GM/T 0129-2023 SSH 密码协议实战：基于 Tongsuo 部署国密 OpenSSH 完整指南

from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend
import os

# 生成随机密钥和 IV
key = os.urandom(16)
iv = os.urandom(16)

# 加密
cipher = Cipher(algorithms.SM4(key), modes.CTR(iv), backend=default_backend())
encryptor = cipher.encryptor()
data = b'Hello, GM SSH test data!!'
ct = encryptor.update(data) + encryptor.finalize()

# 解密（使用相同 key 和 iv）
cipher2 = Cipher(algorithms.SM4(key), modes.CTR(iv), backend=default_backend())
decryptor = cipher2.decryptor()
pt = decryptor.update(ct) + decryptor.finalize()

assert pt == data, "SM4-CTR 加解密失败"
print(f"明文:  {data.hex()}")
print(f"密文:  {ct.hex()}")
print(f"解密:  {pt.hex()}")

import hashlib
import struct

def sm3_kdf(z: bytes, key_length: int) -> bytes:
    """
    基于 SM3 的 KDF（GM/T 0003.3-2012 附录 A）
    Z: 共享秘密（Sx || Sy || session_id）
    key_length: 需要的密钥材料长度（字节）
    """
    ct = 0x00000001
    key = b""
    while len(key) < key_length:
        # SM3(ct || Z)
        h = hashlib.new("sm3", struct.pack(">I", ct) + z)
        key += h.digest()
        ct += 1
    return key[:key_length]

# 模拟：从共享点 S 和 session_id 派生密钥
# 实际场景中 Sx/Sy 是 SM2 密钥交换输出的 32 字节坐标
Sx = bytes.fromhex("a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6" * 2)
Sy = bytes.fromhex("f6e5d4c3b2a1f0e1d2c3b4a596877869" * 2)
session_id = bytes.fromhex("0102030405060708090a0b0c0d0e0f10")

# 派生 128 字节密钥材料（6 段密钥）
key_material = sm3_kdf(Sx + Sy + session_id, 128)

iv_c2s = key_material[0:16]
enc_c2s = key_material[16:32]
iv_s2c = key_material[32:48]
enc_s2c = key_material[48:64]
mac_c2s = key_material[64:96]
mac_s2c = key_material[96:128]

print(f"Key material length: {len(key_material)}")
print(f"Key material hex: {key_material.hex()}")

# 克隆国密 OpenSSH
git clone https://github.com/Tongsuo-Project/OpenSSH.git
cd OpenSSH
autoreconf

# 配置：指向 Tongsuo 的 SSL 库
./configure \
    --prefix=/usr \
    --sysconfdir=/etc/ssh \
    --with-ssl-dir=/opt/tongsuo \
    --with-privsep-path=/var/empty/sshd \
    --with-privsep-user=sshd

make -j$(nproc)
sudo make install

# 密钥交换算法（优先国密，兼容国际）
KexAlgorithms sm2-exch-sm3,sm2-exch,curve25519-sha256

# 服务器认证算法
HostKeyAlgorithms sm2-sign-sm3,rsa-sha2-512

# 对称加密算法
Ciphers sm4-ctr,aes256-ctr

# MAC 算法
MACs hmac-sm3,hmac-sha2-256

# 国密主机密钥
HostKey /etc/ssh/ssh_host_sm2_key

# 安全加固
PermitRootLogin no
PasswordAuthentication no
PubkeyAuthentication yes
MaxAuthTries 3

# 重启 sshd
sudo systemctl restart sshd

# 查看支持的算法列表
ssh -Q kex server@localhost | grep sm2
ssh -Q cipher server@localhost | grep sm4
ssh -Q mac server@localhost | grep sm3

# 客户端连接测试
ssh -o KexAlgorithms=sm2-exch-sm3 \
    -o Ciphers=sm4-ctr \
    -o MACs=hmac-sm3 \
    user@your-server

# 生成新密钥
sudo /opt/tongsuo/bin/openssl genpkey -algorithm SM2 \
    -out /etc/ssh/ssh_host_sm2_key_new

# 备份旧密钥并替换
sudo mv /etc/ssh/ssh_host_sm2_key /etc/ssh/ssh_host_sm2_key_old
sudo mv /etc/ssh/ssh_host_sm2_key_new /etc/ssh/ssh_host_sm2_key
sudo chmod 600 /etc/ssh/ssh_host_sm2_key

# 重启 sshd
sudo systemctl restart sshd

# 通知所有客户端更新 known_hosts