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(Marek Wrzosek) Update docs to reflect random 'digits' use instead of 'bytes'

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Suggested doc update to fwknop man pages to accurately describe the usage
of digits instead of bytes for SPA random data.  About 53 bits of entropy
are actually used, although this is in addition to the 64-bit random salt
in for key derivation used by PBKDF1 in Rjindael CBC mode.
This commit is contained in:
Michael Rash
2014-01-02 20:47:41 -05:00
parent 6add06f76c
commit 551b243007
3 changed files with 21 additions and 12 deletions
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CREDITS
+8
View File
@@ -160,3 +160,11 @@ Les Aker
pcap_dispatch() packet count of zero when using libpcap-1.5.1. This
issue was tracked on github as issue #110, and the default packet count
is now set at 100 as a result.
Marek Wrzosek
- Suggested doc update to fwknop man pages to accurately describe the usage
of digits instead of bytes for SPA random data. About 53 bits of entropy
are actually used, although this is in addition to the 64-bit random salt
in for key derivation used by PBKDF1 in Rjindael CBC mode.
- Various excellent feedback on crypto design, including the need to remove
the GPG_IGNORE_SIG_VERIFY_ERROR mode.
client/fwknop.8.in
+5 -5
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@@ -1,13 +1,13 @@
'\" t
.\" Title: fwknop
.\" Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
.\" Date: 08/08/2013
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\" Date: 01/02/2014
.\" Manual: Fwknop Client
.\" Source: Fwknop Client
.\" Language: English
.\"
.TH "FWKNOP" "8" "08/08/2013" "Fwknop Client" "Fwknop Client"
.TH "FWKNOP" "8" "01/02/2014" "Fwknop Client" "Fwknop Client"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
@@ -48,7 +48,7 @@ SPA packets generated by \fBfwknop\fR leverage HMAC for authenticated encryption
.RS 4
.\}
.nf
random data (16 bytes)
random data (16 digits)
username
timestamp
software version
@@ -61,7 +61,7 @@ SPA packets generated by \fBfwknop\fR leverage HMAC for authenticated encryption
.RE
.\}
.sp
Each of the above fields are separated by a ":" character due to the variable length of several of the fields, and those that might contain ":" characters are base64 encoded\&. The message digest (\fBSHA256\fR by default) is part of the data to be encrypted and is independent of the HMAC which is appended to the SPA packet data after encryption\&. The 16 bytes of random data ensures that no two SPA packets are identical, and this is in addition to and independent of using PBKDF1 for key derivation for Rijndael in CBC mode\&. Because \fBfwknopd\fR tracks the SHA256 digest of all incoming valid SPA packets and throws out duplicates, replay attacks are not feasible against \fBfwknop\fR\&. Syslog alerts are generated if a replay is detected\&.
Each of the above fields are separated by a ":" character due to the variable length of several of the fields, and those that might contain ":" characters are base64 encoded\&. The message digest (\fBSHA256\fR by default) is part of the data to be encrypted and is independent of the HMAC which is appended to the SPA packet data after encryption\&. The 16 digits of random data (about 53 bits) ensures that no two SPA packets are identical, and this is in addition to and independent of using PBKDF1 for key derivation for Rijndael in CBC mode (which uses an 8\-byte random "salt" value)\&. Because \fBfwknopd\fR tracks the SHA256 digest of all incoming valid SPA packets and throws out duplicates, replay attacks are not feasible against \fBfwknop\fR\&. Syslog alerts are generated if a replay is detected\&.
.sp
By default, the \fBfwknop\fR client sends authorization packets over UDP port 62201, but this can be altered with the \fB\-\-server\-port\fR argument (this requires \fBfwknopd\fR to be configured to acquire SPA data over the selected port)\&. Also, \fBfwknop\fR can send the SPA packet over a random port via the \fB\-\-rand\-port\fR argument\&. See \fIfwknopd(8)\fR for further details\&. See the \fBEXAMPLES\fR section for example invocations of the \fBfwknop\fR client\&.
.sp
doc/fwknop.man.asciidoc
+8 -7
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@@ -76,7 +76,7 @@ packets generated by fwknop running as a client adhere to the following
format (before encryption and the HMAC is applied):
..........................
random data (16 bytes)
random data (16 digits)
username
timestamp
software version
@@ -90,12 +90,13 @@ Each of the above fields are separated by a ":" character due to the variable
length of several of the fields, and those that might contain ":" characters
are base64 encoded. The message digest (*SHA256* by default) is part of the
data to be encrypted and is independent of the HMAC which is appended to the
SPA packet data after encryption. The 16 bytes of random data ensures that no
two SPA packets are identical, and this is in addition to and independent of
using PBKDF1 for key derivation for Rijndael in CBC mode. Because *fwknopd*
tracks the SHA256 digest of all incoming valid SPA packets and throws out
duplicates, replay attacks are not feasible against *fwknop*. Syslog
alerts are generated if a replay is detected.
SPA packet data after encryption. The 16 digits of random data (about 53 bits)
ensures that no two SPA packets are identical, and this is in addition to and
independent of using PBKDF1 for key derivation for Rijndael in CBC mode (which
uses an 8-byte random "salt" value). Because *fwknopd* tracks the SHA256
digest of all incoming valid SPA packets and throws out duplicates, replay
attacks are not feasible against *fwknop*. Syslog alerts are generated if a
replay is detected.
By default, the *fwknop* client sends authorization packets over UDP port
62201, but this can be altered with the *--server-port* argument (this requires