Kris
16455cb303
新增 Nostr 渠道扩展，支持在 Yuxi 平台中集成 Nostr 去中心化社交协议。 包含以下功能模块： - bus: 事件总线与中继通信 - account: 账户管理 - key_utils: 密钥工具 - gateway: SSE/WebSocket 网关接入 - outbound: 外发消息管理 - gift_wrap: Gift Wrap 加密 - nip44: NIP-44 加密协议 - config_schema: 配置模式 - defaults: 默认配置 - profile_core: 用户资料核心 - profile_publisher: 资料发布 - event_utils: 事件工具 - deletion: 事件删除 - reactions: 表情反应 - metrics: 指标监控 - seen_tracker: 已读追踪 - session_route: 会话路由 - state_store: 状态存储
129 lines
4.1 KiB
Python
129 lines
4.1 KiB
Python
import base64
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import hashlib
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import hmac
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import os
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import struct
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from cryptography.hazmat.primitives.ciphers import Cipher, algorithms
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from cryptography.hazmat.primitives.hashes import SHA256
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from cryptography.hazmat.primitives.kdf.hkdf import HKDF
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from coincurve import PublicKey
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NIP44_V2_VERSION = 0x02
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NIP44_V2_SALT = b"nip44-v2"
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MIN_PADDING_SIZE = 32
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MAX_PADDING_SIZE = 65535
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def _get_shared_x(sk_bytes: bytes, pk_hex: str) -> bytes:
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pk = PublicKey(bytes.fromhex("02" + pk_hex))
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shared_point = pk.multiply(sk_bytes)
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return shared_point.format(compressed=False)[1:33]
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def get_conversation_key(sk_bytes: bytes, pk_hex: str) -> bytes:
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shared_x = _get_shared_x(sk_bytes, pk_hex)
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hkdf = HKDF(
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algorithm=SHA256(),
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length=32,
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salt=NIP44_V2_SALT,
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info=b"",
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)
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return hkdf.derive(shared_x)
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def get_message_keys(conversation_key: bytes, nonce: bytes) -> tuple[bytes, bytes, bytes]:
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hkdf = HKDF(
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algorithm=SHA256(),
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length=76,
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salt=None,
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info=nonce,
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)
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keys = hkdf.derive(conversation_key)
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chacha_key = keys[0:32]
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chacha_nonce = keys[32:48]
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hmac_key = keys[48:76]
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return chacha_key, chacha_nonce, hmac_key
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def _calc_padding_len(plaintext_len: int) -> int:
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if plaintext_len <= 0:
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return MIN_PADDING_SIZE
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if plaintext_len > MAX_PADDING_SIZE:
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raise ValueError(f"plaintext too long: {plaintext_len}")
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if plaintext_len <= 32:
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return 32
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next_power = 1
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while next_power < plaintext_len:
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next_power <<= 1
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chunk = next_power // 8
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if chunk < 32:
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chunk = 32
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padded = ((plaintext_len - 1) // chunk + 1) * chunk
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return padded
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def pad(plaintext: str) -> bytes:
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data = plaintext.encode("utf-8")
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length = len(data)
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padded_len = _calc_padding_len(length)
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padding = padded_len - length
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result = struct.pack("<H", length) + data + b"\x00" * padding
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return result
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def unpad(padded: bytes) -> str:
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if len(padded) < 2:
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raise ValueError("padded data too short")
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length = struct.unpack("<H", padded[:2])[0]
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if length > len(padded) - 2:
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raise ValueError(f"invalid padding length: {length}")
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data = padded[2:2 + length]
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return data.decode("utf-8")
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def _chacha20_encrypt(key: bytes, nonce: bytes, plaintext: bytes) -> bytes:
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cipher = Cipher(algorithms.ChaCha20(key, nonce), mode=None)
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encryptor = cipher.encryptor()
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return encryptor.update(plaintext) + encryptor.finalize()
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def _chacha20_decrypt(key: bytes, nonce: bytes, ciphertext: bytes) -> bytes:
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cipher = Cipher(algorithms.ChaCha20(key, nonce), mode=None)
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decryptor = cipher.decryptor()
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return decryptor.update(ciphertext) + decryptor.finalize()
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def _hmac_sha256(key: bytes, data: bytes) -> bytes:
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return hmac.new(key, data, hashlib.sha256).digest()
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def nip44_encrypt(sk_bytes: bytes, pk_hex: str, plaintext: str) -> str:
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conversation_key = get_conversation_key(sk_bytes, pk_hex)
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nonce = bytes([NIP44_V2_VERSION]) + os.urandom(31)
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chacha_key, chacha_nonce, hmac_key = get_message_keys(conversation_key, nonce)
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padded = pad(plaintext)
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ciphertext = _chacha20_encrypt(chacha_key, chacha_nonce, padded)
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mac = _hmac_sha256(hmac_key, nonce + ciphertext)
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payload = nonce + ciphertext + mac
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return base64.b64encode(payload).decode()
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def nip44_decrypt(sk_bytes: bytes, pk_hex: str, payload_b64: str) -> str:
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payload = base64.b64decode(payload_b64)
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if len(payload) < 64:
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raise ValueError("payload too short")
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version = payload[0]
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if version != NIP44_V2_VERSION:
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raise ValueError(f"unsupported nip44 version: {version}")
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nonce = payload[:32]
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ciphertext = payload[32:-32]
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mac = payload[-32:]
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conversation_key = get_conversation_key(sk_bytes, pk_hex)
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chacha_key, chacha_nonce, hmac_key = get_message_keys(conversation_key, nonce)
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expected_mac = _hmac_sha256(hmac_key, nonce + ciphertext)
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if not hmac.compare_digest(expected_mac, mac):
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raise ValueError("invalid mac")
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padded = _chacha20_decrypt(chacha_key, chacha_nonce, ciphertext)
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return unpad(padded)
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