Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/SqlClient/SqlColumnEncryptionKeyStoreProvider.cs

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+//------------------------------------------------------------------------------
+// <copyright file="SqlException.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">balnee</owner>
+// <owner current="true" primary="false">krishnib</owner>
+//------------------------------------------------------------------------------
+namespace System.Data.SqlClient
+{
+    using System;
+
+    /// <summary>
+    /// Abstract base class for all column encryption Key Store providers. It exposes two functions
+    ///		1. DecryptColumnEncryptionKey - This is the function used by SqlClient under the covers to decrypt encrypted column encryption key blob.
+    ///		2. EncryptColumnEncryptionKey - This will be used by client tools that generate DDL for customers
+    /// </summary>
+    public abstract class SqlColumnEncryptionKeyStoreProvider
+    {
+        /// <summary>
+        /// This function must be implemented by the corresponding Key Store providers. This function should use an asymmetric key identified by the key path
+        /// and decrypt an encrypted column encryption key with a given encryption algorithm.
+        /// </summary>
+        /// <param name="masterKeyPath">Complete path of an asymmetric key. Path format is specific to a key store provider.</param>
+        /// <param name="encryptionAlgorithm">Asymmetric Key Encryption Algorithm</param>
+        /// <param name="encryptedColumnEncryptionKey">Encrypted Column Encryption Key</param>
+        /// <returns>Plain text column encryption key</returns>
+        public abstract byte[] DecryptColumnEncryptionKey(string masterKeyPath, string encryptionAlgorithm, byte[] encryptedColumnEncryptionKey);
+
+        /// <summary>
+        /// This function must be implemented by the corresponding Key Store providers. This function should use an asymmetric key identified by a key path
+        /// and encrypt a plain text column encryption key with a given asymmetric key encryption algorithm.
+        /// </summary>
+        /// <param name="keyPath">Complete path of an asymmetric key. Path format is specific to a key store provider.</param>
+        /// <param name="encryptionAlgorithm">Asymmetric Key Encryption Algorithm</param>
+        /// <param name="columnEncryptionKey">Plain text column encryption key to be encrypted</param>
+        /// <returns>Encrypted column encryption key</returns>
+        public abstract byte[] EncryptColumnEncryptionKey(string masterKeyPath, string encryptionAlgorithm, byte[] columnEncryptionKey);
+    }
+}