git ssb

1
var ssbKeys = require('ssb-keys')
2
var timestamp = require('monotonic-timestamp')
3
var isRef = require('ssb-ref')
4
var isHash = isRef.isHash
5
var isFeedId = isRef.isFeedId
6
7
var encode = exports.encode = function (obj) {
8
  return JSON.stringify(obj, null, 2)
9
}
10
11
function isString (s) {
12
  return 'string' === typeof s
13
}
14
15
function isInteger (n) {
16
  return ~~n === n
17
}
18
19
function isObject (o) {
20
  return o && 'object' === typeof o
21
}
22
23
function clone (obj) {
24
  var o = {}
25
  for(var k in obj) o[k] = obj[k];
26
  return o
27
}
28
29
function isEncrypted (str) {
30
  return isString(str) && /^[0-9A-Za-z\/+]+={0,2}\.box/.test(str)
31
}
32
33
exports.BatchQueue = function BatchQueue (db) {
34
35
  var batch = [], writing = false
36
37
  function drain () {
38
    writing = true
39
    var _batch = batch
40
    batch = []
41
42
    db.batch(_batch, function () {
43
      writing = false
44
      write.size = batch.length
45
      if(batch.length) drain()
46
      _batch.forEach(function (op) {
47
        op.cb(null, {key:op.key, value: op.value})
48
      })
49
    })
50
  }
51
52
  function write (op) {
53
    batch.push(op)
54
    write.size = batch.length
55
    if(!writing) drain()
56
  }
57
58
  write.size = 0
59
60
  return write
61
}
62
63
exports.create = function (keys, type, content, prev, prev_key) {
64
65
  //this noise is to handle things calling this with legacy api.
66
  if(isString(type) && (Buffer.isBuffer(content) || isString(content)))
67
    content = {type: type, value: content}
68
  if(isObject(content))
69
    content.type = content.type || type
70
  //noise end
71
72
  prev_key = !prev_key && prev ? ('%'+ssbKeys.hash(encode(prev))) : prev_key || null
73
74
  return ssbKeys.signObj(keys, {
75
    previous: prev_key,
76
    author: keys.id,
77
    sequence: prev ? prev.sequence + 1 : 1,
78
    timestamp: timestamp(),
79
    hash: 'sha256',
80
    content: content,
81
  })
82
}
83
84
var isInvalidContent = exports.isInvalidContent = function (content) {
85
  if(!isEncrypted(content)) {
86
87
    type = content.type
88
89
    if (!(isString(type) && type.length <= 52 && type.length >= 3)) {
90
      return new Error('type must be a string' +
91
        '3 <= type.length < 52, was:' + type
92
      )
93
    }
94
  }
95
  return false
96
}
97
98
exports.isInvalidShape = function (msg) {
99
  if(
100
    !isObject(msg) ||
101
    !isInteger(msg.sequence) ||
102
    !isFeedId(msg.author) ||
103
    !(isObject(msg.content) || isEncrypted(msg.content))
104
  )
105
    return new Error('message has invalid properties')
106
107
  //allow encrypted messages, where content is a base64 string.
108
109
  var asJson = encode(msg)
110
  if (asJson.length > 8192) // 8kb
111
    return new Error( 'encoded message must not be larger than 8192 bytes')
112
113
  return isInvalidContent(msg.content)
114
}
115
116
exports.isInvalid = function validateSync (pub, msg, previous) {
117
  // :TODO: is there a faster way to measure the size of this message?
118
119
  var key = previous.key
120
  var prev = previous.value
121
122
  if(prev) {
123
    if(msg.previous !== key)
124
      return new Error(
125
          'expected previous: '
126
        + key
127
        + 'but found:' + msg.previous
128
      )
129
130
    if(msg.sequence !== prev.sequence + 1
131
     || msg.timestamp <= prev.timestamp)
132
        return new Error('out of order')
133
  }
134
  else {
135
    if(!(msg.previous == null
136
      && msg.sequence === 1 && msg.timestamp > 0))
137
        return new Error('expected initial message')
138
  }
139
140
  if(msg.author !== pub) {
141
142
    return new Error(
143
        'expected different author:'
144
      + hash(pub.public || pub).toString('base64')
145
      + 'but found:' + msg.author.toString('base64')
146
    )
147
  }
148
149
  if(!ssbKeys.verifyObj(pub, msg))
150
    return new Error('signature was invalid')
151
152
  return false
153
}
154
155