Re: How do I make the private key on a OpenPGP smartcard non exportable ?
On 06/19/2013 03:21 PM, Heinz Diehl wrote: > On 18.06.2013, NdK wrote: > >> If the key is generated on-card, you have no way to backup it. No need >> for "unexportable" flag: simply there's no command to export it. > > And if the key is generated off-card and properly moved to the > smartcard afterwards, there's no way to export it either. It's only > the stub which points to the smartcard left on disk. Is the original poster still there? I was going to write and decided it was wiser to wait for these responses which I almost knew were coming. Try the backup from GPA's menu. I doubt you will get anything that can be exported. If you get a backupg.gpg (or similar), then try importing your secret keys onto a second system with GPGWIN installed. If all that flies (you were actually able to do a --export of your private keys despite these two people's responses to the contrary and then are able to do a --import on the second system) then try these tests: 1. Make a detached signature of a file on system one (with OpenPGP card). Copy the base file and the signature file to system two and see if it verifies. 2. Sign on second, copy to first, and see if it verifies on first. IOW, reverse of previous. 3. Enciper a file using public-key of said key you supposedly was able to import on either of the system. By that I mean a public-key enciphering, not just a symmetric cipher, e.g.: http://www.securemecca.com/public/GnuPG/pcrypt.txt Copy the public-key enciphered file to the other system. Flash drive, et al. Decipher it on the other system. I don't think your tests will work. In fact I don't believe you will even get to these three tests. What is the advantage of using the OpenPGP key and having a public-key enciphered file over a symmetric enciphered file? Symmetric Enciphered: = Let's say your machine gets infected. Let's also suppose that a key logger has been installed. I can assure you that most malware today either has a mini key-logger as part of the initial install or a key-logger can be downloaded and installed. Actually, most malware will almost do it automatically. I have over 10,000 malware to back that statement up. Either the key-logger got the password to encipher the enciphered file or they saw it when you temporarily deciphered the file. So now all the hackers need are either the plain-text file or the enciphered file and to know what created the enciphered file. But even if all the hackers have are the enciphered file and the pass-phrase they are now only one step away. PeskySpammer has even installed SMTP agents on tens of thousands of Microsoft Windows machines, one of which was at RIPE, one more at ICANN, and one at Yahoo. The hackers have your file and its name alone or what is in the file header reveals what was used to create the enciphered file. Within a few minutes they will have a deciphered file. The only thing that can protect you is to NEVER encipher or decipher the file while the key-logger is there and to never have the deciphered file available. But once they have the enciphered file and know the password to decipher the file the game is over and you have lost. OpenPGP Public-Key Enciphered: == All the same things hold. Assume they know the key's pass-phrase. They can also pull down the enciphered file. But you cannot just copy the keys since an OpenPGP card doesn't have a file system. If you cannot --export the secret-keys then the hackers will never get them. FOILED! The hackers have no choice but to move on or set some sort of trigger that knows when you decipher the public-key enciphered file. The longer you let the unenciphered file hang around the more likely it is to fly the coop. So even if the hackers know the pass-phrase (assume they do) and have the public-key enciphered file, they can NOT decipher the file. Now do you see the difference between a symmetric enciphered file and a public-key enciphered file where the OpenPGP keys are on an OpenPGP card? Just don't let the unenciphered file hang around any longer than normal. Do not just delete the unenciphered file - securely erase it when you don't need it. If you need higher security use an OS which has moderately more security (Linux) or even higher security (OpenBSD) with an OpenPGP card to hold the keys. Every layer of defense you add encourabes the hackers to move on in search of an easier target. ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: How do I make the private key on a OpenPGP smartcard non exportable ?
On 18.06.2013, NdK wrote: > If the key is generated on-card, you have no way to backup it. No need > for "unexportable" flag: simply there's no command to export it. And if the key is generated off-card and properly moved to the smartcard afterwards, there's no way to export it either. It's only the stub which points to the smartcard left on disk. ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: cleartext signature: digest determination
On Jun 19, 2013, at 8:19 AM, Hauke Laging wrote: > Hello, > > in RfC4880 I read this: > > https://tools.ietf.org/html/rfc4880#section-7 > > «If the "Hash" Armor Header is given, the specified message digest > algorithm(s) are used for the signature. If there are no such headers, MD5 > is > used.» > > That doesn't make sense to me. I checked a cleartext signature with > gpg --list-packets and got this: > > :signature packet: algo 1, keyid 4CB66C1B33FB59FC >version 4, created 1364174035, md5len 0, sigclass 0x01 >digest algo 2, begin of digest a1 0d >hashed subpkt 2 len 4 (sig created 2013-03-25) >subpkt 16 len 8 (issuer key ID 4CB66C1B33FB59FC) >data: [4093 bits] > > This looks like a normal signature packet to me, and it does contain the used > digest algo. So why should it be necessary to write the used digest into the > cleartext part? Is that a compatibility issue with older OpenPGP versions? > Usually that is mentioned but not in the text I quoted. It's an ordering issue. Cleartext signatures are designed to be able to be read in a single pass - thus the need for the Hash header at the beginning of the document, so the receiving program doesn't have to read to the end, find out what hash is in use, then jump back to the beginning to actually hash the document. David ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
cleartext signature: digest determination
Hello, in RfC4880 I read this: https://tools.ietf.org/html/rfc4880#section-7 «If the "Hash" Armor Header is given, the specified message digest algorithm(s) are used for the signature. If there are no such headers, MD5 is used.» That doesn't make sense to me. I checked a cleartext signature with gpg --list-packets and got this: :signature packet: algo 1, keyid 4CB66C1B33FB59FC version 4, created 1364174035, md5len 0, sigclass 0x01 digest algo 2, begin of digest a1 0d hashed subpkt 2 len 4 (sig created 2013-03-25) subpkt 16 len 8 (issuer key ID 4CB66C1B33FB59FC) data: [4093 bits] This looks like a normal signature packet to me, and it does contain the used digest algo. So why should it be necessary to write the used digest into the cleartext part? Is that a compatibility issue with older OpenPGP versions? Usually that is mentioned but not in the text I quoted. Hauke -- ☺ PGP: 7D82 FB9F D25A 2CE4 5241 6C37 BF4B 8EEF 1A57 1DF5 (seit 2012-11-04) http://www.openpgp-courses.org/ signature.asc Description: This is a digitally signed message part. ___ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: gpg --fingerprint show only fingerprints and nothing else?
Peter Lebbing:
> On 19/06/13 00:10, Hauke Laging wrote:
>> gpg --with-colons --fingerprint | awk -F: '$1 == "fpr" {print $10;}'
>
>>> when the output ever changes
>>
>> It won't (it's designed not to change).
>
> At the risk of sounding pedantic, let me point out that the output you get
> with
> --with-colons is designed not to change. --with-colons is an option added
> precisely because the output without that option might change and break
> scripts.
Thats awesome! Thank you both!
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Re: gpg --fingerprint show only fingerprints and nothing else?
On 19/06/13 00:10, Hauke Laging wrote:
> gpg --with-colons --fingerprint | awk -F: '$1 == "fpr" {print $10;}'
>> when the output ever changes
>
> It won't (it's designed not to change).
At the risk of sounding pedantic, let me point out that the output you get with
--with-colons is designed not to change. --with-colons is an option added
precisely because the output without that option might change and break scripts.
HTH,
Peter.
--
I use the GNU Privacy Guard (GnuPG) in combination with Enigmail.
You can send me encrypted mail if you want some privacy.
My key is available at
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