modules/config/login.go

@@ -6,17 +6,21 @@ package config
 
 import (
 	"crypto/tls"
+	"encoding/base64"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
 	"code.gitea.io/tea/modules/utils"
+	"golang.org/x/crypto/ssh"
 
 	"code.gitea.io/sdk/gitea"
 )
@@ -97,6 +101,68 @@ func (l *Login) GenerateToken(user, pass string) (string, error) {
 	return t.Token, err
 }
 
+// FindSSHKey retrieves the ssh keys registered in gitea, and tries to find
+// a matching private key in ~/.ssh/. If no match is found, path is empty.
+func (l *Login) FindSSHKey() (string, error) {
+	// get keys registered on gitea instance
+	keys, _, err := l.Client().ListMyPublicKeys(gitea.ListPublicKeysOptions{})
+	if err != nil || len(keys) == 0 {
+		return "", err
+	}
+
+	// enumerate ~/.ssh/*.pub files
+	glob, err := utils.AbsPathWithExpansion("~/.ssh/*.pub")
+	if err != nil {
+		return "", err
+	}
+	localPubkeyPaths, err := filepath.Glob(glob)
+	if err != nil {
+		return "", err
+	}
+
+	// parse each local key with present privkey & compare fingerprints to online keys
+	for _, pubkeyPath := range localPubkeyPaths {
+		var pubkeyFile []byte
+		pubkeyFile, err = ioutil.ReadFile(pubkeyPath)
+		if err != nil {
+			continue
+		}
+		fields := strings.Split(string(pubkeyFile), " ")
+		if len(fields) < 2 { // first word is key type, second word is key material
+			continue
+		}
+
+		var keymaterial []byte
+		keymaterial, err = base64.StdEncoding.DecodeString(fields[1])
+		if err != nil {
+			continue
+		}
+
+		var pubkey ssh.PublicKey
+		pubkey, err = ssh.ParsePublicKey(keymaterial)
+		if err != nil {
+			continue
+		}
+
+		privkeyPath := strings.TrimSuffix(pubkeyPath, ".pub")
+		var exists bool
+		exists, err = utils.FileExist(privkeyPath)
+		if err != nil || !exists {
+			continue
+		}
+
+		// if pubkey fingerprints match, return path to corresponding privkey.
+		fingerprint := ssh.FingerprintSHA256(pubkey)
+		for _, key := range keys {
+			if fingerprint == key.Fingerprint {
+				return privkeyPath, nil
+			}
+		}
+	}
+
+	return "", err
+}
+
 // GetDefaultLogin return the default login
 func GetDefaultLogin() (*Login, error) {
 	if len(Config.Logins) == 0 {
@@ -194,6 +260,14 @@ func AddLogin(name, token, user, passwd, sshKey, giteaURL string, insecure bool)
 	// so we just use the hostname
 	login.SSHHost = serverURL.Hostname()
 
+	if len(sshKey) == 0 {
+		login.SSHKey, err = login.FindSSHKey()
+		fmt.Println(login.SSHKey)
+		if err != nil {
+			fmt.Printf("Warning: problem while finding a SSH key: %s\n", err)
+		}
+	}
+
 	// save login to global var
 	Config.Logins = append(Config.Logins, login)