Python：pyasn1 库高级用法举例和应用详解

from pyasn1.type.univ import Integer, OctetString, Sequence
from pyasn1.codec.der import encoder, decoder

# 定义一个ASN.1序列，包含一个整数和一个字节串
class MySequence(Sequence):
    componentType = Integer(), OctetString()  # 组件类型为整数和字节串

my_data = MySequence()  # 创建ASN.1序列实例
my_data.setComponentByPosition(0, 123)  # 设置第一个组件的值为123
my_data.setComponentByPosition(1, 'hello'.encode('utf-8'))  # 设置第二个组件的字节串

encoded_data = encoder.encode(my_data)  # 编码为DER格式
print(f'Encoded data: {encoded_data}')  # 输出编码后的数据

decoded_data, _ = decoder.decode(encoded_data, asn1Spec=MySequence())  # 解码
print(f'Decoded data: {decoded_data}')  # 输出解码后的数据

import socket
from pyasn1.codec.der import decoder
from pyasn1.type.univ import Sequence, Integer, OctetString

# 示例：从网络接收ASN.1序列数据
HOST, PORT = 'localhost', 9999  # 定义服务器地址与端口

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
    sock.connect((HOST, PORT))  # 连接到服务器
    data = sock.recv(1024)  # 接收数据

# 假设接收到的数据是一个ASN.1格式的编码数据
decoded_data, _ = decoder.decode(data, asn1Spec=Sequence())  # 解码接收到的数据

# 输出解码后的数据
print(f'Received and decoded data: {decoded_data}')  

from pyasn1.type.namedtype import NamedType, NamedTypes
from pyasn1.type.univ import Sequence, Integer, OctetString
from pyasn1.codec.der import encoder

# 定义一个复杂的ASN.1数据模型
class Address(Sequence):
    componentType = NamedTypes(
        NamedType('street', OctetString()),
        NamedType('city', OctetString()),
        NamedType('zip', Integer())
    )

class Person(Sequence):
    componentType = NamedTypes(
        NamedType('name', OctetString()),
        NamedType('age', Integer()),
        NamedType('address', Address())
    )

# 创建一个示例对象
person = Person()
person.setComponentByPosition(0, 'Alice'.encode('utf-8'))  # 设置姓名
person.setComponentByPosition(1, 30)  # 设置年龄
address = Address()  # 创建地址对象
address.setComponentByPosition(0, '123 Apple St.'.encode('utf-8'))  # 设置街道
address.setComponentByPosition(1, 'Wonderland'.encode('utf-8'))  # 设置城市
address.setComponentByPosition(2, 12345)  # 设置邮政编码
person.setComponentByPosition(2, address)  # 将地址设置到人员对象中

# 编码并输出结果
encoded_person = encoder.encode(person)  # 编码为DER格式
print(f'Encoded person data: {encoded_person}')