Ensure Subkeys are verified (go-gitea#12155)

When attempting to verify subkeys the email address verification step
requires checking the emails however, these emails are not stored on
subkeys but instead on the primary key.

This PR will obtain the primaryKey and check against these emails too.

Fix go-gitea#12128

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

models/gpg_key.go

@@ -509,6 +509,18 @@ func hashAndVerifyForKeyID(sig *packet.Signature, payload string, committer *Use
 		return nil
 	}
 	for _, key := range keys {
+		var primaryKeys []*GPGKey
+		if key.PrimaryKeyID != "" {
+			primaryKeys, err = GetGPGKeysByKeyID(key.PrimaryKeyID)
+			if err != nil {
+				log.Error("GetGPGKeysByKeyID: %v", err)
+				return &CommitVerification{
+					CommittingUser: committer,
+					Verified:       false,
+					Reason:         "gpg.error.failed_retrieval_gpg_keys",
+				}
+			}
+		}
 		activated := false
 		if len(email) != 0 {
 			for _, e := range key.Emails {
@@ -518,6 +530,20 @@ func hashAndVerifyForKeyID(sig *packet.Signature, payload string, committer *Use
 					break
 				}
 			}
+			if !activated {
+				for _, pkey := range primaryKeys {
+					for _, e := range pkey.Emails {
+						if e.IsActivated && strings.EqualFold(e.Email, email) {
+							activated = true
+							email = e.Email
+							break
+						}
+					}
+					if activated {
+						break
+					}
+				}
+			}
 		} else {
 			for _, e := range key.Emails {
 				if e.IsActivated {
@@ -526,7 +552,22 @@ func hashAndVerifyForKeyID(sig *packet.Signature, payload string, committer *Use
 					break
 				}
 			}
+			if !activated {
+				for _, pkey := range primaryKeys {
+					for _, e := range pkey.Emails {
+						if e.IsActivated {
+							activated = true
+							email = e.Email
+							break
+						}
+					}
+					if activated {
+						break
+					}
+				}
+			}
 		}
+
 		if !activated {
 			continue
 		}
@@ -614,7 +655,6 @@ func ParseCommitWithSignature(c *git.Commit) *CommitVerification {
 	if keyID == "" && sig.IssuerFingerprint != nil && len(sig.IssuerFingerprint) > 0 {
 		keyID = fmt.Sprintf("%X", sig.IssuerFingerprint[12:20])
 	}
-
 	defaultReason := NoKeyFound
 
 	// First check if the sig has a keyID and if so just look at that