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authorBram Moolenaar <Bram@vim.org>2014-08-10 13:38:34 +0200
committerBram Moolenaar <Bram@vim.org>2014-08-10 13:38:34 +0200
commit8f4ac01544b44bdd906d241e4f203de7496e5ac8 (patch)
tree52ee7ff7368d7953f2baa3d7d015c539b11a345e /runtime/doc/editing.txt
parent0106b4b89127b043eddf711c750364b487deb794 (diff)
downloadvim-git-8f4ac01544b44bdd906d241e4f203de7496e5ac8.tar.gz
updated for version 7.4.399v7.4.399
Problem: Encryption implementation is messy. Blowfish encryption has a weakness. Solution: Refactor the encryption, store the state in an allocated struct instead of using a save/restore mechanism. Introduce the "blowfish2" method, which does not have the weakness and encrypts the whole undo file. (largely by David Leadbeater)
Diffstat (limited to 'runtime/doc/editing.txt')
-rw-r--r--runtime/doc/editing.txt34
1 files changed, 25 insertions, 9 deletions
diff --git a/runtime/doc/editing.txt b/runtime/doc/editing.txt
index 0b5f69a7b..cbb9b90e5 100644
--- a/runtime/doc/editing.txt
+++ b/runtime/doc/editing.txt
@@ -1,4 +1,4 @@
-*editing.txt* For Vim version 7.4. Last change: 2014 Jul 19
+*editing.txt* For Vim version 7.4. Last change: 2014 Aug 09
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -1370,8 +1370,13 @@ lose your work. The undo file can be disabled without much disadvantage. >
Note: The text in memory is not encrypted. A system administrator may be able
to see your text while you are editing it. When filtering text with
-":!filter" or using ":w !command" the text is not encrypted, this may reveal
-it to others. The 'viminfo' file is not encrypted.
+":!filter" or using ":w !command" the text is also not encrypted, this may
+reveal it to others. The 'viminfo' file is not encrypted.
+
+You could do this to edit very secret text: >
+ :set noundofile viminfo=
+ :noswapfile edit secrets.txt
+Keep in mind that without a swap file you risk loosing your work in a crash.
WARNING: If you make a typo when entering the key and then write the file and
exit, the text will be lost!
@@ -1398,18 +1403,25 @@ To disable the encryption, reset the 'key' option to an empty value: >
:set key=
You can use the 'cryptmethod' option to select the type of encryption, use one
-of these two: >
- :setlocal cm=zip " weak method, backwards compatible
- :setlocal cm=blowfish " strong method
+of these: >
+ :setlocal cm=zip " weak method, backwards compatible
+ :setlocal cm=blowfish " method with flaws
+ :setlocal cm=blowfish2 " medium strong method
+
Do this before writing the file. When reading an encrypted file it will be
set automatically to the method used when that file was written. You can
change 'cryptmethod' before writing that file to change the method.
+
To set the default method, used for new files, use one of these in your
|vimrc| file: >
set cm=zip
- set cm=blowfish
+ set cm=blowfish2
+Use the first one if you need to be compatible with Vim 7.2 and older. Using
+"blowfish2" is highly recommended if you can use a Vim version that supports
+it.
+
The message given for reading and writing a file will show "[crypted]" when
-using zip, "[blowfish]" when using blowfish.
+using zip, "[blowfish]" when using blowfish, etc.
When writing an undo file, the same key and method will be used for the text
in the undo file. |persistent-undo|.
@@ -1444,7 +1456,7 @@ lines to "/etc/magic", "/usr/share/misc/magic" or wherever your system has the
0 string VimCrypt~ Vim encrypted file
>9 string 01 - "zip" cryptmethod
>9 string 02 - "blowfish" cryptmethod
-
+ >9 string 03 - "blowfish2" cryptmethod
Notes:
- Encryption is not possible when doing conversion with 'charconvert'.
@@ -1468,6 +1480,10 @@ Notes:
- Pkzip uses the same encryption as 'cryptmethod' "zip", and US Govt has no
objection to its export. Pkzip's public file APPNOTE.TXT describes this
algorithm in detail.
+- The implmentation of 'cryptmethod' "blowfish" has a flaw. It is possible to
+ crack the first 64 bytes of a file and in some circumstances more of the
+ file. Use of it is not recommended, but it's still the strongest method
+ supported by Vim 7.3 and 7.4. The "zip" method is even weaker.
- Vim originates from the Netherlands. That is where the sources come from.
Thus the encryption code is not exported from the USA.