Re: How to avoid weird mestage on file deciphering
On Fri, 10 Nov 2023 13:48, Stephan Verbücheln said: > Notifications, warnings and errors are sent to stderr (rather than > stdout), so the solution for bash would be: > > $ gpg --decrypt file.txt.gpg 2> /dev/null Or to suppress the specific diagnostics mentioned but still show important error message use gpg -q ... or gpg --quiet ... Salam-Shalom, Werner -- The pioneers of a warless world are the youth that refuse military service. - A. Einstein openpgp-digital-signature.asc Description: PGP signature ___ Gnupg-users mailing list Gnupg-users@gnupg.org https://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: gnupg 'signing server'? Looking for advice on key management/security
On Sun, 2023-11-12 at 19:46 -0600, Jacob Bachmeyer wrote: > A PIN does not solve the problem, since the PIN is entered on > the device, which could be backdoored to store the PIN That's why card readers with pinpads were invented, and GnuPG also supports that: https://www.gnupg.org/howtos/card-howto/en/ch02s02.html Other ideas to improve isolation: * If you trust your Linux distribution in general but not every single desktop app, you can use a separate Linux user for sensitive activities. * You can use GnuPG Agent Forwarding via SSH to sign a file on a less trusted server from a more trusted client. This way your PIN is entered on the more trusted client machine. Regards Stephan signature.asc Description: This is a digitally signed message part ___ Gnupg-users mailing list Gnupg-users@gnupg.org https://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: gnupg 'signing server'? Looking for advice on key management/security
Daniel Cerqueira via Gnupg-users wrote: Jeff Schmidt writes: [...] You may want to consider using an OpenPGP smartcard (for example, a Yubikey). Seems that you are a good fit. Using a OpenPGP smartcard, the private key never leaves the smartcard. The smartcard can also be used on a smartphone that has NFC support. The problem here is that, while the key never leaves the smartcard, the /entire/ device that accesses the smartcard must be trusted, as a backdoor on the device could steal plaintext or submit extra items for signing. A PIN does not solve the problem, since the PIN is entered on the device, which could be backdoored to store the PIN and submit it along with Mallory's messages for the smartcard to sign---and the card will sign it, since the PIN checks out... Smartcards make silently duplicating the key difficult (supposedly infeasible) but do not solve the general problems with network-connected devices. -- Jacob ___ Gnupg-users mailing list Gnupg-users@gnupg.org https://lists.gnupg.org/mailman/listinfo/gnupg-users
Re: gnupg 'signing server'? Looking for advice on key management/security
Jeff Schmidt writes: > Hi, > > So, I want to start using Gnupg more to sign things. Right now, in > addition to GnuPG having access to my private key, to use > signing/encryption in my email client, requires allowing the openpgp > implementation in the email client to access my private key. Which, I > think I'm OK with as it's a local client, but, I got to thinking about > the problem of access to the private key. > > Of course, the whole premise of public key encryption is that your > private key is a closely guarded secret. Which raises the question, > how does one USE the private key, without risking exposing it. > > There are multiple problems, it seems to me, and I'm sure as I'm about > 20 years late to the party, that others have identified these and > more, so I wonder if I can get recommendations to articles/blog posts > online, or books, or any wisdom the subscribers of this list can > impart. > > But, the problems that have occurred to me: > > * Even if one only uses the key locally on one or two 'trusted' > devices, there is still the problem of multiplying how many > different apps might have access to your private key - and the more > apps, the more points of potential failure/leakage of your key. Any > app that has been maliciously trojaned by some bad actor, could > steal your private key, and transmit it to some third party, or even > allow a third party to simply sign or encrypt data using the local > app, that isn't yours, as if it came from you. > > * The problem gets worse when you think about things like online > services - if you are using an online email or messaging provider, > or photo sharing service, document/file sharing service, online > social media service, it seems like it would be a really bad idea to > upload your private key to those services and trust them with that. > Now, maybe you might use subkeys are a sort of partial solution to > that - generating service-specific and revocable subkeys for each > specific service, and never providing the master private key, but > that still presents a risk that any of those subkeys might be > stolen. > > * Using a strong password to encrypt and protect the private key, > while a good idea, doesn't really solve the problem, because at some > point, to use the private key, you have to provide the password so > it can be decrypted to be used, and every time you provide the > password, it presents an opportunity for the key to be stolen. > > It seems to me that maybe the best way to resolve many of these risks, > at least, to reduce the 'surface area' of the risk, is to only have > ONE app (ideally, gnupg) that EVER accesses the private key, and that > ALL other requests to encrypt or sign data be brokered through a > 'gnupg server' running on my trusted device, where connections to the > server are encrypted, and when I want data to be signed or encrypted > with my private key, whatever app I'm using to originate the data > connects to gnupg and requests signing or encryption as a service from > the server. Then, gnupg could present the data to me for verification > that no man-in-the-middle or malicious app has altered the data before > submitting it for signing/encryption, then I provide my password just > to gnupg, which would sign or encrypt the payload and pass it back to > the original app or web service. > > Is there an easy way to use gnupg like this? It would be lovely if, > for example, when I'm posting on a social media platform, if I could > configure the social media app to connect to my local 'gnupg server' > and have all my posts and shared photos/videos signed. Of course, this > would require support in those third party apps to have the necessary > code to make that connection to gnupg, but, as a starting point, I'm > not clear if there is even any standard protocol for such a service, > or if gnupg implements it? You may want to consider using an OpenPGP smartcard (for example, a Yubikey). Seems that you are a good fit. Using a OpenPGP smartcard, the private key never leaves the smartcard. The smartcard can also be used on a smartphone that has NFC support. Cheers ___ Gnupg-users mailing list Gnupg-users@gnupg.org https://lists.gnupg.org/mailman/listinfo/gnupg-users
gnupg 'signing server'? Looking for advice on key management/security
Hi, So, I want to start using Gnupg more to sign things. Right now, in addition to GnuPG having access to my private key, to use signing/encryption in my email client, requires allowing the openpgp implementation in the email client to access my private key. Which, I think I'm OK with as it's a local client, but, I got to thinking about the problem of access to the private key. Of course, the whole premise of public key encryption is that your private key is a closely guarded secret. Which raises the question, how does one USE the private key, without risking exposing it. There are multiple problems, it seems to me, and I'm sure as I'm about 20 years late to the party, that others have identified these and more, so I wonder if I can get recommendations to articles/blog posts online, or books, or any wisdom the subscribers of this list can impart. But, the problems that have occurred to me: * Even if one only uses the key locally on one or two 'trusted' devices, there is still the problem of multiplying how many different apps might have access to your private key - and the more apps, the more points of potential failure/leakage of your key. Any app that has been maliciously trojaned by some bad actor, could steal your private key, and transmit it to some third party, or even allow a third party to simply sign or encrypt data using the local app, that isn't yours, as if it came from you. * The problem gets worse when you think about things like online services - if you are using an online email or messaging provider, or photo sharing service, document/file sharing service, online social media service, it seems like it would be a really bad idea to upload your private key to those services and trust them with that. Now, maybe you might use subkeys are a sort of partial solution to that - generating service-specific and revocable subkeys for each specific service, and never providing the master private key, but that still presents a risk that any of those subkeys might be stolen. * Using a strong password to encrypt and protect the private key, while a good idea, doesn't really solve the problem, because at some point, to use the private key, you have to provide the password so it can be decrypted to be used, and every time you provide the password, it presents an opportunity for the key to be stolen. It seems to me that maybe the best way to resolve many of these risks, at least, to reduce the 'surface area' of the risk, is to only have ONE app (ideally, gnupg) that EVER accesses the private key, and that ALL other requests to encrypt or sign data be brokered through a 'gnupg server' running on my trusted device, where connections to the server are encrypted, and when I want data to be signed or encrypted with my private key, whatever app I'm using to originate the data connects to gnupg and requests signing or encryption as a service from the server. Then, gnupg could present the data to me for verification that no man-in-the-middle or malicious app has altered the data before submitting it for signing/encryption, then I provide my password just to gnupg, which would sign or encrypt the payload and pass it back to the original app or web service. Is there an easy way to use gnupg like this? It would be lovely if, for example, when I'm posting on a social media platform, if I could configure the social media app to connect to my local 'gnupg server' and have all my posts and shared photos/videos signed. Of course, this would require support in those third party apps to have the necessary code to make that connection to gnupg, but, as a starting point, I'm not clear if there is even any standard protocol for such a service, or if gnupg implements it? OpenPGP_0x566331566E95AC02.asc Description: OpenPGP public key OpenPGP_signature.asc Description: OpenPGP digital signature ___ Gnupg-users mailing list Gnupg-users@gnupg.org https://lists.gnupg.org/mailman/listinfo/gnupg-users
