From 80770da39ebba0101079477611b7ce2f426653c5 Mon Sep 17 00:00:00 2001 From: Emilia Kasper Date: Fri, 17 Feb 2017 19:00:15 +0100 Subject: [PATCH] X509 time: tighten validation per RFC 5280 - Reject fractional seconds - Reject offsets - Check that the date/time digits are in valid range. - Add documentation for X509_cmp_time GH issue 2620 Reviewed-by: Richard Levitte Reviewed-by: Rich Salz --- CHANGES | 5 + crypto/x509/x509_vfy.c | 147 ++++++++-------------- doc/man3/X509_cmp_time.pod | 39 ++++++ test/build.info | 6 +- test/recipes/60-test_x509_time.t | 12 ++ test/x509_time_test.c | 201 +++++++++++++++++++++++++++++++ 6 files changed, 310 insertions(+), 100 deletions(-) create mode 100644 doc/man3/X509_cmp_time.pod create mode 100644 test/recipes/60-test_x509_time.t create mode 100644 test/x509_time_test.c diff --git a/CHANGES b/CHANGES index 3e91a0899e..cda3790cc1 100644 --- a/CHANGES +++ b/CHANGES @@ -4,6 +4,11 @@ Changes between 1.1.0e and 1.1.1 [xx XXX xxxx] + *) Certificate time validation (X509_cmp_time) enforces stricter + compliance with RFC 5280. Fractional seconds and timezone offsets + are no longer allowed. + [Emilia Käsper] + *) Add support for SipHash [Todd Short] diff --git a/crypto/x509/x509_vfy.c b/crypto/x509/x509_vfy.c index ebc4424005..2f1cd1ae3a 100644 --- a/crypto/x509/x509_vfy.c +++ b/crypto/x509/x509_vfy.c @@ -7,6 +7,7 @@ * https://www.openssl.org/source/license.html */ +#include #include #include #include @@ -1754,119 +1755,67 @@ int X509_cmp_current_time(const ASN1_TIME *ctm) int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time) { - char *str; - ASN1_TIME atm; - long offset; - char buff1[24], buff2[24], *p; - int i, j, remaining; + static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1; + static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1; + ASN1_TIME *asn1_cmp_time = NULL; + int i, day, sec, ret = 0; - p = buff1; - remaining = ctm->length; - str = (char *)ctm->data; /* - * Note that the following (historical) code allows much more slack in the - * time format than RFC5280. In RFC5280, the representation is fixed: + * Note that ASN.1 allows much more slack in the time format than RFC5280. + * In RFC5280, the representation is fixed: * UTCTime: YYMMDDHHMMSSZ * GeneralizedTime: YYYYMMDDHHMMSSZ + * + * We do NOT currently enforce the following RFC 5280 requirement: + * "CAs conforming to this profile MUST always encode certificate + * validity dates through the year 2049 as UTCTime; certificate validity + * dates in 2050 or later MUST be encoded as GeneralizedTime." */ - if (ctm->type == V_ASN1_UTCTIME) { - /* YYMMDDHHMM[SS]Z or YYMMDDHHMM[SS](+-)hhmm */ - int min_length = sizeof("YYMMDDHHMMZ") - 1; - int max_length = sizeof("YYMMDDHHMMSS+hhmm") - 1; - if (remaining < min_length || remaining > max_length) + switch (ctm->type) { + case V_ASN1_UTCTIME: + if (ctm->length != (int)(utctime_length)) return 0; - memcpy(p, str, 10); - p += 10; - str += 10; - remaining -= 10; - } else { - /* YYYYMMDDHHMM[SS[.fff]]Z or YYYYMMDDHHMM[SS[.f[f[f]]]](+-)hhmm */ - int min_length = sizeof("YYYYMMDDHHMMZ") - 1; - int max_length = sizeof("YYYYMMDDHHMMSS.fff+hhmm") - 1; - if (remaining < min_length || remaining > max_length) + break; + case V_ASN1_GENERALIZEDTIME: + if (ctm->length != (int)(generalizedtime_length)) return 0; - memcpy(p, str, 12); - p += 12; - str += 12; - remaining -= 12; + break; + default: + return 0; } - if ((*str == 'Z') || (*str == '-') || (*str == '+')) { - *(p++) = '0'; - *(p++) = '0'; - } else { - /* SS (seconds) */ - if (remaining < 2) + /** + * Verify the format: the ASN.1 functions we use below allow a more + * flexible format than what's mandated by RFC 5280. + * Digit and date ranges will be verified in the conversion methods. + */ + for (i = 0; i < ctm->length - 1; i++) { + if (!isdigit(ctm->data[i])) return 0; - *(p++) = *(str++); - *(p++) = *(str++); - remaining -= 2; - /* - * Skip any (up to three) fractional seconds... - * TODO(emilia): in RFC5280, fractional seconds are forbidden. - * Can we just kill them altogether? - */ - if (remaining && *str == '.') { - str++; - remaining--; - for (i = 0; i < 3 && remaining; i++, str++, remaining--) { - if (*str < '0' || *str > '9') - break; - } - } - } - *(p++) = 'Z'; - *(p++) = '\0'; - - /* We now need either a terminating 'Z' or an offset. */ - if (!remaining) + if (ctm->data[ctm->length - 1] != 'Z') return 0; - if (*str == 'Z') { - if (remaining != 1) - return 0; - offset = 0; - } else { - /* (+-)HHMM */ - if ((*str != '+') && (*str != '-')) - return 0; - /* Historical behaviour: the (+-)hhmm offset is forbidden in RFC5280. */ - if (remaining != 5) - return 0; - if (str[1] < '0' || str[1] > '9' || str[2] < '0' || str[2] > '9' || - str[3] < '0' || str[3] > '9' || str[4] < '0' || str[4] > '9') - return 0; - offset = ((str[1] - '0') * 10 + (str[2] - '0')) * 60; - offset += (str[3] - '0') * 10 + (str[4] - '0'); - if (*str == '-') - offset = -offset; - } - atm.type = ctm->type; - atm.flags = 0; - atm.length = sizeof(buff2); - atm.data = (unsigned char *)buff2; - if (X509_time_adj(&atm, offset * 60, cmp_time) == NULL) - return 0; + /* + * There is ASN1_UTCTIME_cmp_time_t but no + * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t, + * so we go through ASN.1 + */ + asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time); + if (asn1_cmp_time == NULL) + goto err; + if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time)) + goto err; - if (ctm->type == V_ASN1_UTCTIME) { - i = (buff1[0] - '0') * 10 + (buff1[1] - '0'); - if (i < 50) - i += 100; /* cf. RFC 2459 */ - j = (buff2[0] - '0') * 10 + (buff2[1] - '0'); - if (j < 50) - j += 100; - - if (i < j) - return -1; - if (i > j) - return 1; - } - i = strcmp(buff1, buff2); - if (i == 0) /* wait a second then return younger :-) */ - return -1; - else - return i; + /* + * X509_cmp_time comparison is <=. + * The return value 0 is reserved for errors. + */ + ret = (day >= 0 && sec >= 0) ? -1 : 1; + + err: + ASN1_TIME_free(asn1_cmp_time); + return ret; } ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj) diff --git a/doc/man3/X509_cmp_time.pod b/doc/man3/X509_cmp_time.pod new file mode 100644 index 0000000000..31826ad84d --- /dev/null +++ b/doc/man3/X509_cmp_time.pod @@ -0,0 +1,39 @@ +=pod + +=head1 NAME + +X509_cmp_time - X509 time functions + +=head1 SYNOPSIS + + X509_cmp_time(const ASN1_TIME *asn1_time, time_t *cmp_time); + +=head1 DESCRIPTION + +X509_cmp_time() compares the ASN1_TIME in B with the time in +. + +B must satisfy the ASN1_TIME format mandated by RFC 5280, i.e., +its format must be either YYMMDDHHMMSSZ or YYYYMMDDHHMMSSZ. + +If B is NULL the current time is used. + +=head1 BUGS + +Unlike many standard comparison functions, X509_cmp_time returns 0 on error. + +=head1 RETURN VALUES + +X509_cmp_time() returns -1 if B is earlier than, or equal to, +B, and 1 otherwise. It returns 0 on error. + +=head1 COPYRIGHT + +Copyright 2017 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L. + +=cut diff --git a/test/build.info b/test/build.info index 7c1a055cf7..443848b962 100644 --- a/test/build.info +++ b/test/build.info @@ -28,7 +28,7 @@ IF[{- !$disabled{tests} -}] dtlsv1listentest ct_test threadstest afalgtest d2i_test \ ssl_test_ctx_test ssl_test x509aux cipherlist_test asynciotest \ bioprinttest sslapitest dtlstest sslcorrupttest bio_enc_test \ - pkey_meth_test uitest cipherbytes_test + pkey_meth_test uitest cipherbytes_test x509_time_test SOURCE[aborttest]=aborttest.c INCLUDE[aborttest]=../include @@ -295,6 +295,10 @@ IF[{- !$disabled{tests} -}] INCLUDE[pkey_meth_test]=../include DEPEND[pkey_meth_test]=../libcrypto + SOURCE[x509_time_test]=x509_time_test.c testutil.c test_main.c + INCLUDE[x509_time_test]=.. ../include + DEPEND[x509_time_test]=../libcrypto + IF[{- !$disabled{psk} -}] PROGRAMS_NO_INST=dtls_mtu_test SOURCE[dtls_mtu_test]=dtls_mtu_test.c ssltestlib.c diff --git a/test/recipes/60-test_x509_time.t b/test/recipes/60-test_x509_time.t new file mode 100644 index 0000000000..8b311ad314 --- /dev/null +++ b/test/recipes/60-test_x509_time.t @@ -0,0 +1,12 @@ +#! /usr/bin/env perl +# Copyright 2017 The OpenSSL Project Authors. All Rights Reserved. +# +# Licensed under the OpenSSL license (the "License"). You may not use +# this file except in compliance with the License. You can obtain a copy +# in the file LICENSE in the source distribution or at +# https://www.openssl.org/source/license.html + + +use OpenSSL::Test::Simple; + +simple_test("test_x509_time", "x509_time_test"); diff --git a/test/x509_time_test.c b/test/x509_time_test.c new file mode 100644 index 0000000000..5f69ebdf41 --- /dev/null +++ b/test/x509_time_test.c @@ -0,0 +1,201 @@ +/* + * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +/* Tests for X509 time functions */ + +#include +#include + +#include +#include +#include "testutil.h" +#include "test_main.h" +#include "e_os.h" + +typedef struct { + const char *data; + int type; + time_t cmp_time; + /* -1 if asn1_time <= cmp_time, 1 if asn1_time > cmp_time, 0 if error. */ + int expected; +} TESTDATA; + +static TESTDATA x509_cmp_tests[] = { + { + "20170217180154Z", V_ASN1_GENERALIZEDTIME, + /* The same in seconds since epoch. */ + 1487354514, -1, + }, + { + "20170217180154Z", V_ASN1_GENERALIZEDTIME, + /* One second more. */ + 1487354515, -1, + }, + { + "20170217180154Z", V_ASN1_GENERALIZEDTIME, + /* One second less. */ + 1487354513, 1, + }, + /* Same as UTC time. */ + { + "170217180154Z", V_ASN1_UTCTIME, + /* The same in seconds since epoch. */ + 1487354514, -1, + }, + { + "170217180154Z", V_ASN1_UTCTIME, + /* One second more. */ + 1487354515, -1, + }, + { + "170217180154Z", V_ASN1_UTCTIME, + /* One second less. */ + 1487354513, 1, + }, + /* UTCTime from the 20th century. */ + { + "990217180154Z", V_ASN1_UTCTIME, + /* The same in seconds since epoch. */ + 919274514, -1, + }, + { + "990217180154Z", V_ASN1_UTCTIME, + /* One second more. */ + 919274515, -1, + }, + { + "990217180154Z", V_ASN1_UTCTIME, + /* One second less. */ + 919274513, 1, + }, + /* Various invalid formats. */ + { + /* No trailing Z. */ + "20170217180154", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* No trailing Z, UTCTime. */ + "170217180154", V_ASN1_UTCTIME, 0, 0, + }, + { + /* No seconds. */ + "201702171801Z", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* No seconds, UTCTime. */ + "1702171801Z", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Fractional seconds. */ + "20170217180154.001Z", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* Fractional seconds, UTCTime. */ + "170217180154.001Z", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Timezone offset. */ + "20170217180154+0100", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* Timezone offset, UTCTime. */ + "170217180154+0100", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Extra digits. */ + "2017021718015400Z", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* Extra digits, UTCTime. */ + "17021718015400Z", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Non-digits. */ + "2017021718015aZ", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* Non-digits, UTCTime. */ + "17021718015aZ", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Trailing garbage. */ + "20170217180154Zlongtrailinggarbage", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* Trailing garbage, UTCTime. */ + "170217180154Zlongtrailinggarbage", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Swapped type. */ + "20170217180154Z", V_ASN1_UTCTIME, 0, 0, + }, + { + /* Swapped type. */ + "170217180154Z", V_ASN1_GENERALIZEDTIME, 0, 0, + }, + { + /* Bad type. */ + "20170217180154Z", V_ASN1_OCTET_STRING, 0, 0, + }, +}; + +static int test_x509_cmp_time(int idx) +{ + ASN1_TIME t; + int result; + + memset(&t, 0, sizeof(t)); + t.type = x509_cmp_tests[idx].type; + t.data = (unsigned char*)(x509_cmp_tests[idx].data); + t.length = strlen(x509_cmp_tests[idx].data); + + result = X509_cmp_time(&t, &x509_cmp_tests[idx].cmp_time); + if (result != x509_cmp_tests[idx].expected) { + fprintf(stderr, "test_x509_cmp_time(%d) failed: expected %d, got %d\n", + idx, x509_cmp_tests[idx].expected, result); + return 0; + } + return 1; +} + +static int test_x509_cmp_time_current() +{ + time_t now = time(NULL); + /* Pick a day earlier and later, relative to any system clock. */ + ASN1_TIME *asn1_before = NULL, *asn1_after = NULL; + int cmp_result, failed = 0; + + asn1_before = ASN1_TIME_adj(NULL, now, -1, 0); + asn1_after = ASN1_TIME_adj(NULL, now, 1, 0); + + cmp_result = X509_cmp_time(asn1_before, NULL); + if (cmp_result != -1) { + fprintf(stderr, "test_x509_cmp_time_current failed: expected -1, got %d\n", + cmp_result); + failed = 1; + } + + cmp_result = X509_cmp_time(asn1_after, NULL); + if (cmp_result != 1) { + fprintf(stderr, "test_x509_cmp_time_current failed: expected 1, got %d\n", + cmp_result); + failed = 1; + } + + ASN1_TIME_free(asn1_before); + ASN1_TIME_free(asn1_after); + + return failed == 0; +} + +void register_tests() +{ + ADD_TEST(test_x509_cmp_time_current); + ADD_ALL_TESTS(test_x509_cmp_time, OSSL_NELEM(x509_cmp_tests)); +} -- 2.25.1