![\"\"](\"http:\/\/hackarandas.com\/blog\/wp-content\/uploads\/2010\/08\/file-shredding_medium.jpeg\" "\\"File")
We needed to guarantee to one of our customers that a file will be securely deleted. Since the server was a HPUX Unix and we can’t compile nor install new applications, I managed to write this script to wipe the file.<\/p>\n We needed to guarantee to one of our customers that a file will be securely deleted. Since the server was a HPUX Unix and we can’t compile nor install new applications, I managed to write this script to wipe the file.<\/p>\n
The file is overwritten 7 times as the US Department of Defense clearing standard DoD 5220.22-M<\/a> specifies and renamed another 7 times before being deleted. It is written for the KSH shell as many UNIX has it by default. It doesn’t run in bash but you can edit it to fit your needs.<\/p>\n Here is the code:<\/p>\n The syntax is simple:<\/p>\n You can follow this commands to test the script:<\/p>\n Now we wipe the file<\/p>\n In the next release I will make a recursive version for directories and you can visit my other projects here<\/a>.<\/p>\n Troubleshoot: <\/strong> Some Unix systems doesn’t have \/dev\/urandom device so you can play with the RANDEV variable to use the one you have.<\/p>\n Update: <\/strong> Some versions of HPUX doesn’t have \/dev\/[u]random so you can use as a desperate alternative the \/dev\/zero device. I found in a forum<\/a> that some versions of HPUX doesn’t have the \/dev\/zero device so you can create it with this command:<\/p>\n Adri\u00c3\u00a1n Puente Z.<\/em><\/p>\n hackarandas<\/a>, wipe<\/a>, Adrian Puente Z.<\/a>, security<\/a>, Secure Delete<\/a>, unix<\/a>, security<\/a>, seguridad<\/a>, ksh code<\/a><\/p>\n\n We needed to guarantee to one of our customers that a file will be securely deleted. Since the server was a HPUX Unix and we can’t compile nor install new applications, I managed to write this script to wipe the … Continue reading \r\n#!\/usr\/bin\/ksh\r\n# Script by Adrian Puente Z..\r\n# Powered by Hackarandas www.hackarandas.com\r\n# Licensed by GNU GPLv3\r\n# http:\/\/www.gnu.org\/licenses\/gpl-3.0.txt\r\n\r\n# US Department of Defense clearing standard DOD 5220.22-M (ECE)\r\nPASES=7\r\n# Device to overwrite the file.\r\n# Can be:\r\n# \/dev\/random\r\n# \/dev\/urandom\r\n# \/dev\/zero (less secure, overwritten with zeros)\r\nRANDEV=\/dev\/urandom\r\nNAME=$$\r\nCOUNT=0\r\nFILE=$1\r\n\r\nif [[ $# -eq 0 ]];then\r\n\tprint \"Syntax: $0
\r\n --.^ (ch0ks@xipe)*(20:38:05)*(~) ^.--\r\n-=:)> uncomplicatedwipe.ksh \r\nSyntax: uncomplicatedwipe.ksh
hexdump \/dev\/urandom > foo.txt \r\n#after some seconds press CTRL+C <\/pre>\n
\r\n --.^ (ch0ks@xipe)*(20:36:00)*(tmp) ^.--\r\n-=:)> uncomplicatedwipe.sh foo.txt \r\nAbout to wipe file: foo.txt are you sure? \"N\/y\": y\r\n\r\nPass number: 1\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 4.01637 s, 3.9 MB\/s\r\nPass number: 2\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 3.87637 s, 4.0 MB\/s\r\nPass number: 3\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 5.451 s, 2.8 MB\/s\r\nPass number: 4\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 4.48904 s, 3.4 MB\/s\r\nPass number: 5\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 3.88731 s, 4.0 MB\/s\r\nPass number: 6\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 3.98379 s, 3.9 MB\/s\r\nPass number: 7\r\n1+0 records in\r\n1+0 records out\r\n15477760 bytes (15 MB) copied, 3.2128 s, 4.8 MB\/s\r\nRenaming...\r\n`foo.txt' -> `69257'\r\n`69257' -> `761829'\r\n`761829' -> `8380122'\r\n`8380122' -> `92181346'\r\n`92181346' -> `1013994811'\r\n`1013994811' -> `11153942927'\r\n`11153942927' -> `122693372204'\r\nremoved `122693372204'\r\nFile: foo.txt deleted.<\/pre>\n
\r\n#!\/bin\/sh\r\n\r\n# major\/minor for HPUX 11.X\r\nmknod \/dev\/zero c 3 4\r\nchown bin:bin \/dev\/zero\r\nchmod 666 \/dev\/zero<\/pre>\n
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