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The RSA public key:
pubkey = 'MIGfMA0GCSqGSIb3DQEBA3UAA4GNADCBiQKBgQC35eMaYoJXEoJt5HxarHkzDBEMU3qIWE0HSQ77CwP/8UbX07W2XKwngUyY4k6Hl2M/n9TOZMZsiBzer/fqV+QNPN1m9M94eUm2gQgwkoRj5battRCaNJK/23GGpCsTQatJN8PZBhJBb2Vlsvw5lFrSdMT1R7vaz+2EeNR/FitFXwIDAQAB'
how to import it and use it to encrypt a string?
I tried the following code but RSA.construct() raises exception (TypeError: must be long, not str).
from Crypto.PublicKey import RSA
from Crypto.Util import asn1
from base64 import b64decode
keyDER = b64decode(pubkey)
seq = asn1.DerSequence()
seq.decode(keyDER)
keyPub = RSA.construct((seq[0], seq[1]))
print keyPub.encrypt('mysecret', 32)
Thanks.
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_PKCS1_v1_5
from base64 import b64decode,b64encode
pubkey = 'MIGfMA0GCSqGSIb3DQEBA3UAA4GNADCBiQKBgQC35eMaYoJXEoJt5HxarHkzDBEMU3qIWE0HSQ77CwP/8UbX07W2XKwngUyY4k6Hl2M/n9TOZMZsiBzer/fqV+QNPN1m9M94eUm2gQgwkoRj5battRCaNJK/23GGpCsTQatJN8PZBhJBb2Vlsvw5lFrSdMT1R7vaz+2EeNR/FitFXwIDAQAB'
msg = "test"
keyDER = b64decode(pubkey)
keyPub = RSA.importKey(keyDER)
cipher = Cipher_PKCS1_v1_5.new(keyPub)
cipher_text = cipher.encrypt(msg.encode())
emsg = b64encode(cipher_text)
print emsg
–
–
–
msg = "attack at dawn"
emsg = pubKeyObj.encrypt(msg, 'x')[0]
dmsg = privKeyObj.decrypt(emsg)
assert(msg == dmsg)
If you're writing to files, you may find it easier to deal with hex strings instead of binary strings. I'm using these helper functions a lot
def bin2hex(binStr):
return binascii.hexlify(binStr)
def hex2bin(hexStr):
return binascii.unhexlify(hexStr)
–
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAybVqRvfYvWbLsB98BqkD
lWd0/5y6SyhHt6/r6M0l7JXBweqMvxVt7XmI2yqPL56YxzcgQ8ycDkoqHJ+XozgP
iRnLNpYRlCzsiaOElbmQcnrI8iOb9Ahm6j0cbBB1S8VNvD+u9RQJt53zPxPj8/Dq
f1oNGFXOM8udNYWZaRCukLs/TumsAn0a+BF4639WtFiUvTWdVhlyvCQTs49ytRkH
rXH30RkB528RIvTGeW8xBTV4NaiTIzAEKCVSPagLr4Hzbb9b5+bODic/zkLGQazy
/NKOFgiB7kD2+WEMcuhTr5noeXau0PDAhgmrBhzzWOjUwwaO+ACvJLkPXZfjhy7P
+wIDAQAB
-----END PUBLIC KEY-----
You shouldn't b64decode the externKey and the string should start with "-----BEGIN PUBLIC KEY-----" and "-----END PUBLIC KEY-----".
–
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_PKCS1_v1_5
def encrypt_data(data):
with open("/path/to/public.pem", "rb") as k:
key = RSA.importKey(k.read())
cipher = Cipher_PKCS1_v1_5.new(key)
return cipher.encrypt(data.encode())
def decrypt_data(data):
with open("path/to/private.pem", "rb") as k:
key = RSA.importKey(k.read())
decipher = Cipher_PKCS1_v1_5.new(key)
return decipher.decrypt(data, None).decode()
message = "hello world!"
encrypted = encrypt_data(message)
decrypted = decrypt_data(message)
–
my env: win10x64 python3.6.4 pycrypto2.6.1
here's my code, encrypt end decrypt, the key was from someone's blog.(if U occured with "ValueError: RSA key format is not supported", check the key format, it should be warpped with some thing like "-----BEGIN XXXX KEY-----")
pubkey = """-----BEGIN PUBLIC KEY-----
-----END PUBLIC KEY-----"""
prvkey = """-----BEGIN RSA PRIVATE KEY-----
-----END RSA PRIVATE KEY-----"""
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_PKCS1_v1_5
msg = "test"
print("raw msg->", msg)
keyPub = RSA.importKey(pubkey) # import the public key
cipher = Cipher_PKCS1_v1_5.new(keyPub)
#print(cipher.encrypt.__doc__)
cipher_text = cipher.encrypt(msg.encode()) # now we have the cipher
print("cipher text->", cipher_text)
keyPriv = RSA.importKey(prvkey) # import the private key
cipher = Cipher_PKCS1_v1_5.new(keyPriv)
#print(cipher.decrypt.__doc__)
decrypt_text = cipher.decrypt(cipher_text, None).decode()
print("decrypted msg->", decrypt_text)
assert msg == decrypt_text # check that
print("test passed")
the output:
raw msg-> test
cipher text-> b'\xb0]\x1f@B\x8b\xb5\xbf\x891:\t4D\x80$\xc0y\xaa\xb4\x86t/|\xeaM%\xf06\x14,\x9e?\x86R\x83\xd72\xe5\xfdsr:\x99\xe7v\xd9]&\xbc\x85\xd3\x16\x80\x19q\xe7\xb1\x89\xff/\x12\xe5\xb3\x9cu\x1f\x04x\xa5\xdfl\xcd\xae_\xba\x1b\x97\x9fa\xcf9O\xbfB\xf6\xd1N\xf5|<\xbf^\x84R\xecSo\x9a*\xf7\x8d\x8e\xbe0Q\xcd\x14\x13\xf98x\xe7\xd8x\x19\xaf\x98\xefu\xa8\xb1\xd3\xfa\xf2N\xca\xb5'
decrypted msg-> test
test passed
If you want to import an external key using RSA.importkey( ), you have two options:
Read key from file:
file = open('external.pem','r')
external_key = file.read()
key = RSA.import_key(external_key)
and your external key format must be something like this:
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsDcmhF1kqsMw9HAUc231
IEr3OwVwocSM4JPUGVSTBDcM9tGoflx8UoN4M9EJrdCcVicZEt709L13jhUxo/hX
jUDqyQ6U+zyOYhoSwQpHKju2bwn6HMC8iq/ZwNqRFiqa23O2L8WSjZq4J/U1wWZ9
Zh7f0E5w8GZDkngceQI8nBWFPSAeQNAh0b4Vy1SYKapPrvUJdS9LsT3V9B2k2Nm1
4lUOtfufpWP5xjoC3MwOxgBsPJsuqpe7sZddG4YzQi3IuMAcc+C/ms9mA7OX5yxt
xgU3tAIzzBHgvwn9vANNJPzJMaOcm9kKMVJYXLHfg37IfIk1oV+/3BxMQ26ErNcC
9wIDAQAB
-----END PUBLIC KEY-----
In Linux (I don't know about Windows) you can check it by this command:
less exteralkey.pem
If you wanna hardcode your key into your code, your key must be like this:
pubkey = "-----BEGIN PUBLIC KEY-----\n\
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsDcmhF1kqsMw9HAUc231\n\
IEr3OwVwocSM4JPUGVSTBDcM9tGoflx8UoN4M9EJrdCcVicZEt709L13jhUxo/hX\n\
jUDqyQ6U+zyOYhoSwQpHKju2bwn6HMC8iq/ZwNqRFiqa23O2L8WSjZq4J/U1wWZ9\n\
Zh7f0E5w8GZDkngceQI8nBWFPSAeQNAh0b4Vy1SYKapPrvUJdS9LsT3V9B2k2Nm1\n\
4lUOtfufpWP5xjoC3MwOxgBsPJsuqpe7sZddG4YzQi3IuMAcc+C/ms9mA7OX5yxt\n\
xgU3tAIzzBHgvwn9vANNJPzJMaOcm9kKMVJYXLHfg37IfIk1oV+/3BxMQ26ErNcC\n\
9wIDAQAB\n\
-----END PUBLIC KEY-----"
then you can import it:
key = RSA.importkey(pubkey)
Note: if you do not add "\n" to the end of each line of your RSA key the RSA.importkey( ) will raise an error:
RSA key format is not supported
Note 2: I used "\" to indicate that statement is continued on the next line.
–
ubuntu@ubuntu:~$ sudo pip3 list|grep crypto
cryptography 2.8
cryptography-vectors 2.8
pycrypto 2.6.1
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_PKCS1_v1_5
def encrypt_data(data):
with open("/home/echague/.ssh/id_rsa.pub", "rb") as k:
key_pub = RSA.importKey(k.read())
cipher = Cipher_PKCS1_v1_5.new(key_pub)
return cipher.encrypt(data.encode())
def decrypt_data(data):
with open("/home/echague/.ssh/id_rsa", "rb") as k:
key_priv = RSA.importKey(k.read())
decipher = Cipher_PKCS1_v1_5.new(key_priv)
return decipher.decrypt(data, None).decode()
message = "hello world!"
encrypted = encrypt_data(message)
decrypted = decrypt_data(encrypted)
print(message)
print(encrypted)
print(decrypted)
–
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