Synnefo

from django import http

from django.template import RequestContext, loader

from django.utils import simplejson as json

from django.conf import settings

from synnefo.userdata import rest

from synnefo.userdata.models import PublicKeyPair

from synnefo.userdata import asn1

from Crypto.PublicKey import RSA

from Crypto.Util.number import inverse

import binascii

import base64

class PublicKeyPairResourceView(rest.UserResourceView):

    model = PublicKeyPair

    exclude_fields = ["user"]

class PublicKeyPairCollectionView(rest.UserCollectionView):

    model = PublicKeyPair

    exclude_fields = ["user"]

SSH_KEY_LENGTH = getattr(settings, 'UI_SSH_KEY_LENGTH', 1024)

def generate_key_pair(request):

    """

    Response to generate private/public RSA key pair

    """

    key = RSA.generate(SSH_KEY_LENGTH)

    # generate private content in PEM format

    seq = asn1.DerSequence()

    seq[:] = [ 0, key.n, key.e, key.d, key.p, key.q, key.d % (key.p-1), key.d % (key.q-1), inverse(key.q, key.p)]

    pem = asn1.b("-----BEGIN PRIVATE KEY-----\n")

    binaryKey = seq.encode()

    chunks = [ binascii.b2a_base64(binaryKey[i:i+48]) for i in range(0, len(binaryKey), 48) ]

    pem += asn1.b('').join(chunks)

    pem += asn1.b("-----END PRIVATE KEY-----\n")

    # generate public content

    seq = asn1.DerSequence()

    ssh_rsa = '00000007' + base64.b16encode('ssh_rsa')

    exponent = '%x' % (key.e, )

    if len(exponent) % 2:

        exponent = '0' + exponent

    ssh_rsa += '%08x' % (len(exponent) / 2, )

    ssh_rsa += exponent

    modulus = '%x' % (key.n, )

    if len(modulus) % 2:

        modulus = '0' + modulus

    if modulus[0] in '89abcdef':

        modulus = '00' + modulus

    ssh_rsa += '%08x' % (len(modulus) / 2, )

    ssh_rsa += modulus

    public = 'ssh-rsa %s' % (base64.b64encode(base64.b16decode(ssh_rsa.upper())),)

    print pem

    print

    print

    print public

    data = {'private': pem, 'public': public}

    return http.HttpResponse(json.dumps(data), mimetype="application/json")