Hi,
this post describes the en- and decryption of a file with a asymmetric encryption algorithm.
Asymmetric encryption means you encrypt data by a public key and can only decrypt this data with a private key associated with the public key.
Continue reading OpenSSL: Asymmetric en- and decryption of a file
Hi,
this post describes the en- and decryption of a file with a symmetric encryption algorithm.
Symmetric encryption means encryption and decryption is only possible with the same secret/password.
Continue reading OpenSSL: Symmetric en- and decryption of a file
Hi,
sometimes you simply want to copy a vdi file and attach it to another virtual machine.
This will fail because in a VirtualBox Installation each vdi Harddisk must have an unique UUID. This command line changes the UUID of a VDI file.
Continue reading VirtualBox: Changing the UUID of a VDI virtual disk File
Hi,
there are several ways to mount a partition which is within a diskimage file created for example with dd.
The first and hard way is to determine the offset of the partition start sector and mounting the disk by specifing the offset as parameter for the loop device.
You can use the file or fdisk command to examine the file.
root@ubdev:/mnt/RaspberryPI # file 2012-07-15-wheezy-raspbian.img
2012-07-15-wheezy-raspbian.img: x86 boot sector; partition 1: ID=0xc, starthead 130, startsector 8192, 114688 sectors; partition 2: ID=0x83, starthead 165, startsector 122880, 3665920 sectors, code offset 0xb8
or
root@ubdev:/mnt/RaspberryPI# fdisk 2012-07-15-wheezy-raspbian.imgCommand (m for help): pDisk 2012-07-15-wheezy-raspbian.img: 1939 MB, 1939865600 bytes 255 heads, 63 sectors/track, 235 cylinders, total 3788800 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 Disk identifier: 0x000714e9Device Boot Start End Blocks Id System2012-07-15-wheezy-raspbian.img1 8192 122879 57344 c W95 FAT32 (LBA)2012-07-15-wheezy-raspbian.img2 122880 3788799 1832960 83 Linux
For example the startsector of partition 2 is 122880, this multiplied with the 512 bytes per sector is the byte offset of the partition. 122880*512=62914560.
Continue reading Linux: Multiple ways to mount a partition in a disk image file
Hi,
difficult Windows issue today. A user had the problem that he could not delete a Folder (C:\Temp\orders) , also renaming or moving is not possible. The same behaviour with the command line tools rmdir, ren and move.
The folder was created from Excel with a vba macro.
The error message was: Cannot delete file: Cannot read from the source file or disk.
Continue reading Windows: Error: Cannot read from the source file or disk, Could not find this item. This is no longer locate…