release/src/router/tinc/src/ed25519/ecdsa.c

   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 //
  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         if(len != 32) {
  48                 logger(DEBUG_ALWAYS, LOG_ERR, "Invalid format of public key! len = %d", len);
  49                 free(ecdsa);
  50                 return 0;
  51         }
  52
  53         return ecdsa;
  54 }
  55
  56 char *ecdsa_get_base64_public_key(ecdsa_t *ecdsa) {
  57         char *base64 = xmalloc(44);
  58         b64encode(ecdsa->public, base64, sizeof ecdsa->public);
  59
  60         return base64;
  61 }
  62
  63 // Read PEM ECDSA keys
  64
  65 static bool read_pem(FILE *fp, const char *type, void *buf, size_t size) {
  66         char line[1024];
  67         bool data = false;
  68         size_t typelen = strlen(type);
  69
  70         while(fgets(line, sizeof line, fp)) {
  71                 if(!data) {
  72                         if(strncmp(line, "-----BEGIN ", 11))
  73                                 continue;
  74                         if(strncmp(line + 11, type, typelen))
  75                                 continue;
  76                         data = true;
  77                         continue;
  78                 }
  79
  80                 if(!strncmp(line, "-----END ", 9))
  81                         break;
  82
  83                 size_t linelen = strcspn(line, "\r\n");
  84                 size_t len = b64decode(line, line, linelen);
  85                 if(!len) {
  86                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid base64 data in PEM file\n");
  87                         return false;
  88                 }
  89
  90                 if(len > size) {
  91                         logger(DEBUG_ALWAYS, LOG_ERR, "Too much base64 data in PEM file\n");
  92                         return false;
  93                 }
  94
  95                 memcpy(buf, line, len);
  96                 buf += len;
  97                 size -= len;
  98         }
  99
 100         if(size) {
 101                 logger(DEBUG_ALWAYS, LOG_ERR, "Too little base64 data in PEM file\n");
 102                 return false;
 103         }
 104
 105         return true;
 106 }
 107
 108 ecdsa_t *ecdsa_read_pem_public_key(FILE *fp) {
 109         ecdsa_t *ecdsa = xzalloc(sizeof *ecdsa);
 110         if(read_pem(fp, "ED25519 PUBLIC KEY", ecdsa->public, sizeof ecdsa->public))
 111                 return ecdsa;
 112         free(ecdsa);
 113         return 0;
 114 }
 115
 116 ecdsa_t *ecdsa_read_pem_private_key(FILE *fp) {
 117         ecdsa_t *ecdsa = xmalloc(sizeof *ecdsa);
 118         if(read_pem(fp, "ED25519 PRIVATE KEY", ecdsa->private, sizeof *ecdsa))
 119                 return ecdsa;
 120         free(ecdsa);
 121         return 0;
 122 }
 123
 124 size_t ecdsa_size(ecdsa_t *ecdsa) {
 125         return 64;
 126 }
 127
 128 // TODO: standardise output format?
 129
 130 bool ecdsa_sign(ecdsa_t *ecdsa, const void *in, size_t len, void *sig) {
 131         ed25519_sign(sig, in, len, ecdsa->public, ecdsa->private);
 132         return true;
 133 }
 134
 135 bool ecdsa_verify(ecdsa_t *ecdsa, const void *in, size_t len, const void *sig) {
 136         return ed25519_verify(sig, in, len, ecdsa->public);
 137 }
 138
 139 bool ecdsa_active(ecdsa_t *ecdsa) {
 140         return ecdsa;
 141 }
 142
 143 void ecdsa_free(ecdsa_t *ecdsa) {
 144         free(ecdsa);
 145 }