Copyright (c) 2003 Tero Karvinen tero.karvinen atta iki.fi
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
Redhat Mandrake Suse Debian Slackware
Tätä kirjoittaessa uusin vakaa versio Debian GNU/Linuxista on Debian 3.0 Woody. Asennuksen yhteydessä kannattaa käyttää Debianin virallista asennusopasta[1]. Jos et tiedä vastausta johonkin asennusohjelman kysymykseen, kannattaa vastata asennusohjelman tarjoama oletusvaihtoehto.
Jos asennat useita käyttöjärjestelmiä, asenna Linux viimeisenä. Suositeltu partitiointi Windows & Linux dual-boot:
| Windows | fat32 | 2 GB |
| Linux / | ext2 | 2+ GB |
| Linux swap | swap | RAM |
Windows-osion voit tehdä myös Windows-asennusohjelmalla, jätä vain osioimatonta tilaa levylle Linuxia varten. Linuxissa on erinomainen tuki FAT ja FAT32 tiedostojärjestelmille, mutta NTFS se osaa vain lukea. Windows ei ymmärrä mitään Linux-formaatteja.
Linux-asennuksessa tee ensin swap, joka on yhtä suuri kuin koneesi RAM, esimerkiksi 256 MB. Tee sitten kaiken lopun tilan vievä Linux ext2 osio.
Asennusohjelman mukana tulee kernel eli ydin 2.2. Uusin vakaa versio 2.4 mahdollistaa esimerkiksi iptables-tulimuurin ja DVD-elokuvien katselun. Ydintä ei välttämättä tarvitse itse kääntää, vaan voi hakea omalle prosessorille tarkoitetun kuvan.
nano /etc/lilo.conf
Seuraa apt-getin antamaa ohjetta: vmlinuz: initrd=initrd.img
reboot
modconf
Käynnistä verkko uudelleen
ifup eth0
Tarvittavat modulit voi asentaa myös automaattisesti. Olen kokeillut tätä vasta alustavasti
# discover
Starting discover...
Found hardware 3c59x ide-sci [..]
Loading 3c59x
[..]
Aluksi tulimuuri päästää kaiken läpi. Lisätään perussäännöt työaseman tulimuurille
# iptables -P INPUT DROP
# iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# iptables-save > /etc/iptables
/sbin/iptables-restore /etc/iptables
Packet Filtering Howto[5] on erinomainen esitys iptablesista. Debianissa se löytyy kansiosta /usr/share/doc/iptables/.
Seuraavaksi tulimuuriin tutustumista, joka ei ole välttämätöntä jokaisen asennuksen yhteydessä. Katsotaan valmista tulimuuria
Pidetään lokia kielletyistä yhteydenotoista
Koska viimenen sääntö kirjoittaa lokiin /var/log/messages kaikki hylätyt paketit, ja loki kirjoitetaan virtuaalikonsoleille 1-6 (alt-ctrl-f1), ruudulle tulee paljon turhaa tavaraa. Parasta on lisätä ennen LOG riviä sääntö, joka pudottaa tavanomaiset (smb, dhcp, upnp) paketit kirjoittamatta lokiin.
Toinen vaihtoehto on kieltää lokin kirjoittaminen ruudulle
Jotta konetta ei tarvitse enää sammuttaa asennuksen jälkeen, pitää koneessa toimia
Työasemakäyttöä varten koneessa tulee olla ainakin weppiselain (lynx, graafisessa galeon), ssh ja scp, tekstieditori (vi tai nano).
Komento adduser lisää uuden käyttäjän. Samalla uusi käyttäjä saa salasanan ja kotihakemiston.
Tiedostoja käsitellään kaikissa unixeissa komennoilla ls, cp -r, rm -rf
Alla dollarin merkki $ tarkoittaa normaalin käyttäjän (siis ei root) komentokehotetta, johon käskyt kirjoitetaan.
README.Debian changelog.Debian.gz changelog.gz copyright html
$ ls -l
total 24
-rw-r-r- 1 root root 1909 Apr 14 00:50 README.Debian
-rw-r-r- 1 root root 3977 Apr 14 18:01 changelog.Debian.gz
-rw-r-r- 1 root root 5498 Apr 14 00:50 changelog.gz
-rw-r-r- 1 root root 1234 Apr 14 17:35 copyright drwxr-xr-x 2 root root 4096 Sep 8 01:07 html
$ ls -a
. .. .hiddenfile README.Debian changelog.Debian.gz changelog.gz copyright html
$ ls
411toppm
822-date
AbiWord
[...]
MakeTeXPK
X11
-More-
cat, more, less, grep
apropos, komento --help, man, info, /usr/share/doc, linuxdoc.org, kotisivu, google.com, groups.google.com
vi, nano, pico, emacs
Esimerkeissä editoidaan tiedostoja milloin milläkin editorilla. On tietysti vain itsestäsi kiinni, haluatko
nano on vapaa, pico ainoastaan ilmainen.
ctrl-X tallentaa ja poistuu.
$ wget http://iki.fi/karvinen/vintuitive/vimrc
$ mv vimrc .vimrc
``Hyvä käyttöjärjestelmä, josta tosin puuttuu tekstieditori.''
Sisältää kaiken mahdollisen sähköpostin luvusta ohjelmoitavuuteen. Vie paljon muistia (tekstieditoriksi). Vanha ja testattu.
ssh, ssh-keygen, tunnelit, X-tunneli, älä käytä telnet tai rsh
vnc
mutt, pine, agrep, grepm, spamassasin, procmail
ping, fping, traceroute, dig www.helia.fi all, tethereal, ngrep
mc, mc -a
Kaikki linuxit muistuttavat toisiaan. POSIX. LSB. FHS.
Linuxin tiedostojärjestelmän määrittelee (samoin kuin muissa unixeissa) Filesystem Hierarchy Standard[7].
Tiedostot kannattaa pyrkiä tallentamaan avoimissa standardeissa
JPG on häviöllinen pakkaus, joka soveltuu valokuvalle.
PNG on häviötön pakkaus kuville. PNG-kuvat aukeavat uusissa weppiselaimissa. Valokuvissa PNG-muotoa kannattaa käyttää vain muokattavien kuvien välivaiheisiin, sillä se vie paljon enemmän tilaa kuin JPG. Toisin kuin TIFF, PNG on yksiselitteisesti määritelty.
PNG korvaa vähitellen GIF-muodon www-sivuilla. GIF on erinomainen esimerkki ohjelmistopatenttien huvittavuudesta, sillä sitä koskee kaksi päällekkäistä patenttia, IBM:n ja Unisysin. PNG on myös tehokkaampi tallennusmuoto kuin GIF.
Ogg on häviöllinen pakkaus musiikille. Sitä tukevia ilmaisia soittimia on lähes kaikille alustoille: Linuxille (ogg123, xmms), Windowsille (WinAmp) ja Macintoshille.
OGG on paljon suositumman MP3:n kilpailija. Koska mikään yleisesti saatavilla oleva MP3-pakkaaja ei todellisuudessa pakkaa Fraunhoverin kehittämällä MP3-tekniikalla, MP3:n teoreettiseen maksimiin laadussa ei koskaan päästä. Saman kokoisena tiedostona OGG soi paremmin kuin MP3.
World Wide Web Consortiumin suosittelema, nykyinen versio HTML-kielestä.
Salaamaton PDF on hyvä formaatti. PDF on salattu, jos esimerkiksi Adoben tuotteissa valitsee ``Kiellä tulostus''-vaihtoehdon. PDF-salaus on erittäin helppo murtaa. Salatut PDF:t aukeavat esimerkiksi komennolla xpdf. Salaamattomia pdf-tiedostoja voi tallentaa useimmista Linux-ohjelmista.
tasksel, dpkg-reconfigure xserver-xfree86. Älä käytä xfree86config, xf86cfg
Mukana abiword, gnumeric, gnome-terminal, mozilla -edit, galeon, gmc, xmms, gimp
Harvemmin käytettyjä ethereal gnomecc lyx
Lisäksi mplayer, mencoder
sh bash perl php
less README
./configure && make && make install
hello.cc
sourceforge.net freshmeat.net
Asenna ja käynnistä www-palvelin
Welcome to Your New Home in Cyberspace!
__________________________________________
This is a placeholder page installed by the [1]Debian release of the [2]Apache Web server package [...]
Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT all - anywhere anywhere state RELATED,ESTABLISHED
ACCEPT all - localhost localhost DROP tcp - anywhere anywhere tcp
LOG all - anywhere anywhere LOG level warning
DROP all - anywhere anywhere
Kaikkien palvelinten asentamisessa on yleensä samat vaiheet kuin tässä: paketin asennus, asetukset ja reikä tulimuuriin.
# touch /var/www/stuff/foobar
Tarvittaessa palvelimen antaman vastauksen saa ruudulle
$ echo "GET http://localhost/stuff" | nc localhost 80
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<HTML><HEAD>
...
Tavallisesti www-sivuja on hakemistoissa
| hakemisto | näkyy webissä |
| /var/www/ | http://localhost/, https://localhost |
| /home/USER/public_html | http://USER/public_html |
Sivuja kannattaa tehdä lähinnä käyttäjien kotihakemistoihin, sillä normaalit käyttäjät eivät saa kirjoittaa hakemistoon /var/www/. Matomerkin (tilde ) saa pois osoitteesta tekemällä symbolisen linkin käyttäjän kotihakemistoon.
# chmod og-rw+x /var/www/user
Webbiin julkaistavien kansioiden oikeuksien tulee olla drwx-x-x, eli käyttäjä (eli kansion omistaja eli u) saa tehdä kansiolle mitä haluaa, muut ja ryhmä (og) vain käyttää sen alla olevia tiedostoja (x). Kansioissa lukuoikeus (r) tarkoittaa, että kansion tiedostolistausta saa katsella, eikä webissä yleensä haluta tätä. Tiedostoihin tulee olla lukuoikeus.
drwxr-xr-x 39 user user 4096 Sep 16 09:50 /home/user
drwx-x-x 2 user user 4096 Sep 15 19:11 /home/user/public_html
-rw-r-r- 1 user user 12 Sep 15 19:11 /home/user/public_html/index.html
chmod og-rw+x $HOME/public_html
Sivujen graafiseen WYSIWYG editointii sopii mozilla tai netscape
DirectoryIndex index.html index.htm index.shtml index.cgi index.php
AddType application/x-httpd-php .php AddType application/x-httpd-php-source .phps
Weppipalvelimena Apache-modSSL-php4-mySQL on aika ilmeinen vaihtoehto. Onko todella tarpeen näpytellä kymmenen minuttia asetuksia käsin saadakseen tämän toimimaan? Yksi vaihtoehto nopeampaan asetukseen olisi paketoida httpd.conf pakettiin, joka vaatii (requires) paketit (apache, mod-ssl...).
Samba tarkoittaa Windows-yhteensopivaa tiedostojen ja tulostimien jakamista ja käyttämistä Linuxista.
Asennetaan Samba-asiakasohjelmat
# iptables-save > /etc/iptables
$ nmblookup -T "*"
querying * on 123.123.123.255
x1.domain.com, 123.123.123.1 *<00>
x33.domain.com, 123.123.123.33 *<00> [..]
FOO <20> - B <ACTIVE>
added interface ip=10.0.0.1 bcast=194.142.138.127 nmask=255.255.255.128
Got a positive name query response from 10.0.0.2 ( 10.0.0.2 )
Password:
Sharename Type Comment
----- -- ----
MINDFOOD Disk
KALAA Disk
IPC$ IPC Remote Inter Process Communication
Server Comment
----- ----
Workgroup Master
----- ----
added interface ip=10.0.0.1 bcast=194.142.138.127 nmask=255.255.255.128
Got a positive name query response from 10.0.0.2 ( 10.0.0.2 )
Password:
smb: \> ls
. D 0 Wed Aug 29 13:08:38 2001
.. D 0 Wed Aug 29 13:08:38 2001
bar A 335 Sat Sep 7 10:43:24 2002
[..]
smb: \> exit
$
Tiedostojaon idea on käyttää toisella koneella olevia tiedostoja aivan kuin ne olisivat omalla koneella. Siksi jaettu kansio liitetään tiedostojärjestelmään.
# mount -t smbfs //foo/kalaa /mnt/foo-kalaa
Pelkästään mount-komennolla liitetty kansio ei näy enää uudelleenkäynnistyksen jälkeen. Käynnistyksessä automaattisesti liitettävät tiedostojärjestelmät luetellaan tiedostossa /etc/fstab
//foo/kalaa /mnt/foo-kalaa smbfs password=sikrit,rw,fmask=0666,dmask=0777,users 0 0
Kaikki käyttäjät voivat lukea ja kirjoittaa jaettuihin hakemistoihin, koska oletusoikeudet on asetettu fmask=0666 (-rw-rw-rw-) ja dmask=0777 (drwxrwxrwx).
Jos on tarpeen selailla lähiverkon tiedostojakoja, tähän löytyy paljon graafisia ohjelmia, esimerkiksi jags. Webbiliittymän saa smb2www paketilla (asennuksen jälkeen /etc/apache/httpd.conf cgi-bin kansion kuvaukseen pitää lisätä Options ExecCGI Followsymlinks).
Hakumoottoreita tiedostojakoihin ovat esimerkiksi Untz ja FemFind.
Katso myös Using Samba [4] ja uudistettu versio samasta kirjasta[8].
Katso myös kalvot.
Helpoin tapa päästä nopeasti alkuun. Syötä POP tai IMAP -postilaatikot, oman internet-palveluntarjoajan SMTP-palvelin ja sähköpostiosoitteesi.
Sähköpostia voi lähettää komennolla Compose ja lukea komennolla Get All.
Evolution on ``kaikki paitsi tiskiallas'' -tyyppinen sähköpostiohjelma, joka muistuttaa Outlookia. Evolutionissa on erittäin nopea vanhojen sähköpostiviestien haku.
Imp näyttää olevan suosituin webbisähköposti suurilla organisaatioilla. Suomessa sitä käyttävät esimerkiksi TKK, HY ja Helia.
gpg: /home/lists/.gnupg: directory created
gpg: you have to start GnuPG again, so it can read the new options
$ gpg -gen-key
Keysize: default keysize is 1024 bits
How long the key should be valid: 0 = key does not expire
Key does not expire at all - Is this correct (y/n)? y
Real name: Etunimi Sukunimi
Email address: oma.email@osoite.fi
Comment:
Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
Enter passphrase:
Repeat passphrase:
public and secret key created and signed.
gpg: Warning: using insecure memory! /home/lists/.gnupg/pubring.gpg
---------------
pub 1024D/BEA1E9F0 2002-09-29 Maija Maitoparta <maito@example.com>
sub 1024g/59CA61A8 2002-09-29
gpg: Warning: using insecure memory!
---BEGIN PGP PUBLIC KEY BLOCK---
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org
mQGiBD2W0cQRBACYkGYMtDH/p6L7+4COGjo8p0ZK4WA3ZA5XCt/LCM4fkuz7LPz+ K9hea2J5oXr7MvHuL6W9dCBU0fhnP9fvZPjb7Md+7yYUVqXNAVukgfvQ6xfc1Ccu ltFNIL1VVu3vM0ozPU4dKmaiv7Hy1Q/yFOl5NE6YWV+G373T/WNJVP9euwCg3kQx RqhehbIfxDMMxKukjF+5hAcD/1iTDb7YdyzWbkpu983HVmrLILZj6lHpAutphTxR EyFUprbexBlLyMme63Z1f3OfVPHjv5x/bByLp4Uino4P9LxO5yRAL1XLdOWXgjzf oacfAErrxY2PXrL28PXStEt/xa807UDtU0Joy4hZsaCOCo76YB52pHGJK8XeA5ao OND+A/92CRf1h8/EJ1SjhaxgPu5FC5nl1vf5p30RVzTRYxsfzoPGHVZZw0oNim6O LPsUCFqSCqspPz/j9PlNzQfelrkT+A8TEaCdwjgpXb9SAQLrJ/rZKn9a6idXV/Mz GM4fGHSLX1DoFNNKg1GCscIV40Fn6d5syrL3J3FaJCDerTkqebRITGlzdGFuIEtl csOkw6Rqw6QgKFRlc3Qga2V5IC0gZG8gbm90IHNlbmQgbWUgc2VjcmV0cykgPGxp c3RzQHdhYXNpcy5uZXQ+iFcEExECABcFAj2W0cQFCwcKAwQDFQMCAxYCAQIXgAAK CRBoAHP6vqHp8HHzAKCjF9vM9fvQFq7AAlhh17O2svcE7wCgq+4K1bEh5G10GaAE l2f7x3f8yTm5AQ0EPZbRyRAEAKNu44uBuZzUkpZN14jzsod/UIDKH/T1glz0hwG/ DMxy2FX7LuTMqV0OfRIsXqUv5XaXRc2mVzBZklZ9dmtGwR+yQ1+83ybcGal/WgEi Iv1fj4pZXeupeQYYaM8l5j3dLIH+YyBmukT5NYg8DzNuLl6Velu1zXZS2vCO9Po3 JNRXAAMFA/4jwweaQ5nVlhgH3XQVFmVRcZwb+UpQBTSEA+oVLeyt5u+4n8TfRCKT +yGxuOlEYgZdaR1zYzruCHHpag28SdWUB9X+0/7kyARfMxIoVIlUXXVDC5mrTi+t Q5HE2JntmHDASZcS4u4p6+qGZIp+b2WV+SFEk62l96pTJWcn7m7CO4hGBBgRAgAG BQI9ltHJAAoJEGgAc/q+oenwEl4AnR3v76vRMzj4CXgPhVurTlizSdkkAJ4jRdbF XVGGnWTabE5POOu5VyFJhg== =gn/1
---END PGP PUBLIC KEY BLOCK---
Jotta voisit lähettää jollekin salatun viestin, sinun pitää tietää vastaanottajan julkinen avain. Saat sen esimerkiksi sähköpostilla pyytämällä, kotisivulta tai avainpalvelimelta (keyserver). Käyttöä varten avain liitetään avainrenkaaseen komennolla
---BEGIN PGP PUBLIC KEY BLOCK---
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org
mQGiBD2W0cQRBACYkGYMtDH/p6L7+4COGjo8p0ZK4WA3ZA5XCt/LCM4fkuz7LPz+ K9hea2J5oXr7MvHuL6W9dCBU0fhnP9fvZPjb7Md+7yYUVqXNAVukgfvQ6xfc1Ccu ltFNIL1VVu3vM0ozPU4dKmaiv7Hy1Q/yFOl5NE6YWV+G373T/WNJVP9euwCg3kQx RqhehbIfxDMMxKukjF+5hAcD/1iTDb7YdyzWbkpu983HVmrLILZj6lHpAutphTxR EyFUprbexBlLyMme63Z1f3OfVPHjv5x/bByLp4Uino4P9LxO5yRAL1XLdOWXgjzf oacfAErrxY2PXrL28PXStEt/xa807UDtU0Joy4hZsaCOCo76YB52pHGJK8XeA5ao OND+A/92CRf1h8/EJ1SjhaxgPu5FC5nl1vf5p30RVzTRYxsfzoPGHVZZw0oNim6O LPsUCFqSCqspPz/j9PlNzQfelrkT+A8TEaCdwjgpXb9SAQLrJ/rZKn9a6idXV/Mz GM4fGHSLX1DoFNNKg1GCscIV40Fn6d5syrL3J3FaJCDerTkqebRITGlzdGFuIEtl csOkw6Rqw6QgKFRlc3Qga2V5IC0gZG8gbm90IHNlbmQgbWUgc2VjcmV0cykgPGxp c3RzQHdhYXNpcy5uZXQ+iFcEExECABcFAj2W0cQFCwcKAwQDFQMCAxYCAQIXgAAK CRBoAHP6vqHp8HHzAKCjF9vM9fvQFq7AAlhh17O2svcE7wCgq+4K1bEh5G10GaAE l2f7x3f8yTm5AQ0EPZbRyRAEAKNu44uBuZzUkpZN14jzsod/UIDKH/T1glz0hwG/ DMxy2FX7LuTMqV0OfRIsXqUv5XaXRc2mVzBZklZ9dmtGwR+yQ1+83ybcGal/WgEi Iv1fj4pZXeupeQYYaM8l5j3dLIH+YyBmukT5NYg8DzNuLl6Velu1zXZS2vCO9Po3 JNRXAAMFA/4jwweaQ5nVlhgH3XQVFmVRcZwb+UpQBTSEA+oVLeyt5u+4n8TfRCKT +yGxuOlEYgZdaR1zYzruCHHpag28SdWUB9X+0/7kyARfMxIoVIlUXXVDC5mrTi+t Q5HE2JntmHDASZcS4u4p6+qGZIp+b2WV+SFEk62l96pTJWcn7m7CO4hGBBgRAgAG BQI9ltHJAAoJEGgAc/q+oenwEl4AnR3v76vRMzj4CXgPhVurTlizSdkkAJ4jRdbF XVGGnWTabE5POOu5VyFJhg== =gn/1
---END PGP PUBLIC KEY BLOCK---
gpg: /home/tee/.gnupg/trustdb.gpg: trustdb created
gpg: Total number processed: 1 gpg: imported: 1
/home/fobar/.gnupg/pubring.gpg
--------------
pub 1024D/86E7FC12 2002-09-29 Maija Maitoparta <maito@example.com>
sub 1024g/AB8B03C6 2002-09-29
pub 1024D/BEA1E9F0 2002-09-29 Erkki Testinen <etesti@secret.fi>
sub 1024g/59CA61A8 2002-09-29
Really sign? yes
Salataan (encrypt) hieman tekstiä Erkille
Tämä on salainen viesti! Kerro mulle jos aukesi.
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org
hQENA5W3tVNZymGoEAP+MFEX1omKQQL3EJjSghgFNA2zQA8okOVHJZxDpXzeM+Nu qJrQY/+V4rhQX6HBKdfMLqMW7kEfUfIQRtToel0qK2Be83zAxpvQwvgpWWeE4n2a eKgdwr3sxsJSQKxtnb5uVyJBGtxfAl8GJ87BRXmG0WsfgSSNbTjYUw6Kil6SnkYD 9jd7kDRCD0hIaMiNTQ7DAzLd+AC+WCD3igEipcLgA+va4MGoyAtA/k5FddA06ShX mXk+4K8qMNCC4hdTTcXqcPfhibMRXEfWdescGMQIPsq1TGist79pRSJ4C4CC7PjK ijh68hWKLpYve8tKQRlyKupHZ6USoMPpghbAzp6GS1nSVAHjtBJWsJfEO2Zt9wQ5 QL3fo9RtvPEcwD3gt/AghbhzqGlNt2UHzpoLPTqSOF9exrEDQrozIFhE/GScjHiB 0Jwy7f+CXoW3hcXOIrUJCAnYdBzBVg== =lSmu
---END PGP MESSAGE---
Erkki testilä voi avata (decrypt) äsken kirjoittamamme viestin omalla salaisella avaimellaan. (alla etesti$ tarkoittaa Erkin komentokehotetta, sitä ei siis kirjoiteta osaksi komentoa)
Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org
hQENA5W3tVNZymGoEAP+MFEX1omKQQL3EJjSghgFNA2zQA8okOVHJZxDpXzeM+Nu qJrQY/+V4rhQX6HBKdfMLqMW7kEfUfIQRtToel0qK2Be83zAxpvQwvgpWWeE4n2a eKgdwr3sxsJSQKxtnb5uVyJBGtxfAl8GJ87BRXmG0WsfgSSNbTjYUw6Kil6SnkYD 9jd7kDRCD0hIaMiNTQ7DAzLd+AC+WCD3igEipcLgA+va4MGoyAtA/k5FddA06ShX mXk+4K8qMNCC4hdTTcXqcPfhibMRXEfWdescGMQIPsq1TGist79pRSJ4C4CC7PjK ijh68hWKLpYve8tKQRlyKupHZ6USoMPpghbAzp6GS1nSVAHjtBJWsJfEO2Zt9wQ5 QL3fo9RtvPEcwD3gt/AghbhzqGlNt2UHzpoLPTqSOF9exrEDQrozIFhE/GScjHiB 0Jwy7f+CXoW3hcXOIrUJCAnYdBzBVg== =lSmu
---END PGP MESSAGE---
Jotta kaikkien sähköpostien salaaminen onnistuu helposti, pitää salauksen olla helppoa. Siksi useimmat Linuxin sähköpostiohjelmat tukevat GPG:tä helpolla tavalla.
Jos koneen RAM-muisti tulee täyteen, osa muistista kirjoitetaan kovalevylle virtuaalimuistiin (swap). Koska virtuaalimuisti ei ole salattu, koneellesi murtautunut voi saada sieltä salaisen avaimen. Toisaalta koneelle murtautunut saa ennen pitkää kaikki tietosi joka tapauksessa. Siispä varoituksesta ei tarvitse normaalisti välittää. Katso myös GPG Faq ``6.1) Why do I get 'gpg: Warning: using insecure memory!'''.
Kyllä. Lisäksi Windowsille on kaupallinen tuote PGP. Moniin sähköpostiohjelmiin, kuten Eudoraan ja Outlookiin saa PGP-lisäosan (plugin). PGP-lisäosat toimivat ilmeisesti myös GPG:n kanssa. Onko kellään kokemuksia GPG:n käytöstä PGP-plugineilla?
GNU Free Documentation License
Version 1.2, November 2002
Copyright (C) 2000,2001,2002 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it, with
or without modifying it, either commercially or noncommercially.
Secondarily, this License preserves for the author and publisher a way
to get credit for their work, while not being considered responsible
for modifications made by others.
This License is a kind of "copyleft", which means that derivative works
of the document must themselves be free in the same sense. It
complements the GNU General Public License, which is a copyleft license
designed for free software.
We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free
program should come with manuals providing the same freedoms that the
software does. But this License is not limited to software manuals; it
can be used for any textual work, regardless of subject matter or
whether it is published as a printed book. We recommend this License
principally for works whose purpose is instruction or reference.
1. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium, that
contains a notice placed by the copyright holder saying it can be
distributed under the terms of this License. Such a notice grants a
world-wide, royalty-free license, unlimited in duration, to use that
work under the conditions stated herein. The "Document", below, refers
to any such manual or work. Any member of the public is a licensee, and
is addressed as "you". You accept the license if you copy, modify or
distribute the work in a way requiring permission under copyright law.
A "Modified Version" of the Document means any work containing the
Document or a portion of it, either copied verbatim, or with
modifications and/or translated into another language.
A "Secondary Section" is a named appendix or a front-matter section of
the Document that deals exclusively with the relationship of the
publishers or authors of the Document to the Document's overall subject
(or to related matters) and contains nothing that could fall directly
within that overall subject. (Thus, if the Document is in part a
textbook of mathematics, a Secondary Section may not explain any
mathematics.) The relationship could be a matter of historical
connection with the subject or with related matters, or of legal,
commercial, philosophical, ethical or political position regarding
them.
The "Invariant Sections" are certain Secondary Sections whose titles
are designated, as being those of Invariant Sections, in the notice
that says that the Document is released under this License. If a
section does not fit the above definition of Secondary then it is not
allowed to be designated as Invariant. The Document may contain zero
Invariant Sections. If the Document does not identify any Invariant
Sections then there are none.
The "Cover Texts" are certain short passages of text that are listed,
as Front-Cover Texts or Back-Cover Texts, in the notice that says that
the Document is released under this License. A Front-Cover Text may be
at most 5 words, and a Back-Cover Text may be at most 25 words.
A "Transparent" copy of the Document means a machine-readable copy,
represented in a format whose specification is available to the general
public, that is suitable for revising the document straightforwardly
with generic text editors or (for images composed of pixels) generic
paint programs or (for drawings) some widely available drawing editor,
and that is suitable for input to text formatters or for automatic
translation to a variety of formats suitable for input to text
formatters. A copy made in an otherwise Transparent file format whose
markup, or absence of markup, has been arranged to thwart or discourage
subsequent modification by readers is not Transparent. An image format
is not Transparent if used for any substantial amount of text. A copy
that is not "Transparent" is called "Opaque".
Examples of suitable formats for Transparent copies include plain ASCII
without markup, Texinfo input format, LaTeX input format, SGML or XML
using a publicly available DTD, and standard-conforming simple HTML,
PostScript or PDF designed for human modification. Examples of
transparent image formats include PNG, XCF and JPG. Opaque formats
include proprietary formats that can be read and edited only by
proprietary word processors, SGML or XML for which the DTD and/or
processing tools are not generally available, and the machine-generated
HTML, PostScript or PDF produced by some word processors for output
purposes only.
The "Title Page" means, for a printed book, the title page itself, plus
such following pages as are needed to hold, legibly, the material this
License requires to appear in the title page. For works in formats
which do not have any title page as such, "Title Page" means the text
near the most prominent appearance of the work's title, preceding the
beginning of the body of the text.
A section "Entitled XYZ" means a named subunit of the Document whose
title either is precisely XYZ or contains XYZ in parentheses following
text that translates XYZ in another language. (Here XYZ stands for a
specific section name mentioned below, such as "Acknowledgements",
"Dedications", "Endorsements", or "History".) To "Preserve the Title"
of such a section when you modify the Document means that it remains a
section "Entitled XYZ" according to this definition.
The Document may include Warranty Disclaimers next to the notice which
states that this License applies to the Document. These Warranty
Disclaimers are considered to be included by reference in this License,
but only as regards disclaiming warranties: any other implication that
these Warranty Disclaimers may have is void and has no effect on the
meaning of this License.
2. VERBATIM COPYING
You may copy and distribute the Document in any medium, either
commercially or noncommercially, provided that this License, the
copyright notices, and the license notice saying this License applies
to the Document are reproduced in all copies, and that you add no other
conditions whatsoever to those of this License. You may not use
technical measures to obstruct or control the reading or further
copying of the copies you make or distribute. However, you may accept
compensation in exchange for copies. If you distribute a large enough
number of copies you must also follow the conditions in section 3.
You may also lend copies, under the same conditions stated above, and
you may publicly display copies.
3. COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly have
printed covers) of the Document, numbering more than 100, and the
Document's license notice requires Cover Texts, you must enclose the
copies in covers that carry, clearly and legibly, all these Cover
Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
the back cover. Both covers must also clearly and legibly identify you
as the publisher of these copies. The front cover must present the full
title with all words of the title equally prominent and visible. You
may add other material on the covers in addition. Copying with changes
limited to the covers, as long as they preserve the title of the
Document and satisfy these conditions, can be treated as verbatim
copying in other respects.
If the required texts for either cover are too voluminous to fit
legibly, you should put the first ones listed (as many as fit
reasonably) on the actual cover, and continue the rest onto adjacent
pages.
If you publish or distribute Opaque copies of the Document numbering
more than 100, you must either include a machine-readable Transparent
copy along with each Opaque copy, or state in or with each Opaque copy
a computer-network location from which the general network-using public
has access to download using public-standard network protocols a
complete Transparent copy of the Document, free of added material. If
you use the latter option, you must take reasonably prudent steps, when
you begin distribution of Opaque copies in quantity, to ensure that
this Transparent copy will remain thus accessible at the stated
location until at least one year after the last time you distribute an
Opaque copy (directly or through your agents or retailers) of that
edition to the public.
It is requested, but not required, that you contact the authors of the
Document well before redistributing any large number of copies, to give
them a chance to provide you with an updated version of the Document.
4. MODIFICATIONS
You may copy and distribute a Modified Version of the Document under
the conditions of sections 2 and 3 above, provided that you release the
Modified Version under precisely this License, with the Modified
Version filling the role of the Document, thus licensing distribution
and modification of the Modified Version to whoever possesses a copy of
it. In addition, you must do these things in the Modified Version:
* A. Use in the Title Page (and on the covers, if any) a title
distinct from that of the Document, and from those of previous versions
(which should, if there were any, be listed in the History section of
the Document). You may use the same title as a previous version if the
original publisher of that version gives permission.
* B. List on the Title Page, as authors, one or more persons or
entities responsible for authorship of the modifications in the
Modified Version, together with at least five of the principal authors
of the Document (all of its principal authors, if it has fewer than
five), unless they release you from this requirement.
* C. State on the Title page the name of the publisher of the
Modified Version, as the publisher.
* D. Preserve all the copyright notices of the Document.
* E. Add an appropriate copyright notice for your modifications
adjacent to the other copyright notices.
* F. Include, immediately after the copyright notices, a license
notice giving the public permission to use the Modified Version under
the terms of this License, in the form shown in the Addendum below.
* G. Preserve in that license notice the full lists of Invariant
Sections and required Cover Texts given in the Document's license
notice.
* H. Include an unaltered copy of this License.
* I. Preserve the section Entitled "History", Preserve its Title,
and add to it an item stating at least the title, year, new authors,
and publisher of the Modified Version as given on the Title Page. If
there is no section Entitled "History" in the Document, create one
stating the title, year, authors, and publisher of the Document as
given on its Title Page, then add an item describing the Modified
Version as stated in the previous sentence.
* J. Preserve the network location, if any, given in the Document
for public access to a Transparent copy of the Document, and likewise
the network locations given in the Document for previous versions it
was based on. These may be placed in the "History" section. You may
omit a network location for a work that was published at least four
years before the Document itself, or if the original publisher of the
version it refers to gives permission.
* K. For any section Entitled "Acknowledgements" or "Dedications",
Preserve the Title of the section, and preserve in the section all the
substance and tone of each of the contributor acknowledgements and/or
dedications given therein.
* L. Preserve all the Invariant Sections of the Document, unaltered
in their text and in their titles. Section numbers or the equivalent
are not considered part of the section titles.
* M. Delete any section Entitled "Endorsements". Such a section may
not be included in the Modified Version.
* N. Do not retitle any existing section to be Entitled
"Endorsements" or to conflict in title with any Invariant Section.
* O. Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no material
copied from the Document, you may at your option designate some or all
of these sections as invariant. To do this, add their titles to the
list of Invariant Sections in the Modified Version's license notice.
These titles must be distinct from any other section titles.
You may add a section Entitled "Endorsements", provided it contains
nothing but endorsements of your Modified Version by various
parties--for example, statements of peer review or that the text has
been approved by an organization as the authoritative definition of a
standard.
You may add a passage of up to five words as a Front-Cover Text, and a
passage of up to 25 words as a Back-Cover Text, to the end of the list
of Cover Texts in the Modified Version. Only one passage of Front-Cover
Text and one of Back-Cover Text may be added by (or through
arrangements made by) any one entity. If the Document already includes
a cover text for the same cover, previously added by you or by
arrangement made by the same entity you are acting on behalf of, you
may not add another; but you may replace the old one, on explicit
permission from the previous publisher that added the old one.
The author(s) and publisher(s) of the Document do not by this License
give permission to use their names for publicity for or to assert or
imply endorsement of any Modified Version.
5. COMBINING DOCUMENTS
You may combine the Document with other documents released under this
License, under the terms defined in section 4 above for modified
versions, provided that you include in the combination all of the
Invariant Sections of all of the original documents, unmodified, and
list them all as Invariant Sections of your combined work in its
license notice, and that you preserve all their Warranty Disclaimers.
The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy. If there are multiple Invariant Sections with the same name but
different contents, make the title of each such section unique by
adding at the end of it, in parentheses, the name of the original
author or publisher of that section if known, or else a unique number.
Make the same adjustment to the section titles in the list of Invariant
Sections in the license notice of the combined work.
In the combination, you must combine any sections Entitled "History" in
the various original documents, forming one section Entitled "History";
likewise combine any sections Entitled "Acknowledgements", and any
sections Entitled "Dedications". You must delete all sections Entitled
"Endorsements."
6. COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other
documents released under this License, and replace the individual
copies of this License in the various documents with a single copy that
is included in the collection, provided that you follow the rules of
this License for verbatim copying of each of the documents in all other
respects.
You may extract a single document from such a collection, and
distribute it individually under this License, provided you insert a
copy of this License into the extracted document, and follow this
License in all other respects regarding verbatim copying of that
document.
7. AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, is called an "aggregate" if the copyright
resulting from the compilation is not used to limit the legal rights of
the compilation's users beyond what the individual works permit. When
the Document is included in an aggregate, this License does not apply
to the other works in the aggregate which are not themselves derivative
works of the Document.
If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half of
the entire aggregate, the Document's Cover Texts may be placed on
covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic form.
Otherwise they must appear on printed covers that bracket the whole
aggregate.
8. TRANSLATION
Translation is considered a kind of modification, so you may distribute
translations of the Document under the terms of section 4. Replacing
Invariant Sections with translations requires special permission from
their copyright holders, but you may include translations of some or
all Invariant Sections in addition to the original versions of these
Invariant Sections. You may include a translation of this License, and
all the license notices in the Document, and any Warranty Disclaimers,
provided that you also include the original English version of this
License and the original versions of those notices and disclaimers. In
case of a disagreement between the translation and the original version
of this License or a notice or disclaimer, the original version will
prevail.
If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual title.
9. TERMINATION
You may not copy, modify, sublicense, or distribute the Document except
as expressly provided for under this License. Any other attempt to
copy, modify, sublicense or distribute the Document is void, and will
automatically terminate your rights under this License. However,
parties who have received copies, or rights, from you under this
License will not have their licenses terminated so long as such parties
remain in full compliance.
10. FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of the
GNU Free Documentation License from time to time. Such new versions
will be similar in spirit to the present version, but may differ in
detail to address new problems or concerns. See
http://www.gnu.org/copyleft/.
Each version of the License is given a distinguishing version number.
If the Document specifies that a particular numbered version of this
License "or any later version" applies to it, you have the option of
following the terms and conditions either of that specified version or
of any later version that has been published (not as a draft) by the
Free Software Foundation. If the Document does not specify a version
number of this License, you may choose any version ever published (not
as a draft) by the Free Software Foundation.
How to use this License for your documents
To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and license
notices just after the title page:
Copyright (c) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this
document
under the terms of the GNU Free Documentation License, Version
1.2
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no
Back-Cover Texts.
A copy of the license is included in the section entitled "GNU
Free Documentation License".
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the "with...Texts." line with this:
with the Invariant Sections being LIST THEIR TITLES, with the
Front-Cover Texts being LIST, and with the Back-Cover Texts being
LIST.
If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.
If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License, to
permit their use in free software.