Re: Corrupting files
On Mon, Jun 12, 2006 at 11:55:54PM +0200, Ingo Klöcker wrote: No, it doesn't. You are still believing in security-by-obscurity meaning that your additional encryption only works as long as you and the recipient are the only ones who know the secret rule. Please Ingo, _all_ encryption is based on security-by-obscurity if an attacker finds the secret key _any_ encryption system is toast. Anyway, why do you actually think that what you want to do would make any sense? If the encryption algorithm you use is too weak so that additional encryption methods are necessary then you probably shouldn't use this encryption algorithm in the first place. And if the encryption algorithm you use is strong enough (e.g. AES) then you gain nothing by additional encyrption methods unless those additional encryption methods are an even stronger encryption algorithm than the first one (but then why apply the first one). I can think of some possible scenarios; if an attacker is has automated the attacks, especially with attacks tailored for each known algorithm, then making the message not conform to known algorithms and structure should break the automation. Another could be, how would an attacker tell the difference between a random intercepted file that has been corrupted in transit and one with an additional human decryption step, e.g. during the window between key compromise and revocation. In this case we are dealing with humans that does not necessarily have huge amounts of resources and patience. I'd be impressed by any people communicating that actually had the patience to keep up this kind of scheme, since any communication needs manual intervention. //Samuel ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: Corrupting files
Am Dienstag, 13. Juni 2006 09:02 schrieb Samuel ]slund: On Mon, Jun 12, 2006 at 11:55:54PM +0200, Ingo Klöcker wrote: No, it doesn't. You are still believing in security-by-obscurity meaning that your additional encryption only works as long as you and the recipient are the only ones who know the secret rule. Please Ingo, _all_ encryption is based on security-by-obscurity if an attacker finds the secret key _any_ encryption system is toast. You know very well that security by obscurity refers to keeping the encryption algorithm secret. Anyway, why do you actually think that what you want to do would make any sense? If the encryption algorithm you use is too weak so that additional encryption methods are necessary then you probably shouldn't use this encryption algorithm in the first place. And if the encryption algorithm you use is strong enough (e.g. AES) then you gain nothing by additional encyrption methods unless those additional encryption methods are an even stronger encryption algorithm than the first one (but then why apply the first one). I can think of some possible scenarios; if an attacker is has automated the attacks, especially with attacks tailored for each known algorithm, then making the message not conform to known algorithms and structure should break the automation. I don't see why such a scenario would make any sense. If the automated attack would have any chance of success then the used encryption algorithm was too weak. Otherwise it doesn't matter whether the automation works for the message or not. Another could be, how would an attacker tell the difference between a random intercepted file that has been corrupted in transit and one with an additional human decryption step, e.g. during the window between key compromise and revocation. In this case we are dealing with humans that does not necessarily have huge amounts of resources and patience. Maybe you have a point. Still using a self-created obfuscation scheme doesn't feel like a really good solution for this threat model. I'd be impressed by any people communicating that actually had the patience to keep up this kind of scheme, since any communication needs manual intervention. Sure. But as others have said earlier there are better ways to use a secure channel than to agree on such a stupid additional obfuscation step. If anything, then use a second symmetric encryption step for this special two-way-only communication. Regards, Ingo pgpL0FVxJ90rB.pgp Description: PGP signature ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
OpenPGP smartcard restore
I am experimenting with the OpenPGP smartcard. I have two OpenPGP smart cards (smartA and smartB) and I want to verify that I can restore my on-card generated private key should I loose the master card (smartA). I only want to verify that I can do it - not discuss the merits of on-card vs. off-card key generation. I start with an empty ~/.gnupg For smartA I have (1) an on-card generated key (2) the backup file created ~/.gnupg/sk_X.gpg at key generation (3) a backup of ~/.gnupg/secring.gpg when the (4) a file with the exported associated public key (5) a test file encrypted with above public key which decrypts with smartA (6) the pass phrase used at key generation (7) second OpenPGP smartcard (smartB) I then I imagine that I have lost my card (smartA), my computer hard disk has died and I have to restore to a fresh new gpg environment (i.e. no ~/.gnupg) and smartB I then issues these commands gpg --list-keys which creates ~/.gnupg and various files within it. gpg --import public_key.asc using (4) from my backups gpg --list-keys shows that the public key has been imported I then copy my backup secring.gpg to ~/.gnugpg gpg --edit-key KEYID shows that the secret key is present gpg --list-secret-keys shows that the secret key is linked to card-no smartA gpg --edit-key KEYID toggle bkuptocard sk_X.gpg choose the (1) the signature replace existing key yes enter pass phrase save changes yes Now gpg --list-keys shows the key still linked to card-no smartA and not smartB any action needing the private key using smartB results in gpg requesting that you put in smartA (which is lost...) Has anyone actually managed a functional OpenPGP card restore with on-card key generation? And if so how please! Tristan Williams ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
-BEGIN PGP SIGNED MESSAGE- Hash: RIPEMD160 On Tue, Jun 13, 2006 at 02:01:27PM +0100, Tristan Williams wrote: I am experimenting with the OpenPGP smartcard. I have two OpenPGP smart cards (smartA and smartB) and I want to verify that I can restore my on-card generated private key should I loose the master card (smartA). I only want to verify that I can do it - not discuss the merits of on-card vs. off-card key generation. I start with an empty ~/.gnupg For smartA I have (1) an on-card generated key You can stop here. In order to use card B you need to transfer the PRIVATE key from card A to card B. It is _impossible_ to export the private key under any circumstances (minus backdoors/implementation bugs in the smart- card software). Period. If you want to have the same private key on several physical cards, your only option is off-card generation, with import of the key afterwards. -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFEjuLdFtofFpCIfhMRA76IAJwPcBSIb0J2F07FMIwBxE/FGXso/QCcC8xq mBs0HDxYJudS0YWpz6O9XEA= =e9hh -END PGP SIGNATURE- ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
On 13Jun06 18:07, [EMAIL PROTECTED] wrote: On Tue, Jun 13, 2006 at 02:01:27PM +0100, Tristan Williams wrote: I am experimenting with the OpenPGP smartcard. I have two OpenPGP smart cards (smartA and smartB) and I want to verify that I can restore my on-card generated private key should I loose the master card (smartA). I only want to verify that I can do it - not discuss the merits of on-card vs. off-card key generation. I start with an empty ~/.gnupg For smartA I have (1) an on-card generated key You can stop here. In order to use card B you need to transfer the PRIVATE key from card A to card B. It is _impossible_ to export the private key under any circumstances (minus backdoors/implementation bugs in the smart- card software). Period. If you want to have the same private key on several physical cards, your only option is off-card generation, with import of the key afterwards. Then it makes me wonder what is the purpose of the off card backup file sk_X.gpg created when the original private key was created via the on-card method? I can appreciate there might be reasons for not permitting export of the private key from the card but I did expect that restoring a private key using the backup file made at key creation time would be possible. It looks like I was wrong in that thought. ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: False Decrypt Error...
On Tue, Jun 13, 2006 at 10:37:07AM -0500, Eric Robinson wrote: Is anyone familiar with the following error? Standard Error: gpg: WARNING: unsafe permissions on homedir /opt/fxnet/gpggpg: WARNING: using insecure memory!gpg: please see http://www.gnupg.org/faq.html for more informationgpg: encrypted with 1024-bit ELG-E key, ID 07B01208, created 2004-07-14 entsys (FedExNet GPG Key) gpg: [don't know]: invalid packet (ctb=2f)gpg: WARNING: message was not integrity protected My tech guy says it has nothing to do with the 'WARNING: using insecure memory!' message, but it is the 'WARNING: message was not integrity protected' messagei have checked the FAQ's and found some info on the insecure memory that he says isn't the issue... You've got a bunch of warnings here. Let's take them one at a time: gpg: WARNING: unsafe permissions on homedir /opt/fxnet/gpg Just what it says: the directory /opt/fxnet/gpg is writable by someone other than you. It's a good idea for you to fix it, but it isn't the cause of your problem. gpg: WARNING: using insecure memory! gpg: please see http://www.gnupg.org/faq.html for more information GPG tries to lock a small amount of memory so you can't accidentally swap a passphrase out to disk. Depending on how you are using GPG, this may not be significant to you. Either way, it's not the cause of your problem. gpg: WARNING: message was not integrity protected This means that there is no integrity protection packet on the message. There is a very difficult attack against the old PGP message format that the integrity protected format combats. This isn't the cause of your problem either. gpg: [don't know]: invalid packet (ctb=2f) THIS is your problem. GPG found garbage in the message that could not be parsed. Since you say the message was decrypted correctly before the garbage was found, it's likely the garbage is at the end. Is this an armored (i.e. --- BEGIN PGP MESSAGE ---) message or binary (not printable ASCII)? David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
mime and pgp.asc
I am currently using GPG 1.4.3 on my mac powerbook G4 OSX 10.4.6 I hope that this is the right forum to post this question, but when i send an email with attachment and encrypt and sign it, it converts the message into two attachments, one that says mime-attachment and one that says pgp.asc. I don't want this. I want it to encrypt and sign it and it have an encrypted message at the top and an encrypted attachment at the bottom. I am currently sending these emails with the two attachments to a coworker with a PC that uses PGP and he cannot decrypt my emails. Any help would be greatly appreciated. -- View this message in context: http://www.nabble.com/mime-and-pgp.asc-t1781584.html#a4851086 Sent from the GnuPG - User forum at Nabble.com. ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
-BEGIN PGP SIGNED MESSAGE- Hash: RIPEMD160 On Tue, Jun 13, 2006 at 07:03:42PM +0200, markus reichelt wrote: Sorry, that was heat-induced and shall read of course as follows: No need to apologize :) Essentially you're saying: a private key generated on/via a smartcard cannot be exported, so no backup of the private key in question is possible. Because if the private key(s) could be exported, import of the key(s) in question just works without problems. Exactly. If you want a smart-card that allows both export and import, then you don't have a problem. But this defeats the point of having a smart-card (a virus can wait until you authorize yourself to the card and unnoticed copy your private key to the attacker, for example). Bottom line, what's the use of importing to smartcards when no export Importing means that you have an off-card key backup. If you don't have an off-card key backup (to import to another smart-card in case of theft or HW failure of the 1st card), *and* you've used that smart-card for decryption purposes... well, tough luck! from smartcards is possible? In other words: Why is the export of plain smartcard private keys prohibited in the first place? Security. This is the point of having a smart-card. Not even the owner of the smart card knows the private key. You are _entitled_ to use it to perform private key operations (if you know the PIN), but you don't know the key itself. For example, some digital signature laws require such level of security (FIPS level 2 or better). Additionally, why is importing of off-card generated private keys allowed then? Where's the difference? Backup. The difference being that importing an off-card generated private key may be stolen (either in transit to the smart card or from the disk) and thus doesn't provide the level of security required for some purposes (eg. non-repudiation digital signature). IMHO, it's no great damage if you loose your signing key. Loosing your decryption key is admittedly a problem that people think about usually only when it's too late. -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFEjvjYFtofFpCIfhMRA3QRAJwMS5FFIFs3F70pEVu2qPaQRc85ZACeJOwS tFCOWI5EscGStcPmu9e/dik= =8lVR -END PGP SIGNATURE- ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: mime and pgp.asc
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 alifbaa wrote: I am currently using GPG 1.4.3 on my mac powerbook G4 OSX 10.4.6 I hope that this is the right forum to post this question, but when i send an email with attachment and encrypt and sign it, it converts the message into two attachments, one that says mime-attachment and one that says pgp.asc. I don't want this. I want it to encrypt and sign it and it have an encrypted message at the top and an encrypted attachment at the bottom. I am currently sending these emails with the two attachments to a coworker with a PC that uses PGP and he cannot decrypt my emails. Any help would be greatly appreciated. It sounds like you are sending mail using the PGP/MIME format and your coworker's mail client can't handle that. What mail clients are you and your recipient using? What version of PGP is your coworker using? Knowing that, someone here may be able to let you know what, if any, settings scan be changed on either system to enable you to communicate. - -- ToddOpenPGP - KeyID: 0xD654075A | URL: www.pobox.com/~tmz/pgp == What it means to take rights seriously is that one will honor them even when there is a significant social cost in doing so. -- Ronald Dworkin -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.3 (GNU/Linux) Comment: When crypto is outlawed bayl bhgynjf jvyy unir cevinpl. iG0EARECAC0FAkSPAbomGGh0dHA6Ly93d3cucG9ib3guY29tL350bXovcGdwL3Rt ei5hc2MACgkQuv+09NZUB1rvIwCgtnOK0D6MSVwgGnopoaUHjSNLcd0AnArkRlBC 5ZazzBt0RhUjd9qLY4w5 =VR9o -END PGP SIGNATURE- ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: False Decrypt Error...
On Tue, Jun 13, 2006 at 01:40:51PM -0500, Eric Robinson wrote: Hello David, Thanks so much for responding... We have switched from PGP to GPG and we have some of our customers are still using PGP, ¨PGPÁÀNŠˆæ ° is the first part of the message. What you said below is suspicous, I did notice a null value 00, hex 20 20, at the end of the file, I stripped it out and resubmitted it and it processed fine. I will go on that assumption for now and edit these files that come in and fail. If that's the case I'll get our development team towrite a program to strip these out automatically before decryption. Take a look at how you're transferring the files around. It's a very common problem where people use FTP in ascii mode to copy the files around and end up with them mangled. David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
On Tuesday 13 June 2006 19:03, markus reichelt wrote: * markus reichelt [EMAIL PROTECTED] wrote: Essentially you're saying: no backup of a private key generated on/via a smartcard cannot be exported. Because if it could be exported, importing the key(s) in question just works. Sorry, that was heat-induced and shall read of course as follows: Essentially you're saying: a private key generated on/via a smartcard cannot be exported, so no backup of the private key in question is possible. Because if the private key(s) could be exported, import of the key(s) in question just works without problems. The rest of my message still stands though. Bottom line, what's the use of importing to smartcards when no export from smartcards is possible? Obviously, to be able to import keys which were generated off-card. Because some people don't seem to be able to sleep without a backup of the private key. In other words: Why is the export of plain smartcard private keys prohibited in the first place? Is that a trick question? Short answer: Security. Longer answer: It's prohibited because if nobody can export the private key from the smartcard then nobody can steal the private key without your knowledge. You would surely notice that your smartcard is missing but you might never know that some trojan horse has stolen your private key. Additionally, why is importing of off-card generated private keys allowed then? See above. Other use case: My key is signed by many people. If I couldn't import my key to a smartcard (well, I think I can't because it's no RSA key, but let's pretend for the moment that it were an importable key), then I'd have to regather all those signatures again for my new on-card generated key. Regards, Ingo pgp4rpv9BPga2.pgp Description: PGP signature ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
-BEGIN PGP SIGNED MESSAGE- Hash: RIPEMD160 On Tue, Jun 13, 2006 at 06:46:48PM +0100, Tristan Williams wrote: Then it makes me wonder what is the purpose of the off card backup file sk_X.gpg created when the original private key was created via the on-card method? Huh, according to the OpenPGP card specification v1.1, the GENERATE KEY command returns only the public part of the key. If the backup file really contains the private key, then the key is _not_ generated on the card, even though you believe that it is. Look for yourself here: http://g10code.com/docs/openpgp-card-1.1.pdf in section 7.2.11 at page 38. Have you checked what is inside the backup file? Of course, I might be wrong, but publicly available sources seem to tell that I'm right. I tried to dig into the gnupg source to see what is really happening, but it's too large :/ -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFEjwmfFtofFpCIfhMRA+O8AJwNTSdBzCBGPmJX6Sh6XqzJejTYLACdEfVI PdagoBhaeMOdwjq1AfYR0D4= =0vOZ -END PGP SIGNATURE- ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
On Tue, Jun 13, 2006 at 06:46:48PM +0100, Tristan Williams wrote: On 13Jun06 18:07, [EMAIL PROTECTED] wrote: On Tue, Jun 13, 2006 at 02:01:27PM +0100, Tristan Williams wrote: I am experimenting with the OpenPGP smartcard. I have two OpenPGP smart cards (smartA and smartB) and I want to verify that I can restore my on-card generated private key should I loose the master card (smartA). I only want to verify that I can do it - not discuss the merits of on-card vs. off-card key generation. I start with an empty ~/.gnupg For smartA I have (1) an on-card generated key You can stop here. In order to use card B you need to transfer the PRIVATE key from card A to card B. It is _impossible_ to export the private key under any circumstances (minus backdoors/implementation bugs in the smart- card software). Period. If you want to have the same private key on several physical cards, your only option is off-card generation, with import of the key afterwards. Then it makes me wonder what is the purpose of the off card backup file sk_X.gpg created when the original private key was created via the on-card method? I can appreciate there might be reasons for not permitting export of the private key from the card but I did expect that restoring a private key using the backup file made at key creation time would be possible. It looks like I was wrong in that thought. There is a little misunderstanding here. When you generate a card key with off-card backup, the key is not generated via the on-card method. The key is generated like any other key, and then uploaded to the card (and saved to the backup file). The card does not allow reading a secret key off the card, so if you really generated it on-card, there would be no way of making the backup file. David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
On Tue, Jun 13, 2006 at 02:01:27PM +0100, Tristan Williams wrote: I am experimenting with the OpenPGP smartcard. I have two OpenPGP smart cards (smartA and smartB) and I want to verify that I can restore my on-card generated private key should I loose the master card (smartA). I only want to verify that I can do it - not discuss the merits of on-card vs. off-card key generation. I start with an empty ~/.gnupg For smartA I have (1) an on-card generated key (2) the backup file created ~/.gnupg/sk_X.gpg at key generation (3) a backup of ~/.gnupg/secring.gpg when the (4) a file with the exported associated public key (5) a test file encrypted with above public key which decrypts with smartA (6) the pass phrase used at key generation (7) second OpenPGP smartcard (smartB) I then I imagine that I have lost my card (smartA), my computer hard disk has died and I have to restore to a fresh new gpg environment (i.e. no ~/.gnupg) and smartB I then issues these commands gpg --list-keys which creates ~/.gnupg and various files within it. gpg --import public_key.asc using (4) from my backups gpg --list-keys shows that the public key has been imported I then copy my backup secring.gpg to ~/.gnugpg gpg --edit-key KEYID shows that the secret key is present gpg --list-secret-keys shows that the secret key is linked to card-no smartA gpg --edit-key KEYID toggle bkuptocard sk_X.gpg choose the (1) the signature replace existing key yes enter pass phrase save changes yes Now gpg --list-keys shows the key still linked to card-no smartA and not smartB any action needing the private key using smartB results in gpg requesting that you put in smartA (which is lost...) Try this: do everything you did above, but at the end, delete the secret key stub: gpg --delete-secret-keys KEYID (or gpg --edit-key, toggle, and delkey if you're doing just a subkey). And now recreate the stub: gpg --card-edit I don't have my card with me so I can't test this, but it should do what you want. David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: OpenPGP smartcard restore
On 13 Jun 2006, at 20:37, David Shaw wrote: On Tue, Jun 13, 2006 at 02:01:27PM +0100, Tristan Williams wrote: I am experimenting with the OpenPGP smartcard. I have two OpenPGP smart cards (smartA and smartB) and I want to verify that I can restore my on-card generated private key should I loose the master card (smartA). I only want to verify that I can do it - not discuss the merits of on-card vs. off-card key generation. I start with an empty ~/.gnupg For smartA I have (1) an on-card generated key (2) the backup file created ~/.gnupg/sk_X.gpg at key generation (3) a backup of ~/.gnupg/secring.gpg when the (4) a file with the exported associated public key (5) a test file encrypted with above public key which decrypts with smartA (6) the pass phrase used at key generation (7) second OpenPGP smartcard (smartB) I then I imagine that I have lost my card (smartA), my computer hard disk has died and I have to restore to a fresh new gpg environment (i.e. no ~/.gnupg) and smartB I then issues these commands gpg --list-keys which creates ~/.gnupg and various files within it. gpg --import public_key.asc using (4) from my backups gpg --list-keys shows that the public key has been imported I then copy my backup secring.gpg to ~/.gnugpg gpg --edit-key KEYID shows that the secret key is present gpg --list-secret-keys shows that the secret key is linked to card-no smartA gpg --edit-key KEYID toggle bkuptocard sk_X.gpg choose the (1) the signature replace existing key yes enter pass phrase save changes yes Now gpg --list-keys shows the key still linked to card-no smartA and not smartB any action needing the private key using smartB results in gpg requesting that you put in smartA (which is lost...) Try this: do everything you did above, but at the end, delete the secret key stub: gpg --delete-secret-keys KEYID (or gpg --edit-key, toggle, and delkey if you're doing just a subkey). And now recreate the stub: gpg --card-edit I don't have my card with me so I can't test this, but it should do what you want. David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users It works as you suggested. gpg is now happy with smartB (and longer asks for smartA). The file I encrypted with the public key is decrypted correctly. gpg now references smartB not smartA when listing keys. So what is in sk_X.gpg if it is not a standalone importable secret key? Thanks and regards, Tristan Williams ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
RE: False Decrypt Error...
Ok, will do, in this case they send 10 files each day and maybe 1 a week errors out like this... Thanks again, Eric - Eric Robinson Business Application Advisor FedEx Corporate Services Internet Engineering EC Integration 901.263.5749 - -Original Message- From: David Shaw [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 1:47 PM To: Eric Robinson Cc: gnupg-users@gnupg.org Subject: Re: False Decrypt Error... On Tue, Jun 13, 2006 at 01:40:51PM -0500, Eric Robinson wrote: Hello David, Thanks so much for responding... We have switched from PGP to GPG and we have some of our customers are still using PGP, ¨PGPÁÀNŠˆæ ° is the first part of the message. What you said below is suspicous, I did notice a null value 00, hex 20 20, at the end of the file, I stripped it out and resubmitted it and it processed fine. I will go on that assumption for now and edit these files that come in and fail. If that's the case I'll get our development team towrite a program to strip these out automatically before decryption. Take a look at how you're transferring the files around. It's a very common problem where people use FTP in ascii mode to copy the files around and end up with them mangled. David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: Corrupting files
Atom Smasher wrote: btw, what's the threat model where this is advantageous? I can imagine it might be used for plausible deniability: if some law enforcement agency would force you to decrypt the messsage, you could claim you can't and you didn't read it anyway because it's corrupted. Of course, this might be automated in a hacked copy of gpg instead of hand-editing a file. Also safer since it leaves no intermediate evidence around on your harddisk. Of course it would be better to store the changed source code somewhere safe. Might work against police drones, employers, etc. The NSA is unlikely to be fooled by such a scheme. -- ir. J.C.A. Wevers // Physics and science fiction site: [EMAIL PROTECTED] // http://www.xs4all.nl/~johanw/index.html PGP/GPG public keys at http://www.xs4all.nl/~johanw/pgpkeys.html ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
RE: False Decrypt Error...
Hello David, Thanks so much for responding... We have switched from PGP to GPG and we have some of our customers are still using PGP, ¨PGPÁÀNŠˆæ ° is the first part of the message. What you said below is suspicous, I did notice a null value 00, hex 20 20, at the end of the file, I stripped it out and resubmitted it and it processed fine. I will go on that assumption for now and edit these files that come in and fail. If that's the case I'll get our development team towrite a program to strip these out automatically before decryption. Thanks for your time in this. Eric - Eric Robinson Business Application Advisor FedEx Corporate Services Internet Engineering EC Integration 901.263.5749 - -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of David Shaw Sent: Tuesday, June 13, 2006 12:52 PM To: gnupg-users@gnupg.org Subject: Re: False Decrypt Error... On Tue, Jun 13, 2006 at 10:37:07AM -0500, Eric Robinson wrote: Is anyone familiar with the following error? Standard Error: gpg: WARNING: unsafe permissions on homedir /opt/fxnet/gpggpg: WARNING: using insecure memory!gpg: please see http://www.gnupg.org/faq.html for more informationgpg: encrypted with 1024-bit ELG-E key, ID 07B01208, created 2004-07-14 entsys (FedExNet GPG Key) gpg: [don't know]: invalid packet (ctb=2f)gpg: WARNING: message was not integrity protected My tech guy says it has nothing to do with the 'WARNING: using insecure memory!' message, but it is the 'WARNING: message was not integrity protected' messagei have checked the FAQ's and found some info on the insecure memory that he says isn't the issue... You've got a bunch of warnings here. Let's take them one at a time: gpg: WARNING: unsafe permissions on homedir /opt/fxnet/gpg Just what it says: the directory /opt/fxnet/gpg is writable by someone other than you. It's a good idea for you to fix it, but it isn't the cause of your problem. gpg: WARNING: using insecure memory! gpg: please see http://www.gnupg.org/faq.html for more information GPG tries to lock a small amount of memory so you can't accidentally swap a passphrase out to disk. Depending on how you are using GPG, this may not be significant to you. Either way, it's not the cause of your problem. gpg: WARNING: message was not integrity protected This means that there is no integrity protection packet on the message. There is a very difficult attack against the old PGP message format that the integrity protected format combats. This isn't the cause of your problem either. gpg: [don't know]: invalid packet (ctb=2f) THIS is your problem. GPG found garbage in the message that could not be parsed. Since you say the message was decrypted correctly before the garbage was found, it's likely the garbage is at the end. Is this an armored (i.e. --- BEGIN PGP MESSAGE ---) message or binary (not printable ASCII)? David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
