Hi, I'm writing a little code to do some RSA stuff and I need to extract the public exponent and modulus for passing to a browser that will use them in Javascript. I've done considerable digging but have drawn a blank as I can't find any complete documentation of the full RSA class definition. What I am trying right now is to do: key = RSA.new(1024) private_key = key.to_pem public_modulus = key.public_key.n public_exponent = key.public_key.e This generates a new key and assigns the private key to a variable. I'd like to get the public exponent and modulus returned as a hex encoded string, similar to the output of "openssl rsa -noout -modulus" However, I can't find suitable documentation so I don't know what method (if any) I can use. I'd hoped for "key.public_key.n.to_h" but that does not seem to work. So, If anyone can give advice I'd appreciate it! Also, A general question: how do I look up class definitions of "standard" classes that are not documented in RDoc? Is there something similar to a C header file? (sorry, I'm quite new to Ruby). Many thanks for your help.

on 2007-08-08 00:05

on 2007-08-08 01:26

On Wed, Aug 08, 2007 at 07:05:22AM +0900, Starfry Starfry wrote: > key = RSA.new(1024) > not seem to work. How about Base64 ecoding? [key.public_key.n.to_s].pack('m')

on 2007-08-09 10:31

Aaron Patterson wrote: > On Wed, Aug 08, 2007 at 07:05:22AM +0900, Starfry Starfry wrote: >> key = RSA.new(1024) >> not seem to work. > How about Base64 ecoding? > > [key.public_key.n.to_s].pack('m') I could not get pack to work as you described. My code is below. I have taken a different tack, to get my Javaption side to work with the modulus and exponent in decimal. def generate_keys unless session[:private_key] k = RSA.new(128) session[:private_key] = k.to_pem session[:public_modulus] = k.public_key.n.to_s session[:public_exponent] = k.public_key.e.to_s end @private_key = session[:private_key] @public_modulus = session[:public_modulus] @public_exponent = session[:public_exponent] end I'd still like to be able to get this out of Ruby in Hex If only I could find out the available methods in the RSA class (as I said before the RDoc does not include anything about this class). Thanks!

on 2007-12-13 16:24

John Lane wrote: > def generate_keys > unless session[:private_key] > k = RSA.new(128) > session[:private_key] = k.to_pem > session[:public_modulus] = k.public_key.n.to_s > session[:public_exponent] = k.public_key.e.to_s > > end > @private_key = session[:private_key] > @public_modulus = session[:public_modulus] > @public_exponent = session[:public_exponent] > end > > I'd still like to be able to get this out of Ruby in Hex > > If only I could find out the available methods in the RSA class (as I > said before the RDoc does not include anything about this class). > > Thanks! Did this ever get resolved? This is the exact problem that I am trying to solve. Thanks, -S

on 2007-12-13 16:50

On Dec 13, 9:24 am, Shandy Nantz <shandyb...@yahoo.com> wrote: > > @public_modulus = session[:public_modulus] > Did this ever get resolved? This is the exact problem that I am trying > to solve. Thanks, > > -S > -- > Posted viahttp://www.ruby-forum.com/. This seems to work if you want it as a hex string: key = OpenSSL::PKey::RSA.new(1024) private_key = key.to_pem public_modulus = key.public_key.n.to_s(16) public_exponent = key.public_key.e.to_s(16)

on 2007-12-13 17:52

yermej wrote: > On Dec 13, 9:24 am, Shandy Nantz <shandyb...@yahoo.com> wrote: >> > @public_modulus = session[:public_modulus] >> Did this ever get resolved? This is the exact problem that I am trying >> to solve. Thanks, >> >> -S >> -- >> Posted viahttp://www.ruby-forum.com/. > > This seems to work if you want it as a hex string: > > key = OpenSSL::PKey::RSA.new(1024) > private_key = key.to_pem > public_modulus = key.public_key.n.to_s(16) > public_exponent = key.public_key.e.to_s(16) This does work thank you. Does anyone know how to get at all the parts that make up a public key such as the inverse? Thanks

on 2007-12-13 21:06

On 12/13/07, Shandy Nantz <shandybleu@yahoo.com> wrote: > > This seems to work if you want it as a hex string: > > > > key = OpenSSL::PKey::RSA.new(1024) > > private_key = key.to_pem > > public_modulus = key.public_key.n.to_s(16) > > public_exponent = key.public_key.e.to_s(16) > > This does work thank you. Does anyone know how to get at all the parts > that make up a public key such as the inverse? Thanks I'm pretty sure that you can't extract the inverse from a public key. The whole point of a public/private key pair is that it's extremely difficult to compute the private key from the public key. -- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.com/

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