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
|
// Copyright 2019 Google LLC
//
// 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 hybrid
import (
"fmt"
"slices"
"github.com/tink-crypto/tink-go/v2/internal/internalapi"
"github.com/tink-crypto/tink-go/v2/internal/internalregistry"
"github.com/tink-crypto/tink-go/v2/internal/monitoringutil"
"github.com/tink-crypto/tink-go/v2/internal/primitiveset"
"github.com/tink-crypto/tink-go/v2/keyset"
"github.com/tink-crypto/tink-go/v2/monitoring"
"github.com/tink-crypto/tink-go/v2/tink"
)
// NewHybridEncrypt returns an HybridEncrypt primitive from the given keyset handle.
func NewHybridEncrypt(handle *keyset.Handle) (tink.HybridEncrypt, error) {
ps, err := keyset.Primitives[tink.HybridEncrypt](handle, internalapi.Token{})
if err != nil {
return nil, fmt.Errorf("hybrid_factory: cannot obtain primitive set: %s", err)
}
return newWrappedHybridEncrypt(ps)
}
// fullHybridEncryptAdapter is an [tink.HybridEncrypt] implementation that
// makes a given RAW [tink.HybridEncrypt] a full primitive prepending the
// prefix the resulting ciphertext.
type fullHybridEncryptAdapter struct {
rawHybridEncrypt tink.HybridEncrypt
prefix []byte
}
var _ tink.HybridEncrypt = (*fullHybridEncryptAdapter)(nil)
func (e *fullHybridEncryptAdapter) Encrypt(plaintext, contextInfo []byte) ([]byte, error) {
ct, err := e.rawHybridEncrypt.Encrypt(plaintext, contextInfo)
if err != nil {
return nil, err
}
return slices.Concat(e.prefix, ct), nil
}
// encryptPrimitiveSet is an HybridEncrypt implementation that uses the underlying primitive set for encryption.
type wrappedHybridEncrypt struct {
fullPrimitive tink.HybridEncrypt
logger monitoring.Logger
keyID uint32
}
// compile time assertion that wrappedHybridEncrypt implements the HybridEncrypt interface.
var _ tink.HybridEncrypt = (*wrappedHybridEncrypt)(nil)
// Encrypt encrypts the given plaintext binding contextInfo to the resulting ciphertext.
// It returns the concatenation of the primary's identifier and the ciphertext.
func (a *wrappedHybridEncrypt) Encrypt(plaintext, contextInfo []byte) ([]byte, error) {
ct, err := a.fullPrimitive.Encrypt(plaintext, contextInfo)
if err != nil {
a.logger.LogFailure()
return nil, err
}
a.logger.Log(a.keyID, len(plaintext))
return ct, nil
}
func isAEAD(p any) bool {
if p == nil {
return false
}
_, ok := p.(tink.AEAD)
return ok
}
func newWrappedHybridEncrypt(ps *primitiveset.PrimitiveSet[tink.HybridEncrypt]) (*wrappedHybridEncrypt, error) {
// Make sure the primitives do not implement tink.AEAD.
if isAEAD(ps.Primary.Primitive) || isAEAD(ps.Primary.FullPrimitive) {
return nil, fmt.Errorf("hybrid_factory: primary primitive must NOT implement tink.AEAD")
}
for _, primitives := range ps.Entries {
for _, p := range primitives {
if isAEAD(p.Primitive) || isAEAD(p.FullPrimitive) {
return nil, fmt.Errorf("hybrid_factory: primitive must NOT implement tink.AEAD")
}
}
}
primitive := ps.Primary.FullPrimitive
if primitive == nil {
primitive = &fullHybridEncryptAdapter{
rawHybridEncrypt: ps.Primary.Primitive,
prefix: ps.Primary.OutputPrefix(),
}
}
logger, err := createEncryptLogger(ps)
if err != nil {
return nil, err
}
return &wrappedHybridEncrypt{
fullPrimitive: primitive,
logger: logger,
keyID: ps.Primary.KeyID,
}, nil
}
func createEncryptLogger(ps *primitiveset.PrimitiveSet[tink.HybridEncrypt]) (monitoring.Logger, error) {
if len(ps.Annotations) == 0 {
return &monitoringutil.DoNothingLogger{}, nil
}
keysetInfo, err := monitoringutil.KeysetInfoFromPrimitiveSet(ps)
if err != nil {
return nil, err
}
return internalregistry.GetMonitoringClient().NewLogger(&monitoring.Context{
KeysetInfo: keysetInfo,
Primitive: "hybrid_encrypt",
APIFunction: "encrypt",
})
}
|
