[X-Unix] Problem with xxd tools

[Eugene]

On Sun, May 29, 2005 at 11:11:44PM CDT, Hudson Barton <hhbv at highwinds.com> wrote:
: 
: I'm using the "XXD" tools for hexing and unhexing the result of 
: encryptions produced by the "openssl" commands.  I'm using a 
: Macintosh G4 with Tiger.  The environment is shell scripts 
: (Applescript).
: 
: The Encrpytion process is... [Plaintext ==>> Encryption  ==>> Hexed 
: String].  Then the reverse is...  [Hexed String  ==>> Decryption ==>> 
: Plaintext].
: 
: When I use XXD, the encryption result produced by openssl (a string) 
: is usually different (unpredictably) after being hexed and unhexed by 
: XXD.  The error causes my decryption to fail.
: 
: Specifically, the problem is that the input string for XXD almost 
: always contains ASCII character 10 (a line feed) in one or more 
: places, and XXD often (or always - ????) returns ASCII character 13 
: instead (a carriage return) when unhexing.  I don't think there is 
: any way for me to work around this problem.  XXD needs to return 
: exactly what it started with.
: 
: To recap, the original text (in file "fin") contains one or more 
: incidents of ascii character 10==>>
: 
: The relevant lines of my code are:
: Hexing:  	do shell script "xxd  -p -u  -c 20  " & fin
: Unhexing:  	do shell script "xxd -r  -p -u -c 20 " & fin
: 
: ===>>> result contains ascii character 13 instead of ascii character 10
: 
: Suggestions?

I'm not familiar with xxd, but I did the following with a JPEG file:

	$ xxd blah.jpg | xxd -r > blah2.jpg
	$ diff blah.jpg blah2.jpg && echo "identical"
	identical


-- 
Eugene
http://www.coxar.pwp.blueyonder.co.uk/