* Fix crash on receiving requests with missing Digest header
Return an error pointing out that Digest is missing, instead of crashing.
Fixes#15743
* Fix from review feedback
* Add more specific error message when request body digest is invalid
This may help other implementors debug their implementation.
* Relax Host parameter requirement to GET requests
The only POST requests processed by Mastodon need objects/actors (including
their host) to be explicitly mentioned in the request's body, so replaying
a legitimate request to another host should not be a security issue.
* Support Digest headers using multiple algorithms or lowercase alogirthm names
* Add support for latest HTTP Signatures spec draft
https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html
- add support for the “hs2019” signature algorithm (assumed to be equivalent
to RSA-SHA256, since we do not have a mechanism to specify the algorithm
within the key metadata yet)
- add support for (created) and (expires) pseudo-headers and related
signature parameters, when using the hs2019 signature algorithm
- adjust default “headers” parameter while being backwards-compatible with
previous implementation
- change the acceptable time window logic from 12 hours surrounding the “date”
header to accepting signatures created up to 1 hour in the future and
expiring up to 1 hour in the past (but only allowing expiration dates up to
12 hours after the creation date)
This doesn't conform with the current draft, as it doesn't permit accounting
for clock skew.
This, however, should be addressed in a next version of the draft:
https://github.com/httpwg/http-extensions/pull/1235
* Add additional signature requirements
* Rewrite signature params parsing using Parslet
* Make apparent which signature algorithm Mastodon on verification failure
Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications,
and new implementers may thus unknowingly use RSASSA-PSS.
* Add workaround for PeerTube's invalid signature header
The previous parser allowed incorrect Signature headers, such as
those produced by old versions of the `http-signature` node.js package,
and seemingly used by PeerTube.
This commit adds a workaround for that.
* Fix `signature_key_id` raising an exception
Previously, parsing failures would result in `signature_key_id` being nil,
but the parser changes made that result in an exception.
This commit changes the `signature_key_id` method to return `nil` in case
of parsing failures.
* Move extra HTTP signature helper methods to private methods
* Relax (request-target) requirement to (request-target) || digest
This lets requests from Plume work without lowering security significantly.
Instead of returning a signature verification error, pretend there
was no signature (i.e., this does not allow access to resources that
need a valid signature), so public resources can still be fetched
Fix#13011
* Move signature verification stoplight to the requests themselves
This avoids blocking messages from known keys for 5 minutes when only one fails…
* Put the stoplight on the actual client IP, not a potential reverse proxy
* Refactor signature verification a bit
* Rescue signature verification if recorded public key is invalid
Fixes#8822
* Always re-fetch AP signing key when HTTP Signature verification fails
But when the account is not marked as stale, avoid fetching collections and
media, and avoid webfinger round-trip.
* Apply stoplight to key/account update as well as initial key retrieval
* Downcase signed_headers string before building the signed string
The HTTP Signatures draft does not mandate the “headers” field to be downcased,
but mandates the header field names to be downcased in the signed string, which
means that prior to this patch, Mastodon could fail to process signatures from
some compliant clients. It also means that it would not actually check the
Digest of non-compliant clients that wouldn't use a lowercased Digest field
name.
Thankfully, I don't know of any such client.
* Revert "Remove dead code (#8919)"
This reverts commit a00ce8c92c.
* Restore time window checking, change it to 12 hours
By checking the Date header, we can prevent replaying old vulnerable
signatures. The focus is to prevent replaying old vulnerable requests
from software that has been fixed in the meantime, so a somewhat long
window should be fine and accounts for timezone misconfiguration.
* Escape users' URLs when formatting them
Fixes possible HTML injection
* Escape all string interpolations in Formatter class
Slightly improve performance by reducing class allocations
from repeated Formatter#encode calls
* Fix code style issues
* Downcase signed_headers string before building the signed string
The HTTP Signatures draft does not mandate the “headers” field to be downcased,
but mandates the header field names to be downcased in the signed string, which
means that prior to this patch, Mastodon could fail to process signatures from
some compliant clients. It also means that it would not actually check the
Digest of non-compliant clients that wouldn't use a lowercased Digest field
name.
Thankfully, I don't know of any such client.
* Revert "Remove dead code (#8919)"
This reverts commit a00ce8c92c.
* Restore time window checking, change it to 12 hours
By checking the Date header, we can prevent replaying old vulnerable
signatures. The focus is to prevent replaying old vulnerable requests
from software that has been fixed in the meantime, so a somewhat long
window should be fine and accounts for timezone misconfiguration.
* Escape users' URLs when formatting them
Fixes possible HTML injection
* Escape all string interpolations in Formatter class
Slightly improve performance by reducing class allocations
from repeated Formatter#encode calls
* Fix code style issues
`@signature_verification_failure_reason` is used in most places but`@signed_verification_failure_reason` appears in two places. Likely those errors are not returned.
Additionally, ActivityPub::FetchRemoteStatusService no longer parses
activities.
OStatus::Activity::Creation no longer delegates to ActivityPub because
the provided ActivityPub representations are not signed while OStatus
representations are.
* Return sensible HTTP status for ActivityPub inbox processing
* Return sensible HTTP status for salmon slap processing
* Return additional information to debug signature verification failures
If the signature could not be verified and the webfinger of the account
was last retrieved longer than the cache period, try re-resolving the
account and then attempting to verify the signature again
- Tries to avoid performing HTTP request if the keyId is an actor URI
- Likewise if the URI is a fragment URI on top of actor URI
- Resolves public key, returns owner if the owner links back to the key
* Add Request class with HTTP signature generator
Spec: https://tools.ietf.org/html/draft-cavage-http-signatures-06
* Add HTTP signature verification concern
* Add test for SignatureVerification concern
* Add basic test for Request class
* Make PuSH subscribe/unsubscribe requests use new Request class
Accidentally fix lease_seconds not being set and sent properly, and
change the new minimum subscription duration to 1 day
* Make all PuSH workers use new Request class
* Make Salmon sender use new Request class
* Make FetchLinkService use new Request class
* Make FetchAtomService use the new Request class
* Make Remotable use the new Request class
* Make ResolveRemoteAccountService use the new Request class
* Add more tests
* Allow +-30 seconds window for signed request to remain valid
* Disable time window validation for signed requests, restore 7 days
as PuSH subscription duration (which was previous default due to a bug)
Claire