.TH "SILC" "1" "December 7 2002" "silc-client" "silc-client" .PP .SH "NAME" silc \- client for SILC, a secure and flexible conferencing network .PP .SH "SYNOPSIS" \fBsilc\fP \fB[\fP -S \fIfile\fP | -d | -C | -c \fIhost\fP | -w \fIpass\fP | -p \fIport\fP | -! | -n \fInick\fP | -h \fIhost\fP | -v | -? \fB]\fP .PP .SH "DESCRIPTION" SILC (Secure Internet Live Conferencing) is a secure conferencing network\&. \fBSilc\fP is the SILC client which is used to connect to SILC server and the SILC network\&. The silc client resembles IRC clients to make the using easier for new users\&. .PP \fBSilc\fP supports sending of practically any kind of messages in addition of normal text messages in the SILC network\&. This includes multimedia messages like images, video and audio stream\&. The session to SILC server is secured with session key, channel messages are protected with channel key and private messages with session keys\&. It is also possible to use private channel keys and private message keys in addition to server generated keys\&. It is also possible to digitally sign all messages\&. .PP \fBSilc\fP supports \fIpassphrase\fP authentication and public key authentication based on \fIdigital signatures\fP, when connecting to SILC server\&. \fBSilc\fP also supports key exchange (key agreement) between other \fBSilc\fP users in the SILC network to negotiate secret key material\&. This key material then can be used to secure for example private messages\&. It is also possible to exchange public keys and certificates in the SILC network between clients and servers\&. .PP The \fBsilc\fP also supports \fIdetaching\fP from the SILC network by closing the connection to the server but without quitting from the network\&. Next time the \fBsilc\fP connects to the server it \fIresumes\fP the session in the SILC network\&. During the detaching the user remains in the network and other users may query the user information and see that user is in network but currently detached\&. Messages sent to user while being detached are dropped by the server\&. When resuming is over the user has automatically same nickname than before detaching and remains on all channels, and it seems like user never left the network\&. .PP The \fBsilc\fP also supports creation of \fIfriends\fP list, which is kind of a buddy list familiar from IM (Instant Messaging) clients\&. By using the \fBWHOIS\fP SILC command with \fI-details\fP option it is possible to fetch the user\'s information such as their public keys and certificates, business card, pictures, and other information and save them to the friends list\&. The friends list is located at \fB~/\&.silc/friends/\fP directory\&. .PP The SILC public key and private key pair is used to authenticate the user to the SILC server when connecting a server\&. This key pair is created automatically when the \fBsilc\fP is run for the first time\&. It can also be created with \fB-C\fP option\&. .PP When connecting for the first time to SILC server, user will be asked to accept the server\'s public key\&. When key is accepted the \fBsilc\fP saves the public key for future into \fB~/\&.silc/serverkeys/\fP directory\&. The next time user connects to same server the public key is verified against the saved public key\&. The purpose of this public key saving is to avoid man-in-the-middle attacks which could be possible if the key would have to be verified every time user connects to the server\&. .PP .SH "OPTIONS" \fB-c\fP \fIhost\fP Connect to given host .PP \fB-p\fP \fIport\fP Connect to \fIport\fP .PP \fB-C\fP Create new public key pair .PP \fB-P\fP Change the passphrase of the private key file .PP \fB-S\fP \fIkeyfile\fP Display the contents of given SILC public key from file .PP \fB-n\fP \fInick\fP Specify what nick to use .PP \fB-h\fP \fIhost\fP Give \fIhost\fP as your hostname .PP \fB-w\fP \fIpass\fP Use \fIpass\fP as password for connection .PP \fB-d\fP \fIstring\fP Enable debugging .PP \fB-v\fP Display client version .PP \fB-!\fP Do not autoconnect .PP \fB-?\fP Display client help message .PP .SH "LONG OPTIONS" .PP \fB--connect\fP=\fISERVER\fP Same as \fB-c\fP\&. .PP \fB--port\fP=\fIPORT\fP Same as \fB-p\fP\&. .PP \fB--home\fP=\fIPATH\fP Client home dir (\fI~/\&.silc\fP)\&. .PP \fB--config\fP=\fIPATH\fP Configuration file location (\fI~/\&.silc/silc\&.conf\fP)\&. .PP \fB--list-ciphers\fP List supported ciphers\&. .PP \fB--list-hash-funcs\fP List supported hash functions\&. .PP \fB--list-hmacs\fP List supported HMACs\&. .PP \fB--list-pkcs\fP List supported PKCSs\&. .PP \fB--create-key-pair\fP Same as \fB-C\fP\&. .PP \fB--passphrase-change\fP Same as \fB-P\fP\&. .PP \fB--nick\fP=\fINICK\fP Same as \fB-n\fP\&. .PP \fB--hostname\fP=\fIHOST\fP Same as \fB-h\fP\&. .PP \fB--password\fP=\fIPASS\fP Same as \fB-w\fP\&. .PP \fB--debug\fP=\fISTRING\fP Same as \fB-d\fP, limit to messages *\fISTRING\fP*\&. .PP \fB--dummy\fP Use dummy terminal mode\&. .PP \fB--version\fP Same as \fB-v\fP\&. .PP \fB--noconnect\fP Same as \fB-!\fP\&. .PP \fB--help\fP Same as \fB-?\fP\&. .PP \fB--usage\fP Display very brief usage summary\&. .PP .SH "KEY GENERATION" When generating key pair(s) for silc (\fB-C\fP), the following extra switches apply: .PP \fB--pkcs\fP=\fIPKCS\fP Set the public key algorithm of key pair\&. For example \fBrsa\fP\&. .PP \fB--bits\fP=\fIVALUE\fP Set the length of public key pair, in bits\&. .PP .SH "CONFIGURATION FILE" The \fBsilc\fP configuration file is \fB~/\&.silc/silc\&.conf\fP and can be used to configure the behaviour of the client\&. The configuration file format is equivalent to Irssi IRC client\'s configuration file\&. See the documentation for the configuration file at \fBhttp://irssi\&.org\fP\&. .PP There are a few \fBsilc\fP configuration settings in \fIsilc\&.conf\fP which can be configured in \fIsettings\fP section under \fI"server"\fP block\&. They can be set also with the \fB/SET\fP command in the \fBsilc\fP client\&. .PP \fBcrypto_default_cipher\fP .RS The default cipher to use to secure the session to the server\&. Values can be for example \fBaes-256-cbc\fP, \fBaes-192-cbc\fP, \fBaes-128-cbc\fP, \fBtwofish-256-cbc\fP, \fBtwofish-192-cbc\fP, \fBtwofish-128-cbc\fP\&. .RE .PP \fBcrypto_default_hash\fP .RS The default hash function to use in session with the server\&. Values can be \fBsha1\fP or \fBmd5\fP\&. .RE .PP \fBcrypto_default_hmac\fP .RS The default HMAC to be use in session with the server\&. Value can be \fBhmac-sha1-96\fP, \fBhmac-md5-96\fP, \fBhmac-sha1\fP or \fBhmac-md5\fP\&. .RE .PP .SH "FILES" \fB~/\&.silc/silc\&.conf\fP .RS Client\'s configuration file .RE .PP \fB~/\&.silc/public_key\&.pub\fP .RS The SILC public key of the user .RE .PP \fB~/\&.silc/private_key\&.pub\fP .RS The SILC private key of the user .RE .PP \fB~/\&.silc/clientkeys/\fP .RS The directory holding the public keys of other users the user has accepted and trusted in the SILC network\&. The public keys can be received with \fBGETKEY\fP SILC command or during key agreement between two users\&. .RE .PP \fB~/\&.silc/serverkeys/\fP .RS The directory holding the public keys of servers the user has accepted and trusted when connecting to a server\&. .RE .PP \fB~/\&.silc/friends/\fP .RS The directory holding the information of \fIfriends\fP that user has\&. User can create a friend list with \fBWHOIS -details\fP SILC command\&. This directory holds the friends\' public keys, business cards, pictures, and other information\&. .RE .PP .SH "SEE ALSO" \fBsilcd(8)\fP \fBsilcd\&.conf(5)\fP .PP .SH "NETWORK RESOURCES" Homepage: \fBhttp://silcnet\&.org\fP .PP SILC Client is based on Irssi IRC client: \fBhttp://irssi\&.org\fP .PP User\'s guide: \fBhttp://silcnet\&.org/docs/\fP .PP .SH "AUTHOR" SILC is designed and written by Pekka Riikonen and rest of the SILC Project\&. .PP This manpage was written by Mika \'Bostik\' Boström .PP See \fBCREDITS\fP for full list of contributors\&. .PP