move minimum key sizes to config

This moves the minimum key sizes into the config file, so that anyone
can modify the restrictions.

conf/app.ini

@@ -116,6 +116,16 @@ DISABLE_MINIMUM_KEY_SIZE_CHECK = false
 ; Enable captcha validation for registration
 ENABLE_CAPTCHA = true
 
+; used to filter keys which are too short
+[service.minimum_key_sizes]
+ED25519 = 256
+ECDSA   = 256
+NTRU    = 1087
+MCE     = 1702
+McE     = 1702
+RSA     = 1024
+DSA     = 1024
+
 [webhook]
 ; Hook task queue length
 QUEUE_LENGTH = 1000

models/publickey.go

@@ -117,16 +117,6 @@ func (key *PublicKey) GetAuthorizedString() string {
 	return fmt.Sprintf(_TPL_PUBLICK_KEY, appPath, key.ID, setting.CustomConf, key.Content)
 }
 
-var minimumKeySizes = map[string]int{
-	"(ED25519)": 256,
-	"(ECDSA)":   256,
-	"(NTRU)":    1087,
-	"(MCE)":     1702,
-	"(McE)":     1702,
-	"(RSA)":     1024,
-	"(DSA)":     1024,
-}
-
 func extractTypeFromBase64Key(key string) (string, error) {
 	b, err := base64.StdEncoding.DecodeString(key)
 	if err != nil || len(b) < 4 {
@@ -251,8 +241,8 @@ func CheckPublicKeyString(content string) (_ string, err error) {
 		if keySize == 0 {
 			return "", errors.New("cannot get key size of the given key")
 		}
-		keyType := strings.TrimSpace(sshKeygenOutput[len(sshKeygenOutput)-1])
+		keyType := strings.Trim(sshKeygenOutput[len(sshKeygenOutput)-1], " ()")
-		if minimumKeySize := minimumKeySizes[keyType]; minimumKeySize == 0 {
+		if minimumKeySize := setting.Service.MinimumKeySizes[keyType]; minimumKeySize == 0 {
 			return "", errors.New("sorry, unrecognized public key type")
 		} else if keySize < minimumKeySize {
 			return "", fmt.Errorf("the minimum accepted size of a public key %s is %d", keyType, minimumKeySize)

modules/setting/setting.go

@@ -434,6 +434,7 @@ var Service struct {
 	EnableReverseProxyAuth         bool
 	EnableReverseProxyAutoRegister bool
 	DisableMinimumKeySizeCheck     bool
+	MinimumKeySizes                map[string]int
 	EnableCaptcha                  bool
 }
 
@@ -449,6 +450,11 @@ func newService() {
 	Service.EnableReverseProxyAutoRegister = sec.Key("ENABLE_REVERSE_PROXY_AUTO_REGISTRATION").MustBool()
 	Service.DisableMinimumKeySizeCheck = sec.Key("DISABLE_MINIMUM_KEY_SIZE_CHECK").MustBool()
 	Service.EnableCaptcha = sec.Key("ENABLE_CAPTCHA").MustBool()
+
+	minimumKeySizes := Cfg.Section("service.minimum_key_sizes").Keys()
+	for _, key := range minimumKeySizes {
+		Service.MinimumKeySizes[key.Name()] = key.MustInt()
+	}
 }
 
 var logLevels = map[string]string{