/// <summary>
/// Decrypts the symmetric key and saves it in metadata.
/// </summary>
internal static void DecryptSymmetricKey(SqlTceCipherInfoEntry sqlTceCipherInfoEntry, out SqlClientSymmetricKey sqlClientSymmetricKey, out SqlEncryptionKeyInfo encryptionkeyInfoChosen, SqlConnection connection, SqlCommand command)
{
Debug.Assert(sqlTceCipherInfoEntry is not null, "sqlTceCipherInfoEntry should not be null in DecryptSymmetricKey.");
Debug.Assert(sqlTceCipherInfoEntry.ColumnEncryptionKeyValues is not null,
"sqlTceCipherInfoEntry.ColumnEncryptionKeyValues should not be null in DecryptSymmetricKey.");
sqlClientSymmetricKey = null;
encryptionkeyInfoChosen = null;
Exception lastException = null;
SqlSymmetricKeyCache globalCekCache = SqlSymmetricKeyCache.GetInstance();
foreach (SqlEncryptionKeyInfo keyInfo in sqlTceCipherInfoEntry.ColumnEncryptionKeyValues)
{
try
{
sqlClientSymmetricKey = ShouldUseInstanceLevelProviderFlow(keyInfo.keyStoreName, connection, command) ?
GetKeyFromLocalProviders(keyInfo, connection, command) :
globalCekCache.GetKey(keyInfo, connection, command);
encryptionkeyInfoChosen = keyInfo;
break;
}
catch (Exception e)
{
lastException = e;
}
}
if (sqlClientSymmetricKey is null)
{
Debug.Assert(lastException is not null, "CEK decryption failed without raising exceptions");
throw lastException;
}
Debug.Assert(encryptionkeyInfoChosen is not null, "encryptionkeyInfoChosen must have a value.");
}
/// <summary>
/// <para> Decrypts the symmetric key and saves it in metadata.
/// </summary>
internal static void DecryptSymmetricKey(SqlTceCipherInfoEntry?sqlTceCipherInfoEntry, string serverName, out SqlClientSymmetricKey sqlClientSymmetricKey, out SqlEncryptionKeyInfo?encryptionkeyInfoChosen)
{
Debug.Assert(serverName != null, @"serverName should not be null in DecryptSymmetricKey.");
Debug.Assert(sqlTceCipherInfoEntry.HasValue, "sqlTceCipherInfoEntry should not be null in DecryptSymmetricKey.");
Debug.Assert(sqlTceCipherInfoEntry.Value.ColumnEncryptionKeyValues != null,
"sqlTceCipherInfoEntry.ColumnEncryptionKeyValues should not be null in DecryptSymmetricKey.");
sqlClientSymmetricKey = null;
encryptionkeyInfoChosen = null;
Exception lastException = null;
SqlSymmetricKeyCache cache = SqlSymmetricKeyCache.GetInstance();
foreach (SqlEncryptionKeyInfo keyInfo in sqlTceCipherInfoEntry.Value.ColumnEncryptionKeyValues)
{
try {
if (cache.GetKey(keyInfo, serverName, out sqlClientSymmetricKey))
{
encryptionkeyInfoChosen = keyInfo;
break;
}
} catch (Exception e) {
lastException = e;
}
}
if (null == sqlClientSymmetricKey)
{
Debug.Assert(null != lastException, "CEK decryption failed without raising exceptions");
throw lastException;
}
Debug.Assert(encryptionkeyInfoChosen.HasValue, "encryptionkeyInfoChosen must have a value.");
}