1 /*
2 ecdsa.c -- ECDSA key handling
3 Copyright (C) 2011-2013 Guus Sliepen <guus@tinc-vpn.org>
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #include "../system.h"
21
22 #include "ed25519.h"
23
24 #define TINC_ECDSA_INTERNAL
25 typedef struct {
26 uint8_t private[64];
27 uint8_t public[32];
28 } ecdsa_t;
29
30 #include "../logger.h"
31 #include "../ecdsa.h"
32 #include "../utils.h"
33 #include "../xalloc.h"
34
35 // Get and set ECDSA keys
36 //
ecdsa_set_base64_public_key(const char * p)37 ecdsa_t *ecdsa_set_base64_public_key(const char *p) {
38 int len = strlen(p);
39
40 if(len != 43) {
41 logger(DEBUG_ALWAYS, LOG_ERR, "Invalid size %d for public key!", len);
42 return 0;
43 }
44
45 ecdsa_t *ecdsa = xzalloc(sizeof(*ecdsa));
46 len = b64decode(p, ecdsa->public, len);
47
48 if(len != 32) {
49 logger(DEBUG_ALWAYS, LOG_ERR, "Invalid format of public key! len = %d", len);
50 free(ecdsa);
51 return 0;
52 }
53
54 return ecdsa;
55 }
56
ecdsa_get_base64_public_key(ecdsa_t * ecdsa)57 char *ecdsa_get_base64_public_key(ecdsa_t *ecdsa) {
58 char *base64 = xmalloc(44);
59 b64encode(ecdsa->public, base64, sizeof(ecdsa->public));
60
61 return base64;
62 }
63
64 // Read PEM ECDSA keys
65
read_pem(FILE * fp,const char * type,void * vbuf,size_t size)66 static bool read_pem(FILE *fp, const char *type, void *vbuf, size_t size) {
67 char line[1024];
68 bool data = false;
69 size_t typelen = strlen(type);
70 char *buf = vbuf;
71
72 while(fgets(line, sizeof(line), fp)) {
73 if(!data) {
74 if(strncmp(line, "-----BEGIN ", 11)) {
75 continue;
76 }
77
78 if(strncmp(line + 11, type, typelen)) {
79 continue;
80 }
81
82 data = true;
83 continue;
84 }
85
86 if(!strncmp(line, "-----END ", 9)) {
87 break;
88 }
89
90 size_t linelen = strcspn(line, "\r\n");
91 size_t len = b64decode(line, line, linelen);
92
93 if(!len) {
94 logger(DEBUG_ALWAYS, LOG_ERR, "Invalid base64 data in PEM file\n");
95 errno = EINVAL;
96 return false;
97 }
98
99 if(len > size) {
100 logger(DEBUG_ALWAYS, LOG_ERR, "Too much base64 data in PEM file\n");
101 errno = EINVAL;
102 return false;
103 }
104
105 memcpy(buf, line, len);
106 buf += len;
107 size -= len;
108 }
109
110 if(size) {
111 if(data) {
112 errno = EINVAL;
113 logger(DEBUG_ALWAYS, LOG_ERR, "Too little base64 data in PEM file\n");
114 } else {
115 errno = ENOENT;
116 }
117
118 return false;
119 }
120
121 return true;
122 }
123
ecdsa_read_pem_public_key(FILE * fp)124 ecdsa_t *ecdsa_read_pem_public_key(FILE *fp) {
125 ecdsa_t *ecdsa = xzalloc(sizeof(*ecdsa));
126
127 if(read_pem(fp, "ED25519 PUBLIC KEY", ecdsa->public, sizeof(ecdsa->public))) {
128 return ecdsa;
129 }
130
131 free(ecdsa);
132 return 0;
133 }
134
ecdsa_read_pem_private_key(FILE * fp)135 ecdsa_t *ecdsa_read_pem_private_key(FILE *fp) {
136 ecdsa_t *ecdsa = xmalloc(sizeof(*ecdsa));
137
138 if(read_pem(fp, "ED25519 PRIVATE KEY", ecdsa->private, sizeof(*ecdsa))) {
139 return ecdsa;
140 }
141
142 free(ecdsa);
143 return 0;
144 }
145
ecdsa_size(ecdsa_t * ecdsa)146 size_t ecdsa_size(ecdsa_t *ecdsa) {
147 (void)ecdsa;
148 return 64;
149 }
150
151 // TODO: standardise output format?
152
ecdsa_sign(ecdsa_t * ecdsa,const void * in,size_t len,void * sig)153 bool ecdsa_sign(ecdsa_t *ecdsa, const void *in, size_t len, void *sig) {
154 ed25519_sign(sig, in, len, ecdsa->public, ecdsa->private);
155 return true;
156 }
157
ecdsa_verify(ecdsa_t * ecdsa,const void * in,size_t len,const void * sig)158 bool ecdsa_verify(ecdsa_t *ecdsa, const void *in, size_t len, const void *sig) {
159 return ed25519_verify(sig, in, len, ecdsa->public);
160 }
161
ecdsa_active(ecdsa_t * ecdsa)162 bool ecdsa_active(ecdsa_t *ecdsa) {
163 return ecdsa;
164 }
165
ecdsa_free(ecdsa_t * ecdsa)166 void ecdsa_free(ecdsa_t *ecdsa) {
167 free(ecdsa);
168 }
169