticationTag)

Encryption Algorithm cell_iv = HMAC_SHA-2-256(iv_key, cell_data) truncated to 128 bits cell_ciphertext = AES-CBC-256(enc_key, cell_iv, cell_data) with PKCS7 padding. (optional) cell_tag = HMAC_SHA-2-256(mac_key, versionbyte + cell_iv + cell_ciphertext + versionbyte_length) cell_blob = versionbyte + [cell_tag] + cell_iv + cell_ciphertext