git ssb

1
var I = require('./valid')
2
3
/*
4
uxer (someone who observes an invite, but not directly involved):
5
6
if we see
7
  someone post an invite I
8
  someone else post a confirmation C that I has been accepted A
9
  // OOO that A
10
  emded that A inside a C(A)
11
  match valid I->A's and interpret them like follows.
12
13
  we only care about confirmations if it's of an invite we follow,
14
  and it hasn't been confirmed already.
15
16
{
17
  invited: {
18
    <alice>: { <bob>: true, ...}
19
  }
20
21
  invites: { <invites>, ...}
22
  accepts: { <accepts>, ...}
23
24
}
25
26
---
27
28
pub
29
30
  someone connects, using key from an open invite I
31
  they request that invite I (by it's id)
32
  they send a message accepting A the invite.
33
  the pub then posts confirmation (I,A)
34
35
*/
36
37
exports.name = 'invites'
38
39
exports.version = '1.0.0'
40
exports.manifest = {
41
42
}
43
44
// KNOWN BUG: it's possible to accept an invite more than once,
45
// but peers will ignore subsequent acceptances. it's possible
46
// that this could create confusion in certain situations.
47
// (but you'd get a feed that some peers thought was invited by Alice
48
// other peers would think a different feed accepted that invite)
49
// I guess the answer is to let alice reject the second invite?)
50
// that would be easier to do if this was a levelreduce? (keys: reduce, instead of a single reduce?)
51
exports.init = function (sbot, config) {
52
53
  var index = sbot._flumeUse('invites', Reduce(1, function (acc, data) {
54
    if(!acc) acc = {invited: {}, invites:{}, accepts: {}}
55
56
    var msg = data.value
57
    var invite, accept
58
    if(msg.content.type === 'invite') {
59
      invite = msg
60
      accept = acc.accepts[data.key]
61
    }
62
    else if(msg.content.type === 'invite/accept') {
63
      accept = msg
64
      invite = acc.invites[accept.content.receipt]
65
    }
66
    else if(msg.content.type === 'invite/confirm') {
67
      accept = msg.content.embed
68
      invite = acc.invites[accept.content.receipt]
69
    }
70
    if(invite && accept) {
71
      if(invite === true)
72
        return acc
73
      try {
74
        I.validateAccept(accept, invite)
75
        //delete matched invites, but _only_ if they are valid.
76
        delete acc.accepts[accept.receipt]
77
        //but remember that this invite has been processed.
78
        acc.invites[accept.receipt] = true
79
      } catch (err) {
80
        return acc //? or store something?
81
      }
82
    }
83
    else if(invite)
84
      acc.invites[data.key] = invite
85
    else if(accept)
86
      acc.accepts[accept.receipt] = accept
87
88
    return acc
89
90
  }))
91
92
  sbot.auth.hook(function (fn, args) {
93
    var id = args[0], cb = args[1]
94
    index.get(function (err, v) {
95
      if(err) return cb(err)
96
      for(var k in v.invites)
97
        if(v.invites[k].invite === id)
98
          return cb(null, {
99
            allow: ['invite.getInvite', 'invites.accept'],
100
            deny: null
101
          })
102
    })
103
  })
104
105
  invites.getInvite = function (invite_id, cb) {
106
    var self = this
107
    invites.get(function (err, v) {
108
      var invite = v.invites[invite_id]
109
      if(err) return cb(err)
110
      if(!invite)
111
        cb(code(
112
          new Error('unknown invite:'+invite_id),
113
          'unknown-invite'
114
        ))
115
      else if(invite === true)
116
        //TODO just retrive all confirmations we know about
117
        //via links.
118
        cb(code(
119
          new Error('invite already used:'+invite_id),
120
          'invite-already-used'
121
        ))
122
      //only allow the guest to request their own invite.
123
      else if(self.id !== invite.content.invite)
124
        cb(code(
125
          new Error('invite did not match client id'),
126
          'invite-mismatch'
127
        ))
128
      else
129
        cb(null, v.invites[invite_id])
130
    })
131
  }
132
133
  var accepted = {}
134
135
  invites.accept = function (accept, cb) {
136
    //check if the invite in question hasn't already been accepted.
137
    invites.get(function (err, v) {
138
      var invite_id = accept.content.receipt
139
      var invite = v.invites[invite_id]
140
      if(invite === true || accepted[invite_id])
141
        //TODO: this should return the confirmation, not an error.
142
        return cb(code(
143
          new Error('invite already used:'+invite_id),
144
          'invite-already-used'
145
        ))
146
147
      try {
148
        I.validateAccept(accept, invite)
149
      } catch (err) {
150
        return cb(err)
151
      }
152
      //there is a little race condition here
153
      accepted[invite_id] = true
154
      sbot.publish({type: 'invite/confirm', embed: accept}, function (err, msg) {
155
        delete accepted[invite_id]
156
        cb(err, msg)
157
      })
158
    })
159
  }
160
161
  return invites
162
163
}
164
165
166