Don Newton | 379ae25 | 2019-04-01 12:17:06 -0400 | [diff] [blame^] | 1 | // Copyright (C) MongoDB, Inc. 2017-present. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 4 | // not use this file except in compliance with the License. You may obtain |
| 5 | // a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| 6 | |
| 7 | package auth |
| 8 | |
| 9 | import ( |
| 10 | "context" |
| 11 | |
| 12 | "github.com/mongodb/mongo-go-driver/x/network/description" |
| 13 | "github.com/mongodb/mongo-go-driver/x/network/wiremessage" |
| 14 | ) |
| 15 | |
| 16 | func newDefaultAuthenticator(cred *Cred) (Authenticator, error) { |
| 17 | return &DefaultAuthenticator{ |
| 18 | Cred: cred, |
| 19 | }, nil |
| 20 | } |
| 21 | |
| 22 | // DefaultAuthenticator uses SCRAM-SHA-1 or MONGODB-CR depending |
| 23 | // on the server version. |
| 24 | type DefaultAuthenticator struct { |
| 25 | Cred *Cred |
| 26 | } |
| 27 | |
| 28 | // Auth authenticates the connection. |
| 29 | func (a *DefaultAuthenticator) Auth(ctx context.Context, desc description.Server, rw wiremessage.ReadWriter) error { |
| 30 | var actual Authenticator |
| 31 | var err error |
| 32 | |
| 33 | switch chooseAuthMechanism(desc) { |
| 34 | case SCRAMSHA256: |
| 35 | actual, err = newScramSHA256Authenticator(a.Cred) |
| 36 | case SCRAMSHA1: |
| 37 | actual, err = newScramSHA1Authenticator(a.Cred) |
| 38 | default: |
| 39 | actual, err = newMongoDBCRAuthenticator(a.Cred) |
| 40 | } |
| 41 | |
| 42 | if err != nil { |
| 43 | return newAuthError("error creating authenticator", err) |
| 44 | } |
| 45 | |
| 46 | return actual.Auth(ctx, desc, rw) |
| 47 | } |
| 48 | |
| 49 | // If a server provides a list of supported mechanisms, we choose |
| 50 | // SCRAM-SHA-256 if it exists or else MUST use SCRAM-SHA-1. |
| 51 | // Otherwise, we decide based on what is supported. |
| 52 | func chooseAuthMechanism(desc description.Server) string { |
| 53 | if desc.SaslSupportedMechs != nil { |
| 54 | for _, v := range desc.SaslSupportedMechs { |
| 55 | if v == SCRAMSHA256 { |
| 56 | return v |
| 57 | } |
| 58 | } |
| 59 | return SCRAMSHA1 |
| 60 | } |
| 61 | |
| 62 | if err := description.ScramSHA1Supported(desc.WireVersion); err == nil { |
| 63 | return SCRAMSHA1 |
| 64 | } |
| 65 | |
| 66 | return MONGODBCR |
| 67 | } |