pax_global_header00006660000000000000000000000064145777644260014540gustar00rootroot0000000000000052 comment=fd19680d81d225640bce8756b1c081d6b8bf6775 golang-github-skeema-knownhosts-1.2.2/000077500000000000000000000000001457776442600177475ustar00rootroot00000000000000golang-github-skeema-knownhosts-1.2.2/.github/000077500000000000000000000000001457776442600213075ustar00rootroot00000000000000golang-github-skeema-knownhosts-1.2.2/.github/workflows/000077500000000000000000000000001457776442600233445ustar00rootroot00000000000000golang-github-skeema-knownhosts-1.2.2/.github/workflows/tests.yml000066400000000000000000000014001457776442600252240ustar00rootroot00000000000000name: Tests on: [push, pull_request] env: GOVERSION: "1.21" jobs: test: name: Check code quality and run tests if: "!contains(github.event.head_commit.message, '[ci skip]')" runs-on: ubuntu-latest steps: - name: Set up Go uses: actions/setup-go@v2 with: go-version: ${{env.GOVERSION}} - name: Check out code uses: actions/checkout@v2 - name: Run gofmt run: test -z "$(gofmt -s -d *.go 2>&1)" - name: Run golint run: go get golang.org/x/lint/golint && go install golang.org/x/lint/golint && golint -set_exit_status - name: Run go vet run: go vet - name: Run tests run: go test -v -coverprofile=coverage.out -covermode=count golang-github-skeema-knownhosts-1.2.2/LICENSE000066400000000000000000000261351457776442600207630ustar00rootroot00000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. "Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity. "You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License. "Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files. "Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types. "Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below). "Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof. "Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution." "Contributor" shall mean Licensor and any individual or Legal Entity on behalf of whom a Contribution has been received by Licensor and subsequently incorporated within the Work. 2. Grant of Copyright License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form. 3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed. 4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions: (a) You must give any other recipients of the Work or Derivative Works a copy of this License; and (b) You must cause any modified files to carry prominent notices stating that You changed the files; and (c) You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License. You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License. 5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions. 6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file. 7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License. 8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages. 9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability. END OF TERMS AND CONDITIONS APPENDIX: How to apply the Apache License to your work. To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "{}" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives. Copyright {yyyy} {name of copyright owner} 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. golang-github-skeema-knownhosts-1.2.2/NOTICE000066400000000000000000000011111457776442600206450ustar00rootroot00000000000000Copyright 2024 Skeema LLC and the Skeema Knownhosts authors 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. golang-github-skeema-knownhosts-1.2.2/README.md000066400000000000000000000135751457776442600212410ustar00rootroot00000000000000# knownhosts: enhanced Golang SSH known_hosts management [![build status](https://img.shields.io/github/actions/workflow/status/skeema/knownhosts/tests.yml?branch=main)](https://github.com/skeema/knownhosts/actions) [![godoc](https://img.shields.io/badge/godoc-reference-blue.svg)](https://pkg.go.dev/github.com/skeema/knownhosts) > This repo is brought to you by [Skeema](https://github.com/skeema/skeema), a > declarative pure-SQL schema management system for MySQL and MariaDB. Our > premium products include extensive [SSH tunnel](https://www.skeema.io/docs/options/#ssh) > functionality, which internally makes use of this package. Go provides excellent functionality for OpenSSH known_hosts files in its external package [golang.org/x/crypto/ssh/knownhosts](https://pkg.go.dev/golang.org/x/crypto/ssh/knownhosts). However, that package is somewhat low-level, making it difficult to implement full known_hosts management similar to command-line `ssh`'s behavior for `StrictHostKeyChecking=no` configuration. This repo ([github.com/skeema/knownhosts](https://github.com/skeema/knownhosts)) is a thin wrapper package around [golang.org/x/crypto/ssh/knownhosts](https://pkg.go.dev/golang.org/x/crypto/ssh/knownhosts), adding the following functionality: * Look up known_hosts public keys for any given host * Auto-populate ssh.ClientConfig.HostKeyAlgorithms easily based on known_hosts, providing a solution for [golang/go#29286](https://github.com/golang/go/issues/29286) * Write new known_hosts entries to an io.Writer * Properly format/normalize new known_hosts entries containing ipv6 addresses, providing a solution for [golang/go#53463](https://github.com/golang/go/issues/53463) * Determine if an ssh.HostKeyCallback's error corresponds to a host whose key has changed (indicating potential MitM attack) vs a host that just isn't known yet ## How host key lookup works Although [golang.org/x/crypto/ssh/knownhosts](https://pkg.go.dev/golang.org/x/crypto/ssh/knownhosts) doesn't directly expose a way to query its known_host map, we use a subtle trick to do so: invoke the HostKeyCallback with a valid host but a bogus key. The resulting KeyError allows us to determine which public keys are actually present for that host. By using this technique, [github.com/skeema/knownhosts](https://github.com/skeema/knownhosts) doesn't need to duplicate or re-implement any of the actual known_hosts management from [golang.org/x/crypto/ssh/knownhosts](https://pkg.go.dev/golang.org/x/crypto/ssh/knownhosts). ## Populating ssh.ClientConfig.HostKeyAlgorithms based on known_hosts Hosts often have multiple public keys, each of a different type (algorithm). This can be [problematic](https://github.com/golang/go/issues/29286) in [golang.org/x/crypto/ssh/knownhosts](https://pkg.go.dev/golang.org/x/crypto/ssh/knownhosts): if a host's first public key is *not* in known_hosts, but a key of a different type *is*, the HostKeyCallback returns an error. The solution is to populate `ssh.ClientConfig.HostKeyAlgorithms` based on the algorithms of the known_hosts entries for that host, but [golang.org/x/crypto/ssh/knownhosts](https://pkg.go.dev/golang.org/x/crypto/ssh/knownhosts) does not provide an obvious way to do so. This package uses its host key lookup trick in order to make ssh.ClientConfig.HostKeyAlgorithms easy to populate: ```golang import ( "golang.org/x/crypto/ssh" "github.com/skeema/knownhosts" ) func sshConfigForHost(hostWithPort string) (*ssh.ClientConfig, error) { kh, err := knownhosts.New("/home/myuser/.ssh/known_hosts") if err != nil { return nil, err } config := &ssh.ClientConfig{ User: "myuser", Auth: []ssh.AuthMethod{ /* ... */ }, HostKeyCallback: kh.HostKeyCallback(), // or, equivalently, use ssh.HostKeyCallback(kh) HostKeyAlgorithms: kh.HostKeyAlgorithms(hostWithPort), } return config, nil } ``` ## Writing new known_hosts entries If you wish to mimic the behavior of OpenSSH's `StrictHostKeyChecking=no` or `StrictHostKeyChecking=ask`, this package provides a few functions to simplify this task. For example: ```golang sshHost := "yourserver.com:22" khPath := "/home/myuser/.ssh/known_hosts" kh, err := knownhosts.New(khPath) if err != nil { log.Fatal("Failed to read known_hosts: ", err) } // Create a custom permissive hostkey callback which still errors on hosts // with changed keys, but allows unknown hosts and adds them to known_hosts cb := ssh.HostKeyCallback(func(hostname string, remote net.Addr, key ssh.PublicKey) error { err := kh(hostname, remote, key) if knownhosts.IsHostKeyChanged(err) { return fmt.Errorf("REMOTE HOST IDENTIFICATION HAS CHANGED for host %s! This may indicate a MitM attack.", hostname) } else if knownhosts.IsHostUnknown(err) { f, ferr := os.OpenFile(khPath, os.O_APPEND|os.O_WRONLY, 0600) if ferr == nil { defer f.Close() ferr = knownhosts.WriteKnownHost(f, hostname, remote, key) } if ferr == nil { log.Printf("Added host %s to known_hosts\n", hostname) } else { log.Printf("Failed to add host %s to known_hosts: %v\n", hostname, ferr) } return nil // permit previously-unknown hosts (warning: may be insecure) } return err }) config := &ssh.ClientConfig{ User: "myuser", Auth: []ssh.AuthMethod{ /* ... */ }, HostKeyCallback: cb, HostKeyAlgorithms: kh.HostKeyAlgorithms(sshHost), } ``` ## License **Source code copyright 2024 Skeema LLC and the Skeema Knownhosts authors** ```text 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. ``` golang-github-skeema-knownhosts-1.2.2/example_test.go000066400000000000000000000041571457776442600227770ustar00rootroot00000000000000package knownhosts_test import ( "fmt" "log" "net" "os" "github.com/skeema/knownhosts" "golang.org/x/crypto/ssh" ) func ExampleNew() { sshHost := "yourserver.com:22" kh, err := knownhosts.New("/home/myuser/.ssh/known_hosts") if err != nil { log.Fatal("Failed to read known_hosts: ", err) } config := &ssh.ClientConfig{ User: "myuser", Auth: []ssh.AuthMethod{ /* ... */ }, HostKeyCallback: kh.HostKeyCallback(), // or, equivalently, use ssh.HostKeyCallback(kh) HostKeyAlgorithms: kh.HostKeyAlgorithms(sshHost), } client, err := ssh.Dial("tcp", sshHost, config) if err != nil { log.Fatal("Failed to dial: ", err) } defer client.Close() } func ExampleWriteKnownHost() { sshHost := "yourserver.com:22" khPath := "/home/myuser/.ssh/known_hosts" kh, err := knownhosts.New(khPath) if err != nil { log.Fatal("Failed to read known_hosts: ", err) } // Create a custom permissive hostkey callback which still errors on hosts // with changed keys, but allows unknown hosts and adds them to known_hosts cb := ssh.HostKeyCallback(func(hostname string, remote net.Addr, key ssh.PublicKey) error { err := kh(hostname, remote, key) if knownhosts.IsHostKeyChanged(err) { return fmt.Errorf("REMOTE HOST IDENTIFICATION HAS CHANGED for host %s! This may indicate a MitM attack.", hostname) } else if knownhosts.IsHostUnknown(err) { f, ferr := os.OpenFile(khPath, os.O_APPEND|os.O_WRONLY, 0600) if ferr == nil { defer f.Close() ferr = knownhosts.WriteKnownHost(f, hostname, remote, key) } if ferr == nil { log.Printf("Added host %s to known_hosts\n", hostname) } else { log.Printf("Failed to add host %s to known_hosts: %v\n", hostname, ferr) } return nil // permit previously-unknown hosts (warning: may be insecure) } return err }) config := &ssh.ClientConfig{ User: "myuser", Auth: []ssh.AuthMethod{ /* ... */ }, HostKeyCallback: cb, HostKeyAlgorithms: kh.HostKeyAlgorithms(sshHost), } client, err := ssh.Dial("tcp", sshHost, config) if err != nil { log.Fatal("Failed to dial: ", err) } defer client.Close() } golang-github-skeema-knownhosts-1.2.2/go.mod000066400000000000000000000002001457776442600210450ustar00rootroot00000000000000module github.com/skeema/knownhosts go 1.17 require golang.org/x/crypto v0.13.0 require golang.org/x/sys v0.12.0 // indirect golang-github-skeema-knownhosts-1.2.2/go.sum000066400000000000000000000073111457776442600211040ustar00rootroot00000000000000github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY= golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w= golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc= golang.org/x/crypto v0.13.0 h1:mvySKfSWJ+UKUii46M40LOvyWfN0s2U+46/jDd0e6Ck= golang.org/x/crypto v0.13.0/go.mod h1:y6Z2r+Rw4iayiXXAIxJIDAJ1zMW4yaTpebo8fPOliYc= golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4= golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs= golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s= golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg= golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c= golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs= golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg= golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o= golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo= golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8= golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k= golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo= golang.org/x/term v0.12.0 h1:/ZfYdc3zq+q02Rv9vGqTeSItdzZTSNDmfTi0mBAuidU= golang.org/x/term v0.12.0/go.mod h1:owVbMEjm3cBLCHdkQu9b1opXd4ETQWc3BhuQGKgXgvU= golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ= golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ= golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8= golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8= golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE= golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ= golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo= golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc= golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU= golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0= golang-github-skeema-knownhosts-1.2.2/knownhosts.go000066400000000000000000000166031457776442600225210ustar00rootroot00000000000000// Package knownhosts is a thin wrapper around golang.org/x/crypto/ssh/knownhosts, // adding the ability to obtain the list of host key algorithms for a known host. package knownhosts import ( "encoding/base64" "errors" "fmt" "io" "net" "sort" "strings" "golang.org/x/crypto/ssh" xknownhosts "golang.org/x/crypto/ssh/knownhosts" ) // HostKeyCallback wraps ssh.HostKeyCallback with an additional method to // perform host key algorithm lookups from the known_hosts entries. type HostKeyCallback ssh.HostKeyCallback // New creates a host key callback from the given OpenSSH host key files. The // returned value may be used in ssh.ClientConfig.HostKeyCallback by casting it // to ssh.HostKeyCallback, or using its HostKeyCallback method. Otherwise, it // operates the same as the New function in golang.org/x/crypto/ssh/knownhosts. func New(files ...string) (HostKeyCallback, error) { cb, err := xknownhosts.New(files...) return HostKeyCallback(cb), err } // HostKeyCallback simply casts the receiver back to ssh.HostKeyCallback, for // use in ssh.ClientConfig.HostKeyCallback. func (hkcb HostKeyCallback) HostKeyCallback() ssh.HostKeyCallback { return ssh.HostKeyCallback(hkcb) } // HostKeys returns a slice of known host public keys for the supplied host:port // found in the known_hosts file(s), or an empty slice if the host is not // already known. For hosts that have multiple known_hosts entries (for // different key types), the result will be sorted by known_hosts filename and // line number. func (hkcb HostKeyCallback) HostKeys(hostWithPort string) (keys []ssh.PublicKey) { var keyErr *xknownhosts.KeyError placeholderAddr := &net.TCPAddr{IP: []byte{0, 0, 0, 0}} placeholderPubKey := &fakePublicKey{} var kkeys []xknownhosts.KnownKey if hkcbErr := hkcb(hostWithPort, placeholderAddr, placeholderPubKey); errors.As(hkcbErr, &keyErr) { kkeys = append(kkeys, keyErr.Want...) knownKeyLess := func(i, j int) bool { if kkeys[i].Filename < kkeys[j].Filename { return true } return (kkeys[i].Filename == kkeys[j].Filename && kkeys[i].Line < kkeys[j].Line) } sort.Slice(kkeys, knownKeyLess) keys = make([]ssh.PublicKey, len(kkeys)) for n := range kkeys { keys[n] = kkeys[n].Key } } return keys } // HostKeyAlgorithms returns a slice of host key algorithms for the supplied // host:port found in the known_hosts file(s), or an empty slice if the host // is not already known. The result may be used in ssh.ClientConfig's // HostKeyAlgorithms field, either as-is or after filtering (if you wish to // ignore or prefer particular algorithms). For hosts that have multiple // known_hosts entries (for different key types), the result will be sorted by // known_hosts filename and line number. func (hkcb HostKeyCallback) HostKeyAlgorithms(hostWithPort string) (algos []string) { // We ensure that algos never contains duplicates. This is done for robustness // even though currently golang.org/x/crypto/ssh/knownhosts never exposes // multiple keys of the same type. This way our behavior here is unaffected // even if https://github.com/golang/go/issues/28870 is implemented, for // example by https://github.com/golang/crypto/pull/254. hostKeys := hkcb.HostKeys(hostWithPort) seen := make(map[string]struct{}, len(hostKeys)) addAlgo := func(typ string) { if _, already := seen[typ]; !already { algos = append(algos, typ) seen[typ] = struct{}{} } } for _, key := range hostKeys { typ := key.Type() if typ == ssh.KeyAlgoRSA { // KeyAlgoRSASHA256 and KeyAlgoRSASHA512 are only public key algorithms, // not public key formats, so they can't appear as a PublicKey.Type. // The corresponding PublicKey.Type is KeyAlgoRSA. See RFC 8332, Section 2. addAlgo(ssh.KeyAlgoRSASHA512) addAlgo(ssh.KeyAlgoRSASHA256) } addAlgo(typ) } return algos } // HostKeyAlgorithms is a convenience function for performing host key algorithm // lookups on an ssh.HostKeyCallback directly. It is intended for use in code // paths that stay with the New method of golang.org/x/crypto/ssh/knownhosts // rather than this package's New method. func HostKeyAlgorithms(cb ssh.HostKeyCallback, hostWithPort string) []string { return HostKeyCallback(cb).HostKeyAlgorithms(hostWithPort) } // IsHostKeyChanged returns a boolean indicating whether the error indicates // the host key has changed. It is intended to be called on the error returned // from invoking a HostKeyCallback to check whether an SSH host is known. func IsHostKeyChanged(err error) bool { var keyErr *xknownhosts.KeyError return errors.As(err, &keyErr) && len(keyErr.Want) > 0 } // IsHostUnknown returns a boolean indicating whether the error represents an // unknown host. It is intended to be called on the error returned from invoking // a HostKeyCallback to check whether an SSH host is known. func IsHostUnknown(err error) bool { var keyErr *xknownhosts.KeyError return errors.As(err, &keyErr) && len(keyErr.Want) == 0 } // Normalize normalizes an address into the form used in known_hosts. This // implementation includes a fix for https://github.com/golang/go/issues/53463 // and will omit brackets around ipv6 addresses on standard port 22. func Normalize(address string) string { host, port, err := net.SplitHostPort(address) if err != nil { host = address port = "22" } entry := host if port != "22" { entry = "[" + entry + "]:" + port } else if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") { entry = entry[1 : len(entry)-1] } return entry } // Line returns a line to append to the known_hosts files. This implementation // uses the local patched implementation of Normalize in order to solve // https://github.com/golang/go/issues/53463. func Line(addresses []string, key ssh.PublicKey) string { var trimmed []string for _, a := range addresses { trimmed = append(trimmed, Normalize(a)) } return strings.Join([]string{ strings.Join(trimmed, ","), key.Type(), base64.StdEncoding.EncodeToString(key.Marshal()), }, " ") } // WriteKnownHost writes a known_hosts line to writer for the supplied hostname, // remote, and key. This is useful when writing a custom hostkey callback which // wraps a callback obtained from knownhosts.New to provide additional // known_hosts management functionality. The hostname, remote, and key typically // correspond to the callback's args. func WriteKnownHost(w io.Writer, hostname string, remote net.Addr, key ssh.PublicKey) error { // Always include hostname; only also include remote if it isn't a zero value // and doesn't normalize to the same string as hostname. hostnameNormalized := Normalize(hostname) if strings.ContainsAny(hostnameNormalized, "\t ") { return fmt.Errorf("knownhosts: hostname '%s' contains spaces", hostnameNormalized) } addresses := []string{hostnameNormalized} remoteStrNormalized := Normalize(remote.String()) if remoteStrNormalized != "[0.0.0.0]:0" && remoteStrNormalized != hostnameNormalized && !strings.ContainsAny(remoteStrNormalized, "\t ") { addresses = append(addresses, remoteStrNormalized) } line := Line(addresses, key) + "\n" _, err := w.Write([]byte(line)) return err } // fakePublicKey is used as part of the work-around for // https://github.com/golang/go/issues/29286 type fakePublicKey struct{} func (fakePublicKey) Type() string { return "fake-public-key" } func (fakePublicKey) Marshal() []byte { return []byte("fake public key") } func (fakePublicKey) Verify(_ []byte, _ *ssh.Signature) error { return errors.New("Verify called on placeholder key") } golang-github-skeema-knownhosts-1.2.2/knownhosts_test.go000066400000000000000000000260551457776442600235620ustar00rootroot00000000000000package knownhosts import ( "bytes" "crypto/ecdsa" "crypto/ed25519" "crypto/elliptic" "crypto/rand" "crypto/rsa" "net" "os" "path/filepath" "testing" "golang.org/x/crypto/ssh" ) func TestNew(t *testing.T) { khPath := getTestKnownHosts(t) // Valid path should return a callback and no error; callback should be usable // in ssh.ClientConfig.HostKeyCallback if kh, err := New(khPath); err != nil { t.Errorf("Unexpected error from New on valid known_hosts path: %v", err) } else { _ = ssh.ClientConfig{ HostKeyCallback: kh.HostKeyCallback(), } } // Invalid path should return an error if _, err := New(khPath + "_does_not_exist"); err == nil { t.Error("Expected error from New with invalid path, but error was nil") } } func TestHostKeyAlgorithms(t *testing.T) { khPath := getTestKnownHosts(t) kh, err := New(khPath) if err != nil { t.Fatalf("Unexpected error from New: %v", err) } expectedAlgorithms := map[string][]string{ "only-rsa.example.test:22": {"rsa-sha2-512", "rsa-sha2-256", "ssh-rsa"}, "only-ecdsa.example.test:22": {"ecdsa-sha2-nistp256"}, "only-ed25519.example.test:22": {"ssh-ed25519"}, "multi.example.test:2233": {"rsa-sha2-512", "rsa-sha2-256", "ssh-rsa", "ecdsa-sha2-nistp256", "ssh-ed25519"}, "192.168.1.102:2222": {"ecdsa-sha2-nistp256", "ssh-ed25519"}, "unknown-host.example.test": {}, // host not in file "multi.example.test:22": {}, // different port than entry in file "192.168.1.102": {}, // different port than entry in file } for host, expected := range expectedAlgorithms { actual := kh.HostKeyAlgorithms(host) if len(actual) != len(expected) { t.Errorf("Unexpected number of algorithms returned by HostKeyAlgorithms(%q): expected %d, found %d", host, len(expected), len(actual)) continue } for n := range expected { if expected[n] != actual[n] { t.Errorf("Unexpected algorithms returned by HostKeyAlgorithms(%q): expected %v, found %v", host, expected, actual) break } } } } func TestIsHostKeyChanged(t *testing.T) { khPath := getTestKnownHosts(t) kh, err := New(khPath) if err != nil { t.Fatalf("Unexpected error from New: %v", err) } noAddr, _ := net.ResolveTCPAddr("tcp", "0.0.0.0:0") pubKey := generatePubKeyEd25519(t) // Unknown host: should return false if err := kh("unknown.example.test:22", noAddr, pubKey); IsHostKeyChanged(err) { t.Error("IsHostKeyChanged unexpectedly returned true for unknown host") } // Known host, wrong key: should return true if err := kh("multi.example.test:2233", noAddr, pubKey); !IsHostKeyChanged(err) { t.Error("IsHostKeyChanged unexpectedly returned false for known host with different host key") } // Append the key for a known host that doesn't already have that key type, // re-init the known_hosts, and check again: should return false f, err := os.OpenFile(khPath, os.O_APPEND|os.O_WRONLY, 0600) if err != nil { t.Fatalf("Unable to open %s for writing: %v", khPath, err) } if err := WriteKnownHost(f, "only-ecdsa.example.test:22", noAddr, pubKey); err != nil { t.Fatalf("Unable to write known host line: %v", err) } f.Close() if kh, err = New(khPath); err != nil { t.Fatalf("Unexpected error from New: %v", err) } if err := kh("only-ecdsa.example.test:22", noAddr, pubKey); IsHostKeyChanged(err) { t.Error("IsHostKeyChanged unexpectedly returned true for valid known host") } } func TestIsHostUnknown(t *testing.T) { khPath := getTestKnownHosts(t) kh, err := New(khPath) if err != nil { t.Fatalf("Unexpected error from New: %v", err) } noAddr, _ := net.ResolveTCPAddr("tcp", "0.0.0.0:0") pubKey := generatePubKeyEd25519(t) // Unknown host: should return true if err := kh("unknown.example.test:22", noAddr, pubKey); !IsHostUnknown(err) { t.Error("IsHostUnknown unexpectedly returned false for unknown host") } // Known host, wrong key: should return false if err := kh("multi.example.test:2233", noAddr, pubKey); IsHostUnknown(err) { t.Error("IsHostUnknown unexpectedly returned true for known host with different host key") } // Append the key for an unknown host, re-init the known_hosts, and check // again: should return false f, err := os.OpenFile(khPath, os.O_APPEND|os.O_WRONLY, 0600) if err != nil { t.Fatalf("Unable to open %s for writing: %v", khPath, err) } if err := WriteKnownHost(f, "newhost.example.test:22", noAddr, pubKey); err != nil { t.Fatalf("Unable to write known host line: %v", err) } f.Close() if kh, err = New(khPath); err != nil { t.Fatalf("Unexpected error from New: %v", err) } if err := kh("newhost.example.test:22", noAddr, pubKey); IsHostUnknown(err) { t.Error("IsHostUnknown unexpectedly returned true for valid known host") } } func TestNormalize(t *testing.T) { for in, want := range map[string]string{ "127.0.0.1": "127.0.0.1", "127.0.0.1:22": "127.0.0.1", "[127.0.0.1]:22": "127.0.0.1", "[127.0.0.1]:23": "[127.0.0.1]:23", "127.0.0.1:23": "[127.0.0.1]:23", "[a.b.c]:22": "a.b.c", "abcd::abcd:abcd:abcd": "abcd::abcd:abcd:abcd", "[abcd::abcd:abcd:abcd]": "abcd::abcd:abcd:abcd", "[abcd::abcd:abcd:abcd]:22": "abcd::abcd:abcd:abcd", "[abcd::abcd:abcd:abcd]:23": "[abcd::abcd:abcd:abcd]:23", } { got := Normalize(in) if got != want { t.Errorf("Normalize(%q) = %q, want %q", in, got, want) } } } func TestLine(t *testing.T) { edKeyStr := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIF9Wn63tLEhSWl9Ye+4x2GnruH8cq0LIh2vum/fUHrFQ" edKey, _, _, _, err := ssh.ParseAuthorizedKey([]byte(edKeyStr)) if err != nil { t.Fatalf("Unable to parse authorized key: %v", err) } for in, want := range map[string]string{ "server.org": "server.org " + edKeyStr, "server.org:22": "server.org " + edKeyStr, "server.org:23": "[server.org]:23 " + edKeyStr, "[c629:1ec4:102:304:102:304:102:304]:22": "c629:1ec4:102:304:102:304:102:304 " + edKeyStr, "[c629:1ec4:102:304:102:304:102:304]:23": "[c629:1ec4:102:304:102:304:102:304]:23 " + edKeyStr, } { if got := Line([]string{in}, edKey); got != want { t.Errorf("Line(%q) = %q, want %q", in, got, want) } } } func TestWriteKnownHost(t *testing.T) { edKeyStr := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIF9Wn63tLEhSWl9Ye+4x2GnruH8cq0LIh2vum/fUHrFQ" edKey, _, _, _, err := ssh.ParseAuthorizedKey([]byte(edKeyStr)) if err != nil { t.Fatalf("Unable to parse authorized key: %v", err) } for _, m := range []struct { hostname string remoteAddr string want string err string }{ {hostname: "::1", remoteAddr: "[::1]:22", want: "::1 " + edKeyStr + "\n"}, {hostname: "127.0.0.1", remoteAddr: "127.0.0.1:22", want: "127.0.0.1 " + edKeyStr + "\n"}, {hostname: "ipv4.test", remoteAddr: "192.168.0.1:23", want: "ipv4.test,[192.168.0.1]:23 " + edKeyStr + "\n"}, {hostname: "ipv6.test", remoteAddr: "[ff01::1234]:23", want: "ipv6.test,[ff01::1234]:23 " + edKeyStr + "\n"}, {hostname: "normal.zone", remoteAddr: "[fe80::1%en0]:22", want: "normal.zone,fe80::1%en0 " + edKeyStr + "\n"}, {hostname: "spaces.zone", remoteAddr: "[fe80::1%Ethernet 1]:22", want: "spaces.zone " + edKeyStr + "\n"}, {hostname: "spaces.zone", remoteAddr: "[fe80::1%Ethernet\t2]:23", want: "spaces.zone " + edKeyStr + "\n"}, {hostname: "[fe80::1%Ethernet 1]:22", err: "knownhosts: hostname 'fe80::1%Ethernet 1' contains spaces"}, {hostname: "[fe80::1%Ethernet\t2]:23", err: "knownhosts: hostname '[fe80::1%Ethernet\t2]:23' contains spaces"}, } { remote, err := net.ResolveTCPAddr("tcp", m.remoteAddr) if err != nil { t.Fatalf("Unable to resolve tcp addr: %v", err) } var got bytes.Buffer err = WriteKnownHost(&got, m.hostname, remote, edKey) if m.err != "" { if err == nil || err.Error() != m.err { t.Errorf("WriteKnownHost(%q) expected error %v, found %v", m.hostname, m.err, err) } continue } if err != nil { t.Fatalf("Unable to write known host: %v", err) } if got.String() != m.want { t.Errorf("WriteKnownHost(%q) = %q, want %q", m.hostname, got.String(), m.want) } } } var testKnownHostsContents []byte // getTestKnownHosts returns a path to a test known_hosts file. The file path // will differ between test functions, but the contents are always the same, // containing keys generated upon the first invocation. The file is removed // upon test completion. func getTestKnownHosts(t *testing.T) string { // Re-use previously memoized result if len(testKnownHostsContents) > 0 { dir := t.TempDir() khPath := filepath.Join(dir, "known_hosts") if err := os.WriteFile(khPath, testKnownHostsContents, 0600); err != nil { t.Fatalf("Unable to write to %s: %v", khPath, err) } return khPath } khPath := writeTestKnownHosts(t) if contents, err := os.ReadFile(khPath); err == nil { testKnownHostsContents = contents } return khPath } // writeTestKnownHosts generates the test known_hosts file and returns the // file path to it. The generated file contains several hosts with a mix of // key types; each known host has between 1 and 4 different known host keys. // If generating or writing the file fails, the test fails. func writeTestKnownHosts(t *testing.T) string { t.Helper() hosts := map[string][]ssh.PublicKey{ "only-rsa.example.test:22": {generatePubKeyRSA(t)}, "only-ecdsa.example.test:22": {generatePubKeyECDSA(t)}, "only-ed25519.example.test:22": {generatePubKeyEd25519(t)}, "multi.example.test:2233": {generatePubKeyRSA(t), generatePubKeyECDSA(t), generatePubKeyEd25519(t), generatePubKeyEd25519(t)}, "192.168.1.102:2222": {generatePubKeyECDSA(t), generatePubKeyEd25519(t)}, "[fe80::abc:abc:abcd:abcd]:22": {generatePubKeyEd25519(t), generatePubKeyRSA(t)}, } dir := t.TempDir() khPath := filepath.Join(dir, "known_hosts") f, err := os.OpenFile(khPath, os.O_CREATE|os.O_WRONLY, 0600) if err != nil { t.Fatalf("Unable to open %s for writing: %v", khPath, err) } defer f.Close() noAddr, _ := net.ResolveTCPAddr("tcp", "0.0.0.0:0") for host, keys := range hosts { for _, k := range keys { if err := WriteKnownHost(f, host, noAddr, k); err != nil { t.Fatalf("Unable to write known host line: %v", err) } } } return khPath } func generatePubKeyRSA(t *testing.T) ssh.PublicKey { t.Helper() privKey, err := rsa.GenerateKey(rand.Reader, 4096) if err != nil { t.Fatalf("Unable to generate RSA key: %v", err) } pub, err := ssh.NewPublicKey(&privKey.PublicKey) if err != nil { t.Fatalf("Unable to convert public key: %v", err) } return pub } func generatePubKeyECDSA(t *testing.T) ssh.PublicKey { t.Helper() privKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader) if err != nil { t.Fatalf("Unable to generate ECDSA key: %v", err) } pub, err := ssh.NewPublicKey(privKey.Public()) if err != nil { t.Fatalf("Unable to convert public key: %v", err) } return pub } func generatePubKeyEd25519(t *testing.T) ssh.PublicKey { t.Helper() rawPub, _, err := ed25519.GenerateKey(nil) if err != nil { t.Fatalf("Unable to generate ed25519 key: %v", err) } pub, err := ssh.NewPublicKey(rawPub) if err != nil { t.Fatalf("Unable to convert public key: %v", err) } return pub }