本篇写一下python实现RSA的加密解密功能、私钥签名 公钥验签功能。
主要分三部分来介绍
生成私钥和公钥
脚本如下，运行后会生成public.pem(公钥) 和 private.pem（私钥）
def generateKeys():print("generate priv key start.")random_generator = Random.new().readrsa = RSA.generate(2048, random_generator)private_pem = rsa.exportKey()with open('private.pem', 'w') as f:f.write(private_pem)public_pem = rsa.publickey().exportKey()with open('public.pem', 'w') as f:f.write(public_pem)print("generate priv key done.")
生成的私钥内容如下：
$ cat private.pem -----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
生成的公钥内容如下：
$ cat public.pem -----BEGIN PUBLIC KEY-----MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAm1dN6Ue55QXl+SaBZTDPN3CkQMx+tWMyWP41sk+5jHqSTZrb4zLH7Tvw2YLlMVGJM83jWtpEl1VJTGuHl3J0N7ts3bg7rq3ffU9my7rIC2Lz812AB1n39hp7FcDb/oEGbZnhQJasRVuJwglDrdgePY5hI/PI/mpBj3+tKpmRTU7wl5W58si9xzJnx4aCHgu8jKEQzF9J4wAeSsPHc7ajjDD0c7me1tqFXSXzRlUVUw0i2fT6JmGyw9iNTeyRZ/xQIXq6OOyf+dxsETr1Lwe6ozsdmLU+2bx6ku2BzPc5jpxmTP2je+y1zb+NsEPQUfbeHRH6bFKKi8OwP61J4qMTtwIDAQAB-----END PUBLIC KEY-----
公钥加密 私钥解密
下面是通过公钥加密，然后用公钥解密的实现：
def pubEncryAndprivDecry():content_size = '10000'#encryptwith open("public.pem") as f:key = f.read()rsakey = RSA.importKey(key)cipher = Cipher_pkcs1_v1_5.new(rsakey)cipher_text = base64.b64encode(cipher.encrypt(content_size))print(cipher_text)with open("encrypted_data", "wb") as f: ##save encrypted data to filef.write(cipher_text)#decryptwith open("private.pem") as f:key = f.read()prikey = RSA.importKey(key)cipher2 = Cipher_pkcs1_v1_5.new(prikey)with open("encrypted_data") as f: ### read data from encrypted filedata = f.read()text = cipher2.decrypt(base64.b64decode(data), random_generator)print(text)
运行效果如下，解密后的text为1000，符合预期。
$ ./test.py generate priv key start.generate priv key done.E25FkcAYB7XFil2sI3OvA4S6KnQppTPh7zIO3LgQKnBmLpQaQfdICwEuUEae1nNFntGdn5ahLou5VvyN/2s9TZgvkj5DcJzAlDRX2OZrllM4mbCeTLyWYVyGqTVZx0SIFtQG/F1053j5OTtv2xnlBaveiZasqFzrFtSuDwzgZxL0xKtBbI8GPUKAp/lq9UIHAqL0uewfdsOG6axus3zEnkfHJwIndBQ4Wu8ewDFXmGsD+XDUT/CgIBTMQILE9dxJG/CeoWWUBxJwepZ855zmvEkNSUDFhTEypatkW3DlKOfFEVERWztH0t/J7aRUVv2AaiE5t0iI3Y671MQPz7ytSg==10000
私钥签名 公钥验签
下面是利用私钥进行签名，然后用公钥去验证签名的实现
def privSignAndPubAttesation():print("privSignAndPubAttesation entry.")#private key signwith open("private.pem") as f:key = f.read()rsakey = RSA.importKey(key)signer = Signature_pkcs1_v1_5.new(rsakey)content_size = '3000'digest = SHA.new()digest.update(content_size)sign_data = signer.sign(digest)signature = base64.b64encode(sign_data)print(signature)#public key attesationwith open("public.pem") as f:key = f.read()rsakey = RSA.importKey(key)verifier = Signature_pkcs1_v1_5.new(rsakey)digest = SHA.new()digest.update('3000')is_matched = verifier.verify(digest, base64.b64decode(signature))print(is_matched)
运行效果如下，返回True，验签正常。
$ ./test.py generate priv key start.generate priv key done.privSignAndPubAttesation entry.FBx2QUCHYZy1UU+AB30A7d/kJ3mUeOSSUNDfDQ2ecGK/ATVh8EWW1rQ6gTAOKkuAAd2ejNizC6DR/GvCflh3PnfcH0kGAkWW5M7rZJ0/VMmlx45AHYvstWZmC5fSEfAHLHa0PcR3Y7C7+EH+Bv90YlShghD3ONLAFXo+5hOtANkgJndAsmfYLsIbB2Ap4ikGRPazBU8Xwz4iZN2duyVwjuS1PZ0uXCNenjm+zYn8/Ot0kEsVpXzO8aZ0GDtu2rJbyOZSGLU2YMZ2ynzOwGcIO9Ng+wm/2FMfsEvRiLIQOQhWMMEYem+68d7B3/o4A8Hj4n0T1KJzlzraY4qpbrjT2A==True
完整的python脚本内容如下，供参考：
#!/usr/bin/env pythonimport argparseimport sysimport base64import hashlibfrom Crypto import Randomfrom Crypto.Hash import SHAfrom Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5from Crypto.Signature import PKCS1_v1_5 as Signature_pkcs1_v1_5from Crypto.PublicKey import RSArandom_generator = ""cipher_text = ""content_size = ""signature_data = ""def generateKeys():print("generate priv key start.")random_generator = Random.new().readrsa = RSA.generate(2048, random_generator)private_pem = rsa.exportKey()with open('private.pem', 'w') as f:f.write(private_pem)public_pem = rsa.publickey().exportKey()with open('public.pem', 'w') as f:f.write(public_pem)print("generate priv key done.")def pubEncryAndprivDecry():content_size = '10000'#encryptwith open("public.pem") as f:key = f.read()rsakey = RSA.importKey(key)cipher = Cipher_pkcs1_v1_5.new(rsakey)cipher_text = base64.b64encode(cipher.encrypt(content_size))print(cipher_text)with open("encrypted_data", "wb") as f: ##save encrypted data to filef.write(cipher_text)#decryptwith open("private.pem") as f:key = f.read()prikey = RSA.importKey(key)cipher2 = Cipher_pkcs1_v1_5.new(prikey)with open("encrypted_data") as f: ### read data from encrypted filedata = f.read()text = cipher2.decrypt(base64.b64decode(data), random_generator)print(text)def privSignAndPubAttesation():print("privSignAndPubAttesation entry.")#private key signwith open("private.pem") as f:key = f.read()rsakey = RSA.importKey(key)signer = Signature_pkcs1_v1_5.new(rsakey)content_size = '3000'digest = SHA.new()digest.update(content_size)sign_data = signer.sign(digest)signature = base64.b64encode(sign_data)print(signature)#public key attesationwith open("public.pem") as f:key = f.read()rsakey = RSA.importKey(key)verifier = Signature_pkcs1_v1_5.new(rsakey)digest = SHA.new()digest.update('3000')is_matched = verifier.verify(digest, base64.b64decode(signature))print(is_matched)def main():#generate priv and public keygenerateKeys()#1. public key encrypt,then priv key decrypt#pubEncryAndprivDecry()#2. privkey sign and publickey attestationprivSignAndPubAttesation()return 0if __name__ == '__main__':sys.exit(main())
