1 files changed, 55 insertions, 0 deletions
diff --git a/models/asymkey/ssh_key_verify.go b/models/asymkey/ssh_key_verify.go
new file mode 100644
index 0000000..208288c
--- /dev/null
+++ b/models/asymkey/ssh_key_verify.go
@@ -0,0 +1,55 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package asymkey
+
+import (
+	"bytes"
+	"context"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/log"
+
+	"github.com/42wim/sshsig"
+)
+
+// VerifySSHKey marks a SSH key as verified
+func VerifySSHKey(ctx context.Context, ownerID int64, fingerprint, token, signature string) (string, error) {
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return "", err
+	}
+	defer committer.Close()
+
+	key := new(PublicKey)
+
+	has, err := db.GetEngine(ctx).Where("owner_id = ? AND fingerprint = ?", ownerID, fingerprint).Get(key)
+	if err != nil {
+		return "", err
+	} else if !has {
+		return "", ErrKeyNotExist{}
+	}
+
+	err = sshsig.Verify(bytes.NewBuffer([]byte(token)), []byte(signature), []byte(key.Content), "gitea")
+	if err != nil {
+		// edge case for Windows based shells that will add CR LF if piped to ssh-keygen command
+		// see https://github.com/PowerShell/PowerShell/issues/5974
+		if sshsig.Verify(bytes.NewBuffer([]byte(token+"\r\n")), []byte(signature), []byte(key.Content), "gitea") != nil {
+			log.Error("Unable to validate token signature. Error: %v", err)
+			return "", ErrSSHInvalidTokenSignature{
+				Fingerprint: key.Fingerprint,
+			}
+		}
+	}
+
+	key.Verified = true
+	if _, err := db.GetEngine(ctx).ID(key.ID).Cols("verified").Update(key); err != nil {
+		return "", err
+	}
+
+	if err := committer.Commit(); err != nil {
+		return "", err
+	}
+
+	return key.Fingerprint, nil
+}