Binary Encryption

[Phil Palmieri]

Im using md5 to encrypt and decrypt plain text, this works fine...

When i try to run the same function on a binary file, it does not
decrypt correctly. Is there a way to encrypt binary files correctly,
and be able to decrypt them?

in the perfect situation i would like to be able to store the
encrypted binary file into a mysql blob field, or at least be able to
save an encrypted version of the binary file on the server.

Im not lookign for a copy paste soultion (although i would take one) -
but maybe some reliable documention or examples?

Thanks,
Phil

[Michael Fesser]

Re: Binary Encryption

.oO(Phil Palmieri)
[color=blue]
>Im using md5 to encrypt and decrypt plain text, this works fine...[/color]

Huh?
[color=blue]
>When i try to run the same function on a binary file, it does not
>decrypt correctly. Is there a way to encrypt binary files correctly,
>and be able to decrypt them?[/color]

MD5 is a hash algorithm, which is not reversible by definition. In other
words: You can't decrypt a hash.
[color=blue]
>in the perfect situation i would like to be able to store the
>encrypted binary file into a mysql blob field, or at least be able to
>save an encrypted version of the binary file on the server.[/color]

In most cases it's better to store binary data in real files. Storing it
as BLOBs in a database will probably slow down the db server and make
queries inefficient.

Anyway, you might want to have a look at Mcrypt.

http://www.php.net/mcrypt

PHP's Encryption Functionality [page 3]

http://www.onlamp.com/pub/a/php/2001/07/26/encrypt.html?page=3

Micha

[Phil Palmieri]

Re: Binary Encryption

Ok, maybe i didnt explain that well...

Irregardless of what im using, im encrypting a string so.. "Phil" +
"password(s )" becomes "#sakdhk3hk34s2 "; (not real i just typed
gibbrish); and then can be reversed.

forget the database for now, -- If i run my encryption function on
the contents of a ASCII file (using fopen) i can encrypt and decrypt
it fine, so i tried with my fingers crossed to see if it would work on
a binary file -- it didn't.

So, Pretending im starting from scratch, how would i encrypt a binary
file? and then be able to decrypt it using a 'password'.

So FILE + "password" = 'garbage'
and garbage + "password" = FILE
--

If i cant nativly do it in PHP, is there Server based software i can
install and just run cron system commands?

Thanks,
PHil


Michael Fesser <netizen@gmx.ne t> wrote in message news:<1j0jo0d37 gn1td8imncna2hk m5v5va8r6j@4ax. com>...[color=blue]
> .oO(Phil Palmieri)
>[color=green]
> >Im using md5 to encrypt and decrypt plain text, this works fine...[/color]
>
> Huh?
>[color=green]
> >When i try to run the same function on a binary file, it does not
> >decrypt correctly. Is there a way to encrypt binary files correctly,
> >and be able to decrypt them?[/color]
>
> MD5 is a hash algorithm, which is not reversible by definition. In other
> words: You can't decrypt a hash.
>[color=green]
> >in the perfect situation i would like to be able to store the
> >encrypted binary file into a mysql blob field, or at least be able to
> >save an encrypted version of the binary file on the server.[/color]
>
> In most cases it's better to store binary data in real files. Storing it
> as BLOBs in a database will probably slow down the db server and make
> queries inefficient.
>
> Anyway, you might want to have a look at Mcrypt.
>
> http://www.php.net/mcrypt
>
> PHP's Encryption Functionality [page 3]
> http://www.onlamp.com/pub/a/php/2001...pt.html?page=3
>
> Micha[/color]

[neur0maniak]

Re: Binary Encryption

How can it be irregardless of encryption method?
You're probably not using a binary-safe encryption method.

If that's the case, Base64 encode your binary file, then encrypt that.
When decrypting, just remember to base64 decode the output.

Phil Palmieri wrote:[color=blue]
> Ok, maybe i didnt explain that well...
>
> Irregardless of what im using, im encrypting a string so.. "Phil" +
> "password(s )" becomes "#sakdhk3hk34s2 "; (not real i just typed
> gibbrish); and then can be reversed.
>
> forget the database for now, -- If i run my encryption function on
> the contents of a ASCII file (using fopen) i can encrypt and decrypt
> it fine, so i tried with my fingers crossed to see if it would work on
> a binary file -- it didn't.
>
> So, Pretending im starting from scratch, how would i encrypt a binary
> file? and then be able to decrypt it using a 'password'.
>
> So FILE + "password" = 'garbage'
> and garbage + "password" = FILE
> --
>
> If i cant nativly do it in PHP, is there Server based software i can
> install and just run cron system commands?
>
> Thanks,
> PHil
>
>
> Michael Fesser <netizen@gmx.ne t> wrote in message news:<1j0jo0d37 gn1td8imncna2hk m5v5va8r6j@4ax. com>...
>[color=green]
>>.oO(Phil Palmieri)
>>
>>[color=darkred]
>>>Im using md5 to encrypt and decrypt plain text, this works fine...[/color]
>>
>>Huh?
>>
>>[color=darkred]
>>>When i try to run the same function on a binary file, it does not
>>>decrypt correctly. Is there a way to encrypt binary files correctly,
>>>and be able to decrypt them?[/color]
>>
>>MD5 is a hash algorithm, which is not reversible by definition. In other
>>words: You can't decrypt a hash.
>>
>>[color=darkred]
>>>in the perfect situation i would like to be able to store the
>>>encrypted binary file into a mysql blob field, or at least be able to
>>>save an encrypted version of the binary file on the server.[/color]
>>
>>In most cases it's better to store binary data in real files. Storing it
>>as BLOBs in a database will probably slow down the db server and make
>>queries inefficient.
>>
>>Anyway, you might want to have a look at Mcrypt.
>>
>>http://www.php.net/mcrypt
>>
>>PHP's Encryption Functionality [page 3]
>>http://www.onlamp.com/pub/a/php/2001...pt.html?page=3
>>
>>Micha[/color][/color]