forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 3
/
config.go
295 lines (251 loc) · 9.92 KB
/
config.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
/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package encryptionconfig
import (
"crypto/aes"
"crypto/cipher"
"encoding/base64"
"fmt"
"io"
"io/ioutil"
"os"
yaml "github.com/ghodss/yaml"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apiserver/pkg/storage/value"
aestransformer "k8s.io/apiserver/pkg/storage/value/encrypt/aes"
"k8s.io/apiserver/pkg/storage/value/encrypt/envelope"
"k8s.io/apiserver/pkg/storage/value/encrypt/identity"
"k8s.io/apiserver/pkg/storage/value/encrypt/secretbox"
)
const (
aesCBCTransformerPrefixV1 = "k8s:enc:aescbc:v1:"
aesGCMTransformerPrefixV1 = "k8s:enc:aesgcm:v1:"
secretboxTransformerPrefixV1 = "k8s:enc:secretbox:v1:"
kmsTransformerPrefixV1 = "k8s:enc:kms:v1:"
)
// GetTransformerOverrides returns the transformer overrides by reading and parsing the encryption provider configuration file
func GetTransformerOverrides(filepath string) (map[schema.GroupResource]value.Transformer, error) {
f, err := os.Open(filepath)
if err != nil {
return nil, fmt.Errorf("error opening encryption provider configuration file %q: %v", filepath, err)
}
defer f.Close()
result, err := ParseEncryptionConfiguration(f)
if err != nil {
return nil, fmt.Errorf("error while parsing encryption provider configuration file %q: %v", filepath, err)
}
return result, nil
}
// ParseEncryptionConfiguration parses configuration data and returns the transformer overrides
func ParseEncryptionConfiguration(f io.Reader) (map[schema.GroupResource]value.Transformer, error) {
configFileContents, err := ioutil.ReadAll(f)
if err != nil {
return nil, fmt.Errorf("could not read contents: %v", err)
}
var config EncryptionConfig
err = yaml.Unmarshal(configFileContents, &config)
if err != nil {
return nil, fmt.Errorf("error while parsing file: %v", err)
}
if config.Kind == "" {
return nil, fmt.Errorf("invalid configuration file, missing Kind")
}
if config.Kind != "EncryptionConfig" {
return nil, fmt.Errorf("invalid configuration kind %q provided", config.Kind)
}
// TODO config.APIVersion is unchecked
resourceToPrefixTransformer := map[schema.GroupResource][]value.PrefixTransformer{}
// For each entry in the configuration
for _, resourceConfig := range config.Resources {
transformers, err := GetPrefixTransformers(&resourceConfig)
if err != nil {
return nil, err
}
// For each resource, create a list of providers to use
for _, resource := range resourceConfig.Resources {
gr := schema.ParseGroupResource(resource)
resourceToPrefixTransformer[gr] = append(
resourceToPrefixTransformer[gr], transformers...)
}
}
result := map[schema.GroupResource]value.Transformer{}
for gr, transList := range resourceToPrefixTransformer {
result[gr] = value.NewMutableTransformer(value.NewPrefixTransformers(fmt.Errorf("no matching prefix found"), transList...))
}
return result, nil
}
// GetPrefixTransformers constructs and returns the appropriate prefix transformers for the passed resource using its configuration
func GetPrefixTransformers(config *ResourceConfig) ([]value.PrefixTransformer, error) {
var result []value.PrefixTransformer
for _, provider := range config.Providers {
found := false
var transformer value.PrefixTransformer
var err error
if provider.AESGCM != nil {
transformer, err = GetAESPrefixTransformer(provider.AESGCM, aestransformer.NewGCMTransformer, aesGCMTransformerPrefixV1)
if err != nil {
return result, err
}
found = true
}
if provider.AESCBC != nil {
if found == true {
return result, fmt.Errorf("more than one provider specified in a single element, should split into different list elements")
}
transformer, err = GetAESPrefixTransformer(provider.AESCBC, aestransformer.NewCBCTransformer, aesCBCTransformerPrefixV1)
found = true
}
if provider.Secretbox != nil {
if found == true {
return result, fmt.Errorf("more than one provider specified in a single element, should split into different list elements")
}
transformer, err = GetSecretboxPrefixTransformer(provider.Secretbox)
found = true
}
if provider.Identity != nil {
if found == true {
return result, fmt.Errorf("more than one provider specified in a single element, should split into different list elements")
}
transformer = value.PrefixTransformer{
Transformer: identity.NewEncryptCheckTransformer(),
Prefix: []byte{},
}
found = true
}
if provider.KMS != nil {
if found == true {
return nil, fmt.Errorf("more than one provider specified in a single element, should split into different list elements")
}
f, err := os.Open(provider.KMS.ConfigFile)
if err != nil {
return nil, fmt.Errorf("error opening KMS provider configuration file %q: %v", provider.KMS.ConfigFile, err)
}
defer f.Close()
envelopeService, pluginFound, err := KMSPluginRegistry.getPlugin(provider.KMS.Name, f)
if err != nil {
return nil, fmt.Errorf("could not configure KMS plugin %q, %v", provider.KMS.Name, err)
}
if pluginFound == false {
return nil, fmt.Errorf("KMS plugin %q not found", provider.KMS.Name)
}
transformer, err = getEnvelopePrefixTransformer(provider.KMS, envelopeService, kmsTransformerPrefixV1)
found = true
}
if err != nil {
return result, err
}
result = append(result, transformer)
if found == false {
return result, fmt.Errorf("invalid provider configuration: at least one provider must be specified")
}
}
return result, nil
}
// BlockTransformerFunc takes an AES cipher block and returns a value transformer.
type BlockTransformerFunc func(cipher.Block) value.Transformer
// GetAESPrefixTransformer returns a prefix transformer from the provided configuration.
// Returns an AES transformer based on the provided prefix and block transformer.
func GetAESPrefixTransformer(config *AESConfig, fn BlockTransformerFunc, prefix string) (value.PrefixTransformer, error) {
var result value.PrefixTransformer
if len(config.Keys) == 0 {
return result, fmt.Errorf("aes provider has no valid keys")
}
for _, key := range config.Keys {
if key.Name == "" {
return result, fmt.Errorf("key with invalid name provided")
}
if key.Secret == "" {
return result, fmt.Errorf("key %v has no provided secret", key.Name)
}
}
keyTransformers := []value.PrefixTransformer{}
for _, keyData := range config.Keys {
key, err := base64.StdEncoding.DecodeString(keyData.Secret)
if err != nil {
return result, fmt.Errorf("could not obtain secret for named key %s: %s", keyData.Name, err)
}
block, err := aes.NewCipher(key)
if err != nil {
return result, fmt.Errorf("error while creating cipher for named key %s: %s", keyData.Name, err)
}
// Create a new PrefixTransformer for this key
keyTransformers = append(keyTransformers,
value.PrefixTransformer{
Transformer: fn(block),
Prefix: []byte(keyData.Name + ":"),
})
}
// Create a prefixTransformer which can choose between these keys
keyTransformer := value.NewPrefixTransformers(
fmt.Errorf("no matching key was found for the provided AES transformer"), keyTransformers...)
// Create a PrefixTransformer which shall later be put in a list with other providers
result = value.PrefixTransformer{
Transformer: keyTransformer,
Prefix: []byte(prefix),
}
return result, nil
}
// GetSecretboxPrefixTransformer returns a prefix transformer from the provided configuration
func GetSecretboxPrefixTransformer(config *SecretboxConfig) (value.PrefixTransformer, error) {
var result value.PrefixTransformer
if len(config.Keys) == 0 {
return result, fmt.Errorf("secretbox provider has no valid keys")
}
for _, key := range config.Keys {
if key.Name == "" {
return result, fmt.Errorf("key with invalid name provided")
}
if key.Secret == "" {
return result, fmt.Errorf("key %v has no provided secret", key.Name)
}
}
keyTransformers := []value.PrefixTransformer{}
for _, keyData := range config.Keys {
key, err := base64.StdEncoding.DecodeString(keyData.Secret)
if err != nil {
return result, fmt.Errorf("could not obtain secret for named key %s: %s", keyData.Name, err)
}
if len(key) != 32 {
return result, fmt.Errorf("expected key size 32 for secretbox provider, got %v", len(key))
}
keyArray := [32]byte{}
copy(keyArray[:], key)
// Create a new PrefixTransformer for this key
keyTransformers = append(keyTransformers,
value.PrefixTransformer{
Transformer: secretbox.NewSecretboxTransformer(keyArray),
Prefix: []byte(keyData.Name + ":"),
})
}
// Create a prefixTransformer which can choose between these keys
keyTransformer := value.NewPrefixTransformers(
fmt.Errorf("no matching key was found for the provided Secretbox transformer"), keyTransformers...)
// Create a PrefixTransformer which shall later be put in a list with other providers
result = value.PrefixTransformer{
Transformer: keyTransformer,
Prefix: []byte(secretboxTransformerPrefixV1),
}
return result, nil
}
// getEnvelopePrefixTransformer returns a prefix transformer from the provided config.
// envelopeService is used as the root of trust.
func getEnvelopePrefixTransformer(config *KMSConfig, envelopeService envelope.Service, prefix string) (value.PrefixTransformer, error) {
envelopeTransformer, err := envelope.NewEnvelopeTransformer(envelopeService, config.CacheSize, aestransformer.NewCBCTransformer)
if err != nil {
return value.PrefixTransformer{}, err
}
return value.PrefixTransformer{
Transformer: envelopeTransformer,
Prefix: []byte(prefix + config.Name + ":"),
}, nil
}