1 /*
2 *
3 * Copyright 2018 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include <grpc/support/port_platform.h>
20
21 #include "src/core/tsi/alts/frame_protector/alts_counter.h"
22
23 #include <string.h>
24
25 #include <grpc/support/alloc.h>
26
maybe_copy_error_msg(const char * src,char ** dst)27 static void maybe_copy_error_msg(const char* src, char** dst) {
28 if (dst != nullptr && src != nullptr) {
29 *dst = static_cast<char*>(gpr_malloc(strlen(src) + 1));
30 memcpy(*dst, src, strlen(src) + 1);
31 }
32 }
33
alts_counter_create(bool is_client,size_t counter_size,size_t overflow_size,alts_counter ** crypter_counter,char ** error_details)34 grpc_status_code alts_counter_create(bool is_client, size_t counter_size,
35 size_t overflow_size,
36 alts_counter** crypter_counter,
37 char** error_details) {
38 /* Perform input sanity check. */
39 if (counter_size == 0) {
40 const char error_msg[] = "counter_size is invalid.";
41 maybe_copy_error_msg(error_msg, error_details);
42 return GRPC_STATUS_INVALID_ARGUMENT;
43 }
44 if (overflow_size == 0 || overflow_size >= counter_size) {
45 const char error_msg[] = "overflow_size is invalid.";
46 maybe_copy_error_msg(error_msg, error_details);
47 return GRPC_STATUS_INVALID_ARGUMENT;
48 }
49 if (crypter_counter == nullptr) {
50 const char error_msg[] = "crypter_counter is nullptr.";
51 maybe_copy_error_msg(error_msg, error_details);
52 return GRPC_STATUS_INVALID_ARGUMENT;
53 }
54 *crypter_counter =
55 static_cast<alts_counter*>(gpr_malloc(sizeof(**crypter_counter)));
56 (*crypter_counter)->size = counter_size;
57 (*crypter_counter)->overflow_size = overflow_size;
58 (*crypter_counter)->counter =
59 static_cast<unsigned char*>(gpr_zalloc(counter_size));
60 if (is_client) {
61 ((*crypter_counter)->counter)[counter_size - 1] = 0x80;
62 }
63 return GRPC_STATUS_OK;
64 }
65
alts_counter_increment(alts_counter * crypter_counter,bool * is_overflow,char ** error_details)66 grpc_status_code alts_counter_increment(alts_counter* crypter_counter,
67 bool* is_overflow,
68 char** error_details) {
69 /* Perform input sanity check. */
70 if (crypter_counter == nullptr) {
71 const char error_msg[] = "crypter_counter is nullptr.";
72 maybe_copy_error_msg(error_msg, error_details);
73 return GRPC_STATUS_INVALID_ARGUMENT;
74 }
75 if (is_overflow == nullptr) {
76 const char error_msg[] = "is_overflow is nullptr.";
77 maybe_copy_error_msg(error_msg, error_details);
78 return GRPC_STATUS_INVALID_ARGUMENT;
79 }
80 /* Increment the internal counter. */
81 size_t i = 0;
82 for (; i < crypter_counter->overflow_size; i++) {
83 (crypter_counter->counter)[i]++;
84 if ((crypter_counter->counter)[i] != 0x00) {
85 break;
86 }
87 }
88 /**
89 * If the lower overflow_size bytes are all zero, the counter has overflowed.
90 */
91 if (i == crypter_counter->overflow_size) {
92 *is_overflow = true;
93 return GRPC_STATUS_FAILED_PRECONDITION;
94 }
95 *is_overflow = false;
96 return GRPC_STATUS_OK;
97 }
98
alts_counter_get_size(alts_counter * crypter_counter)99 size_t alts_counter_get_size(alts_counter* crypter_counter) {
100 if (crypter_counter == nullptr) {
101 return 0;
102 }
103 return crypter_counter->size;
104 }
105
alts_counter_get_counter(alts_counter * crypter_counter)106 unsigned char* alts_counter_get_counter(alts_counter* crypter_counter) {
107 if (crypter_counter == nullptr) {
108 return nullptr;
109 }
110 return crypter_counter->counter;
111 }
112
alts_counter_destroy(alts_counter * crypter_counter)113 void alts_counter_destroy(alts_counter* crypter_counter) {
114 if (crypter_counter != nullptr) {
115 gpr_free(crypter_counter->counter);
116 gpr_free(crypter_counter);
117 }
118 }
119