Does anyone have a suggested alternative for authy? (Please read the whole post before responding)
I’d love to go with an open source solution as I’ve done with my password manager, but that doesn’t seem possible with one of my big requirements:
Scenario: I’ve had my phone robbed abroad and managed to buy a new one and loaded my ESIM back into it—I need to recover access to my 2 factor database via SMS so I’m able to log into my cloud storage and access my password database.
At this point I’d probably be happy to host a service myself on something like AWS and use SNS for this requirement, but I’m not sure anything like that exists ready to go. I’m not particularly interested in rolling something myself for this.
I’d be dubious of jumping from one closed source product to another, but if there’s a particularly good option I’m all ears, I’ve been otherwise happy with authy for about a decade now, but this plus the retirement of the desktop app have me looking elsewhere.
Interesting, I’ve seen this one before but it didn’t seem like it would support my deal-breaker scenario—I still can’t seem to see support for that on the readme, could you point me at some docs?
Forget your existing cloud. Your 2FA backup doesn’t need to be protected by 2FA; just encryption and a strong/unique passphrase. Your 2FA backup can’t be used to access any account on its own, without each password. Most OSS E2EE services allow you to create a free account; many without an email. Pick 2 for redundancy, create a NEW account, and set a NEW passphrase (like your 2nd “master” password). Before you transit upload your OTP backup to both of them.
This approach is probably more secure than SMS to access 2FA, especially vs a closed source provider like Authy, and especially if your 2FA export is also encrypted with a different password. If you’re already using a password manager and unique passwords for everything, you’re already 95% more secure than everyone else, and removed the primary need for 2FA (password reuse and theft). If you’re doing everything else right, 2FA only makes you 5-10% more secure, and covers far less-likely threats (email takeover, MITM, etc). Sys admins have been raw dogging SSH and PGP keys every day without a 2nd factor, for decades.
Interesting, I’ve seen this one before but it didn’t seem like it would support my deal-breaker scenario—I still can’t seem to see support for that on the readme, could you point me at some docs?
The point is you physically and locally back up the database. Put it on your computer, or a flash drive or whatever. You can set a different, longer password for backups, and I would recommend you do that. When you get your new phone, you just copy the database into it and load it into a freshly installed Aegis. You don’t even need to self host anything, there is nothing to host.
Not everything needs to be “in the cloud”. I think this event illustrates nicely why.
This is specifically a scenario where I’m starting from a single blank device because I’ve just been robbed on the other side of the planet.
Edit: for added weight, I’ve been in this exact scenario. I was able to get my ESIM reprovisioned to a new phone and recover everything within a day. I don’t want to replace authy with a solution that doesn’t cover that scenario
Well I thought this was kinda obvious what I meant, but I guess not. What you say is a requirement (sms recovery of a cloud account) is just one of many solutions to your specific problem. I’ll just list off a few solutions below that involve neither SMS (the most insecure communication method in common use today) and only optionally a cloud account. For cimplicity sake I’ll stick to Aegis, where you can create password-protected local backups you can then put wherever you want. This password needs to be very strong for obvious reasons: I would recommend a long sentence (40 characters or more) that you can just remember, like a quote from a movie/tv show/book/poem or something, including normal punctuation as a sentence for example.
Solution 0: This is more of a trivial solution I wouldn’t actually recommend. You can allow account recovery via eMail and have your eMail not use 2fa, but a long/good password so you can login from memory (see above). This is probably more secure than SMS for the recovery-case, but less secure for the everyday use case of eMail, therefore “not recommended”.
Solution 1: USB Sticks are tiny, as in the size of a USB port (slightly longer but slimmer for USB-C). If you want to have a backup “on you”, I’m sure you can find a place where it wouldn’t get robbed with the phone/wallet. A tiny pocket somewhere, a string around your ankle, make a compartment in your shoe, or just have it with your luggage at the hotel. I’m sure you get the point. You get your new phone, you plug in the USB, you install Aegis and restore the backup.
Solution 2a: Dedicated “online” storage. This can be self hosted, or a free account of any cloud provider, but the important part is that it does NOT require 2FA and you do NOT use it for anything else. You have the backup in there. It also needs a very secure password (again: long, but easy to remember, no garbled letter nonsense), but obviously not the same as the Aegis-Backup. So you now need to remember 2 long passwords. You get your new phone, you log in, get the backup and proceed as usual.
Solution 2b: If not having 2FA is not an option for the solution above, you can have a friend/family store the 2FA on his phone. To log in, you go to the login page and enter your password (which your friend doesn’t need to know), and you ask him over the phone for the current 2FA-Code, which he tells you and you can log in, download the backup and proceed as above. I assume such a high security isn’t that critical, since you have been using something involving SMS. Restore then goes as per usual.
Solution 3: Store the whole backup with a friend and when you need it he just temporarily puts it somwhere you can access, and removes it again after. Since the backup is protected by a monster of a password, and the accessibility is temporary anyway, this isn’t security critical.
Solution 4: If you absolutely must, you can find a cloud-provider for 2FA, and use it only as the “first stage”. The only 2FA code in there is the one you need to get access to your main online storage/account where you then have your real Aegis-Backup and/or other files. Obviously this service would need to allow you to login without 2FA, and the usual password rules resulting fom that apply. You can just add the 2FA of your primary service to more than 1 app or service, or if it allows for this, you can generate multiple authenticators so you can also revoke them serperately if needed.
Well I thought this was kinda obvious what I meant, but I guess not.
Alright, drop the sass, if it was obvious your post wouldn’t be the length it is. Now chill, I genuinely appreciate your response
0, no go
1, also a no go, I can’t guarantee I’ll have an extra thing
2a. No 2fa, so this is a reduction in my current security
2b, this could be workable, I already self-host a number of services, but I want to be sure situational neglect (i.e. life is too busy for me to pay attention) cannot compromise this, therefore it’s gotta be a turnkey solution that I can configure to auto update, which is what I’m asking for in my comment. I need your specific solution for this, generalisms are useless here.
3: Not workable, I can’t rely on someone else being able to help in every possible scenario (and tbh I wouldn’t want to put that responsibility on someone)
4: This is a pretty good one tbh, though I guess if I’m going to pick holes, if the first stage is good enough as the gate, it diminishes the reason to have the second stage, so I’d wonder what you would suggest that could tick all the boxes for that first gate.
Edit: weird numbering formatting to combat lemmy formatting doing weird things
2a. No 2fa, so this is a reduction in my current security
That’s open to interpretation. Your current solution you thought was secure, but you used a service that as it turned out had bad security practices, which you just didn’t know (arguably couldn’t know). ANY online/cloud service that you don’t host yourself has this issue with being a black box of unkown quality. Any online service you do host has to be secured by you (or you need to trust that the base setup of that tool is “sufficiently secure”), and is in essence limited by your knowledge of the tool and technology used. Also if you’re reusing any passwords, anywhere, just stopping that practice is likely more secure in practice compared to 2fa in isolation.
2fa in general isn’t just plaing “better” than not having it, security is rarely this black and white. It also depends on what is allowed to be the “second factor”, and since yours included SMS, it really wasn’t secure at all (like others have also mentioned in this thread). And it depends on the password of course. For example if you use a really secure password (30+ characters), and don’t reuse it, it will in practice be more secure than a short(ish) password and a 2nd factor that allows SMS. Generally 2 factor is used as a term for 2 categorically different athentication methods: one thing you know (password, pin) and one thing you own (phone, physical device/key, or a file works too). The problem is that SMS doesn’t require your phone. It’s incredibly easy to get the SMS without having your phone (even easier with physical proximity) or flat out faking owning your phone number (dpends on a lot of factors how easy or hard that is in practice, doesn’t require physical proximity). Basically, if someone actively targets you and/or that account secured by SMS 2fa, it isn’t overly hard, but it’s good enough at preventing giving access through a data leak for example.
So, back to the security of “solution 2a”: how would someone get access to a long password you don’t use anywhere else, that isn’t written down anywhere (or nowhere accessible), and where you essentially never need to use/access the account in the first place? Nobody would even know that whole account exists unless you specifically tell them, let alone knowing how to get in. Note that this can also be combined with the concept in solution 4, so you’re then using it to only restore a single 2fa code. So that “safety net fallback account” very rarely needs to be updated with a newer Aegis-Backup, making it even more obscure/unknown. That 2fa code then lets you access your normal account and backups, and you restore the full suite of 2fa you need.
It boils down to this: local 2fa with a backup means you need to get access to a single file to securely restore full access to everything. That file can be transmitted insecurely (due to strong cryptography and hopefully a good password not used anywhere else), but I wouldn’t store it out in the open either.
On the other hand, any cloud based solution is an inherent black box. You trust them to properly do things, and you only know they didn’t once it’s too late (like Authy). It also means they are, by nature of what they do (storing account access information), a target and if the attacker is successful, you’re the collateral without having been explicitly targeted. Maybe there are sevices out there that let third parties audit their security and publish the results, but I don’t know of any and it would probably increase the price by an prohibitive amount for most people.
Okay I see what you’re saying but it’s still a downgrade from what I thought my security was, the fact authy broke that trust doesn’t mean I want to compromise what I was expecting to the level they ended up providing me
Sure, I guess the thing I’ve not made clear enough is that I accept the compromise of security by having an SMS backup in this scenario for the convenience it provides in restoration. Someone could compromise my SMS but they’d still need my password, and in Authy’s case, they would also then need to be able to sufficiently convince Twilio that I’m me before they allow access again. I understand that the last step is obviously not possible with a non-commercial solution.
Tbh you’ve kinda come up with the solution for me though, if I keep the database in it’s own cloud storage separate from everything else I could set up SMS 2FA and a unique memorable password to get a similar experience to what I have now, albeit without the extra verification when SMS is used.
Since you’ve been helpful already, one last question if you don’t mind: do you have good recommendations for iOS, Mac & Windows clients for aegis? The official repo seems to just be an android app, and I make use of authy across all 4 platforms currently
I’ve looked into this before and unfortunately it doesn’t support the SMS requirement I have in my deal-breaker scenario—do you know if this has changed and can point me to the docs regarding it?
I agree it’s much worse than using a modern OTP app, but I need a way to access my OTP database when the only form of digital identity I have access to is my phone number.
Authy currently supports this scenario for me (with a load of checks, it doesn’t happen instantly), so I would require a like for like replacement
Bitwarden has a 2FA recovery code possible so you could use a unlabeled hard copy of the code. It cycles after every use so it would get you one recovery and doesn’t use SMS so it’s immune to SMS shenanigans.
That’s potentially a solution then, as I guess in order to buy a new phone I would need to have not lost my wallet too at least, so I guess I could keep those items together for equivalent recovery possibility
Okay that may be a goer, I’ll look a bit more into it, thanks!
If you self host vaultwarden you won’t have an SMS backup, but provided you need the code to login to something online, you can log into Vaultwarden from anywhere with an internet connection.
If you’re talking about being able to regain access with no local backups (even just a USB key sewn into your clothing) your going to need to think carefully about the implications if someone else gets hold of your phone, or hijacks your number. Anything you can do to recover from the scenario is a way an attacker can gain access. Attempting to secure this via SMS is going to ne woefully insecure.
That being said, there are a couple of approaches you could consider. One option is to put an encrypted backup on an sftp server or similar and remember the login and passwords, another would be to have a trusted party, say a family member or very close friend, hold the emergency codes for access to your authentication account or backup site.
Storing a backup somewhere is a reasonable approach if you are careful about how you secure it and consider if it meets your threat model. The backup doesn’t need to contain all your credentials, just enough to regain access to your actual password vault, so it doesn’t need to be updated often, unless that access changes.
I would suggest either an export from your authentication app, a copy of the emergency codes, or a text file with the relevant details. Encrypt this with gpg symmetric encryption so you don’t have to worry about a key file, and use a long, complex, but reconstructable passphrase. By this I mean a passphrase you remember how to derive, rather than trying to remember a high entropy string directly, so something like the second letter of each word of a phrase that means something to you, a series of digits that are relevant to you, maybe the digits from your first friend’s address or something similarly pseudo random, then another phrase. The result is long enough to have enough entropy to be secure, and you’ll remember how to generate it more readily than remembering the phrase itself. It needs to be strong as once an adversary has a copy of the file they jave as long as they want to decrypt it. Once encrypted, upload it to a reliable storage location that you can access with just a username and password. Now you need to memorize the storage location, username, password and decryption passphrase generator, but you can recover even to a new phone.
The second option is to generate the emergency, or backup, codes to your authentication account, or the storage you sync it to, and have someone you trust keep them, only to be revealed if you contact them and they’re sure it’s you. To be more secure, split each code into two halves and have each held by a different person.
I have similar requirements to you and honestly the best solution I could find was Microsoft Authenticator. I know Microsoft bad etc, but if you already have a Microsoft account anyway you can back up all your 2fa codes to your iCloud or Google account. If anyone knows of an open source alternative I’d be interested, but the ability to recover my accounts is more important than using something open source
This is a new one to me, but a quick look at their homepage doesn’t seem to suggest SMS support as per my deal-breaker scenario—could you point me to the docs describing that functionality?
Like many others in this thread I love Aegis, I regularly back it up to my nas and it hasn’t failed me yet, but I also selfhost Vaultwarden. Recently I’ve found myself copying a lot of my secrets over so if I don’t have my phone, I still have a way to use TOTP.
I highly recommend 1Password. It’s cross platform, including Linux, and it’s not only a great and sort l super secure password manager, but it also does 2FA codes and if you use their auto fill tool, it will also paste the 2FA code to clipboard so you can paste it in seamlessly.
Everything is full encrypted and needs a really long, unique to you, key to decrypt. So no one will be hacking this anytime soon. Even 1Password cannot open your vault.
Does anyone have a suggested alternative for authy? (Please read the whole post before responding)
I’d love to go with an open source solution as I’ve done with my password manager, but that doesn’t seem possible with one of my big requirements:
Scenario: I’ve had my phone robbed abroad and managed to buy a new one and loaded my ESIM back into it—I need to recover access to my 2 factor database via SMS so I’m able to log into my cloud storage and access my password database.
At this point I’d probably be happy to host a service myself on something like AWS and use SNS for this requirement, but I’m not sure anything like that exists ready to go. I’m not particularly interested in rolling something myself for this.
I’d be dubious of jumping from one closed source product to another, but if there’s a particularly good option I’m all ears, I’ve been otherwise happy with authy for about a decade now, but this plus the retirement of the desktop app have me looking elsewhere.
Edit: added emphasis
I use Aegis, which I periodically back up manually off phone.
(reposted from another comment mentioning aegis)
I think the suggestion here is to back up Aegis. I do something similar using Aegis + SyncThing.
I have a folder on my phone that is synced with my PC. Every so often, I will back up Aegis to that folder, and then it automatically syncs to PC.
Oh, in that case it’s not quite equivalent, because my cloud storage is protected by the two factor code stored in my Authy OTP database.
I would still need to access the OTP database before I could access the cloud storage, which is where it would be stored in this scenario.
Forget your existing cloud. Your 2FA backup doesn’t need to be protected by 2FA; just encryption and a strong/unique passphrase. Your 2FA backup can’t be used to access any account on its own, without each password. Most OSS E2EE services allow you to create a free account; many without an email. Pick 2 for redundancy, create a NEW account, and set a NEW passphrase (like your 2nd “master” password). Before you transit upload your OTP backup to both of them.
This approach is probably more secure than SMS to access 2FA, especially vs a closed source provider like Authy, and especially if your 2FA export is also encrypted with a different password. If you’re already using a password manager and unique passwords for everything, you’re already 95% more secure than everyone else, and removed the primary need for 2FA (password reuse and theft). If you’re doing everything else right, 2FA only makes you 5-10% more secure, and covers far less-likely threats (email takeover, MITM, etc). Sys admins have been raw dogging SSH and PGP keys every day without a 2nd factor, for decades.
Aegis is often recommended as an open source solution : https://github.com/beemdevelopment/Aegis
Interesting, I’ve seen this one before but it didn’t seem like it would support my deal-breaker scenario—I still can’t seem to see support for that on the readme, could you point me at some docs?
The point is you physically and locally back up the database. Put it on your computer, or a flash drive or whatever. You can set a different, longer password for backups, and I would recommend you do that. When you get your new phone, you just copy the database into it and load it into a freshly installed Aegis. You don’t even need to self host anything, there is nothing to host.
Not everything needs to be “in the cloud”. I think this event illustrates nicely why.
This is specifically a scenario where I’m starting from a single blank device because I’ve just been robbed on the other side of the planet.
Edit: for added weight, I’ve been in this exact scenario. I was able to get my ESIM reprovisioned to a new phone and recover everything within a day. I don’t want to replace authy with a solution that doesn’t cover that scenario
Well I thought this was kinda obvious what I meant, but I guess not. What you say is a requirement (sms recovery of a cloud account) is just one of many solutions to your specific problem. I’ll just list off a few solutions below that involve neither SMS (the most insecure communication method in common use today) and only optionally a cloud account. For cimplicity sake I’ll stick to Aegis, where you can create password-protected local backups you can then put wherever you want. This password needs to be very strong for obvious reasons: I would recommend a long sentence (40 characters or more) that you can just remember, like a quote from a movie/tv show/book/poem or something, including normal punctuation as a sentence for example.
Solution 0: This is more of a trivial solution I wouldn’t actually recommend. You can allow account recovery via eMail and have your eMail not use 2fa, but a long/good password so you can login from memory (see above). This is probably more secure than SMS for the recovery-case, but less secure for the everyday use case of eMail, therefore “not recommended”.
Solution 1: USB Sticks are tiny, as in the size of a USB port (slightly longer but slimmer for USB-C). If you want to have a backup “on you”, I’m sure you can find a place where it wouldn’t get robbed with the phone/wallet. A tiny pocket somewhere, a string around your ankle, make a compartment in your shoe, or just have it with your luggage at the hotel. I’m sure you get the point. You get your new phone, you plug in the USB, you install Aegis and restore the backup.
Solution 2a: Dedicated “online” storage. This can be self hosted, or a free account of any cloud provider, but the important part is that it does NOT require 2FA and you do NOT use it for anything else. You have the backup in there. It also needs a very secure password (again: long, but easy to remember, no garbled letter nonsense), but obviously not the same as the Aegis-Backup. So you now need to remember 2 long passwords. You get your new phone, you log in, get the backup and proceed as usual.
Solution 2b: If not having 2FA is not an option for the solution above, you can have a friend/family store the 2FA on his phone. To log in, you go to the login page and enter your password (which your friend doesn’t need to know), and you ask him over the phone for the current 2FA-Code, which he tells you and you can log in, download the backup and proceed as above. I assume such a high security isn’t that critical, since you have been using something involving SMS. Restore then goes as per usual.
Solution 3: Store the whole backup with a friend and when you need it he just temporarily puts it somwhere you can access, and removes it again after. Since the backup is protected by a monster of a password, and the accessibility is temporary anyway, this isn’t security critical.
Solution 4: If you absolutely must, you can find a cloud-provider for 2FA, and use it only as the “first stage”. The only 2FA code in there is the one you need to get access to your main online storage/account where you then have your real Aegis-Backup and/or other files. Obviously this service would need to allow you to login without 2FA, and the usual password rules resulting fom that apply. You can just add the 2FA of your primary service to more than 1 app or service, or if it allows for this, you can generate multiple authenticators so you can also revoke them serperately if needed.
Alright, drop the sass, if it was obvious your post wouldn’t be the length it is. Now chill, I genuinely appreciate your response
0, no go
1, also a no go, I can’t guarantee I’ll have an extra thing
2a. No 2fa, so this is a reduction in my current security
2b, this could be workable, I already self-host a number of services, but I want to be sure situational neglect (i.e. life is too busy for me to pay attention) cannot compromise this, therefore it’s gotta be a turnkey solution that I can configure to auto update, which is what I’m asking for in my comment. I need your specific solution for this, generalisms are useless here.
3: Not workable, I can’t rely on someone else being able to help in every possible scenario (and tbh I wouldn’t want to put that responsibility on someone)
4: This is a pretty good one tbh, though I guess if I’m going to pick holes, if the first stage is good enough as the gate, it diminishes the reason to have the second stage, so I’d wonder what you would suggest that could tick all the boxes for that first gate.
Edit: weird numbering formatting to combat lemmy formatting doing weird things
That’s open to interpretation. Your current solution you thought was secure, but you used a service that as it turned out had bad security practices, which you just didn’t know (arguably couldn’t know). ANY online/cloud service that you don’t host yourself has this issue with being a black box of unkown quality. Any online service you do host has to be secured by you (or you need to trust that the base setup of that tool is “sufficiently secure”), and is in essence limited by your knowledge of the tool and technology used. Also if you’re reusing any passwords, anywhere, just stopping that practice is likely more secure in practice compared to 2fa in isolation.
2fa in general isn’t just plaing “better” than not having it, security is rarely this black and white. It also depends on what is allowed to be the “second factor”, and since yours included SMS, it really wasn’t secure at all (like others have also mentioned in this thread). And it depends on the password of course. For example if you use a really secure password (30+ characters), and don’t reuse it, it will in practice be more secure than a short(ish) password and a 2nd factor that allows SMS. Generally 2 factor is used as a term for 2 categorically different athentication methods: one thing you know (password, pin) and one thing you own (phone, physical device/key, or a file works too). The problem is that SMS doesn’t require your phone. It’s incredibly easy to get the SMS without having your phone (even easier with physical proximity) or flat out faking owning your phone number (dpends on a lot of factors how easy or hard that is in practice, doesn’t require physical proximity). Basically, if someone actively targets you and/or that account secured by SMS 2fa, it isn’t overly hard, but it’s good enough at preventing giving access through a data leak for example.
So, back to the security of “solution 2a”: how would someone get access to a long password you don’t use anywhere else, that isn’t written down anywhere (or nowhere accessible), and where you essentially never need to use/access the account in the first place? Nobody would even know that whole account exists unless you specifically tell them, let alone knowing how to get in. Note that this can also be combined with the concept in solution 4, so you’re then using it to only restore a single 2fa code. So that “safety net fallback account” very rarely needs to be updated with a newer Aegis-Backup, making it even more obscure/unknown. That 2fa code then lets you access your normal account and backups, and you restore the full suite of 2fa you need.
It boils down to this: local 2fa with a backup means you need to get access to a single file to securely restore full access to everything. That file can be transmitted insecurely (due to strong cryptography and hopefully a good password not used anywhere else), but I wouldn’t store it out in the open either. On the other hand, any cloud based solution is an inherent black box. You trust them to properly do things, and you only know they didn’t once it’s too late (like Authy). It also means they are, by nature of what they do (storing account access information), a target and if the attacker is successful, you’re the collateral without having been explicitly targeted. Maybe there are sevices out there that let third parties audit their security and publish the results, but I don’t know of any and it would probably increase the price by an prohibitive amount for most people.
Okay I see what you’re saying but it’s still a downgrade from what I thought my security was, the fact authy broke that trust doesn’t mean I want to compromise what I was expecting to the level they ended up providing me
Sure, I guess the thing I’ve not made clear enough is that I accept the compromise of security by having an SMS backup in this scenario for the convenience it provides in restoration. Someone could compromise my SMS but they’d still need my password, and in Authy’s case, they would also then need to be able to sufficiently convince Twilio that I’m me before they allow access again. I understand that the last step is obviously not possible with a non-commercial solution.
Tbh you’ve kinda come up with the solution for me though, if I keep the database in it’s own cloud storage separate from everything else I could set up SMS 2FA and a unique memorable password to get a similar experience to what I have now, albeit without the extra verification when SMS is used.
Since you’ve been helpful already, one last question if you don’t mind: do you have good recommendations for iOS, Mac & Windows clients for aegis? The official repo seems to just be an android app, and I make use of authy across all 4 platforms currently
What I do is using synching to sync my files on my PC when I am at home. You could also manually back it up on a cloud drive.
Anyway I think it’s best practice to store somewhere recovery codes.
Do you carry your recovery codes with you at all times?
I guess I could do this, but it seems like a downgrade from my current situation
Bitwarden has 2FA built in, and you can host it yourself if you want.
I’ve looked into this before and unfortunately it doesn’t support the SMS requirement I have in my deal-breaker scenario—do you know if this has changed and can point me to the docs regarding it?
Oops, missed that part. Not that I know of, though SMS is a terrible way to do 2FA. It annoys me so many businesses and banks use it.
I agree it’s much worse than using a modern OTP app, but I need a way to access my OTP database when the only form of digital identity I have access to is my phone number.
Authy currently supports this scenario for me (with a load of checks, it doesn’t happen instantly), so I would require a like for like replacement
Bitwarden has a 2FA recovery code possible so you could use a unlabeled hard copy of the code. It cycles after every use so it would get you one recovery and doesn’t use SMS so it’s immune to SMS shenanigans.
That’s potentially a solution then, as I guess in order to buy a new phone I would need to have not lost my wallet too at least, so I guess I could keep those items together for equivalent recovery possibility
Okay that may be a goer, I’ll look a bit more into it, thanks!
If you self host vaultwarden you won’t have an SMS backup, but provided you need the code to login to something online, you can log into Vaultwarden from anywhere with an internet connection.
If you’re talking about being able to regain access with no local backups (even just a USB key sewn into your clothing) your going to need to think carefully about the implications if someone else gets hold of your phone, or hijacks your number. Anything you can do to recover from the scenario is a way an attacker can gain access. Attempting to secure this via SMS is going to ne woefully insecure.
That being said, there are a couple of approaches you could consider. One option is to put an encrypted backup on an sftp server or similar and remember the login and passwords, another would be to have a trusted party, say a family member or very close friend, hold the emergency codes for access to your authentication account or backup site.
Storing a backup somewhere is a reasonable approach if you are careful about how you secure it and consider if it meets your threat model. The backup doesn’t need to contain all your credentials, just enough to regain access to your actual password vault, so it doesn’t need to be updated often, unless that access changes. I would suggest either an export from your authentication app, a copy of the emergency codes, or a text file with the relevant details. Encrypt this with
gpg
symmetric encryption so you don’t have to worry about a key file, and use a long, complex, but reconstructable passphrase. By this I mean a passphrase you remember how to derive, rather than trying to remember a high entropy string directly, so something like the second letter of each word of a phrase that means something to you, a series of digits that are relevant to you, maybe the digits from your first friend’s address or something similarly pseudo random, then another phrase. The result is long enough to have enough entropy to be secure, and you’ll remember how to generate it more readily than remembering the phrase itself. It needs to be strong as once an adversary has a copy of the file they jave as long as they want to decrypt it. Once encrypted, upload it to a reliable storage location that you can access with just a username and password. Now you need to memorize the storage location, username, password and decryption passphrase generator, but you can recover even to a new phone.The second option is to generate the emergency, or backup, codes to your authentication account, or the storage you sync it to, and have someone you trust keep them, only to be revealed if you contact them and they’re sure it’s you. To be more secure, split each code into two halves and have each held by a different person.
I have similar requirements to you and honestly the best solution I could find was Microsoft Authenticator. I know Microsoft bad etc, but if you already have a Microsoft account anyway you can back up all your 2fa codes to your iCloud or Google account. If anyone knows of an open source alternative I’d be interested, but the ability to recover my accounts is more important than using something open source
2FAS
This. Superior in any way to authy.
This is a new one to me, but a quick look at their homepage doesn’t seem to suggest SMS support as per my deal-breaker scenario—could you point me to the docs describing that functionality?
Aegis. Make an encrypted backup. Store the backup safely. Done
Ente auth is new, but open and cross-plat, unlike aegis. Aegis still wins on Android but ente can import aegis encrypted backups.
Like many others in this thread I love Aegis, I regularly back it up to my nas and it hasn’t failed me yet, but I also selfhost Vaultwarden. Recently I’ve found myself copying a lot of my secrets over so if I don’t have my phone, I still have a way to use TOTP.
I highly recommend 1Password. It’s cross platform, including Linux, and it’s not only a great and sort l super secure password manager, but it also does 2FA codes and if you use their auto fill tool, it will also paste the 2FA code to clipboard so you can paste it in seamlessly.
Everything is full encrypted and needs a really long, unique to you, key to decrypt. So no one will be hacking this anytime soon. Even 1Password cannot open your vault.
I use Aegis