minio/internal/event/target/kafka_scram_client_contrib.go

85 lines
3.1 KiB
Go

/*
* MinIO Object Storage (c) 2021 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package target
import (
"crypto/sha256"
"crypto/sha512"
"github.com/Shopify/sarama"
"github.com/xdg/scram"
)
func initScramClient(args KafkaArgs, config *sarama.Config) {
switch args.SASL.Mechanism {
case "sha512":
config.Net.SASL.SCRAMClientGeneratorFunc = func() sarama.SCRAMClient { return &XDGSCRAMClient{HashGeneratorFcn: KafkaSHA512} }
config.Net.SASL.Mechanism = sarama.SASLMechanism(sarama.SASLTypeSCRAMSHA512)
case "sha256":
config.Net.SASL.SCRAMClientGeneratorFunc = func() sarama.SCRAMClient { return &XDGSCRAMClient{HashGeneratorFcn: KafkaSHA256} }
config.Net.SASL.Mechanism = sarama.SASLMechanism(sarama.SASLTypeSCRAMSHA256)
default:
// default to PLAIN
config.Net.SASL.Mechanism = sarama.SASLMechanism(sarama.SASLTypePlaintext)
}
}
// KafkaSHA256 is a function that returns a crypto/sha256 hasher and should be used
// to create Client objects configured for SHA-256 hashing.
var KafkaSHA256 scram.HashGeneratorFcn = sha256.New
// KafkaSHA512 is a function that returns a crypto/sha512 hasher and should be used
// to create Client objects configured for SHA-512 hashing.
var KafkaSHA512 scram.HashGeneratorFcn = sha512.New
// XDGSCRAMClient implements the client-side of an authentication
// conversation with a server. A new conversation must be created for
// each authentication attempt.
type XDGSCRAMClient struct {
*scram.Client
*scram.ClientConversation
scram.HashGeneratorFcn
}
// Begin constructs a SCRAM client component based on a given hash.Hash
// factory receiver. This constructor will normalize the username, password
// and authzID via the SASLprep algorithm, as recommended by RFC-5802. If
// SASLprep fails, the method returns an error.
func (x *XDGSCRAMClient) Begin(userName, password, authzID string) (err error) {
x.Client, err = x.HashGeneratorFcn.NewClient(userName, password, authzID)
if err != nil {
return err
}
x.ClientConversation = x.Client.NewConversation()
return nil
}
// Step takes a string provided from a server (or just an empty string for the
// very first conversation step) and attempts to move the authentication
// conversation forward. It returns a string to be sent to the server or an
// error if the server message is invalid. Calling Step after a conversation
// completes is also an error.
func (x *XDGSCRAMClient) Step(challenge string) (response string, err error) {
response, err = x.ClientConversation.Step(challenge)
return
}
// Done returns true if the conversation is completed or has errored.
func (x *XDGSCRAMClient) Done() bool {
return x.ClientConversation.Done()
}