[ruby-core:93905] [Ruby master Feature#12354] PKey::EC Can't output public key pem when private key exists

Issue #12354 has been updated by jeremyevans0 (Jeremy Evans).

Backport deleted (2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN)
ruby -v deleted (ruby 2.2.4p230 (2015-12-16 revision 53155) [x86_64-linux])
Tracker changed from Bug to Feature

The following is a way to generate a PEM for a `OpenSSL::PKey::EC` with both a private and a public key without allocating a new `OpenSSL::PKey::EC`:

```
pk = key.private_key
key.private_key = nil
key.to_pem
key.private_key = key
```

I agree that this approach is suboptimal, and it may be worthwhile to add a method for this, or a keyword argument to `to_pem`.  However, that is a request for a new feature, not a bug fix.

I checked and `OpenSSL::PKey::RSA` doesn't have the same issue because `OpenSSL::PKey::RSA#public_key` returns `OpenSSL::PKey::RSA` (`OpenSSL::PKey::EC` returns `OpenSSL::PKey::EC::Point`).  However, it still requires allocating a new `OpenSSL::PKey::RSA` object.


----------------------------------------
Feature #12354: PKey::EC Can't output public key pem when private key exists
https://bugs.ruby-lang.org/issues/12354#change-79988

* Author: armour (Armour Comms)
* Status: Assigned
* Priority: Normal
* Assignee: rhenium (Kazuki Yamaguchi)
* Target version: 
----------------------------------------
Steps to reproduce:

Create EC key:

```ruby
key = OpenSSL::PKey::EC.new("prime256v1")
key.generate_key
```

Try and output in pem format

```ruby
key.to_pem #Outputs private key pem
key.public_key.to_pem #Error
```

In order to output a public key pem, a new key object must be created with no private key:

```ruby
key_pub = OpenSSL::PKey::EC.new(key.group)
key_pub.public_key = key.public_key
```

Output pem

```ruby
key_pub.to_pem #Success!
```

From viewing the source, http://rxr.whitequark.org/mri/source/ext/openssl/ossl_pkey_ec.c#466 it seems that if the key is private there is no way to output a public key for that key object



-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:[e-mail]?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>