Fix user's sign email check (go-gitea#35045)

Fix go-gitea#21692

Author: wxiaoguang

models/asymkey/ssh_key_fingerprint.go

@@ -13,9 +13,9 @@ import (
 	"xorm.io/builder"
 )
 
-// The database is used in checkKeyFingerprint however most of these functions probably belong in a module
+// The database is used in checkKeyFingerprint. However, most of these functions probably belong in a module
 
-// checkKeyFingerprint only checks if key fingerprint has been used as public key,
+// checkKeyFingerprint only checks if key fingerprint has been used as a public key,
 // it is OK to use same key as deploy key for multiple repositories/users.
 func checkKeyFingerprint(ctx context.Context, fingerprint string) error {
 	has, err := db.Exist[PublicKey](ctx, builder.Eq{"fingerprint": fingerprint})

models/fixtures/public_key.yml

@@ -9,3 +9,4 @@
   created_unix: 1559593109
   updated_unix: 1565224552
   login_source_id: 0
+  verified: false

services/asymkey/commit.go

@@ -49,6 +49,10 @@ func ParseCommitWithSignature(ctx context.Context, c *git.Commit) *asymkey_model
 	return ParseCommitWithSignatureCommitter(ctx, c, committer)
 }
 
+// ParseCommitWithSignatureCommitter parses a commit's GPG or SSH signature.
+// The caller guarantees that the committer user is related to the commit by checking its activated email addresses or no-reply address.
+// If the commit is singed by an instance key, then committer can be nil.
+// If the signature exists, even if committer is nil, the returned CommittingUser will be a non-nil fake user (e.g.: instance key)
 func ParseCommitWithSignatureCommitter(ctx context.Context, c *git.Commit, committer *user_model.User) *asymkey_model.CommitVerification {
 	// If no signature just report the committer
 	if c.Signature == nil {
@@ -117,20 +121,11 @@ func ParseCommitWithSignatureCommitter(ctx context.Context, c *git.Commit, commi
 			}
 		}
 
-		committerEmailAddresses, _ := cache.GetWithContextCache(ctx, cachegroup.UserEmailAddresses, committer.ID, user_model.GetEmailAddresses)
-		activated := false
-		for _, e := range committerEmailAddresses {
-			if e.IsActivated && strings.EqualFold(e.Email, c.Committer.Email) {
-				activated = true
-				break
-			}
-		}
-
 		for _, k := range keys {
 			// Pre-check (& optimization) that emails attached to key can be attached to the committer email and can validate
 			canValidate := false
 			email := ""
-			if k.Verified && activated {
+			if k.Verified {
 				canValidate = true
 				email = c.Committer.Email
 			}
@@ -220,8 +215,8 @@ func checkKeyEmails(ctx context.Context, email string, keys ...*asymkey_model.GP
 					return true, e.Email
 				}
 			}
-			if user.KeepEmailPrivate && strings.EqualFold(email, user.GetEmail()) {
-				return true, user.GetEmail()
+			if user != nil && strings.EqualFold(email, user.GetPlaceholderEmail()) {
+				return true, user.GetPlaceholderEmail()
 			}
 		}
 	}
@@ -376,21 +371,8 @@ func ParseCommitWithSSHSignature(ctx context.Context, c *git.Commit, committer *
 			}
 		}
 
-		committerEmailAddresses, err := cache.GetWithContextCache(ctx, cachegroup.UserEmailAddresses, committer.ID, user_model.GetEmailAddresses)
-		if err != nil {
-			log.Error("GetEmailAddresses: %v", err)
-		}
-
-		activated := false
-		for _, e := range committerEmailAddresses {
-			if e.IsActivated && strings.EqualFold(e.Email, c.Committer.Email) {
-				activated = true
-				break
-			}
-		}
-
 		for _, k := range keys {
-			if k.Verified && activated {
+			if k.Verified {
 				commitVerification := verifySSHCommitVerification(c.Signature.Signature, c.Signature.Payload, k, committer, committer, c.Committer.Email)
 				if commitVerification != nil {
 					return commitVerification

services/asymkey/commit_test.go

@@ -0,0 +1,98 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package asymkey
+
+import (
+	"strings"
+	"testing"
+
+	asymkey_model "code.gitea.io/gitea/models/asymkey"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/test"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseCommitWithSSHSignature(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	// Here we only need to do some tests that "tests/integration/gpg_ssh_git_test.go" doesn't cover
+
+	// -----BEGIN OPENSSH PRIVATE KEY-----
+	// b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
+	// QyNTUxOQAAACC6T6zF0oPak8dOIzzT1kXB7LrcsVo04SKc3GjuvMllZwAAAJgy08upMtPL
+	// qQAAAAtzc2gtZWQyNTUxOQAAACC6T6zF0oPak8dOIzzT1kXB7LrcsVo04SKc3GjuvMllZw
+	// AAAEDWqPHTH51xb4hy1y1f1VeWL/2A9Q0b6atOyv5fx8x5prpPrMXSg9qTx04jPNPWRcHs
+	// utyxWjThIpzcaO68yWVnAAAAEXVzZXIyQGV4YW1wbGUuY29tAQIDBA==
+	// -----END OPENSSH PRIVATE KEY-----
+	sshPubKey, err := asymkey_model.AddPublicKey(t.Context(), 999, "user-ssh-key-any-name", "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILpPrMXSg9qTx04jPNPWRcHsutyxWjThIpzcaO68yWVn", 0)
+	require.NoError(t, err)
+	_, err = db.GetEngine(t.Context()).ID(sshPubKey.ID).Cols("verified").Update(&asymkey_model.PublicKey{Verified: true})
+	require.NoError(t, err)
+
+	t.Run("UserSSHKey", func(t *testing.T) {
+		commit, err := git.CommitFromReader(nil, git.Sha1ObjectFormat.EmptyObjectID(), strings.NewReader(`tree a3b1fad553e0f9a2b4a58327bebde36c7da75aa2
+author user2 <[email protected]> 1752194028 -0700
+committer user2 <[email protected]> 1752194028 -0700
+gpgsig -----BEGIN SSH SIGNATURE-----
+ U1NIU0lHAAAAAQAAADMAAAALc3NoLWVkMjU1MTkAAAAguk+sxdKD2pPHTiM809ZFwey63L
+ FaNOEinNxo7rzJZWcAAAADZ2l0AAAAAAAAAAZzaGE1MTIAAABTAAAAC3NzaC1lZDI1NTE5
+ AAAAQBfX+6mcKZBnXckwHcBFqRuXMD3vTKi1yv5wgrqIxTyr2LWB97xxmO92cvjsr0POQ2
+ 2YA7mQS510Cg2s1uU1XAk=
+ -----END SSH SIGNATURE-----
+
+init project
+`))
+		require.NoError(t, err)
+
+		// the committingUser is guaranteed by the caller, parseCommitWithSSHSignature doesn't do any more checks
+		committingUser := &user_model.User{ID: 999, Name: "user-x"}
+		ret := ParseCommitWithSSHSignature(t.Context(), commit, committingUser)
+		require.NotNil(t, ret)
+		assert.True(t, ret.Verified)
+		assert.Equal(t, committingUser.Name+" / "+sshPubKey.Fingerprint, ret.Reason)
+		assert.False(t, ret.Warning)
+		assert.Equal(t, committingUser, ret.SigningUser)
+		assert.Equal(t, committingUser, ret.CommittingUser)
+		assert.Equal(t, sshPubKey.ID, ret.SigningSSHKey.ID)
+	})
+
+	t.Run("TrustedSSHKey", func(t *testing.T) {
+		defer test.MockVariableValue(&setting.Repository.Signing.SigningName, "gitea")()
+		defer test.MockVariableValue(&setting.Repository.Signing.SigningEmail, "[email protected]")()
+
+		commit, err := git.CommitFromReader(nil, git.Sha1ObjectFormat.EmptyObjectID(), strings.NewReader(`tree 9a93ffa76e8b72bdb6431910b3a506fa2b39f42e
+author User Two <[email protected]> 1749230009 +0200
+committer User Two <[email protected]> 1749230009 +0200
+gpgsig -----BEGIN SSH SIGNATURE-----
+ U1NIU0lHAAAAAQAAADMAAAALc3NoLWVkMjU1MTkAAAAgfpjiJ1VpbcT5svDW6qgB8kPujl
+ KK74epLnUT2hAs8T0AAAADZ2l0AAAAAAAAAAZzaGE1MTIAAABTAAAAC3NzaC1lZDI1NTE5
+ AAAAQDX2t2iHuuLxEWHLJetYXKsgayv3c43r0pJNfAzdLN55Q65pC5M7rG6++gT2bxcpOu
+ Y6EXbpLqia9sunEF3+LQY=
+ -----END SSH SIGNATURE-----
+
+Initial commit with signed file
+`))
+		require.NoError(t, err)
+		committingUser := &user_model.User{
+			ID:    2,
+			Name:  "User Two",
+			Email: "[email protected]",
+		}
+		ret := ParseCommitWithSSHSignature(t.Context(), commit, committingUser)
+		require.NotNil(t, ret)
+		assert.True(t, ret.Verified)
+		assert.False(t, ret.Warning)
+		assert.Equal(t, committingUser, ret.CommittingUser)
+		if assert.NotNil(t, ret.SigningUser) {
+			assert.Equal(t, "gitea", ret.SigningUser.Name)
+			assert.Equal(t, "[email protected]", ret.SigningUser.Email)
+		}
+	})
+}