commit b6eee531bb546683387fb471b754f24bc40580d0
Author: Nick Mathewson <ni...@torproject.org>
Date: Sun Mar 1 16:40:02 2015 +0100
Support encrypted offline master keys with a new --keygen flag
When --keygen is provided, we prompt for a passphrase when we make a
new master key; if it is nonempty, we store the secret key in a new
crypto_pwbox.
Also, if --keygen is provided and there *is* an encrypted master key,
we load it and prompt for a passphrase unconditionally.
We make a new signing key unconditionally when --keygen is provided.
We never overwrite a master key.
---
src/or/config.c | 5 +-
src/or/main.c | 3 ++
src/or/or.h | 3 +-
src/or/routerkeys.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++--
src/or/routerkeys.h | 6 +++
5 files changed, 161 insertions(+), 5 deletions(-)
diff --git a/src/or/config.c b/src/or/config.c
index ef249a6..d81bc53 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -1909,6 +1909,7 @@ static const struct {
{ "--hash-password", ARGUMENT_NECESSARY },
{ "--dump-config", ARGUMENT_OPTIONAL },
{ "--list-fingerprint", TAKES_NO_ARGUMENT },
+ { "--keygen", TAKES_NO_ARGUMENT },
{ "--verify-config", TAKES_NO_ARGUMENT },
{ "--ignore-missing-torrc", TAKES_NO_ARGUMENT },
{ "--quiet", TAKES_NO_ARGUMENT },
@@ -4434,7 +4435,9 @@ options_init_from_torrc(int argc, char **argv)
command = CMD_RUN_TOR;
for (p_index = cmdline_only_options; p_index; p_index = p_index->next) {
- if (!strcmp(p_index->key,"--list-fingerprint")) {
+ if (!strcmp(p_index->key,"--keygen")) {
+ command = CMD_KEYGEN;
+ } else if (!strcmp(p_index->key,"--list-fingerprint")) {
command = CMD_LIST_FINGERPRINT;
} else if (!strcmp(p_index->key, "--hash-password")) {
command = CMD_HASH_PASSWORD;
diff --git a/src/or/main.c b/src/or/main.c
index bbee8e0..d9ef88b 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -3162,6 +3162,9 @@ tor_main(int argc, char *argv[])
#endif
result = do_main_loop();
break;
+ case CMD_KEYGEN:
+ result = load_ed_keys(get_options(), time(NULL));
+ break;
case CMD_LIST_FINGERPRINT:
result = do_list_fingerprint();
break;
diff --git a/src/or/or.h b/src/or/or.h
index 81e1c1c..230bc47 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3405,7 +3405,8 @@ typedef struct {
/** What should the tor process actually do? */
enum {
CMD_RUN_TOR=0, CMD_LIST_FINGERPRINT, CMD_HASH_PASSWORD,
- CMD_VERIFY_CONFIG, CMD_RUN_UNITTESTS, CMD_DUMP_CONFIG
+ CMD_VERIFY_CONFIG, CMD_RUN_UNITTESTS, CMD_DUMP_CONFIG,
+ CMD_KEYGEN
} command;
char *command_arg; /**< Argument for command-line option. */
diff --git a/src/or/routerkeys.c b/src/or/routerkeys.c
index 556ab45..63d61c3 100644
--- a/src/or/routerkeys.c
+++ b/src/or/routerkeys.c
@@ -4,9 +4,130 @@
#include "or.h"
#include "config.h"
#include "router.h"
+#include "crypto_pwbox.h"
#include "routerkeys.h"
#include "torcert.h"
+#define ENC_KEY_HEADER "Boxed Ed25519 key"
+#define ENC_KEY_TAG "master"
+
+int
+read_encrypted_secret_key(ed25519_secret_key_t *out,
+ const char *fname)
+{
+ int r = -1;
+ uint8_t *secret = NULL;
+ size_t secret_len = 0;
+ char pwbuf[256];
+ uint8_t encrypted_key[256];
+ char *tag = NULL;
+
+ ssize_t encrypted_len = crypto_read_tagged_contents_from_file(fname,
+ ENC_KEY_HEADER,
+ &tag,
+ encrypted_key,
+ sizeof(encrypted_key));
+ if (encrypted_len < 0) {
+ log_info(LD_OR, "%s is missing", fname);
+ return 0;
+ }
+ if (strcmp(tag, ENC_KEY_TAG))
+ return -1;
+
+ while (1) {
+ ssize_t pwlen =
+ tor_getpass("Enter pasphrase for master key:", pwbuf, sizeof(pwbuf));
+ if (pwlen < 0)
+ goto done;
+
+ const int r = crypto_unpwbox(&secret, &secret_len,
+ encrypted_key, encrypted_len,
+ pwbuf, pwlen);
+ if (r == UNPWBOX_CORRUPTED) {
+ log_err(LD_OR, "%s is corrupted.", fname);
+ goto done;
+ } else if (r == UNPWBOX_OKAY) {
+ break;
+ }
+ /* Otherwise, passphrase is bad, so try again till user does ctrl-c or gets
+ * it right. */
+ }
+
+
+ if (secret_len != ED25519_SECKEY_LEN) {
+ log_err(LD_OR, "%s is corrupted.", fname);
+ goto done;
+ }
+ memcpy(out->seckey, secret, ED25519_SECKEY_LEN);
+ r = 1;
+
+ done:
+ memwipe(encrypted_key, 0, encrypted_len);
+ memwipe(pwbuf, 0, sizeof(pwbuf));
+ if (secret) {
+ memwipe(secret, 0, secret_len);
+ tor_free(secret);
+ }
+ return r;
+}
+
+int
+write_encrypted_secret_key(const ed25519_secret_key_t *key,
+ const char *fname)
+{
+ int r = -1;
+ char pwbuf0[256], pwbuf1[256];
+ uint8_t *encrypted_key = NULL;
+ size_t encrypted_len = 0;
+
+ while (1) {
+ if (tor_getpass("Enter passphrase:", pwbuf0, sizeof(pwbuf0)) < 0)
+ return -1;
+ if (tor_getpass(" One more time:", pwbuf1, sizeof(pwbuf1)) < 0)
+ return -1;
+
+ if (!strcmp(pwbuf0, pwbuf1))
+ break;
+ fprintf(stderr, "That didn't match.\n");
+ }
+ if (0 == strlen(pwbuf0))
+ return 0;
+ if (crypto_pwbox(&encrypted_key, &encrypted_len,
+ key->seckey, sizeof(key->seckey),
+ pwbuf0, strlen(pwbuf0), 0) < 0) {
+ log_warn(LD_OR, "crypto_pwbox failed!?");
+ goto done;
+ }
+ if (crypto_write_tagged_contents_to_file(fname,
+ ENC_KEY_HEADER,
+ ENC_KEY_TAG,
+ encrypted_key, encrypted_len) < 0)
+ goto done;
+ r = 1;
+ done:
+ if (encrypted_key) {
+ memwipe(encrypted_key, 0, encrypted_len);
+ tor_free(encrypted_key);
+ }
+ memwipe(pwbuf0, 0, sizeof(pwbuf0));
+ memwipe(pwbuf1, 0, sizeof(pwbuf1));
+ return r;
+}
+
+static int
+write_secret_key(const ed25519_secret_key_t *key, int encrypted,
+ const char *fname,
+ const char *fname_tag,
+ const char *encrypted_fname)
+{
+ if (encrypted) {
+ int r = write_encrypted_secret_key(key, encrypted_fname);
+ if (r != 0)
+ return r;
+ }
+ return ed25519_seckey_write_to_file(key, fname, fname_tag);
+}
+
/**
* Read an ed25519 key and associated certificates from files beginning with
* <b>fname</b>, with certificate type <b>cert_type</b>. On failure, return
@@ -38,6 +159,9 @@
*
* If INIT_ED_KEY_OMIT_SECRET is set in <b>flags</b>, do not even try to
* load or return a secret key (but create and save on if needed).
+ *
+ * If INIT_ED_KEY_TRY_ENCRYPTED is set, we look for an encrypted secret key
+ * and consider encrypting any new secret key.
*/
ed25519_keypair_t *
ed_key_init_from_file(const char *fname, uint32_t flags,
@@ -49,10 +173,12 @@ ed_key_init_from_file(const char *fname, uint32_t flags,
struct tor_cert_st **cert_out)
{
char *secret_fname = NULL;
+ char *encrypted_secret_fname = NULL;
char *public_fname = NULL;
char *cert_fname = NULL;
int created_pk = 0, created_sk = 0, created_cert = 0;
const int try_to_load = ! (flags & INIT_ED_KEY_REPLACE);
+ const int encrypt_key = (flags & INIT_ED_KEY_TRY_ENCRYPTED);
char tag[8];
tor_snprintf(tag, sizeof(tag), "type%d", (int)cert_type);
@@ -62,15 +188,26 @@ ed_key_init_from_file(const char *fname, uint32_t flags,
ed25519_keypair_t *keypair = tor_malloc_zero(sizeof(ed25519_keypair_t));
tor_asprintf(&secret_fname, "%s_secret_key", fname);
+ tor_asprintf(&encrypted_secret_fname, "%s_secret_key_encrypted", fname);
tor_asprintf(&public_fname, "%s_public_key", fname);
tor_asprintf(&cert_fname, "%s_cert", fname);
/* Try to read the secret key. */
- const int have_secret = try_to_load &&
+ int have_secret = try_to_load &&
!(flags & INIT_ED_KEY_OMIT_SECRET) &&
ed25519_seckey_read_from_file(&keypair->seckey,
&got_tag, secret_fname) == 0;
+ /* Should we try for an encrypted key? */
+ if (!have_secret && try_to_load && encrypt_key) {
+ int r = read_encrypted_secret_key(&keypair->seckey,
+ encrypted_secret_fname);
+ if (r > 0) {
+ have_secret = 1;
+ got_tag = tor_strdup(tag);
+ }
+ }
+
if (have_secret) {
if (strcmp(got_tag, tag)) {
tor_log(severity, LD_OR, "%s has wrong tag", secret_fname);
@@ -115,7 +252,9 @@ ed_key_init_from_file(const char *fname, uint32_t flags,
}
created_pk = created_sk = created_cert = 1;
- if (ed25519_seckey_write_to_file(&keypair->seckey, secret_fname, tag) < 0
+ if (write_secret_key(&keypair->seckey,
+ encrypt_key,
+ secret_fname, tag, encrypted_secret_fname) < 0
||
(split &&
ed25519_pubkey_write_to_file(&keypair->pubkey, public_fname, tag) < 0)
@@ -214,6 +353,7 @@ ed_key_init_from_file(const char *fname, uint32_t flags,
unlink(cert_fname);
cleanup:
+ tor_free(encrypted_secret_fname);
tor_free(secret_fname);
tor_free(public_fname);
tor_free(cert_fname);
@@ -324,7 +464,8 @@ load_ed_keys(const or_options_t *options, time_t now)
const int need_new_signing_key =
NULL == use_signing ||
- EXPIRES_SOON(check_signing_cert, 0);
+ EXPIRES_SOON(check_signing_cert, 0) ||
+ options->command == CMD_KEYGEN;
const int want_new_signing_key =
need_new_signing_key ||
EXPIRES_SOON(check_signing_cert, options->TestingSigningKeySlop);
@@ -337,6 +478,8 @@ load_ed_keys(const or_options_t *options, time_t now)
flags |= INIT_ED_KEY_MISSING_SECRET_OK;
if (! want_new_signing_key)
flags |= INIT_ED_KEY_OMIT_SECRET;
+ if (options->command == CMD_KEYGEN)
+ flags |= INIT_ED_KEY_TRY_ENCRYPTED;
id = ed_key_init_from_file(
options_get_datadir_fname2(options, "keys", "ed25519_master_id"),
diff --git a/src/or/routerkeys.h b/src/or/routerkeys.h
index b45a22a..1e0199e 100644
--- a/src/or/routerkeys.h
+++ b/src/or/routerkeys.h
@@ -14,6 +14,7 @@
#define INIT_ED_KEY_EXTRA_STRONG (1u<<5)
#define INIT_ED_KEY_INCLUDE_SIGNING_KEY_IN_CERT (1u<<6)
#define INIT_ED_KEY_OMIT_SECRET (1u<<7)
+#define INIT_ED_KEY_TRY_ENCRYPTED (1u<<8)
struct tor_cert_st;
ed25519_keypair_t *ed_key_init_from_file(const char *fname, uint32_t flags,
@@ -61,6 +62,11 @@ int should_make_new_ed_keys(const or_options_t *options,
const time_t now);
int generate_ed_link_cert(const or_options_t *options, time_t now);
+int read_encrypted_secret_key(ed25519_secret_key_t *out,
+ const char *fname);
+int write_encrypted_secret_key(const ed25519_secret_key_t *out,
+ const char *fname);
+
void routerkeys_free_all(void);
#endif
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