#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/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"
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)";
}
}
dns_secalg_t
alg_fromtext(const char *name) {
if (strcmp(name, "hmac-md5") == 0)
return DST_ALG_HMACMD5;
if (strcmp(name, "hmac-sha1") == 0)
return DST_ALG_HMACSHA1;
if (strcmp(name, "hmac-sha224") == 0)
return DST_ALG_HMACSHA224;
if (strcmp(name, "hmac-sha256") == 0)
return DST_ALG_HMACSHA256;
if (strcmp(name, "hmac-sha384") == 0)
return DST_ALG_HMACSHA384;
if (strcmp(name, "hmac-sha512") == 0)
return DST_ALG_HMACSHA512;
return DST_ALG_UNKNOWN;
}
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;
}
}
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));
if (entropy_source != NULL)
isc_entropy_destroysource(&entropy_source);
if (key != NULL)
dst_key_free(&key);
isc_entropy_detach(&ectx);
dst_lib_destroy();
}
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);
}