keygen.c revision 3759f10fc543747668b1ca4b4671f35b0dea8445
/*
* Copyright (C) 2009, 2012-2015 Internet Systems Consortium, Inc. ("ISC")
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: keygen.c,v 1.4 2009/11/12 14:02:38 marka Exp $ */
/*! \file */
#include <config.h>
#include <stdlib.h>
#include <stdarg.h>
#include <isc/base64.h>
#include <isc/buffer.h>
#include <isc/entropy.h>
#include <isc/file.h>
#include <isc/keyboard.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/string.h>
#include <dns/keyvalues.h>
#include <dns/name.h>
#include <dst/dst.h>
#include <confgen/os.h>
#include "util.h"
#include "keygen.h"
/*%
* Convert algorithm type to string.
*/
const char *
alg_totext(dns_secalg_t alg) {
switch (alg) {
case DST_ALG_HMACMD5:
return "hmac-md5";
case DST_ALG_HMACSHA1:
return "hmac-sha1";
case DST_ALG_HMACSHA224:
return "hmac-sha224";
case DST_ALG_HMACSHA256:
return "hmac-sha256";
case DST_ALG_HMACSHA384:
return "hmac-sha384";
case DST_ALG_HMACSHA512:
return "hmac-sha512";
default:
return "(unknown)";
}
}
/*%
* Convert string to algorithm type.
*/
dns_secalg_t
alg_fromtext(const char *name) {
const char *p = name;
if (strncasecmp(p, "hmac-", 5) == 0)
p = &name[5];
if (strcasecmp(p, "md5") == 0)
return DST_ALG_HMACMD5;
if (strcasecmp(p, "sha1") == 0)
return DST_ALG_HMACSHA1;
if (strcasecmp(p, "sha224") == 0)
return DST_ALG_HMACSHA224;
if (strcasecmp(p, "sha256") == 0)
return DST_ALG_HMACSHA256;
if (strcasecmp(p, "sha384") == 0)
return DST_ALG_HMACSHA384;
if (strcasecmp(p, "sha512") == 0)
return DST_ALG_HMACSHA512;
return DST_ALG_UNKNOWN;
}
/*%
* Return default keysize for a given algorithm type.
*/
int
alg_bits(dns_secalg_t alg) {
switch (alg) {
case DST_ALG_HMACMD5:
return 128;
case DST_ALG_HMACSHA1:
return 160;
case DST_ALG_HMACSHA224:
return 224;
case DST_ALG_HMACSHA256:
return 256;
case DST_ALG_HMACSHA384:
return 384;
case DST_ALG_HMACSHA512:
return 512;
default:
return 0;
}
}
/*%
* Generate a key of size 'keysize' using entropy source 'randomfile',
* and place it in 'key_txtbuffer'
*/
void
generate_key(isc_mem_t *mctx, const char *randomfile, dns_secalg_t alg,
int keysize, isc_buffer_t *key_txtbuffer) {
isc_result_t result = ISC_R_SUCCESS;
isc_entropysource_t *entropy_source = NULL;
int open_keyboard = ISC_ENTROPY_KEYBOARDMAYBE;
int entropy_flags = 0;
isc_entropy_t *ectx = NULL;
isc_buffer_t key_rawbuffer;
isc_region_t key_rawregion;
char key_rawsecret[64];
dst_key_t *key = NULL;
switch (alg) {
case DST_ALG_HMACMD5:
case DST_ALG_HMACSHA1:
case DST_ALG_HMACSHA224:
case DST_ALG_HMACSHA256:
if (keysize < 1 || keysize > 512)
fatal("keysize %d out of range (must be 1-512)\n",
keysize);
break;
case DST_ALG_HMACSHA384:
case DST_ALG_HMACSHA512:
if (keysize < 1 || keysize > 1024)
fatal("keysize %d out of range (must be 1-1024)\n",
keysize);
break;
default:
fatal("unsupported algorithm %d\n", alg);
}
DO("create entropy context", isc_entropy_create(mctx, &ectx));
if (randomfile != NULL && strcmp(randomfile, "keyboard") == 0) {
randomfile = NULL;
open_keyboard = ISC_ENTROPY_KEYBOARDYES;
}
DO("start entropy source", isc_entropy_usebestsource(ectx,
&entropy_source,
randomfile,
open_keyboard));
entropy_flags = ISC_ENTROPY_BLOCKING | ISC_ENTROPY_GOODONLY;
DO("initialize dst library", dst_lib_init(mctx, ectx, entropy_flags));
DO("generate key", dst_key_generate(dns_rootname, alg,
keysize, 0, 0,
DNS_KEYPROTO_ANY,
dns_rdataclass_in, mctx, &key));
isc_buffer_init(&key_rawbuffer, &key_rawsecret, sizeof(key_rawsecret));
DO("dump key to buffer", dst_key_tobuffer(key, &key_rawbuffer));
isc_buffer_usedregion(&key_rawbuffer, &key_rawregion);
DO("bsse64 encode secret", isc_base64_totext(&key_rawregion, -1, "",
key_txtbuffer));
/*
* Shut down the entropy source now so the "stop typing" message
* does not muck with the output.
*/
if (entropy_source != NULL)
isc_entropy_destroysource(&entropy_source);
if (key != NULL)
dst_key_free(&key);
isc_entropy_detach(&ectx);
dst_lib_destroy();
}
/*%
* Write a key file to 'keyfile'. If 'user' is non-NULL,
* make that user the owner of the file. The key will have
* the name 'keyname' and the secret in the buffer 'secret'.
*/
void
write_key_file(const char *keyfile, const char *user,
const char *keyname, isc_buffer_t *secret,
dns_secalg_t alg) {
isc_result_t result;
const char *algname = alg_totext(alg);
FILE *fd = NULL;
DO("create keyfile", isc_file_safecreate(keyfile, &fd));
if (user != NULL) {
if (set_user(fd, user) == -1)
fatal("unable to set file owner\n");
}
fprintf(fd, "key \"%s\" {\n\talgorithm %s;\n"
"\tsecret \"%.*s\";\n};\n",
keyname, algname,
(int)isc_buffer_usedlength(secret),
(char *)isc_buffer_base(secret));
fflush(fd);
if (ferror(fd))
fatal("write to %s failed\n", keyfile);
if (fclose(fd))
fatal("fclose(%s) failed\n", keyfile);
fprintf(stderr, "wrote key file \"%s\"\n", keyfile);
}