don't check minimum key size when disabled (#1754)

* cleanup old comments for ed25519

These comments were added when x/crypto/ed25519 could not yet handle
ed25519. It does now, so it should be removed.
Also the key type is now replaced with the proper constant.

* move the minimum key size config before the check

This moves the actual config lookup before any check is done. This
avoids problems with calling to ssh-keygen which doesn't support the
expected output format and returning an error, when the check is disabled.

diff --git a/models/ssh_key.go b/models/ssh_key.go
index 1cca47f565826b548c827bd6d4d3ef299f23474b..15544efbc6b87507d677959c8b6e09b4ca7a1c45 100644 (file)
--- a/models/ssh_key.go
+++ b/models/ssh_key.go
@@ -202,7 +202,6 @@ func SSHKeyGenParsePublicKey(key string) (string, int, error) {
 }
 
 // SSHNativeParsePublicKey extracts the key type and length using the golang SSH library.
-// NOTE: ed25519 is not supported.
 func SSHNativeParsePublicKey(keyLine string) (string, int, error) {
        fields := strings.Fields(keyLine)
        if len(fields) < 2 {
@@ -251,7 +250,7 @@ func SSHNativeParsePublicKey(keyLine string) (string, int, error) {
                return "ecdsa", 384, nil
        case ssh.KeyAlgoECDSA521:
                return "ecdsa", 521, nil
-       case "ssh-ed25519": // TODO: replace with ssh constant when available
+       case ssh.KeyAlgoED25519:
                return "ed25519", 256, nil
        }
        return "", 0, fmt.Errorf("unsupported key length detection for type: %s", pkey.Type())
@@ -277,6 +276,10 @@ func CheckPublicKeyString(content string) (_ string, err error) {
        // remove any unnecessary whitespace now
        content = strings.TrimSpace(content)
 
+       if !setting.SSH.MinimumKeySizeCheck {
+               return content, nil
+       }
+
        var (
                fnName  string
                keyType string
@@ -294,9 +297,6 @@ func CheckPublicKeyString(content string) (_ string, err error) {
        }
        log.Trace("Key info [native: %v]: %s-%d", setting.SSH.StartBuiltinServer, keyType, length)
 
-       if !setting.SSH.MinimumKeySizeCheck {
-               return content, nil
-       }
        if minLen, found := setting.SSH.MinimumKeySizes[keyType]; found && length >= minLen {
                return content, nil
        } else if found && length < minLen {