Talk:Enc - Revision history

Matt: Further discussion on zlib compression

2013-07-06T13:09:10Z

Further discussion on zlib compression

Frukto: /* Zlib compression */

2013-07-06T12:07:24Z

Zlib compression

Frukto: /* Zlib compression */

2013-07-06T12:06:58Z

Zlib compression

Frukto: /* Block size vs Key size */

2013-07-06T11:57:03Z

Block size vs Key size

Matt: Zlib, and keysize / block size

2013-07-06T11:41:36Z

Zlib, and keysize / block size

Frukto: /* Zlib compression */

2013-07-05T14:05:13Z

Zlib compression

Matt: Zlib compression question

2013-07-05T12:17:02Z

Zlib compression question

Frukto: /* Rarely Used -K option */

2013-06-28T07:27:13Z

Rarely Used -K option

Matt: /* Rarely Used -K option */

2013-06-27T21:39:14Z

Rarely Used -K option

Matt: Option -K

2013-06-27T21:38:50Z

Option -K

New page

==Rarely Used -K option==

"This is rarely used, normally you specify a password from which a key is derived."

Is this true? Does it not depend fairly heavily on your use case? Just not sure what the basis for this statement is.

← Older revision		Revision as of 13:09, 6 July 2013
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	--[[User:Frukto\|Frukto]] 12:07, 6 July 2013 (UTC)		--[[User:Frukto\|Frukto]] 12:07, 6 July 2013 (UTC)
		+
		+	Might be worth raising it on the mailing list to see what the reaction is. I suspect it won't be fixed as it might break scripts etc for people that do use it. A possible feature enhancement could be to add a new option to do it properly. If it won't get fixed then we can edit the wiki version of the manual [[Manual:Enc(1)\|here]], so at least the documentation is right.
		+
		+	--[[User:Matt\|Matt]] 13:09, 6 July 2013 (UTC)

	==Block size vs Key size==		==Block size vs Key size==

← Older revision		Revision as of 12:07, 6 July 2013
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	Maybe, I should file a bug? I mean as you pointed out, the point of encryption is, in some sense, to maximize entropy. It does not make sense to compress afterwards. I don't know what was intended, but as you cite (actually i didn't check) the man page, it is a bug? But obviously nobody is using it, it would have been noticed immediately.		Maybe, I should file a bug? I mean as you pointed out, the point of encryption is, in some sense, to maximize entropy. It does not make sense to compress afterwards. I don't know what was intended, but as you cite (actually i didn't check) the man page, it is a bug? But obviously nobody is using it, it would have been noticed immediately.
		+
		+	--[[User:Frukto\|Frukto]] 12:07, 6 July 2013 (UTC)

	==Block size vs Key size==		==Block size vs Key size==

← Older revision		Revision as of 12:06, 6 July 2013
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	--[[User:Matt\|Matt]] 11:41, 6 July 2013 (UTC)		--[[User:Matt\|Matt]] 11:41, 6 July 2013 (UTC)
		+
		+	Maybe, I should file a bug? I mean as you pointed out, the point of encryption is, in some sense, to maximize entropy. It does not make sense to compress afterwards. I don't know what was intended, but as you cite (actually i didn't check) the man page, it is a bug? But obviously nobody is using it, it would have been noticed immediately.

	==Block size vs Key size==		==Block size vs Key size==

← Older revision		Revision as of 11:57, 6 July 2013
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	--[[User:Matt\|Matt]] 11:41, 6 July 2013 (UTC)		--[[User:Matt\|Matt]] 11:41, 6 July 2013 (UTC)
		+
		+	Yes sure, thx.
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		+	--[[User:Frukto\|Frukto]] 11:57, 6 July 2013 (UTC)

@@ Line 24: / Line 24: @@
 $ openssl enc -des -in message.plain -a -out message.enc -nosalt -z
 $ printf "\x1f\x8b\x08\x00\x00\x00\x00\x00" |cat - message.enc | gzip -dc
@@ Line 31: / Line 32: @@
 --[[User:Frukto|Frukto]] 14:05, 5 July 2013 (UTC)

← Older revision		Revision as of 14:05, 5 July 2013
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	--[[User:Matt\|Matt]] 12:17, 5 July 2013 (UTC)		--[[User:Matt\|Matt]] 12:17, 5 July 2013 (UTC)
		+
		+	Yes, i had the same question. But i tried it and it works actually like this: encryption -> base64 -> zlib
		+
		+	encrypt + unzip:
		+
		+	$ openssl enc -des -in message.plain -a -out message.enc -nosalt -z
		+	$ printf "\x1f\x8b\x08\x00\x00\x00\x00\x00" \|cat - message.enc \| gzip -dc
		+
		+	gives the same as:
		+
		+	$ openssl enc -des -in message.plain -a -out message.enc -nosalt
		+
		+	--[[User:Frukto\|Frukto]] 14:05, 5 July 2013 (UTC)

← Older revision		Revision as of 12:17, 5 July 2013
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	--[[User:Frukto\|Frukto]] 07:27, 28 June 2013 (UTC)		--[[User:Frukto\|Frukto]] 07:27, 28 June 2013 (UTC)
		+
		+	==Zlib compression==
		+
		+	"Use this flag to enable zlib-compression. After a file is encrypted (and maybe base64 encoded) it will be compressed via zlib. Vice versa while decrypting, zlib will be applied first."
		+
		+	I think this happens the other way around. Doesn't compression occur '''before''' encryption, or '''after''' decryption? It doesn't make sense to do it the other way around - after encryption the data will appear indistinguishable from random data, and therefore should not have any appreciable ability to be compressed.
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		+	--[[User:Matt\|Matt]] 12:17, 5 July 2013 (UTC)

← Older revision		Revision as of 07:27, 28 June 2013
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	--[[User:Matt\|Matt]] 21:39, 27 June 2013 (UTC)		--[[User:Matt\|Matt]] 21:39, 27 June 2013 (UTC)
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		+	Probably you are right. Its a biased statement. I'll change it.
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		+	--[[User:Frukto\|Frukto]] 07:27, 28 June 2013 (UTC)

← Older revision		Revision as of 21:39, 27 June 2013
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	Is this true? Does it not depend fairly heavily on your use case? Just not sure what the basis for this statement is.		Is this true? Does it not depend fairly heavily on your use case? Just not sure what the basis for this statement is.
		+
		+	--[[User:Matt\|Matt]] 21:39, 27 June 2013 (UTC)