{"record":{"id":"a28ded389dd11c79","repo":"kubernetes/kops","slug":"creating-signer-for-private-key-q-v","errorCode":null,"errorMessage":"creating signer for private key %q: %v","messagePattern":"creating signer for private key %q: (.+?)","errorType":"error_code","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cmd/kops/toolbox_dump.go","lineNumber":174,"sourceCode":"\n\tif options.Dir != \"\" {\n\t\tprivateKeyPath := options.PrivateKey\n\t\tif strings.HasPrefix(privateKeyPath, \"~/\") {\n\t\t\tprivateKeyPath = filepath.Join(os.Getenv(\"HOME\"), privateKeyPath[2:])\n\t\t}\n\t\tkey, err := os.ReadFile(privateKeyPath)\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"reading private key %q: %v\", privateKeyPath, err)\n\t\t}\n\n\t\tparsedKey, err := ssh.ParseRawPrivateKey(key)\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"parsing private key %q: %v\", privateKeyPath, err)\n\t\t}\n\n\t\tsigner, err := ssh.NewSignerFromKey(parsedKey)\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"creating signer for private key %q: %v\", privateKeyPath, err)\n\t\t}\n\n\t\tcontextName := cluster.ObjectMeta.Name\n\t\tclientGetter := genericclioptions.NewConfigFlags(true)\n\t\tclientGetter.Context = &contextName\n\n\t\tvar nodes corev1.NodeList\n\n\t\t// TODO: We should use the factory to get the kubeconfig\n\t\tkubeConfig, err := clientGetter.ToRESTConfig()\n\t\tif err != nil {\n\t\t\tklog.Warningf(\"cannot load kubeconfig settings for %q: %v\", contextName, err)\n\t\t} else {\n\t\t\tk8sClient, err := kubernetes.NewForConfig(kubeConfig)\n\t\t\tif err != nil {\n\t\t\t\tklog.Warningf(\"cannot build kube client for %q: %v\", contextName, err)\n\t\t\t} else {\n","sourceCodeStart":156,"sourceCodeEnd":192,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/cmd/kops/toolbox_dump.go#L156-L192","documentation":"Once the raw key is parsed, toolbox dump converts it into an ssh.Signer via ssh.NewSignerFromKey. This error means the parsed key's type is not supported for signing (unsupported elliptic curve/algo, malformed key struct) — the key parsed but cannot produce a signer.","triggerScenarios":"ssh.NewSignerFromKey(parsedKey) fails because parsedKey is not one of the supported types (*rsa.PrivateKey, *ecdsa.PrivateKey, ed25519.PrivateKey) — e.g. an exotic curve or malformed key material passed the PEM stage.","commonSituations":"Keys on unusual curves (e.g. secp256k1) or legacy DSA keys unsupported by the vendored x/crypto version; a corrupted-but-parseable key; generated with a tool producing non-standard key structures.","solutions":["Regenerate the key with a standard type: ssh-keygen -t ed25519 (or rsa -b 4096).","Check the key algorithm: ssh-keygen -y -f <key> — failures indicate key problems.","Upgrade kops to pick up newer golang.org/x/crypto with broader key support.","If DSA, migrate to Ed25519/RSA as DSA is unsupported."],"exampleFix":"// before\nkops toolbox dump --private-key old_dsa_key   # unsupported key type\n// after\nssh-keygen -t ed25519 -N '' -f new_key\nkops toolbox dump --private-key new_key","handlingStrategy":"validation","validationCode":"ALGO=$(ssh-keygen -y -e -f \"$KEY_PATH\" 2>/dev/null | head -c 20) || { echo \"cannot read key\"; exit 1; }\ncase \"$KEY_PATH\" in *dsa*) echo \"DSA keys unsupported; regenerate with ed25519\"; exit 1;; esac","typeGuard":null,"tryCatchPattern":"signer, err := ssh.NewSignerFromKey(parsedKey)\nif err != nil {\n    return fmt.Errorf(\"unsupported key type in %q (use rsa/ecdsa/ed25519): %w\", privateKeyPath, err)\n}","preventionTips":["Standardize on ed25519 or rsa-4096 keys for tooling","Avoid exotic curves and legacy DSA keys","Keep kops and x/crypto updated for broader key support","Test key with plain ssh before using in kops toolbox dump"],"tags":["kops","ssh","crypto"],"backgroundTag":"unsupported-ssh-key-type","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}