[pve-devel] [PATCH v2 common] use hmac_sha256 instead of sha1 for csrf token

[Thomas Lamprecht]

On 6/18/19 2:41 PM, Oguz Bektas wrote:
> now generates & verifies with hmac_sha1. also left the old digest format
> for backwards compatibility during verification, to be removed at some
> later time.
> 
> Signed-off-by: Oguz Bektas <o.bektas at proxmox.com>
> ---
> v1 -> v2:
> * only calculate the needed hash, based on the length of the signature (thx thomas)
> 
>  src/PVE/Ticket.pm | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/PVE/Ticket.pm b/src/PVE/Ticket.pm
> index 5935ba5..6c83ec7 100644
> --- a/src/PVE/Ticket.pm
> +++ b/src/PVE/Ticket.pm
> @@ -20,7 +20,7 @@ sub assemble_csrf_prevention_token {
>  
>      my $timestamp = sprintf("%08X", time());
>  
> -    my $digest = Digest::SHA::sha1_base64("$timestamp:$username", $secret);
> +    my $digest = Digest::SHA::hmac_sha256_base64("$timestamp:$username", $secret);
>  
>      return "$timestamp:$digest";
>  }
> @@ -33,7 +33,7 @@ sub verify_csrf_prevention_token {
>  	my $timestamp = $1;
>  	my $ttime = hex($timestamp);
>  
> -	my $digest = Digest::SHA::sha1_base64("$timestamp:$username", $secret);
> +	my $digest = (length($sig) == 27) ? Digest::SHA::sha1_base64("$timestamp:$username", $secret) : Digest::SHA::hmac_sha256_base64("$timestamp:$username", $secret);

Really? This is a >160 character line... NAK! Rather something like:

my $digest;
if (length($sig) == 27) {
    # detected SHA1 from older proxy -> fallback. FIXME: remove with 7.0!
    $digest = Digest::SHA::sha1_base64("$timestamp:$username", $secret);
...

Please also sent all patches with a next version, at least if it's a
small series (if it was a series with >10 patches and only one changed,
OK, then /maybe/ not, but as mails are pretty cheap even then it may be
better :))

Also, the PMG uses that too, so it could be good if you add, test and
send a patch for it too, so that we don't forget it. Thanks! :)

>  
>  	my $age = time() - $ttime;
>  	return 1 if ($digest eq $sig) && ($age > $min_age) &&
>