mirror of https://github.com/go-gitea/gitea
Implement http signatures support for the API (#17565)
Fixes #12338 This allows use to talk to the API with our ssh certificate (and/or ssh-agent) without needing to fetch an API key or tokens. It will just automatically work when users have added their ssh principal in gitea. This needs client code in tea Update: also support normal pubkeys ref: https://tools.ietf.org/html/draft-cavage-http-signatures Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com> Co-authored-by: zeripath <art27@cantab.net> Signed-off-by: Andrew Thornton <art27@cantab.net>pull/18271/head^2
Wim
2 years ago
committed by
GitHub
parent
48be5e77e5
commit
e528e2b435
@ -0,0 +1,137 @@ |
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// Copyright 2022 The Gitea Authors. All rights reserved.
|
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package integrations |
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import ( |
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"encoding/base64" |
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"fmt" |
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"net/http" |
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"net/url" |
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"testing" |
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api "code.gitea.io/gitea/modules/structs" |
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"github.com/go-fed/httpsig" |
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"golang.org/x/crypto/ssh" |
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) |
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const ( |
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httpsigPrivateKey = `-----BEGIN OPENSSH PRIVATE KEY----- |
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b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAABFwAAAAdzc2gtcn |
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NhAAAAAwEAAQAAAQEAqjmQeb5Eb1xV7qbNf9ErQ0XRvKZWzUsLFhJzZz+Ab7q8WtPs91vQ |
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fBiypw4i8OTG6WzDcgZaV8Ndxn7iHnIstdA1k89MVG4stydymmwmk9+mrCMNsu5OmdIy9F |
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AZ61RDcKuf5VG2WKkmeK0VO+OMJIYfE1C6czNeJ6UAmcIOmhGxvjMI83XUO9n0ftwTwayp |
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+XU5prvKx/fTvlPjbraPNU4OzwPjVLqXBzpoXYhBquPaZYFRVyvfFZLObYsmy+BrsxcloM |
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l+9w4P0ATJ9njB7dRDL+RrN4uhhYSihqOK4w4vaiOj1+aA0eC0zXunEfLXfGIVQ/FhWcCy |
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5f72mMiKnQAAA9AxSmzFMUpsxQAAAAdzc2gtcnNhAAABAQCqOZB5vkRvXFXups1/0StDRd |
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G8plbNSwsWEnNnP4Bvurxa0+z3W9B8GLKnDiLw5MbpbMNyBlpXw13GfuIeciy10DWTz0xU |
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biy3J3KabCaT36asIw2y7k6Z0jL0UBnrVENwq5/lUbZYqSZ4rRU744wkhh8TULpzM14npQ |
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CZwg6aEbG+MwjzddQ72fR+3BPBrKn5dTmmu8rH99O+U+Nuto81Tg7PA+NUupcHOmhdiEGq |
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49plgVFXK98Vks5tiybL4GuzFyWgyX73Dg/QBMn2eMHt1EMv5Gs3i6GFhKKGo4rjDi9qI6 |
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PX5oDR4LTNe6cR8td8YhVD8WFZwLLl/vaYyIqdAAAAAwEAAQAAAQBz+nyBNi2SYir6SxPA |
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flcnoq5gBkUl4ndPNosCUbXEakpi5/mQHzJRGtK+F1efIYCVEdGoIsPy/90onNKbQ9dKmO |
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2oI5kx/U7iCzJ+HCm8nqkEp21x+AP9scWdx+Wg/OxmG8j5iU7f4X+gwOyyvTqCuA78Lgia |
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7Oi9wiJCoIEqXr6dRYGJzfASwKA2dj995HzATexleLSD5fQCmZTF+Vh5OQ5WmE+c53JdZS |
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T3Plie/P/smgSWBtf1fWr6JL2+EBsqQsIK1Jo7r/7rxsz+ILoVfnneNQY4QSa9W+t6ZAI+ |
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caSA0Guv7vC92ewjlMVlwKa3XaEjMJb5sFlg1r6TYMwBAAAAgQDQwXvgSXNaSHIeH53/Ab |
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t4BlNibtxK8vY8CZFloAKXkjrivKSlDAmQCM0twXOweX2ScPjE+XlSMV4AUsv/J6XHGHci |
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W3+PGIBfc/fQRBpiyhzkoXYDVrlkSKHffCnAqTUQlYkhr0s7NkZpEeqPE0doAUs4dK3Iqb |
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zdtz8e5BPXZwAAAIEA4U/JskIu5Oge8Is2OLOhlol0EJGw5JGodpFyhbMC+QYK9nYqy7wI |
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a6mZ2EfOjjwIZD/+wYyulw6cRve4zXwgzUEXLIKp8/H3sYvJK2UMeP7y68sQFqGxbm6Rnh |
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tyBBSaJQnOXVOFf9gqZGCyO/J0Illg3AXTuC8KS/cxwasC38EAAACBAMFo/6XQoR6E3ynj |
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VBaz2SilWqQBixUyvcNz8LY73IIDCecoccRMFSEKhWtvlJijxvFbF9M8g9oKAVPuub4V5r |
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CGmwVPEd5yt4C2iyV0PhLp1PA2/i42FpCSnHaz/EXSz6ncTZcOMMuDqUbgUUpQg4VSUDl9 |
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fhTNAzWwZoQ91aHdAAAAFHUwMDIyMTQ2QGljdHMtcC1ueC03AQIDBAUG |
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-----END OPENSSH PRIVATE KEY-----` |
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httpsigCertificate = `ssh-rsa-cert-v01@openssh.com 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` |
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) |
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func TestHTTPSigPubKey(t *testing.T) { |
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// Add our public key to user1
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defer prepareTestEnv(t)() |
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session := loginUser(t, "user1") |
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token := url.QueryEscape(getTokenForLoggedInUser(t, session)) |
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keysURL := fmt.Sprintf("/api/v1/user/keys?token=%s", token) |
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keyType := "ssh-rsa" |
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keyContent := "AAAAB3NzaC1yc2EAAAADAQABAAABAQCqOZB5vkRvXFXups1/0StDRdG8plbNSwsWEnNnP4Bvurxa0+z3W9B8GLKnDiLw5MbpbMNyBlpXw13GfuIeciy10DWTz0xUbiy3J3KabCaT36asIw2y7k6Z0jL0UBnrVENwq5/lUbZYqSZ4rRU744wkhh8TULpzM14npQCZwg6aEbG+MwjzddQ72fR+3BPBrKn5dTmmu8rH99O+U+Nuto81Tg7PA+NUupcHOmhdiEGq49plgVFXK98Vks5tiybL4GuzFyWgyX73Dg/QBMn2eMHt1EMv5Gs3i6GFhKKGo4rjDi9qI6PX5oDR4LTNe6cR8td8YhVD8WFZwLLl/vaYyIqd" |
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rawKeyBody := api.CreateKeyOption{ |
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Title: "test-key", |
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Key: keyType + " " + keyContent, |
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} |
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req := NewRequestWithJSON(t, "POST", keysURL, rawKeyBody) |
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session.MakeRequest(t, req, http.StatusCreated) |
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// parse our private key and create the httpsig request
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sshSigner, _ := ssh.ParsePrivateKey([]byte(httpsigPrivateKey)) |
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keyID := ssh.FingerprintSHA256(sshSigner.PublicKey()) |
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// create the request
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req = NewRequest(t, "GET", "/api/v1/admin/users") |
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signer, _, err := httpsig.NewSSHSigner(sshSigner, httpsig.DigestSha512, []string{httpsig.RequestTarget, "(created)", "(expires)"}, httpsig.Signature, 10) |
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if err != nil { |
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t.Fatal(err) |
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} |
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// sign the request
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err = signer.SignRequest(keyID, req, nil) |
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if err != nil { |
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t.Fatal(err) |
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} |
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// make the request
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MakeRequest(t, req, http.StatusOK) |
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} |
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func TestHTTPSigCert(t *testing.T) { |
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// Add our public key to user1
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defer prepareTestEnv(t)() |
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session := loginUser(t, "user1") |
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csrf := GetCSRF(t, session, "/user/settings/keys") |
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req := NewRequestWithValues(t, "POST", "/user/settings/keys", map[string]string{ |
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"_csrf": csrf, |
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"content": "user1", |
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"title": "principal", |
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"type": "principal", |
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}) |
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session.MakeRequest(t, req, http.StatusSeeOther) |
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pkcert, _, _, _, err := ssh.ParseAuthorizedKey([]byte(httpsigCertificate)) |
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if err != nil { |
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t.Fatal(err) |
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} |
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// parse our private key and create the httpsig request
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sshSigner, _ := ssh.ParsePrivateKey([]byte(httpsigPrivateKey)) |
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keyID := "gitea" |
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// create our certificate signer using the ssh signer and our certificate
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certSigner, err := ssh.NewCertSigner(pkcert.(*ssh.Certificate), sshSigner) |
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if err != nil { |
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t.Fatal(err) |
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} |
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// create the request
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req = NewRequest(t, "GET", "/api/v1/admin/users") |
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// add our cert to the request
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certString := base64.RawStdEncoding.EncodeToString(pkcert.(*ssh.Certificate).Marshal()) |
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req.Header.Add("x-ssh-certificate", certString) |
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signer, _, err := httpsig.NewSSHSigner(certSigner, httpsig.DigestSha512, []string{httpsig.RequestTarget, "(created)", "(expires)", "x-ssh-certificate"}, httpsig.Signature, 10) |
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if err != nil { |
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t.Fatal(err) |
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} |
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// sign the request
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err = signer.SignRequest(keyID, req, nil) |
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if err != nil { |
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t.Fatal(err) |
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} |
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// make the request
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MakeRequest(t, req, http.StatusOK) |
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} |
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@ -0,0 +1,217 @@ |
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// Copyright 2021 The Gitea Authors. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package auth |
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import ( |
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"bytes" |
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"encoding/base64" |
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"errors" |
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"fmt" |
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"net/http" |
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"strings" |
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asymkey_model "code.gitea.io/gitea/models/asymkey" |
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user_model "code.gitea.io/gitea/models/user" |
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"code.gitea.io/gitea/modules/log" |
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"code.gitea.io/gitea/modules/setting" |
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"github.com/go-fed/httpsig" |
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"golang.org/x/crypto/ssh" |
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) |
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// Ensure the struct implements the interface.
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var ( |
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_ Method = &HTTPSign{} |
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_ Named = &HTTPSign{} |
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) |
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// HTTPSign implements the Auth interface and authenticates requests (API requests
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// only) by looking for http signature data in the "Signature" header.
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// more information can be found on https://github.com/go-fed/httpsig
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type HTTPSign struct{} |
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// Name represents the name of auth method
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func (h *HTTPSign) Name() string { |
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return "httpsign" |
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} |
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// Verify extracts and validates HTTPsign from the Signature header of the request and returns
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// the corresponding user object on successful validation.
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// Returns nil if header is empty or validation fails.
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func (h *HTTPSign) Verify(req *http.Request, w http.ResponseWriter, store DataStore, sess SessionStore) *user_model.User { |
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sigHead := req.Header.Get("Signature") |
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if len(sigHead) == 0 { |
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return nil |
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} |
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var ( |
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publicKey *asymkey_model.PublicKey |
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err error |
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) |
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if len(req.Header.Get("X-Ssh-Certificate")) != 0 { |
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// Handle Signature signed by SSH certificates
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if len(setting.SSH.TrustedUserCAKeys) == 0 { |
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return nil |
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} |
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publicKey, err = VerifyCert(req) |
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if err != nil { |
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log.Debug("VerifyCert on request from %s: failed: %v", req.RemoteAddr, err) |
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log.Warn("Failed authentication attempt from %s", req.RemoteAddr) |
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return nil |
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} |
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} else { |
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// Handle Signature signed by Public Key
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publicKey, err = VerifyPubKey(req) |
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if err != nil { |
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log.Debug("VerifyPubKey on request from %s: failed: %v", req.RemoteAddr, err) |
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log.Warn("Failed authentication attempt from %s", req.RemoteAddr) |
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return nil |
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} |
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} |
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u, err := user_model.GetUserByID(publicKey.OwnerID) |
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if err != nil { |
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log.Error("GetUserByID: %v", err) |
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return nil |
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} |
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store.GetData()["IsApiToken"] = true |
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log.Trace("HTTP Sign: Logged in user %-v", u) |
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return u |
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} |
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func VerifyPubKey(r *http.Request) (*asymkey_model.PublicKey, error) { |
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verifier, err := httpsig.NewVerifier(r) |
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if err != nil { |
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return nil, fmt.Errorf("httpsig.NewVerifier failed: %s", err) |
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} |
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keyID := verifier.KeyId() |
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publicKeys, err := asymkey_model.SearchPublicKey(0, keyID) |
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if err != nil { |
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return nil, err |
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} |
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if len(publicKeys) == 0 { |
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return nil, fmt.Errorf("no public key found for keyid %s", keyID) |
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} |
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sshPublicKey, _, _, _, err := ssh.ParseAuthorizedKey([]byte(publicKeys[0].Content)) |
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if err != nil { |
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return nil, err |
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} |
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if err := doVerify(verifier, []ssh.PublicKey{sshPublicKey}); err != nil { |
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return nil, err |
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} |
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return publicKeys[0], nil |
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} |
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// VerifyCert verifies the validity of the ssh certificate and returns the publickey of the signer
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// We verify that the certificate is signed with the correct CA
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// We verify that the http request is signed with the private key (of the public key mentioned in the certificate)
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func VerifyCert(r *http.Request) (*asymkey_model.PublicKey, error) { |
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// Get our certificate from the header
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bcert, err := base64.RawStdEncoding.DecodeString(r.Header.Get("x-ssh-certificate")) |
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if err != nil { |
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return nil, err |
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} |
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pk, err := ssh.ParsePublicKey(bcert) |
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if err != nil { |
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return nil, err |
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} |
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// Check if it's really a ssh certificate
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cert, ok := pk.(*ssh.Certificate) |
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if !ok { |
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return nil, fmt.Errorf("no certificate found") |
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} |
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c := &ssh.CertChecker{ |
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IsUserAuthority: func(auth ssh.PublicKey) bool { |
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marshaled := auth.Marshal() |
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for _, k := range setting.SSH.TrustedUserCAKeysParsed { |
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if bytes.Equal(marshaled, k.Marshal()) { |
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return true |
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} |
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} |
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return false |
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}, |
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} |
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|
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// check the CA of the cert
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if !c.IsUserAuthority(cert.SignatureKey) { |
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return nil, fmt.Errorf("CA check failed") |
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} |
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|
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// Create a verifier
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verifier, err := httpsig.NewVerifier(r) |
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if err != nil { |
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return nil, fmt.Errorf("httpsig.NewVerifier failed: %s", err) |
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} |
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// now verify that this request was signed with the private key that matches the certificate public key
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if err := doVerify(verifier, []ssh.PublicKey{cert.Key}); err != nil { |
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return nil, err |
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} |
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// Now for each of the certificate valid principals
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for _, principal := range cert.ValidPrincipals { |
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// Look in the db for the public key
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publicKey, err := asymkey_model.SearchPublicKeyByContentExact(r.Context(), principal) |
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if asymkey_model.IsErrKeyNotExist(err) { |
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// No public key matches this principal - try the next principal
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continue |
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} else if err != nil { |
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// this error will be a db error therefore we can't solve this and we should abort
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log.Error("SearchPublicKeyByContentExact: %v", err) |
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return nil, err |
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} |
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|
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// Validate the cert for this principal
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if err := c.CheckCert(principal, cert); err != nil { |
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// however, because principal is a member of ValidPrincipals - if this fails then the certificate itself is invalid
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return nil, err |
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} |
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|
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// OK we have a public key for a principal matching a valid certificate whose key has signed this request.
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return publicKey, nil |
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} |
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|
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// No public key matching a principal in the certificate is registered in gitea
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return nil, fmt.Errorf("no valid principal found") |
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} |
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|
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// doVerify iterates across the provided public keys attempting the verify the current request against each key in turn
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func doVerify(verifier httpsig.Verifier, sshPublicKeys []ssh.PublicKey) error { |
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for _, publicKey := range sshPublicKeys { |
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cryptoPubkey := publicKey.(ssh.CryptoPublicKey).CryptoPublicKey() |
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|
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var algos []httpsig.Algorithm |
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|
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switch { |
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case strings.HasPrefix(publicKey.Type(), "ssh-ed25519"): |
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algos = []httpsig.Algorithm{httpsig.ED25519} |
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case strings.HasPrefix(publicKey.Type(), "ssh-rsa"): |
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algos = []httpsig.Algorithm{httpsig.RSA_SHA1, httpsig.RSA_SHA256, httpsig.RSA_SHA512} |
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} |
||||
for _, algo := range algos { |
||||
if err := verifier.Verify(cryptoPubkey, algo); err == nil { |
||||
return nil |
||||
} |
||||
} |
||||
} |
||||
|
||||
return errors.New("verification failed") |
||||
} |
||||
Loading…
Reference in new issue