{"record":{"id":"5b330dfbdf476c6c","repo":"kubernetes/kops","slug":"error-writing-ssl-private-key-v","errorCode":null,"errorMessage":"error writing SSL private key: %v","messagePattern":"error writing SSL private key: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/pki/privatekey.go","lineNumber":88,"sourceCode":"\n\tprivateKey := &PrivateKey{Key: rsaKey}\n\treturn privateKey, nil\n}\n\ntype PrivateKey struct {\n\tKey crypto.Signer\n}\n\nfunc (k *PrivateKey) AsString() (string, error) {\n\t// Nicer behaviour because this is called from templates\n\tif k == nil {\n\t\treturn \"\", fmt.Errorf(\"AsString called on nil private key\")\n\t}\n\n\tvar data bytes.Buffer\n\t_, err := k.WriteTo(&data)\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"error writing SSL private key: %v\", err)\n\t}\n\treturn data.String(), nil\n}\n\nfunc (k *PrivateKey) AsBytes() ([]byte, error) {\n\t// Nicer behaviour because this is called from templates\n\tif k == nil {\n\t\treturn nil, fmt.Errorf(\"AsBytes called on nil private key\")\n\t}\n\n\tvar data bytes.Buffer\n\t_, err := k.WriteTo(&data)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"error writing SSL PrivateKey: %v\", err)\n\t}\n\treturn data.Bytes(), nil\n}\n","sourceCodeStart":70,"sourceCodeEnd":106,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/pki/privatekey.go#L70-L106","documentation":"AsString serializes the private key by calling k.WriteTo into a bytes.Buffer; if WriteTo fails (e.g. PEM/DER encoding of the underlying crypto.Signer fails or the key material is invalid), the error is wrapped as this message.","triggerScenarios":"Calling AsString on a PrivateKey whose underlying Key does not implement the expected RSA signer serialization (nil or unexpected crypto.Signer inside a non-nil PrivateKey), or an internal WriteTo/encoding failure.","commonSituations":"A PrivateKey constructed with an incompatible signer type (e.g. placeholder/test signer), corrupted key material loaded from a keystore, or a nil Key field on a non-nil struct (empty PrivateKey{}).","solutions":["Ensure the PrivateKey was produced by GeneratePrivateKey or a valid keystore load, not hand-constructed.","Verify the keystore key file is a valid PEM RSA private key and re-import if corrupted.","Check that pki.PrivateKey.Key is non-nil and is a *rsa.PrivateKey-compatible signer."],"exampleFix":"// before\nk := &pki.PrivateKey{} // empty Key\ns, _ := k.AsString()\n// after\nk, err := pki.GeneratePrivateKey()\nif err != nil { return err }\ns, err := k.AsString()","handlingStrategy":"type-guard","validationCode":"if privateKey == nil || privateKey.Key == nil {\n    return fmt.Errorf(\"private key missing or uninitialized\")\n}","typeGuard":"func validKey(k *PrivateKey) bool {\n    return k != nil && k.Key != nil\n}","tryCatchPattern":"s, err := privateKey.AsString()\nif err != nil {\n    if strings.Contains(err.Error(), \"error writing SSL private key\") {\n        // regenerate the key rather than retrying serialization\n    }\n    return err\n}","preventionTips":["Only build PrivateKey via GeneratePrivateKey or keystore load","Never assign an arbitrary crypto.Signer into PrivateKey.Key","Round-trip test key serialization after keystore writes"],"tags":["pki","private-key","serialization","pem"],"backgroundTag":"private-key-encoding-failed","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"}