/    Sign up×
Community /Pin to ProfileBookmark

PHP Pack() and unpack()

Copy linkTweet thisAlerts:
Dec 15.2010

Hi , i am currently learning about mcrypt and all its functions, until i came across the “pack()” function in my ebook. The book hashes the encryption key then packs it .e.g.

$encryptionKey = pack(‘H*’, $md5InputKey)

Then the book says the hash hexadecimal value is converted into binary data, so that each byte has a full 256-bit range of values.

I dont understand this explanation. full 256-range of values ? how does that work? Can anyone shed any light on this ? plus, can anyone tell me why someone would use pack and unpack, is there an advantage to converting data into binary format?

Any help is greatly appreciated , thank you.

to post a comment
PHP

1 Comments(s) ↴

Copy linkTweet thisAlerts:
@ehimeDec 16.2010 — I know Binary is easily readable, but it makes me wonder why they don't use hex2bin() instead? Maybe because it doesn't have a reverse function?
×

Success!

Help @Web_avenger spread the word by sharing this article on Twitter...

Tweet This
Sign in
Forgot password?
Sign in with TwitchSign in with GithubCreate Account
about: ({
version: 0.1.9 — BETA 6.16,
whats_new: community page,
up_next: more Davinci•003 tasks,
coming_soon: events calendar,
social: @webDeveloperHQ
});

legal: ({
terms: of use,
privacy: policy
});
changelog: (
version: 0.1.9,
notes: added community page

version: 0.1.8,
notes: added Davinci•003

version: 0.1.7,
notes: upvote answers to bounties

version: 0.1.6,
notes: article editor refresh
)...
recent_tips: (
tipper: @nearjob,
tipped: article
amount: 1000 SATS,

tipper: @meenaratha,
tipped: article
amount: 1000 SATS,

tipper: @meenaratha,
tipped: article
amount: 1000 SATS,
)...