commit 64450c5f775c6453568c5ac218669ff0525dc232 Author: Nick Mathewson <nickm@torproject.org> Date: Sun Mar 1 14:05:00 2015 +0100 Only load master ed25519 secret keys when we absolutely must. --- src/or/routerkeys.c | 88 +++++++++++++++++++++++++++++++++++++++------------ src/or/routerkeys.h | 1 + 2 files changed, 68 insertions(+), 21 deletions(-) diff --git a/src/or/routerkeys.c b/src/or/routerkeys.c index 9ad5a89..ab12b90 100644 --- a/src/or/routerkeys.c +++ b/src/or/routerkeys.c @@ -34,6 +34,9 @@ * * If INIT_ED_KEY_MISSING_SECRET_OK is set in <b>flags</b>, and we find a * public key file but no secret key file, return successfully anyway. + * + * 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). */ ed25519_keypair_t * ed_key_init_from_file(const char *fname, uint32_t flags, @@ -63,6 +66,7 @@ ed_key_init_from_file(const char *fname, uint32_t flags, /* Try to read the secret key. */ const int have_secret = try_to_load && + !(flags & INIT_ED_KEY_OMIT_SECRET) && ed25519_seckey_read_from_file(&keypair->seckey, &got_tag, secret_fname) == 0; @@ -80,7 +84,7 @@ ed_key_init_from_file(const char *fname, uint32_t flags, /* If it's absent and that's okay, try to read the pubkey. */ int found_public = 0; - if (!have_secret && try_to_load && (flags & INIT_ED_KEY_MISSING_SECRET_OK)) { + if (!have_secret && try_to_load) { tor_free(got_tag); found_public = ed25519_pubkey_read_from_file(&keypair->pubkey, &got_tag, public_fname) == 0; @@ -90,6 +94,10 @@ ed_key_init_from_file(const char *fname, uint32_t flags, } } + /* If the secret key is absent and it's not allowed to be, fail. */ + if (!have_secret && found_public && !(flags & INIT_ED_KEY_MISSING_SECRET_OK)) + goto err; + /* If it's absent, and we're not supposed to make a new keypair, fail. */ if (!have_secret && !found_public && !(flags & INIT_ED_KEY_CREATE)) goto err; @@ -274,7 +282,9 @@ load_ed_keys(const or_options_t *options, time_t now) ed25519_keypair_t *sign = NULL; ed25519_keypair_t *link = NULL; ed25519_keypair_t *auth = NULL; + const ed25519_keypair_t *sign_signing_key_with_id = NULL; const ed25519_keypair_t *use_signing = NULL; + const tor_cert_t *check_signing_cert = NULL; tor_cert_t *sign_cert = NULL; tor_cert_t *link_cert = NULL; tor_cert_t *auth_cert = NULL; @@ -299,40 +309,76 @@ load_ed_keys(const or_options_t *options, time_t now) /* XXXX use options. */ (void) options; - id = ed_key_init_from_file( + /* First try to get the signing key to see how it is. */ + if (master_signing_key) { + check_signing_cert = signing_key_cert; + use_signing = master_signing_key; + } else { + sign = ed_key_init_from_file( + options_get_datadir_fname2(options, "keys", "ed25519_signing"), + INIT_ED_KEY_NEEDCERT| + INIT_ED_KEY_INCLUDE_SIGNING_KEY_IN_CERT, + LOG_INFO, + NULL, 0, 0, CERT_TYPE_ID_SIGNING, &sign_cert); + check_signing_cert = sign_cert; + use_signing = sign; + } + + const int need_new_signing_key = + NULL == use_signing || + EXPIRES_SOON(check_signing_cert, 0); + const int want_new_signing_key = + need_new_signing_key || + EXPIRES_SOON(check_signing_cert, 86400/*???*/); + + { + uint32_t flags = + (INIT_ED_KEY_CREATE|INIT_ED_KEY_SPLIT| + INIT_ED_KEY_EXTRA_STRONG); + if (! need_new_signing_key) + flags |= INIT_ED_KEY_MISSING_SECRET_OK; + if (! want_new_signing_key) + flags |= INIT_ED_KEY_OMIT_SECRET; + + id = ed_key_init_from_file( options_get_datadir_fname2(options, "keys", "ed25519_master_id"), - (INIT_ED_KEY_CREATE|INIT_ED_KEY_SPLIT| - INIT_ED_KEY_MISSING_SECRET_OK| - INIT_ED_KEY_EXTRA_STRONG), - LOG_WARN, NULL, 0, 0, 0, NULL); - if (!id) - FAIL("Missing identity key"); - - if (!master_signing_key || EXPIRES_SOON(signing_key_cert, 86400/*???*/)) { + flags, + LOG_WARN, NULL, 0, 0, 0, NULL); + if (!id) + FAIL("Missing identity key"); + if (tor_mem_is_zero((char*)id->seckey.seckey, sizeof(id->seckey))) + sign_signing_key_with_id = NULL; + else + sign_signing_key_with_id = id; + } + + if (need_new_signing_key && NULL == sign_signing_key_with_id) + FAIL("Can't load master key make a new signing key."); + + if (want_new_signing_key && sign_signing_key_with_id) { uint32_t flags = (INIT_ED_KEY_CREATE| + INIT_ED_KEY_REPLACE| INIT_ED_KEY_EXTRA_STRONG| INIT_ED_KEY_NEEDCERT| INIT_ED_KEY_INCLUDE_SIGNING_KEY_IN_CERT); - const ed25519_keypair_t *sign_with_id = id; - if (master_signing_key) { - flags |= INIT_ED_KEY_REPLACE; /* it's expired, so force-replace it. */ - } - if (tor_mem_is_zero((char*)id->seckey.seckey, sizeof(id->seckey))) { - sign_with_id = NULL; - flags &= ~INIT_ED_KEY_CREATE; - } sign = ed_key_init_from_file( options_get_datadir_fname2(options, "keys", "ed25519_signing"), flags, LOG_WARN, - sign_with_id, now, 30*86400/*XXX option*/, + sign_signing_key_with_id, now, + 30*86400/*XXX option*/, CERT_TYPE_ID_SIGNING, &sign_cert); if (!sign) FAIL("Missing signing key"); use_signing = sign; - } else { - use_signing = master_signing_key; + } else if (want_new_signing_key) { + static ratelim_t missing_master = RATELIM_INIT(3600); + log_fn_ratelim(&missing_master, LOG_WARN, LD_OR, + "Signing key will expire soon, but I can't load the " + "master key to sign a new one!"); } + tor_assert(use_signing); + /* At this point we no longer need our secret identity key. So wipe * it, if we loaded it in the first place. */ memwipe(id->seckey.seckey, 0, sizeof(id->seckey)); diff --git a/src/or/routerkeys.h b/src/or/routerkeys.h index 5e2ef45..6c188b7 100644 --- a/src/or/routerkeys.h +++ b/src/or/routerkeys.h @@ -13,6 +13,7 @@ #define INIT_ED_KEY_NEEDCERT (1u<<4) #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) struct tor_cert_st; ed25519_keypair_t *ed_key_init_from_file(const char *fname, uint32_t flags,