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comparison gcm.c @ 1733:d529a52b2f7c coverity coverity

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merge coverity from main
author Matt Johnston <matt@ucc.asn.au>
date Fri, 26 Jun 2020 21:07:34 +0800
parents 5b701bf529aa
children
comparison
equal deleted inserted replaced
1643:b59623a64678 1733:d529a52b2f7c
1 /*
2 * Dropbear SSH
3 *
4 * Copyright (c) 2002,2003 Matt Johnston
5 * Copyright (c) 2020 by Vladislav Grishenko
6 * All rights reserved.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24 * SOFTWARE. */
25
26 #include "includes.h"
27 #include "algo.h"
28 #include "dbutil.h"
29 #include "gcm.h"
30
31 #if DROPBEAR_ENABLE_GCM_MODE
32
33 #define GHASH_LEN 16
34
35 static const struct dropbear_hash dropbear_ghash =
36 {NULL, 0, GHASH_LEN};
37
38 static int dropbear_gcm_start(int cipher, const unsigned char *IV,
39 const unsigned char *key, int keylen,
40 int UNUSED(num_rounds), dropbear_gcm_state *state) {
41 int err;
42
43 TRACE2(("enter dropbear_gcm_start"))
44
45 if ((err = gcm_init(&state->gcm, cipher, key, keylen)) != CRYPT_OK) {
46 return err;
47 }
48 memcpy(state->iv, IV, GCM_NONCE_LEN);
49
50 TRACE2(("leave dropbear_gcm_start"))
51 return CRYPT_OK;
52 }
53
54 static int dropbear_gcm_crypt(unsigned int UNUSED(seq),
55 const unsigned char *in, unsigned char *out,
56 unsigned long len, unsigned long taglen,
57 dropbear_gcm_state *state, int direction) {
58 unsigned char *iv, tag[GHASH_LEN];
59 int i, err;
60
61 TRACE2(("enter dropbear_gcm_crypt"))
62
63 if (len < 4 || taglen != GHASH_LEN) {
64 return CRYPT_ERROR;
65 }
66
67 gcm_reset(&state->gcm);
68
69 if ((err = gcm_add_iv(&state->gcm,
70 state->iv, GCM_NONCE_LEN)) != CRYPT_OK) {
71 return err;
72 }
73
74 if ((err = gcm_add_aad(&state->gcm, in, 4)) != CRYPT_OK) {
75 return err;
76 }
77
78 if ((err = gcm_process(&state->gcm, (unsigned char *) in + 4,
79 len - 4, out + 4, direction)) != CRYPT_OK) {
80 return err;
81 }
82
83 if (direction == LTC_ENCRYPT) {
84 gcm_done(&state->gcm, out + len, &taglen);
85 } else {
86 gcm_done(&state->gcm, tag, &taglen);
87 if (constant_time_memcmp(in + len, tag, taglen) != 0) {
88 return CRYPT_ERROR;
89 }
90 }
91
92 /* increment invocation counter */
93 iv = state->iv + GCM_IVFIX_LEN;
94 for (i = GCM_IVCTR_LEN - 1; i >= 0 && ++iv[i] == 0; i--);
95
96 TRACE2(("leave dropbear_gcm_crypt"))
97 return CRYPT_OK;
98 }
99
100 static int dropbear_gcm_getlength(unsigned int UNUSED(seq),
101 const unsigned char *in, unsigned int *outlen,
102 unsigned long len, dropbear_gcm_state* UNUSED(state)) {
103 TRACE2(("enter dropbear_gcm_getlength"))
104
105 if (len < 4) {
106 return CRYPT_ERROR;
107 }
108
109 LOAD32H(*outlen, in);
110
111 TRACE2(("leave dropbear_gcm_getlength"))
112 return CRYPT_OK;
113 }
114
115 const struct dropbear_cipher_mode dropbear_mode_gcm =
116 {(void *)dropbear_gcm_start, NULL, NULL,
117 (void *)dropbear_gcm_crypt,
118 (void *)dropbear_gcm_getlength, &dropbear_ghash};
119
120 #endif /* DROPBEAR_ENABLE_GCM_MODE */