NewAPIKey create a api key provider.

NewBase64 create a base64 provider.

NewEnv create a env provider.

NewFile create a file provider.

NewHmac create a hmac provider.

Parse will parse config string to create a credential Provider.

ProtocolAPIKey will hold api key credential.

ProtocolBase64 will represents credential binary data in base64 Storage service like gcs will take token files as input, we provide base64 protocol so that user can pass token binary data directly.

ProtocolEnv will represent credential from env.

ProtocolFile will hold file credential.

ProtocolHmac will hold access key and secret key credential.

ErrInvalidValue means value is invalid.

ErrUnsupportedProtocol means protocol is unsupported.

Error represents error related to credential.

Provider will provide credential protocol and values.