[PATCH v2 2/2] keytoc: fix env provided keyspec handling

[Marco Felsch]

On 25-08-05, Sascha Hauer wrote:
> +Cc Basti
> 
> On Thu, Jul 24, 2025 at 03:50:56PM +0200, Marco Felsch wrote:
> > Currently the env provided keyspec is resolved during the gen_key() step
> > by making use of the try_resolve_env(). This is wrong because it will
> > set the complete <hint>:<key> keyspec string for the 'keyname' and 'path'.
> > 
> > To fix this the resolve step must happen during the main-loop as first step
> > because the main-loop is doing the 'keyname' and 'path' split already.
> > 
> > Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
> > ---
> >  scripts/keytoc.c | 13 +++++--------
> >  1 file changed, 5 insertions(+), 8 deletions(-)
> > 
> > diff --git a/scripts/keytoc.c b/scripts/keytoc.c
> > index 617317d6607e..105fa4b5413d 100644
> > --- a/scripts/keytoc.c
> > +++ b/scripts/keytoc.c
> > @@ -615,10 +615,6 @@ static int gen_key(const char *keyname, const char *path)
> >  	char *tmp, *key_name_c;
> >  
> >  	/* key name handling */
> > -	keyname = try_resolve_env(keyname);
> > -	if (!keyname)
> > -		exit(1);
> > -
> >  	tmp = key_name_c = strdup(keyname);
> >  
> >  	while (*tmp) {
> > @@ -628,10 +624,6 @@ static int gen_key(const char *keyname, const char *path)
> >  	}
> >  
> >  	/* path/URI handling */
> > -	path = try_resolve_env(path);
> > -	if (!path)
> > -		exit(1);
> > -
> 
> This was introduced by Basti in 685cc602e0ad ("keytoc: allow __ENV__
> lookup for keyname hint") to support:
> 
> CONFIG_CRYPTO_PUBLIC_KEYS="__ENV__FIT_KEY_NAME_HINT:__ENV__FIT_KEY"

Right, albeit I don't see why there should be two separate environment
variables for specifying one keyspec entry.

> I believe this patch breaks this usecase.

Of course :-/ but at the moment the simple use-case:

__ENV__FITKEY -> FITKEY="hint:<key>"

is broken. IMHO having two separate ENV variables is rather counter
intuitive. I also found myself in the following situation:

__ENV__FITKEYS -> FITKEYS="hint:<key> hint-2:<key-2> <key-3>"

This is not supported as well. So we should really define and document
the ENV behavior.

Regards,
  Marco


> 
> Sascha
> 
> >  	if (!strncmp(path, "pkcs11:", 7)) {
> >  		ret = engine_get_pub_key(path, &key);
> >  		if (ret)
> > @@ -737,6 +729,11 @@ int main(int argc, char *argv[])
> >  		char *keyname = NULL;
> >  		char *path = NULL;
> >  
> > +		/* Check if the keyspec is provided by the ENV first */
> > +		keyspec = try_resolve_env(keyspec);
> > +		if (!keyspec)
> > +			exit(1);
> > +
> >  		if (!strncmp(keyspec, "pkcs11:", 7))
> >  			path = strdup(keyspec);
> >  		else
> > -- 
> > 2.39.5
> > 
> > 
> > 
> 
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