[openssl-users] Converting a p12 or PEM formatted private key to a PKCS#1 format

[Viktor Dukhovni]

On Thu, Sep 03, 2015 at 04:06:06PM +0000, Viktor Dukhovni wrote:
> On Thu, Sep 03, 2015 at 08:21:25AM -0700, tmcclure0501 wrote:
> 
> > We have an embedded MQTT framework that we want to configure for mutual
> > authentication.  The framework is complaining that it needs a key format of
> > PKCS#1.  We have p12 and pem formats of the key.  Does openssl support
> > converting keys to the PKCS#1, if so what is the command? 
> 
> I've never heard of a PKCS#1 key format, I'm only aware of
> 
>     PKCS#8	- Private key
>     PKCS#12	- Private key and related certificates
> 
> Consult the documentation for the product, this is not an OpenSSL
> question until at least the desired key format is known.

Perhaps what you're looking for is the legacy RSA key format (PEM
or DER encoded).

	-----BEGIN RSA PRIVATE KEY-----
	-----END RSA PRIVATE KEY-----

The "openssl rsa" command (unlike the "pkey" command) outputs RSA
keys in either DER or PEM formats.

-- 
	Viktor.