otr_parse(1)							   User Commands						      otr_parse(1)

NAME

       otr_parse, otr_sesskeys, otr_mackey, otr_readforge, otr_modify, otr_remac - process Off-the-Record Messaging transcripts

SYNOPSIS

       otr_parse

       otr_sesskeys our_privkey their_pubkey

       otr_mackey aes_enc_key

       otr_readforge aes_enc_key [newmsg]

       otr_modify mackey old_text new_text offset

       otr_remac mackey flags snd_keyd rcv_keyd pubkey counter encdata revealed_mackeys

DESCRIPTION

       Off-the-Record (OTR) Messaging allows you to have private conversations over IM by providing:

	 o  Encryption

	 o  No one else can read your instant messages.

	 o  Authentication

	 o  You are assured the correspondent is who you think it is.

	 o  Deniability

	 o  The messages you send do not have digital signatures that are checkable by a third party.  Anyone can forge messages after a conversa-
	    tion to make them look like they came from you.  However, during a conversation, your correspondent is assured the	messages  he  sees
	    are authentic and unmodified.

	 o  Perfect forward secrecy

	 o  If you lose control of your private keys,  no  previous conversation is compromised.

       The  OTR Toolkit is useful for analyzing and/or forging OTR messages.  Why do we offer this?  Primarily, to make absolutely sure that tran-
       scripts of OTR conversations are really easy to forge after the fact.  [Note that during an OTR conversation, messages can  not	be  forged
       without real-time access to the secret keys on the participants' computers, and in that case, all security has already been lost.]  Easily-
       forgeable transcripts help us provide the "Deniability" property: if someone claims you said something over OTR, they will have	no  proof,
       as anyone at all can modify a transcript to make it say whatever they like, and still have all the verification come out correctly.

EXTENDED DESCRIPTION

       The following commands are supported:

       otr_parse

	   Parse OTR messages given on stdin, showing the values of all the fields in OTR protocol messages.

       otr_sesskeys our_privkey their_pubkey

	   Shows our public key, the session id, two AES and two MAC keys derived from the given Diffie-Hellman keys (one private, one public).

       otr_mackey aes_enc_key

	   Shows the MAC key derived from the given AES key.

       otr_readforge aes_enc_key [newmsg]

	   Decrypts an OTR Data message using the given AES key, and displays the message.  If newmsg is given, replace the message with that one,
	   encrypt and MAC it properly, and output the resulting OTR Data Message.  This works even if the given key was not correct for the orig-
	   inal message, so as to enable complete forgeries.

       otr_modify_mackey old_text new_text offset

	   Even  if  you can't read the data because you do not know either the AES key or the Diffie-Hellman private key, but you can make a good
	   guess that the substring "old_text" appears at the given offset in the message, replace the old_text with the new_text (which  must	be
	   of  the  same  length), recalculate the MAC with the given mackey, and output the resulting Data message.  Note that, even if you don't
	   know any text in an existing message, you can still forge messages of your choice using the otr_readforge command, above.

       otr_remac mackey flags snd_keyid rcv_keyid pubkey counter encdata revealed_mackeys

	   Make a new OTR Data Message, with the given pieces (note that the data part is already encrypted).  MAC it with the given mackey.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWgnome-im-client	   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Volatile			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       pidgin(1), attributes(5)

       Off-the-Record Messaging, at http://www.cypherpunks.ca/otr/

NOTES

       Written by the OTR Dev team (otr@cypherpunks.ca).  Updated by Brian Cameron, Sun Microsystems Inc., 2007.

SunOS 5.11							    13 Nov 2007 						      otr_parse(1)