From 89c975cc25d4e7c5040a3f657b732dd1704bfb2b Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Thu, 11 Apr 2019 12:11:00 +0200 Subject: prf: add function to retrieve early keying material This adds a new function gnutls_prf_early, which shall be called in a handshake hook waiting for GNUTLS_HANDSHAKE_CLIENT_HELLO. The test needs to be run in a datefudge wrapper as the early secrets depend on the current time (through PSK). Signed-off-by: Daiki Ueno --- .gitignore | 1 + NEWS | 4 +- devel/libgnutls-latest-x86_64.abi | 1 + devel/symbols.last | 1 + doc/Makefile.am | 2 + doc/manpages/Makefile.am | 1 + lib/includes/gnutls/gnutls.h.in | 4 + lib/libgnutls.map | 1 + lib/prf.c | 116 +++++++--- tests/Makefile.am | 4 +- tests/tls13/prf-early.c | 464 ++++++++++++++++++++++++++++++++++++++ tests/tls13/prf-early.sh | 29 +++ 12 files changed, 599 insertions(+), 29 deletions(-) create mode 100644 tests/tls13/prf-early.c create mode 100755 tests/tls13/prf-early.sh diff --git a/.gitignore b/.gitignore index 6716e4c728..0e33b02d40 100644 --- a/.gitignore +++ b/.gitignore @@ -830,6 +830,7 @@ tests/tls13/post-handshake-with-cert-ticket tests/tls13/post-handshake-with-psk tests/tls13/post-handshake-without-cert tests/tls13/prf +tests/tls13/prf-early tests/tls13/psk-dumbfw tests/tls13/psk-ext tests/tls13/supported_versions diff --git a/NEWS b/NEWS index 0be3696576..0ada7c1a31 100644 --- a/NEWS +++ b/NEWS @@ -9,8 +9,10 @@ See the end for copying conditions. ** libgnutls: Added support for AES-XTS cipher (#354) +** libgnutls: Added new function to retrieve early keying material (#329) + ** API and ABI modifications: -No changes since last version. +gnutls_prf_early: Added * Version 3.6.7 (released 2019-03-27) diff --git a/devel/libgnutls-latest-x86_64.abi b/devel/libgnutls-latest-x86_64.abi index 9e23e0221c..c4659d954b 100644 --- a/devel/libgnutls-latest-x86_64.abi +++ b/devel/libgnutls-latest-x86_64.abi @@ -587,6 +587,7 @@ + diff --git a/devel/symbols.last b/devel/symbols.last index e5f0e01c69..d9dedea09c 100644 --- a/devel/symbols.last +++ b/devel/symbols.last @@ -553,6 +553,7 @@ gnutls_pkcs8_info@GNUTLS_3_4 gnutls_pkcs_schema_get_name@GNUTLS_3_4 gnutls_pkcs_schema_get_oid@GNUTLS_3_4 gnutls_prf@GNUTLS_3_4 +gnutls_prf_early@GNUTLS_3_6_6 gnutls_prf_raw@GNUTLS_3_4 gnutls_prf_rfc5705@GNUTLS_3_4 gnutls_priority_certificate_type_list2@GNUTLS_3_6_4 diff --git a/doc/Makefile.am b/doc/Makefile.am index 19982f5ad8..c60d0e46dd 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -1547,6 +1547,8 @@ FUNCS += functions/gnutls_pk_to_sign FUNCS += functions/gnutls_pk_to_sign.short FUNCS += functions/gnutls_prf FUNCS += functions/gnutls_prf.short +FUNCS += functions/gnutls_prf_early +FUNCS += functions/gnutls_prf_early.short FUNCS += functions/gnutls_prf_raw FUNCS += functions/gnutls_prf_raw.short FUNCS += functions/gnutls_prf_rfc5705 diff --git a/doc/manpages/Makefile.am b/doc/manpages/Makefile.am index 0aab479df2..bbf4220c09 100644 --- a/doc/manpages/Makefile.am +++ b/doc/manpages/Makefile.am @@ -575,6 +575,7 @@ APIMANS += gnutls_pk_get_oid.3 APIMANS += gnutls_pk_list.3 APIMANS += gnutls_pk_to_sign.3 APIMANS += gnutls_prf.3 +APIMANS += gnutls_prf_early.3 APIMANS += gnutls_prf_raw.3 APIMANS += gnutls_prf_rfc5705.3 APIMANS += gnutls_priority_certificate_type_list.3 diff --git a/lib/includes/gnutls/gnutls.h.in b/lib/includes/gnutls/gnutls.h.in index 7fc96aaea1..0801203128 100644 --- a/lib/includes/gnutls/gnutls.h.in +++ b/lib/includes/gnutls/gnutls.h.in @@ -1471,6 +1471,10 @@ int gnutls_prf_rfc5705(gnutls_session_t session, size_t label_size, const char *label, size_t context_size, const char *context, size_t outsize, char *out); +int gnutls_prf_early(gnutls_session_t session, + size_t label_size, const char *label, + size_t context_size, const char *context, + size_t outsize, char *out); int gnutls_prf_raw(gnutls_session_t session, size_t label_size, const char *label, diff --git a/lib/libgnutls.map b/lib/libgnutls.map index 19c9f535f9..d10e22b20e 100644 --- a/lib/libgnutls.map +++ b/lib/libgnutls.map @@ -1271,6 +1271,7 @@ GNUTLS_3_6_6 gnutls_certificate_set_rawpk_key_file; gnutls_pcert_import_rawpk; gnutls_pcert_import_rawpk_raw; + gnutls_prf_early; } GNUTLS_3_6_5; GNUTLS_FIPS140_3_4 { diff --git a/lib/prf.c b/lib/prf.c index 19e25cfa8d..6708b00db2 100644 --- a/lib/prf.c +++ b/lib/prf.c @@ -89,6 +89,36 @@ gnutls_prf_raw(gnutls_session_t session, return ret; } +static int +_tls13_derive_exporter(const mac_entry_st *prf, + gnutls_session_t session, + size_t label_size, const char *label, + size_t context_size, const char *context, + size_t outsize, char *out, + bool early) +{ + uint8_t secret[MAX_HASH_SIZE]; + uint8_t digest[MAX_HASH_SIZE]; + unsigned digest_size = prf->output_size; + int ret; + + ret = _tls13_derive_secret2(prf, label, label_size, NULL, 0, + session->key.proto.tls13.ap_expkey, + secret); + if (ret < 0) + return gnutls_assert_val(ret); + + ret = gnutls_hash_fast((gnutls_digest_algorithm_t)prf->id, + context, context_size, digest); + if (ret < 0) + return gnutls_assert_val(ret); + + return _tls13_expand_secret2(prf, + EXPORTER_LABEL, sizeof(EXPORTER_LABEL)-1, + digest, digest_size, + secret, outsize, out); +} + /** * gnutls_prf_rfc5705: * @session: is a #gnutls_session_t type. @@ -99,8 +129,8 @@ gnutls_prf_raw(gnutls_session_t session, * @outsize: size of pre-allocated output buffer to hold the output. * @out: pre-allocated buffer to hold the generated data. * - * Exports keyring material from TLS/DTLS session to an application, - * as specified in RFC5705. + * Exports keying material from TLS/DTLS session to an application, as + * specified in RFC5705. * * In the TLS versions prior to 1.3, it applies the TLS * Pseudo-Random-Function (PRF) on the master secret and the provided @@ -136,30 +166,12 @@ gnutls_prf_rfc5705(gnutls_session_t session, int ret; if (vers && vers->tls13_sem) { - uint8_t secret[MAX_HASH_SIZE]; - uint8_t digest[MAX_HASH_SIZE]; - unsigned digest_size = session->security_parameters.prf->output_size; - - /* exporter_master_secret might not be set, when - * handshake is in progress */ - if (session->internals.handshake_in_progress) { - gnutls_assert(); - return GNUTLS_E_INVALID_REQUEST; - } - - ret = _tls13_derive_secret(session, label, label_size, NULL, 0, - session->key.proto.tls13.ap_expkey, secret); - if (ret < 0) - return gnutls_assert_val(ret); - - ret = gnutls_hash_fast((gnutls_digest_algorithm_t)session->security_parameters.prf->id, - context, context_size, digest); - if (ret < 0) - return gnutls_assert_val(ret); - - ret = _tls13_expand_secret(session, EXPORTER_LABEL, sizeof(EXPORTER_LABEL)-1, - digest, digest_size, - secret, outsize, out); + ret = _tls13_derive_exporter(session->security_parameters.prf, + session, + label_size, label, + context_size, context, + outsize, out, + 0); } else { char *pctx = NULL; @@ -189,6 +201,58 @@ gnutls_prf_rfc5705(gnutls_session_t session, return ret; } +/** + * gnutls_prf_early: + * @session: is a #gnutls_session_t type. + * @label_size: length of the @label variable. + * @label: label used in PRF computation, typically a short string. + * @context_size: length of the @extra variable. + * @context: optional extra data to seed the PRF with. + * @outsize: size of pre-allocated output buffer to hold the output. + * @out: pre-allocated buffer to hold the generated data. + * + * This function is similar to gnutls_prf_rfc5705(), but only works in + * TLS 1.3 or later to export early keying material. + * + * Note that the keying material is only available after the + * ClientHello message is processed and before the application traffic + * keys are established. Therefore this function shall be called in a + * handshake hook function for %GNUTLS_HANDSHAKE_CLIENT_HELLO. + * + * The @label variable usually contains a string denoting the purpose + * for the generated data. + * + * The @context variable can be used to add more data to the seed, after + * the random variables. It can be used to make sure the + * generated output is strongly connected to some additional data + * (e.g., a string used in user authentication). + * + * The output is placed in @out, which must be pre-allocated. + * + * Note that, to provide the RFC5705 context, the @context variable + * must be non-null. + * + * Returns: %GNUTLS_E_SUCCESS on success, or an error code. + * + * Since: 3.6.6 + **/ +int +gnutls_prf_early(gnutls_session_t session, + size_t label_size, const char *label, + size_t context_size, const char *context, + size_t outsize, char *out) +{ + if (session->internals.initial_negotiation_completed || + session->key.binders[0].prf == NULL) + return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST); + + return _tls13_derive_exporter(session->key.binders[0].prf, session, + label_size, label, + context_size, context, + outsize, out, + 1); +} + /** * gnutls_prf: * @session: is a #gnutls_session_t type. diff --git a/tests/Makefile.am b/tests/Makefile.am index 96e10bfc5b..3917967988 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -104,7 +104,7 @@ noinst_LTLIBRARIES = libutils.la libutils_la_SOURCES = utils.h utils.c seccomp.c utils-adv.c libutils_la_LIBADD = ../lib/libgnutls.la -indirect_tests = +indirect_tests = tls13/prf-early ctests = tls13/supported_versions tls13/tls12-no-tls13-exts \ tls13/post-handshake-with-cert tls13/post-handshake-without-cert \ tls13/cookie tls13/key_share tls13/prf tls13/post-handshake-with-cert-ticket \ @@ -458,7 +458,7 @@ tls13_post_handshake_with_cert_pkcs11_LDADD = $(LDADD) $(LIBDL) endif endif -dist_check_SCRIPTS = rfc2253-escape-test rsa-md5-collision/rsa-md5-collision.sh systemkey.sh +dist_check_SCRIPTS = rfc2253-escape-test rsa-md5-collision/rsa-md5-collision.sh systemkey.sh tls13/prf-early.sh if !WINDOWS diff --git a/tests/tls13/prf-early.c b/tests/tls13/prf-early.c new file mode 100644 index 0000000000..758f78efe7 --- /dev/null +++ b/tests/tls13/prf-early.c @@ -0,0 +1,464 @@ +/* + * Copyright (C) 2015-2019 Red Hat, Inc. + * + * This file is part of GnuTLS. + * + * GnuTLS is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * GnuTLS is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program. If not, see + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include +#include +#include + +#if !defined(__linux__) || !defined(__GNUC__) + +int main(int argc, char **argv) +{ + exit(77); +} + +#else + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "cert-common.h" +#include "utils.h" +#include "virt-time.h" + +static void terminate(void); + +#define SESSIONS 2 +#define MAX_BUF 5*1024 +#define MSG "Hello TLS" + +/* This program tests whether the gnutls_prf() works as + * expected. + */ + +static void server_log_func(int level, const char *str) +{ + fprintf(stderr, "server|<%d>| %s", level, str); +} + +static void client_log_func(int level, const char *str) +{ + fprintf(stderr, "client|<%d>| %s", level, str); +} + +/* These are global */ +static pid_t child; + +static const +gnutls_datum_t hrnd = {(void*)"\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 32}; +static const +gnutls_datum_t hsrnd = {(void*)"\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 32}; + +static int gnutls_rnd_works; + +int __attribute__ ((visibility ("protected"))) +gnutls_rnd(gnutls_rnd_level_t level, void *data, size_t len) +{ + gnutls_rnd_works = 1; + + memset(data, 0xff, len); + + /* Flip the first byte to avoid infinite loop in the RSA + * blinding code of Nettle */ + if (len > 0) + memset(data, 0x0, 1); + return 0; +} + +static gnutls_datum_t session_ticket_key = { NULL, 0 }; + +static void dump(const char *name, const uint8_t *data, unsigned data_size) +{ + unsigned i; + + fprintf(stderr, "%s", name); + for (i=0;i 0) { + gnutls_session_set_data(session, session_data.data, + session_data.size); + gnutls_handshake_set_hook_function(session, GNUTLS_HANDSHAKE_CLIENT_HELLO, + GNUTLS_HOOK_POST, + handshake_callback); + } + + /* Perform the TLS handshake + */ + do { + ret = gnutls_handshake(session); + } + while (ret < 0 && gnutls_error_is_fatal(ret) == 0); + + if (ret < 0) { + fail("client: Handshake failed: %s\n", strerror(ret)); + exit(1); + } else { + if (debug) + success("client: Handshake was completed\n"); + } + + if (debug) + success("client: TLS version is: %s\n", + gnutls_protocol_get_name + (gnutls_protocol_get_version(session))); + + ret = gnutls_cipher_get(session); + if (ret != GNUTLS_CIPHER_AES_256_GCM) { + fprintf(stderr, "negotiated unexpected cipher: %s\n", gnutls_cipher_get_name(ret)); + exit(1); + } + + ret = gnutls_mac_get(session); + if (ret != GNUTLS_MAC_AEAD) { + fprintf(stderr, "negotiated unexpected mac: %s\n", gnutls_mac_get_name(ret)); + exit(1); + } + + if (t == 0) { + /* get the session data size */ + ret = + gnutls_session_get_data2(session, + &session_data); + if (ret < 0) + fail("Getting resume data failed\n"); + + if (handshake_callback_called != 0) + fail("client: handshake callback is called\n"); + } else { + if (handshake_callback_called != t) + fail("client: handshake callback is not called\n"); + } + + gnutls_record_send(session, MSG, strlen(MSG)); + + do { + ret = gnutls_record_recv(session, buffer, MAX_BUF); + } while (ret == GNUTLS_E_AGAIN); + if (ret == 0) { + if (debug) + success + ("client: Peer has closed the TLS connection\n"); + } else if (ret < 0) { + fail("client: Error: %s\n", gnutls_strerror(ret)); + } + + if (debug) { + printf("- Received %d bytes: ", ret); + for (ii = 0; ii < ret; ii++) { + fputc(buffer[ii], stdout); + } + fputs("\n", stdout); + } + + gnutls_bye(session, GNUTLS_SHUT_WR); + + close(sds[t]); + + gnutls_deinit(session); + } + + gnutls_free(session_data.data); + gnutls_certificate_free_credentials(clientx509cred); + + gnutls_global_deinit(); +} + +static void terminate(void) +{ + int status = 0; + + kill(child, SIGTERM); + wait(&status); + exit(1); +} + +static void server(int sds[]) +{ + int ret; + gnutls_session_t session; + gnutls_certificate_credentials_t serverx509cred; + int t; + char buffer[MAX_BUF + 1]; + + /* this must be called once in the program + */ + global_init(); + + virt_time_init(); + + if (debug) { + gnutls_global_set_log_function(server_log_func); + gnutls_global_set_log_level(4711); + } + + gnutls_certificate_allocate_credentials(&serverx509cred); + + gnutls_session_ticket_key_generate(&session_ticket_key); + + for (t = 0; t < SESSIONS; t++) { + gnutls_init(&session, GNUTLS_SERVER); + + gnutls_session_ticket_enable_server(session, + &session_ticket_key); + + /* avoid calling all the priority functions, since the defaults + * are adequate. + */ + ret = gnutls_priority_set_direct(session, + "NORMAL:-VERS-ALL:+VERS-TLS1.3:-KX-ALL:-SIGN-ALL:+SIGN-RSA-PSS-RSAE-SHA384:-GROUP-ALL:+GROUP-SECP256R1", NULL); + if (ret < 0) { + fail("server: priority set failed (%s)\n\n", + gnutls_strerror(ret)); + terminate(); + } + + gnutls_certificate_set_x509_key_mem(serverx509cred, + &server_cert, &server_key, + GNUTLS_X509_FMT_PEM); + gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, + serverx509cred); + + gnutls_handshake_set_random(session, &hsrnd); + gnutls_transport_set_int(session, sds[t]); + + if (t > 0) { + if (!gnutls_rnd_works) { + fprintf(stderr, "gnutls_rnd() could not be overridden, skipping prf checks see #584\n"); + exit(77); + } else { + gnutls_handshake_set_hook_function(session, GNUTLS_HANDSHAKE_CLIENT_HELLO, + GNUTLS_HOOK_POST, + handshake_callback); + } + } + + do { + ret = gnutls_handshake(session); + } + while (ret < 0 && gnutls_error_is_fatal(ret) == 0); + if (ret < 0) { + close(sds[t]); + gnutls_deinit(session); + fail("server: Handshake has failed (%s)\n\n", + gnutls_strerror(ret)); + terminate(); + } + if (debug) + success("server: Handshake was completed\n"); + + if (debug) + success("server: TLS version is: %s\n", + gnutls_protocol_get_name + (gnutls_protocol_get_version(session))); + + if (t == 0) { + if (handshake_callback_called != 0) + fail("server: handshake callback is called\n"); + } else { + if (handshake_callback_called != t) + fail("server: handshake callback is not called\n"); + } + + for (;;) { + memset(buffer, 0, MAX_BUF + 1); + ret = gnutls_record_recv(session, buffer, MAX_BUF); + + if (ret == 0) { + if (debug) + success + ("server: Peer has closed the GnuTLS connection\n"); + break; + } else if (ret < 0) { + kill(child, SIGTERM); + fail("server: Received corrupted data(%d). Closing...\n", ret); + break; + } else if (ret > 0) { + /* echo data back to the client + */ + gnutls_record_send(session, buffer, + strlen(buffer)); + } + } + + /* do not wait for the peer to close the connection. + */ + gnutls_bye(session, GNUTLS_SHUT_WR); + + close(sds[t]); + gnutls_deinit(session); + } + + gnutls_certificate_free_credentials(serverx509cred); + + gnutls_free(session_ticket_key.data); + session_ticket_key.data = NULL; + + gnutls_global_deinit(); + + if (debug) + success("server: finished\n"); +} + +void doit(void) +{ + int client_sds[SESSIONS], server_sds[SESSIONS]; + int i; + int ret; + + signal(SIGPIPE, SIG_IGN); + + for (i = 0; i < SESSIONS; i++) { + int sockets[2]; + + ret = socketpair(AF_UNIX, SOCK_STREAM, 0, sockets); + if (ret == -1) { + perror("socketpair"); + fail("socketpair failed\n"); + return; + } + + server_sds[i] = sockets[0]; + client_sds[i] = sockets[1]; + } + + child = fork(); + if (child < 0) { + perror("fork"); + fail("fork"); + exit(1); + } + + if (child) { + int status = 0; + /* parent */ + + for (i = 0; i < SESSIONS; i++) + close(client_sds[i]); + server(server_sds); + wait(&status); + check_wait_status(status); + } else { + for (i = 0; i < SESSIONS; i++) + close(server_sds[i]); + client(client_sds); + exit(0); + } +} + +#endif /* _WIN32 */ diff --git a/tests/tls13/prf-early.sh b/tests/tls13/prf-early.sh new file mode 100755 index 0000000000..5b5ff0c33b --- /dev/null +++ b/tests/tls13/prf-early.sh @@ -0,0 +1,29 @@ +#!/bin/sh + +# Copyright (C) 2019 Daiki Ueno +# +# This file is part of GnuTLS. +# +# GnuTLS is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation; either version 3 of the License, or (at +# your option) any later version. +# +# GnuTLS is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with this program. If not, see +# + +srcdir="${srcdir:-.}" +builddir="${builddir:-.}" + +. "${srcdir}/scripts/common.sh" + +check_for_datefudge + +datefudge 2019-04-12 "${builddir}/tls13/prf-early" "$@" +exit $? -- cgit v1.2.1