detect change of remote page

[will taubin]

hi everyone,

i have some links on my site, i need to be absolutely sure that the
html has not been modified, even one character. i would rather not
rely on http headers, just the html (so it is not dependant on the
webserver). should i make a database to actually mirror the page, and
then check against my copy? any better ideas? :)

thanks

[Geoff Berrow]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I noticed that Message-ID:
<aa5d813d.0311201518.212dda20@posting.google.com > from will taubin
contained the following:

>i have some links on my site, i need to be absolutely sure that the
>html has not been modified, even one character. i would rather not
>rely on http headers, just the html (so it is not dependant on the
>webserver). should i make a database to actually mirror the page,
>and then check against my copy? any better ideas? :)

Don't know how you would do it, but a hash of the page may be
sufficient? A bit like PGP sig?

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Version: PGPfreeware 6.5.8 for non-commercial use <http://www.pgp.com>

iQA/AwUBP71VCmUsPVsZRo4gEQK+cwCfUoGD8tF8SKmidE1E6mjRtO 0cJJ4An2Vd
x0Gv5k/DriaFBcxM7563FePJ
=2nYp
-----END PGP SIGNATURE-----

--
Geoff Berrow (put thecat out to email)
It's only Usenet, no one dies.
My opinions, not the committee's, mine.
Simple RFDs [url]http://www.ckdog.co.uk/rfdmaker/[/url]

[André Næss]

will taubin:

> hi everyone,
>
> i have some links on my site, i need to be absolutely sure that the
> html has not been modified, even one character. i would rather not
> rely on http headers, just the html (so it is not dependant on the
> webserver). should i make a database to actually mirror the page, and
> then check against my copy? any better ideas? :)

Checksum the file, and store the checksum locally. Then you can verify the
file against this checksum when you access it. md5() is ok for this
purpose.

André Næss

[will taubin]

André Næss <andrena.spamreallysucks@ifi.uio.no> wrote in message news:<bpjkk3$h8q$1@maud.ifi.uio.no>...

> will taubin:
>

> > hi everyone,
> >
> > i have some links on my site, i need to be absolutely sure that the
> > html has not been modified, even one character. i would rather not
> > rely on http headers, just the html (so it is not dependant on the
> > webserver). should i make a database to actually mirror the page, and
> > then check against my copy? any better ideas? :)

>
> Checksum the file, and store the checksum locally. Then you can verify the
> file against this checksum when you access it. md5() is ok for this
> purpose.
>
> André Næss

thanks, but if i generate a checksum, then later download the file
again to compare the checksums, will the timestamps affect the new
checksum? or is it generated only based on the content of the file?

[Irnis Haliullin]

> Checksum the file, and store the checksum locally. Then you can verify the

> file against this checksum when you access it. md5() is ok for this
> purpose.
>

If you are using Windows, the Advanced CheckSum Verifier from
[url]http://www.irnis.net[/url] is just for you :)

[André Næss]

will taubin:

> André Næss <andrena.spamreallysucks@ifi.uio.no> wrote in message
> news:<bpjkk3$h8q$1@maud.ifi.uio.no>...

>> will taubin:
>>

>> > hi everyone,
>> >
>> > i have some links on my site, i need to be absolutely sure that the
>> > html has not been modified, even one character. i would rather not
>> > rely on http headers, just the html (so it is not dependant on the
>> > webserver). should i make a database to actually mirror the page, and
>> > then check against my copy? any better ideas? :)

>>
>> Checksum the file, and store the checksum locally. Then you can verify
>> the file against this checksum when you access it. md5() is ok for this
>> purpose.
>>
>> André Næss

>
> thanks, but if i generate a checksum, then later download the file
> again to compare the checksums, will the timestamps affect the new
> checksum? or is it generated only based on the content of the file?

It's generated based on whatever you input, so as long as you only input the
contents, and this doesn't change, you're ok.

André Næss