$ pdftk MEISAI.pdf input_pw PASSWORD output OUTPUT.pdf                                                                                                                                                              [Ret:0 23:02:31]
Error: Unexpected Exception in open_reader()
java.lang.NoClassDefFoundError: org/bouncycastle/crypto/BlockCipher     
        at pdftk.com.lowagie.text.pdf.StandardDecryption.update(StandardDecryption.java:94)
        at pdftk.com.lowagie.text.pdf.PdfEncryption.decryptByteArray(PdfEncryption.java:568)
        at pdftk.com.lowagie.text.pdf.PdfString.decrypt(PdfString.java:273)                                                                                                                                                                    
        at pdftk.com.lowagie.text.pdf.PdfReader.readDecryptedDocObj(PdfReader.java:723)
        at pdftk.com.lowagie.text.pdf.PdfReader.readDocObj(PdfReader.java:1109)
        at pdftk.com.lowagie.text.pdf.PdfReader.readPdf(PdfReader.java:508)
        at pdftk.com.lowagie.text.pdf.PdfReader.<init>(PdfReader.java:172)
        at com.gitlab.pdftk_java.InputPdf.add_reader(InputPdf.java:100)
        at com.gitlab.pdftk_java.TK_Session.add_reader(TK_Session.java:94)
        at com.gitlab.pdftk_java.TK_Session.open_input_pdf_readers(TK_Session.java:111)
        at com.gitlab.pdftk_java.TK_Session.<init>(TK_Session.java:1086)
        at com.gitlab.pdftk_java.pdftk.main_noexit(pdftk.java:152)
        at com.gitlab.pdftk_java.pdftk.main(pdftk.java:130) 
Caused by: java.lang.ClassNotFoundException: org.bouncycastle.crypto.BlockCipher
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        ... 13 more
Error: Failed to open PDF file: 
   202006_0127.pdf
Errors encountered.  No output created.
Done.  Input errors, so no output created.

$ sudo pacman -S bcprov
$ pdftk MEISAI.pdf input_pw PASSWORD output OUTPUT.pdf
WARNING: The creator of the input PDF:
   MEISAI.pdf
   has set an owner password (which is not required to handle this PDF).
   You did not supply this password. Please respect any copyright.

export QTK_IM_MODULE=fcitx
export QT_IM_MODULE=fcitx
export XMODIFIERS=@im=fcitx

$ sudo pacman -S fcitx-im

dhcp-range=192.168.0.0,proxy
dhcp-boot=pxelinux.0
pxe-service=0,"Raspberry Pi Boot",pxelinux,192.168.0.4
enable-tftp
tftp-root=/srv/tftp/pxe-boot

sudo pacman -S nfs-utils
sudo vim /etc/exports
/srv/nfs/pi3/rpi-netboot 192.168.0.0/24(rw,no_root_squash)
sudo systemctl start nfs-server

$ sudo mkdir -p /srv/tftp/pxe-boot/12345678
// Raspbianインストールイメージのboot領域を/mntにmountした前提で
$ sudo cp -r /mnt/* /srv/tftp/pxe-boot/12345678/
$ sudo mv /srv/tftp/pxe-boot/12345678/bootcode.bin /srv/tftp/pxe-boot/
$ cat /srv/tftp/pxe-boot/12345678/cmdline.txt
root=/dev/nfs nfsroot=192.168.0.4:/srv/nfs/pi3/rpi-netboot,vers=4,proto=tcp rw ip=dhcp rootwait elevator=deadline
// Raspbianインストールイメージのroot領域を/mntにmountした前提で
$ sudo mkdir -p /srv/nfs/pi3/rpi-netboot
$ sudo rsync -xa /mnt/ /srv/nfs/pi3/rpi-netboot

$ sudo mount 2020-02-13-raspbian-buster.img /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error.

$ fdisk -l -u 2020-02-13-raspbian-buster.img
Disk 2020-02-13-raspbian-buster.img: 3.54 GiB, 3787456512 bytes, 7397376 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xea7d04d6

Device                          Boot  Start     End Sectors Size Id Type
2020-02-13-raspbian-buster.img1        8192  532479  524288 256M  c W95 FAT32 (LBA)
2020-02-13-raspbian-buster.img2      532480 7397375 6864896 3.3G 83 Linux

// 第1パーティション
$ sudo mount -o loop,offset=`expr 8192 \* 512` 2020-02-13-raspbian-buster.img /mnt
// 第2パーティション
$ sudo mount -o loop,offset=`expr 532480  \* 512` 2020-02-13-raspbian-buster.img /mnt

export IP=`curl inet-ip.info`
expect -c "
spawn env LANG=C openssl s_client -connect ddnsclient.onamae.com:65010 -quiet

send \"LOGIN\n\"
send \"USERID:お名前.comのユーザ名\n\"
send \"PASSWORD:お名前.comのパスワード\n\"
send \".\n\"

expect \"000 COMMAND SUCCESSFUL\" {
  send \"MODIP\n\"
  send \"DOMNAME:tea-soak.org\n\"
  send \"IPV4:${IP}\n\"
  send \".\n\"
  expect \"000 COMMAND SUCCESSFUL\" {
    send \"MODIP\n\"
    send \"HOSTNAME:blog\n\"
    send \"DOMNAME:tea-soak.org\n\"
    send \"IPV4:${IP}\n\"
    send \".\n\"
    expect \"000 COMMAND SUCCESSFUL\" {
      send \"LOGOUT\n\"
      send \".\n\"
      exit 0
    }
  }
  exit 0
}
"