Interesting, designers of HTTP/2 learned how to deal with covert channels that use the header fields with random padding or reserved fields, by setting them to zero, or with covert channels that use PDU reordering, by making the order of the frames for header block
to matter, but still they leave many ways how to build a covert channel.
When you open an already animated gif file in Gif Construction Set you can see the script "blocks" that make up an animated gif (screen figure 1): the header block
, loop block, control block, image block and optional comment and application blocks.
Dubravka's goal did not come under threat until the 11th minute when Salah climbed highest to meet Andy Robertson's cross and after seeing his header blocked
, snatched at the rebound and sent the ball into the sidenetting.
Portsmouth started the second half with fresh impetus and Bogle saw a header blocked
on the line by defender Reece James, although the whistle had already gone for a foul against the forward.
The home side dominated the early stages with Nathan Blissett having a header blocked
on the line after just six minutes before good work from Terry Hawkridge put Jermaine Hylton in the clear and when his shot was blocked by keeper Ben Killlip, Darren Carter put the rebound over the bar.
Quakers' pace and movement caused Chorley all sorts of problems, and after Harvey Saunders had a header blocked
, they took the lead on 43 minutes.
In a late charge, Jack Hobbs had a header blocked
by Jack Clarke while the lively Craig Noone protested that he had been pulled down in the penalty area by Kalvin Phillips.
The centre-back had goalbound header blocked
by Burton before Liam Hogan and Nathan Pond both headed wide.
Sunderland could even have snatched it at the death with Power twice going close in the closing minutes, but he was foiled first by goalkeeper Matt Ingram, who was signed this week on an emergency loan to cover an injury crisis, and soon after saw a header blocked
just in front of the line.
JAMES FORREST6 Shot over and header blocked
at Griffiths winner.
5 OLI MCBURNIE Saw his early header blocked
and didn't have much of a sniff at goal other than that, but gave Swansea a valuable outlet and got through a ton of work as usual.
Dani Ayala had his header blocked
and Traore's shot was turned onto and around the post but there was enough pressure and a flurry of chances to kill the game off long before Seagull's BORO have now lost three out of four home games under Tony Pulis, all in similar circumstances.