国密密码库选型与适配：gmssl、Tongsuo、BabaSSL 三巨头对比实战

# gmssl 签名示例（符合标准）
from gmssl import sm2

# 私钥 64 位 hex
private_key = 'xxxx...'  
# 公钥 128 位 hex
public_key = 'xxxx...'

sm2_crypt = sm2.CryptSM2(
    public_key=public_key,
    private_key=private_key
)

# 自动计算 ZA + SM3 哈希 + 签名
signature = sm2_crypt.sign(b'test message')
print(f'SM2 signature: {signature.hex()}')

# 验签
verified = sm2_crypt.verify(signature, b'test message')
print(f'Verify result: {verified}')  # True

// Tongsuo Go 示例（基于 Tongsuo-Project/Tongsuo）
package main

import (
	"fmt"
	"github.com/Tongsuo-Project/tongsuo-go/sm2"
)

func main() {
	// 密钥生成
	privKey, err := sm2.GenerateKey()
	if err != nil {
		panic(err)
	}

	// 签名
	msg := []byte("test message")
	sig, err := sm2.Sign(privKey, msg)
	if err != nil {
		panic(err)
	}
	fmt.Printf("Signature: %x\n", sig)

	// 验签
	pubKey := &privKey.PublicKey
	ok, err := sm2.Verify(pubKey, msg, sig)
	if err != nil {
		panic(err)
	}
	fmt.Printf("Verify: %v\n", ok)
}

# gmssl 的替代方案：SM4-CBC + HMAC-SM3
from gmssl import sm4, sm3
from gmssl.func import pkcs7_padding, pkcs7_unpadding

key = b'0123456789abcdef'  # 16 字节
iv = b'0123456789abcdef'   # 16 字节
plaintext = b'Hello SM4!'

# 加密
sm4_crypt = sm4.CryptSM4(key, iv)
ciphertext = sm4_crypt.encrypt_CBC(pkcs7_padding(plaintext, 16))

# HMAC-SM3 认证（Encrypt-then-MAC）
mac = sm3.sm3_hash(list(ciphertext))
authenticated_ct = ciphertext + bytes.fromhex(mac)[:32]

# 解密验证
received_ct = authenticated_ct[:-32]
received_mac = authenticated_ct[-32:]
expected_mac = sm3.sm3_hash(list(received_ct))

if received_mac == expected_mac:
    decrypted = sm4_unpadding(
        sm4_crypt.decrypt_CBC(received_ct)
    )
    print(f'Plaintext: {decrypted.decode()}')

# gmssl 签名 → Tongsuo 验签的转换
def gmssl_sig_to_tongsuo(gmssl_sig_hex):
    """将 gmssl 的 R||S 格式转换为 Tongsuo 的 DER 格式"""
    r = int(gmssl_sig_hex[:64], 16)
    s = int(gmssl_sig_hex[64:], 16)
    
    # 构造 DER 序列
    r_der = encode_der_integer(r)
    s_der = encode_der_integer(s)
    
    return b'\x30' + bytes([len(r_der) + len(s_der)]) + r_der + s_der

def encode_der_integer(n):
    """编码整数为 DER 格式"""
    n_bytes = n.to_bytes((n.bit_length() + 7) // 8, 'big')
    if n_bytes[0] & 0x80:  # 负数标记
        n_bytes = b'\x00' + n_bytes
    return b'\x02' + bytes([len(n_bytes)]) + n_bytes

# 统一 IV 传递方案
def cross_library_encrypt(plaintext, pub_key_hex, lib_name='gmssl'):
    if lib_name == 'gmssl':
        # 自动生成 IV，返回 IV + ciphertext
        result = sm2_crypt.encrypt(plaintext)
        iv = result[:32]
        ciphertext = result[32:]
        return iv, ciphertext
    else:
        # 手动生成并返回
        iv = os.urandom(32)
        ciphertext = encrypt_with_lib(plaintext, pub_key_hex, iv)
        return iv, ciphertext

项目需求分析
├── 语言栈
│   ├── Python → BabaSSL (最快) 或 gmssl (生态全)
│   └── Go → Tongsuo (首选)
├── 性能要求
│   ├── 高吞吐 → Tongsuo/BabaSSL (C 底层优化)
│   └── 一般 → gmssl (够用)
├── 合规要求
│   ├── 严格合规 → Tongsuo (审计完善)
│   └── 内部使用 → 任意
└── 国密 TLS 需求
    ├── 需要 → Tongsuo 或 BabaSSL
    └── 不需要 → 都可以