I'm attempting to write a script to generate SSH Identity key pairs for me.
from M2Crypto import RSA
key = RSA.gen_key(1024, 65337)
key.save_key("/tmp/my.key", cipher=None)
The file /tmp/my.key
looks great now.
By running ssh-keygen -y -f /tmp/my.key > /tmp/my.key.pub
I can extract the public key.
My question is how can I extract the public key from python? Using key.save_pub_key("/tmp/my.key.pub")
saves something like:
-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADASDASDASDASDBarYRsmMazM1hd7a+u3QeMP
...
FZQ7Ic+BmmeWHvvVP4Yjyu1t6vAut7mKkaDeKbT3yiGVUgAEUaWMXqECAwEAAQ==
-----END PUBLIC KEY-----
When I'm looking for something like:
ssh-rsa AAAABCASDDBM$%3WEAv/3%$F ..... OSDFKJSL43$%^DFg==
Use cryptography
! pycrypto
is not in active development anymore and if possible you should be using cryptography. Since June it's possible to generate SSH public keys as well:
from cryptography.hazmat.primitives import serialization as crypto_serialization
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.backends import default_backend as crypto_default_backend
key = rsa.generate_private_key(
backend=crypto_default_backend(),
public_exponent=65537,
key_size=2048
)
private_key = key.private_bytes(
crypto_serialization.Encoding.PEM,
crypto_serialization.PrivateFormat.PKCS8,
crypto_serialization.NoEncryption())
public_key = key.public_key().public_bytes(
crypto_serialization.Encoding.OpenSSH,
crypto_serialization.PublicFormat.OpenSSH
)
Note: You need at least version 1.4.0
.
Note: If your SSH client does not understand this private key format, replace PKCS8
with TraditionalOpenSSL
.