manpage(SILC) (1) (December 7 2002) (silc-client) (silc-client) manpagename(silc) (client for SILC, a secure and flexible conferencing network) manpagesynopsis() bf(silc) bf([) -S em(file) | -d | -C | -c em(host) | -w em(pass) | -p em(port) | -! | -n em(nick) | -h em(host) | -v | -? bf(]) manpagedescription() SILC (Secure Internet Live Conferencing) is a secure conferencing network. bf(Silc) 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. bf(Silc) 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. bf(Silc) supports em(passphrase) authentication and public key authentication based on em(digital signatures), when connecting to SILC server. bf(Silc) also supports key exchange (key agreement) between other bf(Silc) 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. The bf(silc) also supports em(detaching) from the SILC network by closing the connection to the server but without quitting from the network. Next time the bf(silc) connects to the server it em(resumes) 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. The bf(silc) also supports creation of em(friends) list, which is kind of a buddy list familiar from IM (Instant Messaging) clients. By using the bf(WHOIS) SILC command with em(-details) 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 bf(~/.silc/friends/) directory. 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 bf(silc) is run for the first time. It can also be created with bf(-C) option. 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 bf(silc) saves the public key for future into bf(~/.silc/serverkeys/) 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. manpageoptions() bf(-c) em(host) Connect to given host bf(-p) em(port) Connect to em(port) bf(-C) Create new public key pair bf(-P) Change the passphrase of the private key file bf(-S) em(keyfile) Display the contents of given SILC public key from file bf(-n) em(nick) Specify what nick to use bf(-h) em(host) Give em(host) as your hostname bf(-w) em(pass) Use em(pass) as password for connection bf(-d) em(string) Enable debugging bf(-v) Display client version bf(-!) Do not autoconnect bf(-?) Display client help message manpagesection(LONG OPTIONS) bf(--connect)=em(SERVER) Same as bf(-c). bf(--port)=em(PORT) Same as bf(-p). bf(--home)=em(PATH) Client home dir (em(~/.silc)). bf(--config)=em(PATH) Configuration file location (em(~/.silc/silc.conf)). bf(--list-ciphers) List supported ciphers. bf(--list-hash-funcs) List supported hash functions. bf(--list-hmacs) List supported HMACs. bf(--list-pkcs) List supported PKCSs. bf(--create-key-pair) Same as bf(-C). bf(--passphrase-change) Same as bf(-P). bf(--nick)=em(NICK) Same as bf(-n). bf(--hostname)=em(HOST) Same as bf(-h). bf(--password)=em(PASS) Same as bf(-w). bf(--debug)=em(STRING) Same as bf(-d), limit to messages *em(STRING)*. bf(--dummy) Use dummy terminal mode. bf(--version) Same as bf(-v). bf(--noconnect) Same as bf(-!). bf(--help) Same as bf(-?). bf(--usage) Display very brief usage summary. manpagesection(KEY GENERATION) When generating key pair(s) for silc (bf(-C)), the following extra switches apply: bf(--pkcs)=em(PKCS) Set the public key algorithm of key pair. For example bf(rsa). bf(--bits)=em(VALUE) Set the length of public key pair, in bits. manpagesection(CONFIGURATION FILE) The bf(silc) configuration file is bf(~/.silc/silc.conf) 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 bf(http://irssi.org). There are a few bf(silc) configuration settings in em(silc.conf) which can be configured in em(settings) section under em("server") block. They can be set also with the bf(/SET) command in the bf(silc) client. bf(crypto_default_cipher) quote(The default cipher to use to secure the session to the server. Values can be for example bf(aes-256-cbc), bf(aes-192-cbc), bf(aes-128-cbc), bf(twofish-256-cbc), bf(twofish-192-cbc), bf(twofish-128-cbc).) bf(crypto_default_hash) quote(The default hash function to use in session with the server. Values can be bf(sha1) or bf(md5).) bf(crypto_default_hmac) quote(The default HMAC to be use in session with the server. Value can be bf(hmac-sha1-96), bf(hmac-md5-96), bf(hmac-sha1) or bf(hmac-md5).) manpagefiles() bf(~/.silc/silc.conf) quote(Client's configuration file) bf(~/.silc/public_key.pub) quote(The SILC public key of the user) bf(~/.silc/private_key.pub) quote(The SILC private key of the user) bf(~/.silc/clientkeys/) quote(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 bf(GETKEY) SILC command or during key agreement between two users.) bf(~/.silc/serverkeys/) quote(The directory holding the public keys of servers the user has accepted and trusted when connecting to a server.) bf(~/.silc/friends/) quote(The directory holding the information of em(friends) that user has. User can create a friend list with bf(WHOIS -details) SILC command. This directory holds the friends' public keys, business cards, pictures, and other information.) manpageseealso() bf(silcd(8)) bf(silcd.conf(5)) manpagesection(NETWORK RESOURCES) Homepage: bf(http://silcnet.org) SILC Client is based on Irssi IRC client: bf(http://irssi.org) User's guide: bf(http://silcnet.org/docs/) manpageauthor() SILC is designed and written by Pekka Riikonen and rest of the SILC Project. This manpage was written by Mika 'Bostik' Boström See bf(CREDITS) for full list of contributors.