{"record":{"id":"a05ded3c8101af52","repo":"siyuan-note/siyuan","slug":"unsupported-encrypted-envelope-spec","errorCode":null,"errorMessage":"unsupported encrypted envelope spec","messagePattern":"unsupported encrypted envelope spec","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"kernel/util/kdf.go","lineNumber":110,"sourceCode":"func Encrypt(key, plaintext []byte) ([]byte, error) {\n\treturn encryptGCM(key, plaintext, nil, \"Encrypt\")\n}\n\n// Decrypt 对应 Encrypt 的解密。密钥错误、格式无效或密文被篡改时返回错误。\nfunc Decrypt(key, ciphertext []byte) ([]byte, error) {\n\treturn decryptGCM(key, ciphertext, nil, \"Decrypt\")\n}\n\n// EncryptionNonce 从 AES-GCM 密文信封中提取 nonce。\nfunc EncryptionNonce(ciphertext []byte) ([]byte, error) {\n\tif !hasEncryptionMagic(ciphertext) {\n\t\treturn nil, errors.New(\"invalid encrypted envelope magic\")\n\t}\n\tif len(ciphertext) < encryptionEnvelopeHeaderSize {\n\t\treturn nil, errors.New(\"encrypted envelope too short\")\n\t}\n\tif ciphertext[len(encryptionMagic)] != EncryptionSpec {\n\t\treturn nil, errors.New(\"unsupported encrypted envelope spec\")\n\t}\n\tif ciphertext[len(encryptionMagic)+1] != encryptionAlgorithmAES256GCM {\n\t\treturn nil, errors.New(\"unsupported encrypted envelope algorithm\")\n\t}\n\tnonceLength := int(ciphertext[len(encryptionMagic)+2])\n\tif nonceLength == 0 || len(ciphertext) < encryptionEnvelopeHeaderSize+nonceLength {\n\t\treturn nil, errors.New(\"invalid encrypted envelope nonce length\")\n\t}\n\treturn append([]byte(nil), ciphertext[encryptionEnvelopeHeaderSize:encryptionEnvelopeHeaderSize+nonceLength]...), nil\n}\n\n// DeriveSubKey 用 HKDF-SHA256 从主 DEK 派生用途隔离的子密钥。\n// 同一 (dek, purpose) 多次调用结果一致；不同 purpose 派生出相互独立的子密钥，\n// 实现用途分离——.sy/assets/AV 各用独立子密钥，互不可替代，限制单点密钥泄漏的影响面。\nfunc DeriveSubKey(dek []byte, purpose string) []byte {\n\t// HKDF info 用 purpose 字节；salt 为 nil（DEK 本身已是高熵随机密钥，无需额外 salt）\n\tr := hkdf.New(sha256.New, dek, nil, []byte(purpose))\n\tout := make([]byte, 32) // AES-256","sourceCodeStart":92,"sourceCodeEnd":128,"githubUrl":"https://github.com/siyuan-note/siyuan/blob/9f775e8a12daef8255556097396f9b2739078892/kernel/util/kdf.go#L92-L128","documentation":"EncryptionNonce validates the envelope's spec version byte immediately after the magic. This library only implements spec 1 (EncryptionSpec). A different byte means the envelope was written by a newer or incompatible format version and cannot be parsed here.","triggerScenarios":"Calling EncryptionNonce on an envelope whose byte at offset 4 is not 0x01 — e.g. data written by a future SiYuan version with spec 2, or bytes that coincidentally start with 'SENC' but are not this format.","commonSituations":"Downgrading SiYuan after the envelope format was bumped, reading encrypted data synced from a newer client, or hand-crafted/foreign data beginning with 'SENC'.","solutions":["Upgrade SiYuan to the version that wrote the envelope (higher spec byte = newer format)","Check the envelope's spec byte; if it is genuinely newer, do not attempt local decryption — sync/upgrade first","If the data is foreign bytes that merely match 'SENC', locate the real envelope produced by Encrypt"],"exampleFix":null,"handlingStrategy":"validation","validationCode":"if len(data) >= 5 && data[4] != 0x01 {\n    return fmt.Errorf(\"envelope spec %d not supported by this version; upgrade SiYuan\", data[4])\n}","typeGuard":"func isSupportedSpec(b []byte) bool {\n    return len(b) >= 5 && string(b[:4]) == \"SENC\" && b[4] == 0x01\n}","tryCatchPattern":"nonce, err := util.EncryptionNonce(ciphertext)\nif err != nil {\n    return fmt.Errorf(\"envelope spec unsupported (upgrade required?): %w\", err)\n}","preventionTips":["Keep all synced clients on compatible SiYuan versions","Check the spec byte before downgrading the kernel and re-reading data","Treat unknown spec values as data for a newer version, never as corrupt"],"tags":["encryption","envelope-format","version-compatibility","forward-compatibility"],"backgroundTag":"unsupported-enum-value","analyzedSha":"9f775e8a12daef8255556097396f9b2739078892","analyzedAt":"2026-09-19T03:17:15.984Z","contentChangedAt":"2026-09-19T03:17:15.984Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}