aboutsummaryrefslogtreecommitdiffstats
path: root/vendor/github.com/minio/minio-go/v7/post-policy.go
blob: 3f4881e82c1217fc24793d974395b41a3320bd53 (plain) (blame)
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
/*
 * MinIO Go Library for Amazon S3 Compatible Cloud Storage
 * Copyright 2015-2023 MinIO, Inc.
 *
 * 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 minio

import (
	"encoding/base64"
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/minio/minio-go/v7/pkg/encrypt"
)

// expirationDateFormat date format for expiration key in json policy.
const expirationDateFormat = "2006-01-02T15:04:05.000Z"

// policyCondition explanation:
// http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-HTTPPOSTConstructPolicy.html
//
// Example:
//
//	policyCondition {
//	    matchType: "$eq",
//	    key: "$Content-Type",
//	    value: "image/png",
//	}
type policyCondition struct {
	matchType string
	condition string
	value     string
}

// PostPolicy - Provides strict static type conversion and validation
// for Amazon S3's POST policy JSON string.
type PostPolicy struct {
	// Expiration date and time of the POST policy.
	expiration time.Time
	// Collection of different policy conditions.
	conditions []policyCondition
	// ContentLengthRange minimum and maximum allowable size for the
	// uploaded content.
	contentLengthRange struct {
		min int64
		max int64
	}

	// Post form data.
	formData map[string]string
}

// NewPostPolicy - Instantiate new post policy.
func NewPostPolicy() *PostPolicy {
	p := &PostPolicy{}
	p.conditions = make([]policyCondition, 0)
	p.formData = make(map[string]string)
	return p
}

// SetExpires - Sets expiration time for the new policy.
func (p *PostPolicy) SetExpires(t time.Time) error {
	if t.IsZero() {
		return errInvalidArgument("No expiry time set.")
	}
	p.expiration = t
	return nil
}

// SetKey - Sets an object name for the policy based upload.
func (p *PostPolicy) SetKey(key string) error {
	if strings.TrimSpace(key) == "" || key == "" {
		return errInvalidArgument("Object name is empty.")
	}
	policyCond := policyCondition{
		matchType: "eq",
		condition: "$key",
		value:     key,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["key"] = key
	return nil
}

// SetKeyStartsWith - Sets an object name that an policy based upload
// can start with.
// Can use an empty value ("") to allow any key.
func (p *PostPolicy) SetKeyStartsWith(keyStartsWith string) error {
	policyCond := policyCondition{
		matchType: "starts-with",
		condition: "$key",
		value:     keyStartsWith,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["key"] = keyStartsWith
	return nil
}

// SetBucket - Sets bucket at which objects will be uploaded to.
func (p *PostPolicy) SetBucket(bucketName string) error {
	if strings.TrimSpace(bucketName) == "" || bucketName == "" {
		return errInvalidArgument("Bucket name is empty.")
	}
	policyCond := policyCondition{
		matchType: "eq",
		condition: "$bucket",
		value:     bucketName,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["bucket"] = bucketName
	return nil
}

// SetCondition - Sets condition for credentials, date and algorithm
func (p *PostPolicy) SetCondition(matchType, condition, value string) error {
	if strings.TrimSpace(value) == "" || value == "" {
		return errInvalidArgument("No value specified for condition")
	}

	policyCond := policyCondition{
		matchType: matchType,
		condition: "$" + condition,
		value:     value,
	}
	if condition == "X-Amz-Credential" || condition == "X-Amz-Date" || condition == "X-Amz-Algorithm" {
		if err := p.addNewPolicy(policyCond); err != nil {
			return err
		}
		p.formData[condition] = value
		return nil
	}
	return errInvalidArgument("Invalid condition in policy")
}

// SetContentType - Sets content-type of the object for this policy
// based upload.
func (p *PostPolicy) SetContentType(contentType string) error {
	if strings.TrimSpace(contentType) == "" || contentType == "" {
		return errInvalidArgument("No content type specified.")
	}
	policyCond := policyCondition{
		matchType: "eq",
		condition: "$Content-Type",
		value:     contentType,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["Content-Type"] = contentType
	return nil
}

// SetContentTypeStartsWith - Sets what content-type of the object for this policy
// based upload can start with.
// Can use an empty value ("") to allow any content-type.
func (p *PostPolicy) SetContentTypeStartsWith(contentTypeStartsWith string) error {
	policyCond := policyCondition{
		matchType: "starts-with",
		condition: "$Content-Type",
		value:     contentTypeStartsWith,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["Content-Type"] = contentTypeStartsWith
	return nil
}

// SetContentLengthRange - Set new min and max content length
// condition for all incoming uploads.
func (p *PostPolicy) SetContentLengthRange(min, max int64) error {
	if min > max {
		return errInvalidArgument("Minimum limit is larger than maximum limit.")
	}
	if min < 0 {
		return errInvalidArgument("Minimum limit cannot be negative.")
	}
	if max <= 0 {
		return errInvalidArgument("Maximum limit cannot be non-positive.")
	}
	p.contentLengthRange.min = min
	p.contentLengthRange.max = max
	return nil
}

// SetSuccessActionRedirect - Sets the redirect success url of the object for this policy
// based upload.
func (p *PostPolicy) SetSuccessActionRedirect(redirect string) error {
	if strings.TrimSpace(redirect) == "" || redirect == "" {
		return errInvalidArgument("Redirect is empty")
	}
	policyCond := policyCondition{
		matchType: "eq",
		condition: "$success_action_redirect",
		value:     redirect,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["success_action_redirect"] = redirect
	return nil
}

// SetSuccessStatusAction - Sets the status success code of the object for this policy
// based upload.
func (p *PostPolicy) SetSuccessStatusAction(status string) error {
	if strings.TrimSpace(status) == "" || status == "" {
		return errInvalidArgument("Status is empty")
	}
	policyCond := policyCondition{
		matchType: "eq",
		condition: "$success_action_status",
		value:     status,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData["success_action_status"] = status
	return nil
}

// SetUserMetadata - Set user metadata as a key/value couple.
// Can be retrieved through a HEAD request or an event.
func (p *PostPolicy) SetUserMetadata(key, value string) error {
	if strings.TrimSpace(key) == "" || key == "" {
		return errInvalidArgument("Key is empty")
	}
	if strings.TrimSpace(value) == "" || value == "" {
		return errInvalidArgument("Value is empty")
	}
	headerName := fmt.Sprintf("x-amz-meta-%s", key)
	policyCond := policyCondition{
		matchType: "eq",
		condition: fmt.Sprintf("$%s", headerName),
		value:     value,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData[headerName] = value
	return nil
}

// SetChecksum sets the checksum of the request.
func (p *PostPolicy) SetChecksum(c Checksum) {
	if c.IsSet() {
		p.formData[amzChecksumAlgo] = c.Type.String()
		p.formData[c.Type.Key()] = c.Encoded()
	}
}

// SetEncryption - sets encryption headers for POST API
func (p *PostPolicy) SetEncryption(sse encrypt.ServerSide) {
	if sse == nil {
		return
	}
	h := http.Header{}
	sse.Marshal(h)
	for k, v := range h {
		p.formData[k] = v[0]
	}
}

// SetUserData - Set user data as a key/value couple.
// Can be retrieved through a HEAD request or an event.
func (p *PostPolicy) SetUserData(key, value string) error {
	if key == "" {
		return errInvalidArgument("Key is empty")
	}
	if value == "" {
		return errInvalidArgument("Value is empty")
	}
	headerName := fmt.Sprintf("x-amz-%s", key)
	policyCond := policyCondition{
		matchType: "eq",
		condition: fmt.Sprintf("$%s", headerName),
		value:     value,
	}
	if err := p.addNewPolicy(policyCond); err != nil {
		return err
	}
	p.formData[headerName] = value
	return nil
}

// addNewPolicy - internal helper to validate adding new policies.
// Can use starts-with with an empty value ("") to allow any content within a form field.
func (p *PostPolicy) addNewPolicy(policyCond policyCondition) error {
	if policyCond.matchType == "" || policyCond.condition == "" {
		return errInvalidArgument("Policy fields are empty.")
	}
	if policyCond.matchType != "starts-with" && policyCond.value == "" {
		return errInvalidArgument("Policy value is empty.")
	}
	p.conditions = append(p.conditions, policyCond)
	return nil
}

// String function for printing policy in json formatted string.
func (p PostPolicy) String() string {
	return string(p.marshalJSON())
}

// marshalJSON - Provides Marshaled JSON in bytes.
func (p PostPolicy) marshalJSON() []byte {
	expirationStr := `"expiration":"` + p.expiration.Format(expirationDateFormat) + `"`
	var conditionsStr string
	conditions := []string{}
	for _, po := range p.conditions {
		conditions = append(conditions, fmt.Sprintf("[\"%s\",\"%s\",\"%s\"]", po.matchType, po.condition, po.value))
	}
	if p.contentLengthRange.min != 0 || p.contentLengthRange.max != 0 {
		conditions = append(conditions, fmt.Sprintf("[\"content-length-range\", %d, %d]",
			p.contentLengthRange.min, p.contentLengthRange.max))
	}
	if len(conditions) > 0 {
		conditionsStr = `"conditions":[` + strings.Join(conditions, ",") + "]"
	}
	retStr := "{"
	retStr = retStr + expirationStr + ","
	retStr += conditionsStr
	retStr += "}"
	return []byte(retStr)
}

// base64 - Produces base64 of PostPolicy's Marshaled json.
func (p PostPolicy) base64() string {
	return base64.StdEncoding.EncodeToString(p.marshalJSON())
}