Re: SSL / zlib compression

2006-09-27 Thread Shahin Khorasani 

Adayadil Thomas wrote:


Greetings.

I have an SSL session in which the client and server has negotiated for
cipherSuite SSL_RSA_WITH_RC4_128_MD5
compressionMethodzlib-compression

Now, is the zlib-compression applied before encryption or after ?

data - zlib-compression - encryption == decrypt - 
zlib-inflate- data


or

data - encryption - zlib-compression == zlib-inflate- decrypt 
- data



Thanks
Ashley Thomas
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Ashly look at RFC 2246  ,  The TLS Record Protocol  part

certainly u see this :
optionally compresses the data, applies a MAC, encrypts, and 
transmits the result 


compression is an optional layer (i think no compression  used  in 
well-known ssl implementation)

and ur question answer :  zlib-compression - encryption

regards

__
Shahin Khorasani
PKI Dept.
Sharif SecureWare Co.
www.parssign.com
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SSL / zlib compression

2006-09-26 Thread Adayadil Thomas 

Greetings.

I have an SSL session in which the client and server has negotiated for
cipherSuite SSL_RSA_WITH_RC4_128_MD5
compressionMethodzlib-compression

Now, is the zlib-compression applied before encryption or after ?

data - zlib-compression - encryption == decrypt - zlib-inflate- data

or

data - encryption - zlib-compression == zlib-inflate- decrypt - data


Thanks
Ashley Thomas
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RE: SSL / zlib compression

2006-09-26 Thread Vinu Thomas 
I am almost sure its after...
First you encrypt and then compress.

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Adayadil Thomas
Sent: Tuesday, September 26, 2006 7:46 PM
To: openssl-dev@openssl.org
Subject: SSL / zlib compression

Greetings.

I have an SSL session in which the client and server has negotiated for
cipherSuite SSL_RSA_WITH_RC4_128_MD5
compressionMethodzlib-compression

Now, is the zlib-compression applied before encryption or after ?

data - zlib-compression - encryption == decrypt -
zlib-inflate- data

or

data - encryption - zlib-compression == zlib-inflate- decrypt
- data


Thanks
Ashley Thomas
__
OpenSSL Project http://www.openssl.org
Development Mailing List   openssl-dev@openssl.org
Automated List Manager   [EMAIL PROTECTED]

__
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Development Mailing List   openssl-dev@openssl.org
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Re: SSL / zlib compression

2006-09-26 Thread Brad House 

I have an SSL session in which the client and server has negotiated for
cipherSuite SSL_RSA_WITH_RC4_128_MD5
compressionMethodzlib-compression

Now, is the zlib-compression applied before encryption or after ?

data - zlib-compression - encryption == decrypt - 
zlib-inflate- data


or

data - encryption - zlib-compression == zlib-inflate- decrypt 
- data




Considering encrypted data, by nature, should not be predictable,
and therefore not compressible, your second listing would not be
logical.

-Brad

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Re: SSL / zlib compression

2006-09-26 Thread Bernhard Froehlich 

Vinu Thomas wrote:

I am almost sure its after...
First you encrypt and then compress.
  


No way. First compression, then encryption, like Brad already said. 
Encrypted data is (almost) incompressible, regardless of cleartext.


Hope it helps.
Ted
;)

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