Adds a key to the storage.
public func importFromFile(filename: String, format: Int32, keyAlgorithm: String, scheme: String, schemeParams: String, keyType: Int32) throws -> Void
Use this method to add a key stored in a file.
|kffUnknown||0||The key format was not recognized as one of the known formats.|
|kffAuto||1||The default format in current circumstances. This depends on the key being loaded or saved.|
|kffDER||2||DER (binary) format|
|kffPEM||3||PEM format (base64-encoded with headers)|
|kffJSON||4||JSON key format|
|ktAuto||0||The default key type in current circumstances. This depends on the operation, the file content, and the storage type.|
|ktPublic||1||The operation should be performed on a public key.|
|ktSecret||2||The operation should be performed on a private or secret key|