[Autocrypt] How to create the "raw key" part from an RSA key

[Bjoern]

Yes, thank you very much.

On Thu, May 18, 2017 at 8:01 PM, Daniel Kahn Gillmor
<dkg at fifthhorseman.net> wrote:
> Hi Bjoern--
>
> On Thu 2017-05-18 19:01:25 +0200, Bjoern wrote:
>> Okay, I figured out how to get the correct public key part.
>>
>> Now, I am a little bit confused about which data are really required
>> in the public key.
>>
>> The key eg. returned by the Autocrypt bot contains the following
>> packets (from https://tools.ietf.org/html/rfc4880)
>>
>> Public-key Packet -- 272 bytes raw
>> User ID Packet --  28 bytes raw, contains `bot123 <bot at autocrypt.org>`
>> Signature packet -- 343 byte raw
>> .... more packets
>>
>> All in all about 3,7 KB of data. I'm no expert, but for the pure
>> encryption, only the first packet is required? What is expected by the
>> Autocrypt-standard.
>
> I think you're looking for this information:
>
>     https://autocrypt.org/en/latest/level0.html#type-p-openpgp-based-key-data
>
> In particular, the expected key should be a series of 5 OpenPGP packets:
>
>        * a signing-capable primary key Kp
>        * a user id
>        * a self signature
>        * an encryption-capable subkey Ke
>        * a binding signature over Ke by Kp
>
>
> is that what you're looking for?
>
>    --dkg