forked from hashicorp/vault
-
Notifications
You must be signed in to change notification settings - Fork 2
/
acl.go
369 lines (322 loc) · 10.5 KB
/
acl.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
package vault
import (
"reflect"
"strings"
"github.com/armon/go-radix"
"github.com/hashicorp/errwrap"
"github.com/hashicorp/vault/helper/strutil"
"github.com/hashicorp/vault/logical"
)
// ACL is used to wrap a set of policies to provide
// an efficient interface for access control.
type ACL struct {
// exactRules contains the path policies that are exact
exactRules *radix.Tree
// globRules contains the path policies that glob
globRules *radix.Tree
// root is enabled if the "root" named policy is present.
root bool
}
// New is used to construct a policy based ACL from a set of policies.
func NewACL(policies []*Policy) (*ACL, error) {
// Initialize
a := &ACL{
exactRules: radix.New(),
globRules: radix.New(),
root: false,
}
// Inject each policy
for _, policy := range policies {
// Ignore a nil policy object
if policy == nil {
continue
}
// Check if this is root
if policy.Name == "root" {
a.root = true
}
for _, pc := range policy.Paths {
// Check which tree to use
tree := a.exactRules
if pc.Glob {
tree = a.globRules
}
// Check for an existing policy
raw, ok := tree.Get(pc.Prefix)
if !ok {
clonedPerms, err := pc.Permissions.Clone()
if err != nil {
return nil, errwrap.Wrapf("error cloning ACL permissions: {{err}}", err)
}
tree.Insert(pc.Prefix, clonedPerms)
continue
}
// these are the ones already in the tree
existingPerms := raw.(*Permissions)
switch {
case existingPerms.CapabilitiesBitmap&DenyCapabilityInt > 0:
// If we are explicitly denied in the existing capability set,
// don't save anything else
continue
case pc.Permissions.CapabilitiesBitmap&DenyCapabilityInt > 0:
// If this new policy explicitly denies, only save the deny value
existingPerms.CapabilitiesBitmap = DenyCapabilityInt
existingPerms.AllowedParameters = nil
existingPerms.DeniedParameters = nil
goto INSERT
default:
// Insert the capabilities in this new policy into the existing
// value
existingPerms.CapabilitiesBitmap = existingPerms.CapabilitiesBitmap | pc.Permissions.CapabilitiesBitmap
}
// Note: In these stanzas, we're preferring minimum lifetimes. So
// we take the lesser of two specified max values, or we take the
// lesser of two specified min values, the idea being, allowing
// token lifetime to be minimum possible.
//
// If we have an existing max, and we either don't have a current
// max, or the current is greater than the previous, use the
// existing.
if pc.Permissions.MaxWrappingTTL > 0 &&
(existingPerms.MaxWrappingTTL == 0 ||
pc.Permissions.MaxWrappingTTL < existingPerms.MaxWrappingTTL) {
existingPerms.MaxWrappingTTL = pc.Permissions.MaxWrappingTTL
}
// If we have an existing min, and we either don't have a current
// min, or the current is greater than the previous, use the
// existing
if pc.Permissions.MinWrappingTTL > 0 &&
(existingPerms.MinWrappingTTL == 0 ||
pc.Permissions.MinWrappingTTL < existingPerms.MinWrappingTTL) {
existingPerms.MinWrappingTTL = pc.Permissions.MinWrappingTTL
}
if len(pc.Permissions.AllowedParameters) > 0 {
if existingPerms.AllowedParameters == nil {
existingPerms.AllowedParameters = pc.Permissions.AllowedParameters
} else {
for key, value := range pc.Permissions.AllowedParameters {
pcValue, ok := existingPerms.AllowedParameters[key]
// If an empty array exist it should overwrite any other
// value.
if len(value) == 0 || (ok && len(pcValue) == 0) {
existingPerms.AllowedParameters[key] = []interface{}{}
} else {
// Merge the two maps, appending values on key conflict.
existingPerms.AllowedParameters[key] = append(value, existingPerms.AllowedParameters[key]...)
}
}
}
}
if len(pc.Permissions.DeniedParameters) > 0 {
if existingPerms.DeniedParameters == nil {
existingPerms.DeniedParameters = pc.Permissions.DeniedParameters
} else {
for key, value := range pc.Permissions.DeniedParameters {
pcValue, ok := existingPerms.DeniedParameters[key]
// If an empty array exist it should overwrite any other
// value.
if len(value) == 0 || (ok && len(pcValue) == 0) {
existingPerms.DeniedParameters[key] = []interface{}{}
} else {
// Merge the two maps, appending values on key conflict.
existingPerms.DeniedParameters[key] = append(value, existingPerms.DeniedParameters[key]...)
}
}
}
}
INSERT:
tree.Insert(pc.Prefix, existingPerms)
}
}
return a, nil
}
func (a *ACL) Capabilities(path string) (pathCapabilities []string) {
// Fast-path root
if a.root {
return []string{RootCapability}
}
// Find an exact matching rule, look for glob if no match
var capabilities uint32
raw, ok := a.exactRules.Get(path)
if ok {
perm := raw.(*Permissions)
capabilities = perm.CapabilitiesBitmap
goto CHECK
}
// Find a glob rule, default deny if no match
_, raw, ok = a.globRules.LongestPrefix(path)
if !ok {
return []string{DenyCapability}
} else {
perm := raw.(*Permissions)
capabilities = perm.CapabilitiesBitmap
}
CHECK:
if capabilities&SudoCapabilityInt > 0 {
pathCapabilities = append(pathCapabilities, SudoCapability)
}
if capabilities&ReadCapabilityInt > 0 {
pathCapabilities = append(pathCapabilities, ReadCapability)
}
if capabilities&ListCapabilityInt > 0 {
pathCapabilities = append(pathCapabilities, ListCapability)
}
if capabilities&UpdateCapabilityInt > 0 {
pathCapabilities = append(pathCapabilities, UpdateCapability)
}
if capabilities&DeleteCapabilityInt > 0 {
pathCapabilities = append(pathCapabilities, DeleteCapability)
}
if capabilities&CreateCapabilityInt > 0 {
pathCapabilities = append(pathCapabilities, CreateCapability)
}
// If "deny" is explicitly set or if the path has no capabilities at all,
// set the path capabilities to "deny"
if capabilities&DenyCapabilityInt > 0 || len(pathCapabilities) == 0 {
pathCapabilities = []string{DenyCapability}
}
return
}
// AllowOperation is used to check if the given operation is permitted. The
// first bool indicates if an op is allowed, the second whether sudo priviliges
// exist for that op and path.
func (a *ACL) AllowOperation(req *logical.Request) (bool, bool) {
// Fast-path root
if a.root {
return true, true
}
op := req.Operation
path := req.Path
// Help is always allowed
if op == logical.HelpOperation {
return true, false
}
var permissions *Permissions
// Find an exact matching rule, look for glob if no match
var capabilities uint32
raw, ok := a.exactRules.Get(path)
if ok {
permissions = raw.(*Permissions)
capabilities = permissions.CapabilitiesBitmap
goto CHECK
}
// Find a glob rule, default deny if no match
_, raw, ok = a.globRules.LongestPrefix(path)
if !ok {
return false, false
} else {
permissions = raw.(*Permissions)
capabilities = permissions.CapabilitiesBitmap
}
CHECK:
// Check if the minimum permissions are met
// If "deny" has been explicitly set, only deny will be in the map, so we
// only need to check for the existence of other values
sudo := capabilities&SudoCapabilityInt > 0
operationAllowed := false
switch op {
case logical.ReadOperation:
operationAllowed = capabilities&ReadCapabilityInt > 0
case logical.ListOperation:
operationAllowed = capabilities&ListCapabilityInt > 0
case logical.UpdateOperation:
operationAllowed = capabilities&UpdateCapabilityInt > 0
case logical.DeleteOperation:
operationAllowed = capabilities&DeleteCapabilityInt > 0
case logical.CreateOperation:
operationAllowed = capabilities&CreateCapabilityInt > 0
// These three re-use UpdateCapabilityInt since that's the most appropriate
// capability/operation mapping
case logical.RevokeOperation, logical.RenewOperation, logical.RollbackOperation:
operationAllowed = capabilities&UpdateCapabilityInt > 0
default:
return false, false
}
if !operationAllowed {
return false, sudo
}
if permissions.MaxWrappingTTL > 0 {
if req.WrapInfo == nil || req.WrapInfo.TTL > permissions.MaxWrappingTTL {
return false, sudo
}
}
if permissions.MinWrappingTTL > 0 {
if req.WrapInfo == nil || req.WrapInfo.TTL < permissions.MinWrappingTTL {
return false, sudo
}
}
// This situation can happen because of merging, even though in a single
// path statement we check on ingress
if permissions.MinWrappingTTL != 0 &&
permissions.MaxWrappingTTL != 0 &&
permissions.MaxWrappingTTL < permissions.MinWrappingTTL {
return false, sudo
}
// Only check parameter permissions for operations that can modify
// parameters.
if op == logical.UpdateOperation || op == logical.CreateOperation {
// If there are no data fields, allow
if len(req.Data) == 0 {
return true, sudo
}
if len(permissions.DeniedParameters) == 0 {
goto ALLOWED_PARAMETERS
}
// Check if all parameters have been denied
if _, ok := permissions.DeniedParameters["*"]; ok {
return false, sudo
}
for parameter, value := range req.Data {
// Check if parameter has been explictly denied
if valueSlice, ok := permissions.DeniedParameters[strings.ToLower(parameter)]; ok {
// If the value exists in denied values slice, deny
if valueInParameterList(value, valueSlice) {
return false, sudo
}
}
}
ALLOWED_PARAMETERS:
// If we don't have any allowed parameters set, allow
if len(permissions.AllowedParameters) == 0 {
return true, sudo
}
_, allowedAll := permissions.AllowedParameters["*"]
if len(permissions.AllowedParameters) == 1 && allowedAll {
return true, sudo
}
for parameter, value := range req.Data {
valueSlice, ok := permissions.AllowedParameters[strings.ToLower(parameter)]
// Requested parameter is not in allowed list
if !ok && !allowedAll {
return false, sudo
}
// If the value doesn't exists in the allowed values slice,
// deny
if ok && !valueInParameterList(value, valueSlice) {
return false, sudo
}
}
}
return true, sudo
}
func valueInParameterList(v interface{}, list []interface{}) bool {
// Empty list is equivalent to the item always existing in the list
if len(list) == 0 {
return true
}
return valueInSlice(v, list)
}
func valueInSlice(v interface{}, list []interface{}) bool {
for _, el := range list {
if reflect.TypeOf(el).String() == "string" && reflect.TypeOf(v).String() == "string" {
item := el.(string)
val := v.(string)
if strutil.GlobbedStringsMatch(item, val) {
return true
}
} else if reflect.DeepEqual(el, v) {
return true
}
}
return false
}