RSA in python

[Abhisek Datta]

Hello,

I am looking for good RSA implementations in python that can import a
public key in PEM format and encrypt a buffer using the imported
public key. I tried m2crypto, but somehow it is giving me exceptions
which I couldnt solve as of now.

I get the following with m2crypto:
rsa = M2Crypto.RSA.lo ad_pub_key("pub key.pem")
gives me:
File "KB_Client. py", line 63, in SessionInit
rsa = M2Crypto.RSA.lo ad_pub_key("pub key.pem")
File "/usr/lib/python2.4/site-packages/M2Crypto/RSA.py", line 225,
in load_pub_key
return load_pub_key_bi o(bio)
File "/usr/lib/python2.4/site-packages/M2Crypto/RSA.py", line 237,
in load_pub_key_bi o
rsa_error()
File "/usr/lib/python2.4/site-packages/M2Crypto/RSA.py", line 162,
in rsa_error
raise RSAError, m2.err_reason_e rror_string(m2. err_get_error() )
M2Crypto.RSA.RS AError: no start line


Any help will be highly appreciated.

Regards,
-abhisek

[wittempj@hotmail.com]

Re: RSA in python

Did you try this: http://www.amk.ca/python/code/crypto ?

[Abhisek Datta]

Re: RSA in python

I tried the ezPyCrypto which is basically a higher level wrapper to pyCrypto
but it fails to import public key in PEM format.

-abhisek

On 17 Feb 2006 07:02:51 -0800, wittempj@hotmai l.com
<martin.witte@g mail.com> wrote:[color=blue]
> Did you try this: http://www.amk.ca/python/code/crypto ?
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>[/color]

[plahey@alumni.caltech.edu]

Re: RSA in python

stupid question, but did you try:

rsa = M2Crypto.RSA.lo ad_pub_key( file("pubkey.pe m") )

It is not clear from the documentation what they want for "file" (and
because Python has no type declarations, you are left to guess...).

May not work... just thought I would ask.

[plahey@alumni.caltech.edu]

Re: RSA in python

Looking at the api documentation again, it is possible that they want
this:

pubkey = open( 'pubkey.pem', 'rb' ).read() # binary read here?
rsa = M2Crypto.RSA.lo ad_pub_key(pubk ey)

Anyway, things to play with...

[Heikki Toivonen]

Re: RSA in python

Abhisek Datta wrote:[color=blue]
> I am looking for good RSA implementations in python that can import a
> public key in PEM format and encrypt a buffer using the imported
> public key. I tried m2crypto, but somehow it is giving me exceptions
> which I couldnt solve as of now.[/color]

What you are trying to do should be covered by M2Crypto. Without more
context for the error (what was the file you were trying load, etc.) it
is hard to say what is wrong. My first guess is that your pem file did
not include the BEGIN/END lines.

I would suggest you take a look at the tests and samples included in
M2Crypto. They do show how to work with PEM files.


M2Crypto 0.15: http://wiki.osafoundation.org/bin/vi...ts/MeTooCrypto

[Abhisek Datta]

Re: RSA in python

Hello,

Here is some debugging output:

---
pyKB-DEBUG: Connecting to http://192.168.0.2:8080/RPC2
pyKB-DEBUG: Initializing session: (sessionKey: ABCDEFGHIJKLMNO )
pyKB-DEBUG: Received public key:
-----BEGIN RSA PUBLIC KEY-----
MIGJAoGBALxi3tG XlSwRgn7/Km6mTSge+5ijQgI n3GvnZOeYyOo1Dk ubVtTaFj26
GWtJo43MEe1a5Ul WKJEOpbKVCr4AAS fFj8YmmRewH4SXd Z+w1Bad8amyzL2h 8F7J
wJojOnocSs6xDE7 o86CpZRUlojBefa nMdCpu074QFktE6 3OD1zBBAgMBAAE=
-----END RSA PUBLIC KEY-----

Traceback (most recent call last):
File "KB_Client. py", line 96, in ?
kb.SessionInit( sessionKey="ABC DEFGHIJKLMNO")
File "KB_Client. py", line 63, in SessionInit
rsa = M2Crypto.RSA.lo ad_pub_key("pub key.pem")
File "/usr/lib/python2.4/site-packages/M2Crypto/RSA.py", line 225,
in load_pub_key
return load_pub_key_bi o(bio)
File "/usr/lib/python2.4/site-packages/M2Crypto/RSA.py", line 237,
in load_pub_key_bi o
rsa_error()
File "/usr/lib/python2.4/site-packages/M2Crypto/RSA.py", line 162,
in rsa_error
raise RSAError, m2.err_reason_e rror_string(m2. err_get_error() )
M2Crypto.RSA.RS AError: no start line
---

You can clearly see the public key which I am receiving from an xmlrpc
server. Then I saved the public key in "pubkey.pem " file and then use
M2Crypto.RSA.lo ad_pub_key() and I am getting the output as show above.

-abhisek

On 2/17/06, Heikki Toivonen <heikki@osafoun dation.org> wrote:[color=blue]
> Abhisek Datta wrote:[color=green]
> > I am looking for good RSA implementations in python that can import a
> > public key in PEM format and encrypt a buffer using the imported
> > public key. I tried m2crypto, but somehow it is giving me exceptions
> > which I couldnt solve as of now.[/color]
>
> What you are trying to do should be covered by M2Crypto. Without more
> context for the error (what was the file you were trying load, etc.) it
> is hard to say what is wrong. My first guess is that your pem file did
> not include the BEGIN/END lines.
>
> I would suggest you take a look at the tests and samples included in
> M2Crypto. They do show how to work with PEM files.
>
>
> M2Crypto 0.15: http://wiki.osafoundation.org/bin/vi...ts/MeTooCrypto
> --
> http://mail.python.org/mailman/listinfo/python-list
>[/color]

[Heikki Toivonen]

Re: RSA in python

Abhisek Datta wrote:[color=blue]
> -----BEGIN RSA PUBLIC KEY-----
> MIGJAoGBALxi3tG XlSwRgn7/Km6mTSge+5ijQgI n3GvnZOeYyOo1Dk ubVtTaFj26
> GWtJo43MEe1a5Ul WKJEOpbKVCr4AAS fFj8YmmRewH4SXd Z+w1Bad8amyzL2h 8F7J
> wJojOnocSs6xDE7 o86CpZRUlojBefa nMdCpu074QFktE6 3OD1zBBAgMBAAE=
> -----END RSA PUBLIC KEY-----
>
> Traceback (most recent call last):[/color]
[...][color=blue]
> M2Crypto.RSA.RS AError: no start line[/color]

The files in M2Crypto tests directory don't have any files that have
"BEGIN RSA PUBLIC KEY" in them - haven't checked if this is legal or not.

However, plain OpenSSL does not like that file either:

$ openssl rsa -in rsa_heikki.pem -pubin
3440:error:0906 D06C:PEM routines:PEM_re ad_bio:no
startline:pem_l ib.c:644:Expect ing: PUBLIC KEY

$ openssl rsa -in rsa_heikki.pem -check
2140:error:0906 D06C:PEM routines:PEM_re ad_bio:no
startline:pem_l ib.c:644:Expect ing: ANY PRIVATE KEY

If I take out the "RSA " part from the delimiter lines I get:

$ openssl rsa -in rsa_heikki2.pem -pubin
unable to load Public Key
3124:error:0D06 80A8:asn1 encoding routines:ASN1_C HECK_TLEN:wrong
tag:tasn_dec.c:
1282:
3124:error:0D07 803A:asn1 encoding routines:ASN1_I TEM_EX_D2I:nest ed asn1
error:ta
sn_dec.c:374:Ty pe=X509_ALGOR
3124:error:0D08 303A:asn1 encoding
routines:ASN1_T EMPLATE_NOEXP_D 2I:nested asn1 e
rror:tasn_dec.c :743:Field=algo r, Type=X509_PUBKE Y
3124:error:0906 700D:PEM routines:PEM_AS N1_read_bio:ASN 1 lib:pem_oth.c:8 3:

$ openssl rsa -in rsa_heikki2.pem -check
unable to load Private Key
2304:error:0906 D06C:PEM routines:PEM_re ad_bio:no start
line:pem_lib.c: 644:Expect
ing: ANY PRIVATE KEY


My suggestion would be to ask on the openssl-users list.

--
Heikki Toivonen



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