M2Crypto Diffie-Hellman parameters as .pem

问题

What is the M2Crypto equivalent of this openssl cli command?

openssl dhparam -out dh.pem 2048

My attempt

Looking through the test cases I can generate diffie-hellman parameters as such:

>>> import M2Crypto.DH
>>> params = M2Crypto.DH.gen_params(2048, 2, lambda: None)

I cannot, however, generate a .pem representation of these params.

There doesn't appear to be a method to do so on the DH object:

>>> help(params)

Help on instance of DH in module M2Crypto.DH:

class DH
 |  Object interface to the Diffie-Hellman key exchange
 |  protocol.
 |  
 |  Methods defined here:
 |  
 |  __del__(self)
 |  
 |  __getattr__(self, name)
 |  
 |  __init__(self, dh, _pyfree=0)
 |  
 |  __len__(self)
 |  
 |  __setattr__(self, name, value)
 |  
 |  check_params(self)
 |  
 |  compute_key(self, pubkey)
 |  
 |  gen_key(self)
 |  
 |  print_params(self, bio)
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  m2_dh_free = <built-in function dh_free>

print_params looks promising, but it's not what I'm looking for:

>>> import M2Crypto.BIO
>>> bio = M2Crypto.BIO.MemoryBuffer()
>>> params.print_params(bio)
1
>>> print bio.read()
    PKCS#3 DH Parameters: (2048 bit)
        prime:
            00:f3:97:79:b0:53:60:15:0c:26:2a:d9:01:8c:52:
            ef:04:74:70:2a:0d:90:8c:97:bd:a3:4a:e4:c0:b9:
            ab:ad:48:3c:e6:51:a3:ea:c4:66:65:11:8f:5f:f3:
            05:1d:bd:c2:10:03:bc:dc:bb:bc:48:42:5b:fc:25:
            bd:60:ce:10:83:bf:62:85:48:bd:51:bb:cd:f6:06:
            71:b1:12:55:74:a2:69:98:90:b5:51:7c:da:8a:c4:
            28:be:94:ff:86:80:d9:65:aa:55:f7:f2:c4:b2:b3:
            b3:7d:33:a1:a8:be:dc:40:40:19:df:c8:0e:b1:ff:
            03:c4:92:97:b6:47:4f:d3:6f:e3:99:63:9b:3f:58:
            a0:6c:46:1e:d9:c6:05:81:76:aa:5c:41:cc:fd:2a:
            cf:7a:e2:5a:66:ce:4d:4c:9b:f3:7c:6f:a9:85:75:
            f3:78:85:d5:59:31:de:03:99:c9:a7:24:a0:65:75:
            ac:3c:98:df:77:5b:2f:80:df:66:36:a2:ca:7e:97:
            94:b8:cc:ff:8c:9b:3a:58:88:cf:a2:4b:7b:0e:0a:
            1d:dc:de:97:37:0d:f4:14:89:80:f6:53:73:7d:4d:
            6c:cc:71:c9:46:3f:b5:c9:05:d8:2d:69:4a:aa:9e:
            ce:bd:d6:33:fa:76:81:26:a2:ea:3e:d9:bc:a6:bf:
            60:fb
        generator: 2 (0x2)

Related functionality

To prove that I'm not insane, the RSA module has what I need to make .pem files like so:

>>> import M2Crypto.RSA, M2Crypto.m2
>>> key = M2Crypto.RSA.gen_key(2048, M2Crypto.m2.RSA_F4)
>>> print key.as_pem(cipher=None)
-----BEGIN RSA PRIVATE KEY-----
MIIEowIBAAKCAQEAnU4l0pyjeqEzzKiWFW3xeFzNveUCXY5rJpfvl0e8Mt9diEMB
ealZO1+HpyRwmRAy6XTX3CTksYaCr7cRy6leF2nKTbm6Knfu9ye6kb8pbFLCjxhG
ouE1tR1Dht3GquJW10pDqjWgxdyrEfjvETqpNoq1axi8WyxIJ0eM0DvYvxg5Meuj
PV99AFwp8FNZJtCpWQDY9ZLYxEY9//1/ehza8MRE+TQVvmm9sAofWYSog2UVk9cf
xx3YjAMINOmBboM7S2/4SbgL30mx+916hw3D1tstYW4mRi1r2EtHP9KaKf8wWqZW
LDUu9DSNd/y58m78xLv5lGXNp6jgE6FyMwjZuQIDAQABAoIBAGQhm5feF3324Rc0
dRy8+ElKobhv7zqIbpKJgnyEsDqdzlbveB/ueZt+qsXtPzNfiVjsBH/giCas3cFm
QhCnBfrXX2xsfiGMaHOxOWSPD5ohcDFQHZ6OxvY744EU6OJb4zV1026kZmuslMSC
9gK8mXvbfbHnc/aBUIiYVf0zKzwv+oLYTbZx0MEL3fq8jBiPlqXgHK008eruunJG
gHS5WSXeDb2UKlGJZpl5sKifN3Pum7Cx0zq33hW2wFctYsJoVVNBrJyLyw2JzLbV
EQ1oN6NCVWtIpKbPrd7pmwnAUuc4l+I/cY438Wh+OomXlICZvJ7yvcmuJVL9NZCR
CIqz4gECgYEA0MDLmfb3/5v1ezBqDvi6yr7huCqlgcTai/1OlQeWecxUnywvtgCC
W3Rf89WSzitavuFMBHqRB7zj2F2BoosZWSXib6VEatc8+s72Bm822R8/KS8CEM7S
DyXMDxisDfOyeagdfXPQmGAZDloOXSdB8DcDO2uO2gxxwsr0aPcOBMECgYEAwOhz
xDvbvXcTumMWBsmQXecWkG1x1YjwCN+0fU6I+EqRULzcKu6i3i48cNtfmvVL0xJp
gM6e3VSM9sWIE2s1poBnsLNflVCN6ecW6iChsBXZY++rA9OvmdnROQ2Fn7xCIJ2p
edtbK7tUHM3DEwyXLH8Yj6RAwjMnZr1+lNlyuvkCgYEAhBPHfhWVGWOasKOUJv7W
aFrXQ4ewCef8AqB1LLONUGiojcEOOtAdqjF6WDMj3E/v7V9sklTeGBA59HZNBAOQ
OShQGSVuoU6nZWS2oqGRCVTMyIjWfL3uh+j5MAADNByhKnnklrBFJXN/xuXRuryQ
6qRT5i+KRYmkHIP+mb7eXsECgYBC1QWueZJyfHugOk3aQiC696GQneovMYb/fAk6
1GeNpb/ceeHJGe3hDaGw87+Wnt8LHDjjADJ3uaAwqlSvbZgjvB6wUCSQRV01KPN+
X5nEuH0dK15TMBaJNbZPjsi5g25hgF3DsuROLVNBu2OXCOii6NFoil5JKZG//WyK
Qx+FeQKBgGWT7kNTAh7zy3Bz0P6rmYe+5Om/u4aGuQ6jVIvzP3ysYWZwiYTwa5C2
CpDHaz4W2JBg3XAhVtRMZn2bW09HH3PN7lJhdzxGBlpaiS5ODdRDURbCbGoe/qPQ
l4FraLtLYJ46+3JPgInVU5e48kQFnfN03yakdSzduNbxraEkJy49
-----END RSA PRIVATE KEY-----

Version info

>>> import platform
>>> print platform.release()
3.11.0-15-generic
>>> import sys
>>> print sys.version
2.7.5+ (default, Feb 27 2014, 19:37:08) 
[GCC 4.8.1]
>>> import M2Crypto
>>> print M2Crypto.version
0.22

来源：https://stackoverflow.com/questions/26560717/m2crypto-diffie-hellman-parameters-as-pem

标签

python

cryptography

OpenSSL

m2crypto

diffie-hellman