How to read a RSA public key in PEM + PKCS#1 format

PyCrypto supports PKCS#1 in the sense that it can read in X.509 SubjectPublicKeyInfo objects that contain an RSA public key encoded in PKCS#1.

Instead, the data encoded in your key is a pure RSAPublicKey object (that is, an ASN.1 SEQUENCE with two INTEGERs, modulus and public exponent).

You can still read it in though. Try something like:

from Crypto.PublicKey import RSAfrom Crypto.Util import asn1from base64 import b64decodekey64 = 'MIGJAoGBAJNrHWRFgWLqgzSmLBq2G89exgi/Jk1NWhbFB9gHc9MLORmP3BOCJS9k\onzT/+Dk1hdZf00JGgZeuJGoXK9PX3CIKQKRQRHpi5e1vmOCrmHN5VMOxGO4d+znJDEbNHOD\ZR4HzsSdpQ9SGMSx7raJJedEIbr0IP6DgnWgiA7R1mUdAgMBAAE='keyDER = b64decode(key64)seq = asn1.DerSequence()seq.decode(keyDER)keyPub = RSA.construct( (seq[0], seq[1]) )

Starting from version 2.6, PyCrypto can import also RsaPublicKey ASN.1 objects.The code is then much simpler:

from Crypto.PublicKey import RSAfrom base64 import b64decodekey64 = b'MIGJAoGBAJNrHWRFgWLqgzSmLBq2G89exgi/Jk1NWhbFB9gHc9MLORmP3BOCJS9k\onzT/+Dk1hdZf00JGgZeuJGoXK9PX3CIKQKRQRHpi5e1vmOCrmHN5VMOxGO4d+znJDEbNHOD\ZR4HzsSdpQ9SGMSx7raJJedEIbr0IP6DgnWgiA7R1mUdAgMBAAE='keyDER = b64decode(key64)keyPub = RSA.importKey(keyDER)