tomb

the crypto undertaker
git clone git://parazyd.org/tomb.git
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commit 6c2077fee1b3a2257a1da3560f185630405d5f4b
parent ba9c0481cca9f4db9baee0fe45473f6b3a1a1c71
Author: Jaromil <jaromil@dyne.org>
Date:   Wed, 22 Mar 2017 16:39:25 +0100

make documentation less opinionated about the u/random issue

fix #253

Diffstat:
Mdoc/tomb.1 | 38+++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/doc/tomb.1 b/doc/tomb.1 @@ -30,25 +30,27 @@ harddisk and its key file on a USB stick. .IP "dig" Generates a file that can be used as a tomb and will occupy as much space as its desired initial size, the unlocked \fI.tomb\fR file can -then be locked using a \fIkey\fR. It takes a mandatory \fI-s\fR option which is -the size in megabytes (MiB). Tombs are digged using -low-quality random data (/dev/urandom). +then be locked using a \fIkey\fR. It takes a mandatory \fI-s\fR option +which is the size in megabytes (MiB). Tombs are digged using random +data gathered from a non-blocking source (/dev/urandom). .B .IP "forge" Creates a new \fIkey\fR and prompts the user for a \fIpassword\fR to -protect its usage using symmetric encryption. This operation requires -high quality random data using /dev/random and can take long when run -on a server with low entropy. The \fI-g\fR option switches on the use -of a GPG key instead of a password (asymmetric encryption), then the -\fI-r\fR option indicates the recipient key; more recipient GPG ids -can be indicated (comma separated) if the option is followed by the -\fI--shared\fR flag. The default cipher to protect the key is AES256, -a custom one can be specified using the \fI-o\fR option, for a list of -supported ciphers use \fI-v\fR. For additional protection against -dictionary attacks on keys, the \fI--kdf\fR option can be used when -forging a key, making sure that the \fItomb-kdb-pbkdf2\fR binaries in -\fIextras/kdf\fR were compiled and installed on the system. +protect its usage using symmetric encryption. This operation uses +random data from a blocking source (/dev/random) and it may take long +when run on a server with low entropy; to switch using a non-blocking +source the \fI--use-urandom\fR flag can be used. The \fI-g\fR option +switches on the use of a GPG key instead of a password (asymmetric +encryption), then the \fI-r\fR option indicates the recipient key; +more recipient GPG ids can be indicated (comma separated) if the +option is followed by the \fI--shared\fR flag. The default cipher to +protect the key is AES256, a custom one can be specified using the +\fI-o\fR option, for a list of supported ciphers use \fI-v\fR. For +additional protection against dictionary attacks on keys, the +\fI--kdf\fR option can be used when forging a key, making sure that +the \fItomb-kdb-pbkdf2\fR binaries in \fIextras/kdf\fR were compiled +and installed on the system. .B .IP "lock" @@ -259,8 +261,10 @@ commandline options. This is mostly used needed for execution by wrappers and testing suite. .B .IP "--use-urandom" -Use an inferior quality random source to improve the speed of key -generation at the cost of security (needed for the testing suite). +Use a non-blocking random source to improve the speed of the +\fIforge\fR command (key generation): tomb uses /dev/urandom instead +of /dev/random. According to some people using the non-blocking source +of Linux kernel doesn't degrades the quality of random. .B .IP "--tomb-pwd <string>" Use string as password when needed on tomb.