[RFC 2/4] Add rsa support

[Jan Lübbe]

On Fr, 2015-03-13 at 10:56 +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > Having an ASN1 parser for DER/x509 is a huge amount of complexity I
> > would not want in a bootloader. Just take a look at the problems the
> > SSL-CAs and browsers had with different interpretations of the same
> > cert.
> 
> der is nothing few under lines

Sorry, I can't parse this.

> x509 a few more as it's based on DER

Could you show me that code?

> > The FIT format (and corresponding public key in the bootloader's DT) has
> > been adopted by depthcharge and u-boot, because it handles the
> > requirements and nothing more.
> 
> if you want to add this format you can but via the keychain loader not in the
> code as today you do have soc such as imx that store the key in OTP as DER

The IMX does not store keys in OTP. It stores a SHA(1 or 256) hash over
a table of "super root keys". This is irrelevant for barebox, as this is
already handled by the ROM code.

> and u-boot is not the best reference EVER.

Depthcharge is much more relevant here, as it's used as a coreboot
payload on chromebooks.

> > What is your use-case for which you need to add keys at runtime?
> 
> simple you want to allow user to put their own key
> or use a CA to handle allowed key
>
> if you want to replace grub this is critical

We have customers which require that do not allow runtime loading of
keys. So it should be possible to disable runtime loading at compile
time. 

Regards,
Jan
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