From 4b6f0055b4a3fa0bc16d8f7a15fc9e086028a768 Mon Sep 17 00:00:00 2001 From: David Shaw Date: Fri, 21 Nov 2003 05:13:23 +0000 Subject: [PATCH] * gpg.sgml: Note the new combinations with --symmetric and --encrypt. Document --bzip2-compress-level, and --bzip2-compress-lowmem. Clarify the plurarility (or not) of various list and verify options. Document BZIP2 in the --compress-algo section. Warn about compatibility issues with ZLIB and BZIP2. --- doc/ChangeLog | 9 ++++++ doc/gpg.sgml | 78 ++++++++++++++++++++++++++++++++++++--------------- 2 files changed, 65 insertions(+), 22 deletions(-) diff --git a/doc/ChangeLog b/doc/ChangeLog index 8eb7f40e1..0ddf6c9bc 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,3 +1,12 @@ +2003-11-21 David Shaw + + * gpg.sgml: Note the new combinations with --symmetric and + --encrypt. Document --bzip2-compress-level, and + --bzip2-compress-lowmem. Clarify the plurarility (or not) of + various list and verify options. Document BZIP2 in the + --compress-algo section. Warn about compatibility issues with + ZLIB and BZIP2. + 2003-11-20 David Shaw * gpg.sgml: Document --compress-level. Some minor tweaks to other diff --git a/doc/gpg.sgml b/doc/gpg.sgml index c9d0dbaa1..9ce09ec9e 100644 --- a/doc/gpg.sgml +++ b/doc/gpg.sgml @@ -96,8 +96,11 @@ special option "--". -s, --sign -Make a signature. This command may be combined -with --encrypt. +Make a signature. This command may be combined with --encrypt (for a +signed and encrypted message), --symmetric (for a signed and +symmetrically encrypted message), or --encrypt and --symmetric +together (for a signed message that may be decrypted via a secret key +or a passphrase). @@ -118,7 +121,11 @@ Make a detached signature. -e, --encrypt -Encrypt data. This option may be combined with --sign. +Encrypt data. This option may be combined with --sign (for a signed +and encrypted message), --symmetric (for a message that may be +decrypted via a secret key or a passphrase), or --sign and --symmetric +together (for a signed message that may be decrypted via a secret key +or a passphrase). @@ -127,7 +134,11 @@ Encrypt data. This option may be combined with --sign. Encrypt with a symmetric cipher using a passphrase. The default symmetric cipher used is CAST5, but may be chosen with the ---cipher-algo option. +--cipher-algo option. This option may be combined with --sign (for a +signed and symmetrically encrypted message), --encrypt (for a message +that may be decrypted via a secret key or a passphrase), or --sign and +--encrypt together (for a signed message that may be decrypted via a +secret key or a passphrase). @@ -898,10 +909,24 @@ Try to be as quiet as possible. -z &ParmN;, --compress-level &ParmN; +--bzip2-compress-level &ParmN; -Set compression level to &ParmN;. A value of 0 for &ParmN; -disables compression. Default is to use the default -compression level of zlib (normally 6). +Set compression level to &ParmN; for the ZIP and ZLIB compression +algorithms. The default is to use the default compression level of +zlib (normally 6). --bzip2-compress-level sets the compression level +for the BZIP2 compression algorithm. This is a different option since +BZIP2 uses a significant amount of memory for each additional +compression level. -z sets both. + + + +--bzip2-compress-lowmem + +Use a different decompression method for BZIP2 compressed files. This +alternate method uses a bit more than half the memory, but also runs +at half the speed. This is useful under extreme low memory +circumstances when the file was originally compressed at a high +--bzip2-compress-level. @@ -1236,21 +1261,21 @@ Defaults to no. See also --photo-viewer. -show-policy-url +show-policy-urls Show policy URLs in the --list-sigs or --check-sigs listings. Defaults to no. -show-notation +show-notations Show signature notations in the --list-sigs or --check-sigs listings. Defaults to no. -show-keyserver-url +show-keyserver-urls Show any preferred keyserver URL in the --list-sigs or --check-sigs listings. Defaults to no. @@ -1264,7 +1289,7 @@ listings. Defaults to no. -show-long-keyid +show-long-keyids Display all 64 bits (16 digits) of key IDs during key listings, rather than the more common 32 bit (8 digit) IDs. Defaults to no. @@ -1309,20 +1334,20 @@ Defaults to no. See also --photo-viewer. -show-policy-url +show-policy-urls Show policy URLs in the signature being verified. Defaults to no. -show-notation +show-notations Show signature notations in the signature being verified. Defaults to no. -show-keyserver-url +show-keyserver-urls Show any preferred keyserver URL in the signature being verified. Defaults to no. @@ -1336,7 +1361,7 @@ the signature. Defaults to no. -show-long-keyid +show-long-keyids Display all 64 bits (16 digits) of key IDs during signature verification, rather than the more common 32 bit (8 digit) IDs. @@ -1748,14 +1773,23 @@ with the command --version yields a list of supported algorithms. --compress-algo &ParmName; -Use compression algorithm &ParmName;. "zlib" is RFC1950 ZLIB +Use compression algorithm &ParmName;. "zlib" is RFC-1950 ZLIB compression. "zip" is RFC-1951 ZIP compression which is used by PGP. -"uncompressed" or "none" disables compression. If this option is not -used, the default behavior is to examine the recipient key preferences -to see which algorithms the recipient supports. If all else fails, -ZIP is used for maximum compatibility. Note, however, that ZLIB may -give better compression results if that is more important, as the -compression window size is not limited to 8k. +"bzip2" is a more modern compression scheme that can compress some +things better than zip or zlib, but at the cost of more memory used +during compression and decompression. "uncompressed" or "none" +disables compression. If this option is not used, the default +behavior is to examine the recipient key preferences to see which +algorithms the recipient supports. If all else fails, ZIP is used for +maximum compatibility. + +ZLIB may give better compression results than ZIP, as the compression +window size is not limited to 8k. BZIP2 may give even better +compression results than that, but will use a significantly larger +amount of memory while compressing and decompressing. This may be +significant in low memory situations. Note, however, that PGP (all +versions) only supports ZIP compression. Using any algorithm other +than ZIP or "none" will make the message unreadable with PGP.