187 lines
5.6 KiB
Markdown
187 lines
5.6 KiB
Markdown
# ActivityPub federation in Mitra
|
|
|
|
Mitra largely follows the [ActivityPub](https://www.w3.org/TR/activitypub/) server-to-server specification but it makes uses of some non-standard extensions, some of which are required for interacting with it.
|
|
|
|
The following activities are supported:
|
|
|
|
- Accept(Follow)
|
|
- Reject(Follow)
|
|
- Undo(Follow)
|
|
- Create(Note)
|
|
- Delete(Note)
|
|
- Like(Note)
|
|
- Undo(Like)
|
|
- Announce(Note)
|
|
- Undo(Announce)
|
|
- Update(Note)
|
|
- Follow(Person)
|
|
- Update(Person)
|
|
- Move(Person)
|
|
- Delete(Person)
|
|
- Add(Person)
|
|
- Remove(Person)
|
|
|
|
And these additional standards:
|
|
|
|
- [Http Signatures](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures)
|
|
- [NodeInfo](https://nodeinfo.diaspora.software/)
|
|
- [WebFinger](https://webfinger.net/)
|
|
|
|
Activities are implemented in way that is compatible with Pleroma, Mastodon and other popular ActivityPub servers.
|
|
|
|
Supported FEPs:
|
|
|
|
- [FEP-f1d5: NodeInfo in Fediverse Software](https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-f1d5.md)
|
|
- [FEP-e232: Object Links](https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-e232.md)
|
|
- [FEP-8b32: Object Integrity Proofs](https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-8b32.md)
|
|
|
|
## Object integrity proofs
|
|
|
|
All outgoing activities are signed with actor's key in accordance with [FEP-8b32](https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-8b32.md) document.
|
|
|
|
Example:
|
|
|
|
```json
|
|
{
|
|
"@context": [
|
|
"https://www.w3.org/ns/activitystreams",
|
|
"https://w3id.org/security/data-integrity/v1"
|
|
],
|
|
"actor": "https://example.com/users/alice",
|
|
"cc": [],
|
|
"id": "https://example.com/objects/0185f5f8-10b5-1b69-f45e-25f06792f411",
|
|
"object": "https://example.net/users/bob/posts/141892712081205472",
|
|
"proof": {
|
|
"created": "2023-01-28T01:22:40.183273595Z",
|
|
"proofPurpose": "assertionMethod",
|
|
"proofValue": "z5djAdMSrV...",
|
|
"type": "MitraJcsRsaSignature2022",
|
|
"verificationMethod": "https://example.com/users/alice#main-key"
|
|
},
|
|
"to": [
|
|
"https://example.net/users/bob",
|
|
"https://www.w3.org/ns/activitystreams#Public"
|
|
],
|
|
"type":"Like"
|
|
}
|
|
```
|
|
|
|
### Supported proof suites
|
|
|
|
#### MitraJcsRsaSignature2022
|
|
|
|
Canonicalization algorithm: JCS
|
|
Hashing algorithm: SHA-256
|
|
Signature algorithm: RSASSA-PKCS1-v1_5
|
|
|
|
#### MitraJcsEip191Signature2022
|
|
|
|
Canonicalization algorithm: JCS
|
|
Hashing algorithm: KECCAK-256 (EIP-191)
|
|
Signature algorithm: ECDSA (EIP-191)
|
|
|
|
#### MitraJcsEd25519Signature2022
|
|
|
|
Canonicalization algorithm: JCS
|
|
Hashing algorithm: BLAKE2b-512
|
|
Signature algorithm: EdDSA
|
|
|
|
## Custom emojis
|
|
|
|
Custom emojis are implemented as described in Mastodon documentation: https://docs.joinmastodon.org/spec/activitypub/#emoji.
|
|
|
|
## Profile extensions
|
|
|
|
### Cryptocurrency addresses
|
|
|
|
Cryptocurrency addresses are represented as `PropertyValue` attachments where `name` attribute is a currency symbol prefixed with `$`:
|
|
|
|
```json
|
|
{
|
|
"name": "$XMR",
|
|
"type": "PropertyValue",
|
|
"value": "8Ahza5RM4JQgtdqvpcF1U628NN5Q87eryXQad3Fy581YWTZU8o3EMbtScuioQZSkyNNEEE1Lkj2cSbG4VnVYCW5L1N4os5p"
|
|
}
|
|
```
|
|
|
|
### Identity proofs
|
|
|
|
Identity proofs are represented as attachments of `IdentityProof` type:
|
|
|
|
```json
|
|
{
|
|
"name": "<did>",
|
|
"type": "IdentityProof",
|
|
"signatureAlgorithm": "<proof-type>",
|
|
"signatureValue": "<proof>"
|
|
}
|
|
```
|
|
|
|
Supported proof types:
|
|
|
|
- EIP-191 (Ethereum personal signatures)
|
|
- [Minisign](https://jedisct1.github.io/minisign/)
|
|
|
|
[FEP-c390](https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-c390.md) identity proofs are not supported yet.
|
|
|
|
## Account migrations
|
|
|
|
After registering an account its owner can upload the list of followers and start the migration process. The server then sends `Move` activity to each follower:
|
|
|
|
```json
|
|
{
|
|
"@context": [
|
|
"https://www.w3.org/ns/activitystreams"
|
|
],
|
|
"actor": "https://server2.com/users/alice",
|
|
"id": "https://server2.com/activities/00000000-0000-0000-0000-000000000001",
|
|
"object": "https://server1.com/users/alice",
|
|
"target": "https://server2.com/users/alice",
|
|
"to": [
|
|
"https://example.com/users/bob"
|
|
],
|
|
"type": "Move"
|
|
}
|
|
```
|
|
|
|
Where `object` is an ID of old account and `target` is an ID of new account. Actors identified by `object` and `target` properties must have at least one identity key in common to be considered aliases. Upon receipt of such activity, actors that follow `object` should un-follow it and follow `target` instead.
|
|
|
|
## Subscription events
|
|
|
|
Local actor profiles have `subscribers` property which points to the collection of actor's paid subscribers.
|
|
|
|
The `Add` activity is used to notify the subscriber about successful subscription payment. Upon receipt of this activity, the receiving server should add specified `object` to actors's `subscribers` collection (specified in `target` property):
|
|
|
|
```json
|
|
{
|
|
"@context": [
|
|
"https://www.w3.org/ns/activitystreams"
|
|
],
|
|
"actor": "https://example.com/users/alice",
|
|
"id": "https://example.com/activities/00000000-0000-0000-0000-000000000001",
|
|
"object": "https://example.com/users/bob",
|
|
"target": "https://example.com/users/alice/collections/subscribers",
|
|
"to": [
|
|
"https://example.com/users/bob"
|
|
],
|
|
"type": "Add"
|
|
}
|
|
```
|
|
|
|
The `Remove` activity is used to notify the subscriber about expired subscription. Upon receipt of this activity, the receiving server should remove specified `object` from actors's `subscribers` collection (specified in `target` property):
|
|
|
|
```json
|
|
{
|
|
"@context": [
|
|
"https://www.w3.org/ns/activitystreams"
|
|
],
|
|
"actor": "https://example.com/users/alice",
|
|
"id": "https://example.com/activities/00000000-0000-0000-0000-000000000002",
|
|
"object": "https://example.com/users/bob",
|
|
"target": "https://example.com/users/alice/collections/subscribers",
|
|
"to": [
|
|
"https://example.com/users/bob"
|
|
],
|
|
"type": "Remove"
|
|
}
|
|
```
|