python3 非对称加密算法RSA

python3 可以使用 Crypto.PublicKey.RSA 和 rsa 生成公钥、私钥。

其中 python3.6 Crypto 库的安装方式请参考连接：https://blog.csdn.net/qq_42486920/article/details/80850974

rsa 加解密的库使用 pip3 install rsa 就行了

C:\WINDOWS\system32>pip3 install rsa
Collecting rsa
  Downloading https://files.pythonhosted.org/packages/e1/ae/baedc9cb175552e95f3395c43055a6a5e125ae4d48a1d7a924baca83e92e/rsa-3.4.2-py2.py3-none-any.whl (46kB)
    100% |████████████████████████████████| 51kB 99kB/s
Collecting pyasn1>=0.1.3 (from rsa)
  Downloading https://files.pythonhosted.org/packages/a0/70/2c27740f08e477499ce19eefe05dbcae6f19fdc49e9e82ce4768be0643b9/pyasn1-0.4.3-py2.py3-none-any.whl (72kB)
    100% |████████████████████████████████| 81kB 289kB/s
Installing collected packages: pyasn1, rsa
Successfully installed pyasn1-0.4.3 rsa-3.4.2

使用 Crypto.PublicKey.RSA 生成公钥、私钥：

import Crypto.PublicKey.RSA
import Crypto.Random

x = Crypto.PublicKey.RSA.generate(2048)
a = x.exportKey("PEM")  # 生成私钥
b = x.publickey().exportKey()   # 生成公钥
with open("a.pem", "wb") as x:
    x.write(a)
with open("b.pem", "wb") as x:
    x.write(b)

y = Crypto.PublicKey.RSA.generate(2048, Crypto.Random.new().read)   # 使用 Crypto.Random.new().read 伪随机数生成器
c = y.exportKey()   # 生成私钥
d = y.publickey().exportKey()   #生成公钥
with open("c.pem", "wb") as x:
    x.write(c)
with open("d.pem", "wb") as x:
    x.write(d)

使用 Crypto.PublicKey.RSA.importKey(private_key) 生成公钥和证书：

import Crypto.PublicKey.RSA

with open("a.pem", "rb") as x:
    xx = Crypto.PublicKey.RSA.importKey(x.read())

b = xx.publickey().exportKey()   # 生成公钥
with open("b.pem", "wb") as x:
    x.write(b)
    
a = xx.exportKey("DER")   # 生成 DER 格式的证书
with open("a.der", "wb") as x:
    x.write(a)

使用 rsa 生成公钥、私钥：

import rsa

f, e = rsa.newkeys(2048)    # 生成公钥、私钥

e = e.save_pkcs1()  # 保存为 .pem 格式
with open("e.pem", "wb") as x:  # 保存私钥
    x.write(e)
f = f.save_pkcs1()  # 保存为 .pem 格式
with open("f.pem", "wb") as x:  # 保存公钥
    x.write(f)

RSA非对称加密算法实现：

使用Crypto模块：

import Crypto.PublicKey.RSA
import Crypto.Cipher.PKCS1_v1_5
import Crypto.Random
import Crypto.Signature.PKCS1_v1_5
import Crypto.Hash

y = b"abcdefg1234567"

with open("b.pem", "rb") as x:
    b = x.read()
    cipher_public = Crypto.Cipher.PKCS1_v1_5.new(Crypto.PublicKey.RSA.importKey(b))
    cipher_text = cipher_public.encrypt(y) # 使用公钥进行加密
with open("a.pem", "rb") as x:
    a = x.read()
    cipher_private = Crypto.Cipher.PKCS1_v1_5.new(Crypto.PublicKey.RSA.importKey(a))
    text = cipher_private.decrypt(cipher_text, Crypto.Random.new().read)    # 使用私钥进行解密
assert text == y    # 断言验证

with open("c.pem", "rb") as x:
    c = x.read()
    c_rsa = Crypto.PublicKey.RSA.importKey(c)
    signer = Crypto.Signature.PKCS1_v1_5.new(c_rsa)
    msg_hash = Crypto.Hash.SHA256.new()
    msg_hash.update(y)
    sign = signer.sign(msg_hash)    # 使用私钥进行'sha256'签名
with open("d.pem", "rb") as x:
    d = x.read()
    d_rsa = Crypto.PublicKey.RSA.importKey(d)
    verifer = Crypto.Signature.PKCS1_v1_5.new(d_rsa)
    msg_hash = Crypto.Hash.SHA256.new()
    msg_hash.update(y)
    verify = verifer.verify(msg_hash, sign) # 使用公钥验证签名
    print(verify)

运行结果：

True

使用 rsa 模块：

import rsa

y = b"abcdefg1234567"

with open("e.pem", "rb") as x:
    e = x.read()
    e = rsa.PrivateKey.load_pkcs1(e)    # load 私钥
with open("f.pem", "rb") as x:
    f = x.read()
    f = rsa.PublicKey.load_pkcs1(f) # load 公钥，由于之前生成的私钥缺少'RSA'字段，故无法 load

cipher_text = rsa.encrypt(y, f) # 使用公钥加密
text = rsa.decrypt(cipher_text, e)   # 使用私钥解密
assert text == y    # 断言验证

sign = rsa.sign(y, e, "SHA-256") # 使用私钥进行'sha256'签名
verify = rsa.verify(y, sign, f)  # 使用公钥验证签名
print(verify)

运行结果：

True