Ruby - Window command line interface

Question

UPDATE -- I tried exactly the same thing using Python and it works perfectly !!

import os
os.system('certutil.exe -v -getkey "614D628A00000000014C" C:/Users/kra/kevin')

Could somebody shed some light on this issue please!

If I run this ruby code:

require 'open3'
stdin, stdout, stderr = Open3.popen3('certutil -v -getkey "614D628A00000000014C" C:/Users/kra/kevin')            
puts stdout.read

I get the following error:

Querying WIN-3CF41NBPT85.demo.com\demo-CA
CommonName: 614D628A00000000014C
CertUtil: -GetKey command FAILED: 0x80092004 (-2146885628)
CertUtil: Cannot find object or property.

However if I run the command directly from the command line, it works.

C:\Users\kra>certutil -getkey "614D628A00000000014C" C:/Users/kra/kevin
Querying WIN-3CF41NBPT85.cjndemo.com\cjndemo-CA.....................

"WIN-3CF41NBPT85.demo.com\demo-CA"
  Serial Number: 614d628a00000000014c
  Subject: CN=Kevin, C=GB
   NotBefore: 11/30/2012 10:20 AM
   NotAfter: 5/7/2013 9:29 AM
  Template: Copy of Web Server
  Version: 3
  Cert Hash(sha1): 88 b1 7a 74 8c be 73 d5 16 07 7f 19 16 57 14 c5 dd a9 79 7f


Recipient Info[0]:
CMSG_KEY_TRANS_RECIPIENT(1)
CERT_ID_ISSUER_SERIAL_NUMBER(1)
    Serial Number: 129e45d3000000000130
    Issuer: CN=demo-CA, DC=demo, DC=com
    Subject: CN=kra, CN=Users, DC=demo, DC=com
CertUtil: -GetKey command completed successfully.

Interestingly if I run this ruby code:-

require 'open3'
stdin, stdout, stderr = Open3.popen3('certutil -recoverkey -p lexicon C:\Users\kra\kevin C:\Users\kra\kevin.pfx')
puts stdout.read

It also works.

Computed Hash: 6e d3 b8 ad 93 16 7b f0 fb b3 f5 cd 7e e4 bb ad fb 95 a0 81

User Certificate:
    Serial Number: 614d628a00000000014c
    Issuer: CN=demo-CA, DC=demo, DC=com
    Subject: CN=Kevin, C=GB
    Cert Hash(sha1): 88 b1 7a 74 8c be 73 d5 16 07 7f 19 16 57 14 c5 dd a9 79 7f
CertUtil: -RecoverKey command completed successfully.

I'm assuming its some kind of weird environmental thing because clearly ruby is able to call the certutil.exe command?

Answer 1

The first parameter for Open3.popen3 is the environment you want to pass to the sub-command. I've had to use this to get things working as I expected on occasion:

Open3.popen3(ENV, 'command') { ... }

which passes the current script's environment to the sub-command. The current script will have inherited its environment from the command-line, so, theoretically, the sub-command will have the same information the command issued at the command-line did.

If necessary, you can also extract subsets of ENV, or temporarily overwrite variables before calling popen3 .

---

Instead of popen3 , try using capture3 . It's very similar, but I consider it a bit less low-level. I've seen some weird behavior with popen3 that capture3 avoided nicely. Also, again, notice that you can pass in ENV .