Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
Hi! Am 22.07.2022 um 21:10 schrieb Mikhail Koliada: What do you think? I like the idea and would like to see that change. Conrad
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On Sat, Jul 23, 2022 at 08:55:14PM -0400, Mike Gilbert wrote: > On Fri, Jul 22, 2022 at 3:10 PM Mikhail Koliada wrote: > > > > Hello! > > > > This idea has been fluctuating in my head for quite a while given that the > > migration had happened > > a while ago [0] and some other major distributions have already adopted > > yescrypt as their default algo > > by now [1]. For us switching is as easy as changing the default use flag in > > pambase and rehashing the password > > with the ‘passwd’ call (a news item will be required). > > > > What do you think? > > Seems like a reasonable idea to me. Just giving my +1 to that, no strong opinion but reading about it sounds like a reasonable choice to me. -- ionen signature.asc Description: PGP signature
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On 7/25/2022 16:29, John Helmert III wrote: > On Mon, Jul 25, 2022 at 03:59:59PM -0400, Joshua Kinard wrote: >> On 7/25/2022 15:30, Joshua Kinard wrote: >> [snip] >> >>> >>> Some really quick looking around, I'm not finding any substantive >>> discussions on why yescrypt is better than argon2. It so far seems that it >>> just got implemented in libxcrypt sooner than argon2 did, so that's why >>> there is this sudden push for it. >>> >>> E.g., on Issue #45 in linux-pam[3], user ldv-alt just states "I'd recommend >>> yescrypt instead. Anyway, it has to be implemented in libcrypt.", but >>> provides no justification for why they recommend yescrypt. Since we're >>> dealing with a fairly important function for system security, I kinda want >>> something with much more context that presents pros and cons for this >>> algorithm over others, especially argon2. >> >> So there is this question and three answers on Crypto StackExchange. It is >> about five years-old, but it's got more detail on why argon2 won the PHC >> instead of one of the other contenders. It is still subjective information, >> but more thorough: >> https://crypto.stackexchange.com/questions/48933/why-did-argon2-win-the-phc >> >> There's some more info if one continues to deep-dive on CSE, but I am >> noticing a lot of the info is several years old. Some more recent things >> make references to a newer algo called Balloon, but that seems to be going >> off into side-tangents. >> >> Anyways, I guess I am just being paranoid. If a change to hashing algos is >> made, it should be based on facts and not popularity contests or feelings. > > I'm not sure it's fair to suggest this change is based on "popularity > contests or feelings". The facts were given in the original mail, just > because one finds them unconvincing doesn't mean those facts aren't > real and convincing to others. > My wording could sometimes be done better, but that's my takeaway in a nutshell. Facts, presented objectively and well, should convince just about anyone. But the Fedora page just doesn't do that for me. It really only presents positives and no negatives of yescrypt. Are there any? I don't know. I assume there have to be, but I'm not a crypto-expert. I've only done a light, cursory search on Google for something basic like "argon2 vs yescrypt", and that gets a few interesting results. A few links to github, one to the PHC website, another to the the now-dead openwall ML posts, and Debian's bug for switching pam_linux over to using yescrypt. The most recent discussion-wise result are the comments on a Hacker News article that is 11 months old[1]. 1. https://news.ycombinator.com/item?id=28181350 -- Joshua Kinard Gentoo/MIPS ku...@gentoo.org rsa6144/5C63F4E3F5C6C943 2015-04-27 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On Mon, Jul 25, 2022 at 03:59:59PM -0400, Joshua Kinard wrote: > On 7/25/2022 15:30, Joshua Kinard wrote: > [snip] > > > > > Some really quick looking around, I'm not finding any substantive > > discussions on why yescrypt is better than argon2. It so far seems that it > > just got implemented in libxcrypt sooner than argon2 did, so that's why > > there is this sudden push for it. > > > > E.g., on Issue #45 in linux-pam[3], user ldv-alt just states "I'd recommend > > yescrypt instead. Anyway, it has to be implemented in libcrypt.", but > > provides no justification for why they recommend yescrypt. Since we're > > dealing with a fairly important function for system security, I kinda want > > something with much more context that presents pros and cons for this > > algorithm over others, especially argon2. > > So there is this question and three answers on Crypto StackExchange. It is > about five years-old, but it's got more detail on why argon2 won the PHC > instead of one of the other contenders. It is still subjective information, > but more thorough: > https://crypto.stackexchange.com/questions/48933/why-did-argon2-win-the-phc > > There's some more info if one continues to deep-dive on CSE, but I am > noticing a lot of the info is several years old. Some more recent things > make references to a newer algo called Balloon, but that seems to be going > off into side-tangents. > > Anyways, I guess I am just being paranoid. If a change to hashing algos is > made, it should be based on facts and not popularity contests or feelings. I'm not sure it's fair to suggest this change is based on "popularity contests or feelings". The facts were given in the original mail, just because one finds them unconvincing doesn't mean those facts aren't real and convincing to others. > -- > Joshua Kinard > Gentoo/MIPS > ku...@gentoo.org > rsa6144/5C63F4E3F5C6C943 2015-04-27 > 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 > > "The past tempts us, the present confuses us, the future frightens us. And > our lives slip away, moment by moment, lost in that vast, terrible > in-between." > > --Emperor Turhan, Centauri Republic > signature.asc Description: PGP signature
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On 7/25/2022 15:30, Joshua Kinard wrote: [snip] > > Some really quick looking around, I'm not finding any substantive > discussions on why yescrypt is better than argon2. It so far seems that it > just got implemented in libxcrypt sooner than argon2 did, so that's why > there is this sudden push for it. > > E.g., on Issue #45 in linux-pam[3], user ldv-alt just states "I'd recommend > yescrypt instead. Anyway, it has to be implemented in libcrypt.", but > provides no justification for why they recommend yescrypt. Since we're > dealing with a fairly important function for system security, I kinda want > something with much more context that presents pros and cons for this > algorithm over others, especially argon2. So there is this question and three answers on Crypto StackExchange. It is about five years-old, but it's got more detail on why argon2 won the PHC instead of one of the other contenders. It is still subjective information, but more thorough: https://crypto.stackexchange.com/questions/48933/why-did-argon2-win-the-phc There's some more info if one continues to deep-dive on CSE, but I am noticing a lot of the info is several years old. Some more recent things make references to a newer algo called Balloon, but that seems to be going off into side-tangents. Anyways, I guess I am just being paranoid. If a change to hashing algos is made, it should be based on facts and not popularity contests or feelings. -- Joshua Kinard Gentoo/MIPS ku...@gentoo.org rsa6144/5C63F4E3F5C6C943 2015-04-27 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On 7/25/2022 15:34, John Helmert III wrote: > On Mon, Jul 25, 2022 at 03:30:08PM -0400, Joshua Kinard wrote: [snip] >> >> "yescrypt" is an odd name for a hashing algorithm. I looked it up on >> Wikipedia, and it just redirects to the 2013 Password Hashing Competition >> (PHC)[1], in which yescrypt was just a runner-up (along w/ catena, makwa, >> and lyra2). The winner was argon2. So unless something has changed in the >> last nine years or there is more recent information, wouldn't it make more >> sense to go with the winner of such a competition (argon2) instead of a >> runner-up? I know marecki said Fedora was waiting for an official RFC for >> argon2, but the wait for that ended almost a year ago in Sept 2021 when >> RFC9106[2] was released. >> >> Some really quick looking around, I'm not finding any substantive >> discussions on why yescrypt is better than argon2. It so far seems that it >> just got implemented in libxcrypt sooner than argon2 did, so that's why >> there is this sudden push for it. >> >> E.g., on Issue #45 in linux-pam[3], user ldv-alt just states "I'd recommend >> yescrypt instead. Anyway, it has to be implemented in libcrypt.", but >> provides no justification for why they recommend yescrypt. Since we're >> dealing with a fairly important function for system security, I kinda want >> something with much more context that presents pros and cons for this >> algorithm over others, especially argon2. >> >> That said, there does appear to be an open pull request on libxcrypt for >> argon2[4], so maybe that is something to follow to see where it goes? >> >> 1. https://en.wikipedia.org/wiki/Password_Hashing_Competition >> 2. https://datatracker.ietf.org/doc/html/rfc9106 >> 3. https://github.com/linux-pam/linux-pam/issues/45 >> 4. https://github.com/besser82/libxcrypt/pull/150 >> >> tl;dr, I'm just a bit uncomfortable adopting a new hashing algo just because >> it seems popular. I would prefer something that's been thoroughly tested. >> The scant info I've found thus far, that points to argon2, not yescrypt. > > There's justification for this in one of the references in zlogene's > original mail: > > https://fedoraproject.org/wiki/Changes/yescrypt_as_default_hashing_method_for_shadow#Detailed_Description > Yeah, I did read that bit, but it still feels like it is written as someone's opinion rather than as an objective comparison. It also states that yescrypt is "based on NIST-approved primitives", whereas argon2 is based on Blake2 (which I assume is not NIST-approved" at this time). But just because something uses a NIST-approved mechanism does not mean it inherits that approval, so that argument doesn't completely convince me. -- Joshua Kinard Gentoo/MIPS ku...@gentoo.org rsa6144/5C63F4E3F5C6C943 2015-04-27 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On Mon, Jul 25, 2022 at 03:30:08PM -0400, Joshua Kinard wrote: > On 7/25/2022 14:44, Sam James wrote: > > > > > >> On 22 Jul 2022, at 20:10, Mikhail Koliada wrote: > >> > >> Hello! > >> > >> This idea has been fluctuating in my head for quite a while given that the > >> migration had happened > >> a while ago [0] and some other major distributions have already adopted > >> yescrypt as their default algo > >> by now [1]. For us switching is as easy as changing the default use flag > >> in pambase and rehashing the password > >> with the ‘passwd’ call (a news item will be required). > >> > >> What do you think? > >> > >> P.S. surely, I am only speaking about the local auth method based on > >> shadow and also about the pam-based systems as the change is going > >> to mainly impact the pam_unix.so calls in the pam’s stack. > >> Pamless or the systems with an alternative auth methods is a different > >> story. > >> > >> [0] - > >> https://www.gentoo.org/support/news-items/2021-10-18-libxcrypt-migration-stable.html > >> [1] - > >> https://fedoraproject.org/wiki/Changes/yescrypt_as_default_hashing_method_for_shadow > > > > It's fine with me although I guess I'm a bit reluctant when the libxcrypt > > stuff is still biting > > some users. > > > > My preference would be to wait a few more months, but I don't feel strongly > > about it, > > and won't object if we want to move forward sooner. > > > > Overall though, it's a good idea, although I'd welcome Jason's input > > on alternatives first. CC'd. > > > > Best, > > sam > > "yescrypt" is an odd name for a hashing algorithm. I looked it up on > Wikipedia, and it just redirects to the 2013 Password Hashing Competition > (PHC)[1], in which yescrypt was just a runner-up (along w/ catena, makwa, > and lyra2). The winner was argon2. So unless something has changed in the > last nine years or there is more recent information, wouldn't it make more > sense to go with the winner of such a competition (argon2) instead of a > runner-up? I know marecki said Fedora was waiting for an official RFC for > argon2, but the wait for that ended almost a year ago in Sept 2021 when > RFC9106[2] was released. > > Some really quick looking around, I'm not finding any substantive > discussions on why yescrypt is better than argon2. It so far seems that it > just got implemented in libxcrypt sooner than argon2 did, so that's why > there is this sudden push for it. > > E.g., on Issue #45 in linux-pam[3], user ldv-alt just states "I'd recommend > yescrypt instead. Anyway, it has to be implemented in libcrypt.", but > provides no justification for why they recommend yescrypt. Since we're > dealing with a fairly important function for system security, I kinda want > something with much more context that presents pros and cons for this > algorithm over others, especially argon2. > > That said, there does appear to be an open pull request on libxcrypt for > argon2[4], so maybe that is something to follow to see where it goes? > > 1. https://en.wikipedia.org/wiki/Password_Hashing_Competition > 2. https://datatracker.ietf.org/doc/html/rfc9106 > 3. https://github.com/linux-pam/linux-pam/issues/45 > 4. https://github.com/besser82/libxcrypt/pull/150 > > tl;dr, I'm just a bit uncomfortable adopting a new hashing algo just because > it seems popular. I would prefer something that's been thoroughly tested. > The scant info I've found thus far, that points to argon2, not yescrypt. There's justification for this in one of the references in zlogene's original mail: https://fedoraproject.org/wiki/Changes/yescrypt_as_default_hashing_method_for_shadow#Detailed_Description > -- > Joshua Kinard > Gentoo/MIPS > ku...@gentoo.org > rsa6144/5C63F4E3F5C6C943 2015-04-27 > 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 > > "The past tempts us, the present confuses us, the future frightens us. And > our lives slip away, moment by moment, lost in that vast, terrible > in-between." > > --Emperor Turhan, Centauri Republic > signature.asc Description: PGP signature
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On 7/25/2022 14:44, Sam James wrote: > > >> On 22 Jul 2022, at 20:10, Mikhail Koliada wrote: >> >> Hello! >> >> This idea has been fluctuating in my head for quite a while given that the >> migration had happened >> a while ago [0] and some other major distributions have already adopted >> yescrypt as their default algo >> by now [1]. For us switching is as easy as changing the default use flag in >> pambase and rehashing the password >> with the ‘passwd’ call (a news item will be required). >> >> What do you think? >> >> P.S. surely, I am only speaking about the local auth method based on shadow >> and also about the pam-based systems as the change is going >> to mainly impact the pam_unix.so calls in the pam’s stack. >> Pamless or the systems with an alternative auth methods is a different story. >> >> [0] - >> https://www.gentoo.org/support/news-items/2021-10-18-libxcrypt-migration-stable.html >> [1] - >> https://fedoraproject.org/wiki/Changes/yescrypt_as_default_hashing_method_for_shadow > > It's fine with me although I guess I'm a bit reluctant when the libxcrypt > stuff is still biting > some users. > > My preference would be to wait a few more months, but I don't feel strongly > about it, > and won't object if we want to move forward sooner. > > Overall though, it's a good idea, although I'd welcome Jason's input > on alternatives first. CC'd. > > Best, > sam "yescrypt" is an odd name for a hashing algorithm. I looked it up on Wikipedia, and it just redirects to the 2013 Password Hashing Competition (PHC)[1], in which yescrypt was just a runner-up (along w/ catena, makwa, and lyra2). The winner was argon2. So unless something has changed in the last nine years or there is more recent information, wouldn't it make more sense to go with the winner of such a competition (argon2) instead of a runner-up? I know marecki said Fedora was waiting for an official RFC for argon2, but the wait for that ended almost a year ago in Sept 2021 when RFC9106[2] was released. Some really quick looking around, I'm not finding any substantive discussions on why yescrypt is better than argon2. It so far seems that it just got implemented in libxcrypt sooner than argon2 did, so that's why there is this sudden push for it. E.g., on Issue #45 in linux-pam[3], user ldv-alt just states "I'd recommend yescrypt instead. Anyway, it has to be implemented in libcrypt.", but provides no justification for why they recommend yescrypt. Since we're dealing with a fairly important function for system security, I kinda want something with much more context that presents pros and cons for this algorithm over others, especially argon2. That said, there does appear to be an open pull request on libxcrypt for argon2[4], so maybe that is something to follow to see where it goes? 1. https://en.wikipedia.org/wiki/Password_Hashing_Competition 2. https://datatracker.ietf.org/doc/html/rfc9106 3. https://github.com/linux-pam/linux-pam/issues/45 4. https://github.com/besser82/libxcrypt/pull/150 tl;dr, I'm just a bit uncomfortable adopting a new hashing algo just because it seems popular. I would prefer something that's been thoroughly tested. The scant info I've found thus far, that points to argon2, not yescrypt. -- Joshua Kinard Gentoo/MIPS ku...@gentoo.org rsa6144/5C63F4E3F5C6C943 2015-04-27 177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943 "The past tempts us, the present confuses us, the future frightens us. And our lives slip away, moment by moment, lost in that vast, terrible in-between." --Emperor Turhan, Centauri Republic
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
> On 22 Jul 2022, at 20:10, Mikhail Koliada wrote: > > Hello! > > This idea has been fluctuating in my head for quite a while given that the > migration had happened > a while ago [0] and some other major distributions have already adopted > yescrypt as their default algo > by now [1]. For us switching is as easy as changing the default use flag in > pambase and rehashing the password > with the ‘passwd’ call (a news item will be required). > > What do you think? > > P.S. surely, I am only speaking about the local auth method based on shadow > and also about the pam-based systems as the change is going > to mainly impact the pam_unix.so calls in the pam’s stack. > Pamless or the systems with an alternative auth methods is a different story. > > [0] - > https://www.gentoo.org/support/news-items/2021-10-18-libxcrypt-migration-stable.html > [1] - > https://fedoraproject.org/wiki/Changes/yescrypt_as_default_hashing_method_for_shadow It's fine with me although I guess I'm a bit reluctant when the libxcrypt stuff is still biting some users. My preference would be to wait a few more months, but I don't feel strongly about it, and won't object if we want to move forward sooner. Overall though, it's a good idea, although I'd welcome Jason's input on alternatives first. CC'd. Best, sam signature.asc Description: Message signed with OpenPGP
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
> On 25 Jul 2022, at 15:35, Peter Stuge wrote: > > Mikhail Koliada wrote: >> This idea has been fluctuating in my head for quite a while given >> that the migration had happened a while ago [0] and some other >> major distributions have already adopted yescrypt as their default algo >> by now [1]. > > Please only do that based on proven merit and nothing else. > > Fedora or anyone else for that matter making a change is a truly > terrible reason to take any action whatsoever, since other > organizations are driven by /their/ interests - with Fedora in > particular being driven by the business interests of Red Hat. > > I consider Gentoo a leader in many regards and it makes me really > sad whenever Gentoo changes based on nothing more than "others did it". > A fair part of the motivation for the libxcrypt migration was allowing use of tougher hashing algorithms like yescrypt. While your concern may be valid in some contexts, it's not what's happening here, as Rich notes. Maybe zlogene's email should have explicitly stated that yescrypt has desirable security properties, but it's not being done simply because "Fedora did it". > > Thanks and kind regards > > //Peter > Best, sam signature.asc Description: Message signed with OpenPGP
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On Mon, Jul 25, 2022 at 11:11 AM Marek Szuba wrote: > > On 2022-07-25 15:35, Peter Stuge wrote: > > > Please only do that based on proven merit and nothing else. > > https://pthree.org/2018/05/23/do-not-use-sha256crypt-sha512crypt-theyre-dangerous/ > , https://www.password-hashing.net/ , the fact we still us the default > number of rounds (i.e. 5000) with SHA512 which is *ridiculously* weak > for modern hardware, lack of Argon2 support in libxcrypt for the time > being due to upstream having decided to wait for an official RFC. You > can probably find more yourself if you look. The fedora link in the original email details why they changed it. I don't think regurgitating the argument will add to it. By all means point out if there is a concern with their reasoning though. My initial question was whether this was some vanity hash change but the changes are intended to greatly increase the cost of cracking attacks. I'm in no position to evaluate their merit but their proposal contains various citations to people who presumably are. -- Rich
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On 2022-07-25 15:35, Peter Stuge wrote: Mikhail Koliada wrote: This idea has been fluctuating in my head for quite a while given that the migration had happened a while ago [0] and some other major distributions have already adopted yescrypt as their default algo by now [1]. Please only do that based on proven merit and nothing else. https://pthree.org/2018/05/23/do-not-use-sha256crypt-sha512crypt-theyre-dangerous/ , https://www.password-hashing.net/ , the fact we still us the default number of rounds (i.e. 5000) with SHA512 which is *ridiculously* weak for modern hardware, lack of Argon2 support in libxcrypt for the time being due to upstream having decided to wait for an official RFC. You can probably find more yourself if you look. -- Marecki OpenPGP_signature Description: OpenPGP digital signature
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
Mikhail Koliada wrote: > This idea has been fluctuating in my head for quite a while given > that the migration had happened a while ago [0] and some other > major distributions have already adopted yescrypt as their default algo > by now [1]. Please only do that based on proven merit and nothing else. Fedora or anyone else for that matter making a change is a truly terrible reason to take any action whatsoever, since other organizations are driven by /their/ interests - with Fedora in particular being driven by the business interests of Red Hat. I consider Gentoo a leader in many regards and it makes me really sad whenever Gentoo changes based on nothing more than "others did it". Thanks and kind regards //Peter
Re: [gentoo-dev] Switching default password hashes from sha512 to yescrypt
On Fri, Jul 22, 2022 at 3:10 PM Mikhail Koliada wrote: > > Hello! > > > > This idea has been fluctuating in my head for quite a while given that the > migration had happened > > a while ago [0] and some other major distributions have already adopted > yescrypt as their default algo > > by now [1]. For us switching is as easy as changing the default use flag in > pambase and rehashing the password > > with the ‘passwd’ call (a news item will be required). > > > > What do you think? Seems like a reasonable idea to me.
