1 // Copyright 2022 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 // This is an implementation of P-384 signature operations using boringssl.
16
17 #include <stdint.h>
18 #include <stdio.h>
19
20 #include "dice/boringssl_ecdsa_utils.h"
21 #include "dice/config/cose_key_config.h"
22 #include "dice/dice.h"
23 #include "dice/ops.h"
24
25 #if DICE_PRIVATE_KEY_SEED_SIZE != 32
26 #error "Private key seed is expected to be 32 bytes."
27 #endif
28 #if DICE_PUBLIC_KEY_BUFFER_SIZE != 96
29 #error "This P-384 implementation needs 96 bytes to store the public key."
30 #endif
31 #if DICE_PRIVATE_KEY_BUFFER_SIZE != 48
32 #error "P-384 needs 48 bytes for the private key."
33 #endif
34 #if DICE_SIGNATURE_BUFFER_SIZE != 96
35 #error "P-384 needs 96 bytes to store the signature."
36 #endif
37
DiceGetKeyParam(void * context_not_used,DicePrincipal principal_not_used,DiceKeyParam * key_param)38 DiceResult DiceGetKeyParam(void* context_not_used,
39 DicePrincipal principal_not_used,
40 DiceKeyParam* key_param) {
41 (void)context_not_used;
42 (void)principal_not_used;
43 key_param->public_key_size = DICE_PUBLIC_KEY_BUFFER_SIZE;
44 key_param->signature_size = DICE_SIGNATURE_BUFFER_SIZE;
45
46 key_param->cose_key_type = kCoseKeyKtyEc2;
47 key_param->cose_key_algorithm = kCoseAlgEs384;
48 key_param->cose_key_curve = kCoseCrvP384;
49 return kDiceResultOk;
50 }
51
DiceKeypairFromSeed(void * context_not_used,DicePrincipal principal_not_used,const uint8_t seed[DICE_PRIVATE_KEY_SEED_SIZE],uint8_t public_key[DICE_PUBLIC_KEY_BUFFER_SIZE],uint8_t private_key[DICE_PRIVATE_KEY_BUFFER_SIZE])52 DiceResult DiceKeypairFromSeed(
53 void* context_not_used, DicePrincipal principal_not_used,
54 const uint8_t seed[DICE_PRIVATE_KEY_SEED_SIZE],
55 uint8_t public_key[DICE_PUBLIC_KEY_BUFFER_SIZE],
56 uint8_t private_key[DICE_PRIVATE_KEY_BUFFER_SIZE]) {
57 (void)context_not_used;
58 (void)principal_not_used;
59 if (1 == P384KeypairFromSeed(public_key, private_key, seed)) {
60 return kDiceResultOk;
61 }
62 return kDiceResultPlatformError;
63 }
64
DiceSign(void * context_not_used,const uint8_t * message,size_t message_size,const uint8_t private_key[DICE_PRIVATE_KEY_BUFFER_SIZE],uint8_t signature[DICE_SIGNATURE_BUFFER_SIZE])65 DiceResult DiceSign(void* context_not_used, const uint8_t* message,
66 size_t message_size,
67 const uint8_t private_key[DICE_PRIVATE_KEY_BUFFER_SIZE],
68 uint8_t signature[DICE_SIGNATURE_BUFFER_SIZE]) {
69 (void)context_not_used;
70 if (1 == P384Sign(signature, message, message_size, private_key)) {
71 return kDiceResultOk;
72 }
73 return kDiceResultPlatformError;
74 }
75
DiceVerify(void * context_not_used,const uint8_t * message,size_t message_size,const uint8_t signature[DICE_SIGNATURE_BUFFER_SIZE],const uint8_t public_key[DICE_PUBLIC_KEY_BUFFER_SIZE])76 DiceResult DiceVerify(void* context_not_used, const uint8_t* message,
77 size_t message_size,
78 const uint8_t signature[DICE_SIGNATURE_BUFFER_SIZE],
79 const uint8_t public_key[DICE_PUBLIC_KEY_BUFFER_SIZE]) {
80 (void)context_not_used;
81 if (1 == P384Verify(message, message_size, signature, public_key)) {
82 return kDiceResultOk;
83 }
84 return kDiceResultPlatformError;
85 }
86