/// <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>
/// Constructor.
/// </summary>
/// <param name="sqlTceCipherInfoEntry"></param>
/// <param name="ordinal"></param>
/// <param name="cipherAlgorithmId"></param>
/// <param name="cipherAlgorithmName"></param>
/// <param name="encryptionType"></param>
/// <param name="normalizationRuleVersion"></param>
internal SqlCipherMetadata(SqlTceCipherInfoEntry sqlTceCipherInfoEntry,
ushort ordinal,
byte cipherAlgorithmId,
string cipherAlgorithmName,
byte encryptionType,
byte normalizationRuleVersion)
{
Debug.Assert(!sqlTceCipherInfoEntry.Equals(default(SqlTceCipherInfoEntry)), "sqlTceCipherInfoEntry should not be un-initialized.");
_sqlTceCipherInfoEntry = sqlTceCipherInfoEntry;
_ordinal = ordinal;
_cipherAlgorithmId = cipherAlgorithmId;
_cipherAlgorithmName = cipherAlgorithmName;
_encryptionType = encryptionType;
_normalizationRuleVersion = normalizationRuleVersion;
_sqlEncryptionKeyInfo = null;
}
