ref: 94f2907dc40a6415a10c252cb9ba3971f1f7e838
dir: /third_party/boringssl/src/crypto/bytestring/cbs.c/
/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/asn1.h>
#include <openssl/bytestring.h>
#include <openssl/mem.h>
#include <assert.h>
#include <ctype.h>
#include <inttypes.h>
#include <string.h>
#include "../asn1/internal.h"
#include "../internal.h"
#include "internal.h"
static int cbs_get(CBS *cbs, const uint8_t **p, size_t n) {
if (cbs->len < n) {
return 0;
}
*p = cbs->data;
cbs->data += n;
cbs->len -= n;
return 1;
}
int CBS_skip(CBS *cbs, size_t len) {
const uint8_t *dummy;
return cbs_get(cbs, &dummy, len);
}
int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len) {
OPENSSL_free(*out_ptr);
*out_ptr = NULL;
*out_len = 0;
if (cbs->len == 0) {
return 1;
}
*out_ptr = OPENSSL_memdup(cbs->data, cbs->len);
if (*out_ptr == NULL) {
return 0;
}
*out_len = cbs->len;
return 1;
}
int CBS_strdup(const CBS *cbs, char **out_ptr) {
if (*out_ptr != NULL) {
OPENSSL_free(*out_ptr);
}
*out_ptr = OPENSSL_strndup((const char*)cbs->data, cbs->len);
return (*out_ptr != NULL);
}
int CBS_contains_zero_byte(const CBS *cbs) {
return OPENSSL_memchr(cbs->data, 0, cbs->len) != NULL;
}
int CBS_mem_equal(const CBS *cbs, const uint8_t *data, size_t len) {
if (len != cbs->len) {
return 0;
}
return CRYPTO_memcmp(cbs->data, data, len) == 0;
}
static int cbs_get_u(CBS *cbs, uint64_t *out, size_t len) {
uint64_t result = 0;
const uint8_t *data;
if (!cbs_get(cbs, &data, len)) {
return 0;
}
for (size_t i = 0; i < len; i++) {
result <<= 8;
result |= data[i];
}
*out = result;
return 1;
}
int CBS_get_u8(CBS *cbs, uint8_t *out) {
const uint8_t *v;
if (!cbs_get(cbs, &v, 1)) {
return 0;
}
*out = *v;
return 1;
}
int CBS_get_u16(CBS *cbs, uint16_t *out) {
uint64_t v;
if (!cbs_get_u(cbs, &v, 2)) {
return 0;
}
*out = v;
return 1;
}
int CBS_get_u16le(CBS *cbs, uint16_t *out) {
if (!CBS_get_u16(cbs, out)) {
return 0;
}
*out = CRYPTO_bswap2(*out);
return 1;
}
int CBS_get_u24(CBS *cbs, uint32_t *out) {
uint64_t v;
if (!cbs_get_u(cbs, &v, 3)) {
return 0;
}
*out = (uint32_t)v;
return 1;
}
int CBS_get_u32(CBS *cbs, uint32_t *out) {
uint64_t v;
if (!cbs_get_u(cbs, &v, 4)) {
return 0;
}
*out = (uint32_t)v;
return 1;
}
int CBS_get_u32le(CBS *cbs, uint32_t *out) {
if (!CBS_get_u32(cbs, out)) {
return 0;
}
*out = CRYPTO_bswap4(*out);
return 1;
}
int CBS_get_u64(CBS *cbs, uint64_t *out) {
return cbs_get_u(cbs, out, 8);
}
int CBS_get_u64le(CBS *cbs, uint64_t *out) {
if (!cbs_get_u(cbs, out, 8)) {
return 0;
}
*out = CRYPTO_bswap8(*out);
return 1;
}
int CBS_get_last_u8(CBS *cbs, uint8_t *out) {
if (cbs->len == 0) {
return 0;
}
*out = cbs->data[cbs->len - 1];
cbs->len--;
return 1;
}
int CBS_get_bytes(CBS *cbs, CBS *out, size_t len) {
const uint8_t *v;
if (!cbs_get(cbs, &v, len)) {
return 0;
}
CBS_init(out, v, len);
return 1;
}
int CBS_copy_bytes(CBS *cbs, uint8_t *out, size_t len) {
const uint8_t *v;
if (!cbs_get(cbs, &v, len)) {
return 0;
}
OPENSSL_memcpy(out, v, len);
return 1;
}
static int cbs_get_length_prefixed(CBS *cbs, CBS *out, size_t len_len) {
uint64_t len;
if (!cbs_get_u(cbs, &len, len_len)) {
return 0;
}
// If |len_len| <= 3 then we know that |len| will fit into a |size_t|, even on
// 32-bit systems.
assert(len_len <= 3);
return CBS_get_bytes(cbs, out, len);
}
int CBS_get_u8_length_prefixed(CBS *cbs, CBS *out) {
return cbs_get_length_prefixed(cbs, out, 1);
}
int CBS_get_u16_length_prefixed(CBS *cbs, CBS *out) {
return cbs_get_length_prefixed(cbs, out, 2);
}
int CBS_get_u24_length_prefixed(CBS *cbs, CBS *out) {
return cbs_get_length_prefixed(cbs, out, 3);
}
int CBS_get_until_first(CBS *cbs, CBS *out, uint8_t c) {
const uint8_t *split = OPENSSL_memchr(CBS_data(cbs), c, CBS_len(cbs));
if (split == NULL) {
return 0;
}
return CBS_get_bytes(cbs, out, split - CBS_data(cbs));
}
int CBS_get_u64_decimal(CBS *cbs, uint64_t *out) {
uint64_t v = 0;
int seen_digit = 0;
while (CBS_len(cbs) != 0) {
uint8_t c = CBS_data(cbs)[0];
if (!OPENSSL_isdigit(c)) {
break;
}
CBS_skip(cbs, 1);
if (// Forbid stray leading zeros.
(v == 0 && seen_digit) ||
// Check for overflow.
v > UINT64_MAX / 10 || //
v * 10 > UINT64_MAX - (c - '0')) {
return 0;
}
v = v * 10 + (c - '0');
seen_digit = 1;
}
*out = v;
return seen_digit;
}
// parse_base128_integer reads a big-endian base-128 integer from |cbs| and sets
// |*out| to the result. This is the encoding used in DER for both high tag
// number form and OID components.
static int parse_base128_integer(CBS *cbs, uint64_t *out) {
uint64_t v = 0;
uint8_t b;
do {
if (!CBS_get_u8(cbs, &b)) {
return 0;
}
if ((v >> (64 - 7)) != 0) {
// The value is too large.
return 0;
}
if (v == 0 && b == 0x80) {
// The value must be minimally encoded.
return 0;
}
v = (v << 7) | (b & 0x7f);
// Values end at an octet with the high bit cleared.
} while (b & 0x80);
*out = v;
return 1;
}
static int parse_asn1_tag(CBS *cbs, CBS_ASN1_TAG *out) {
uint8_t tag_byte;
if (!CBS_get_u8(cbs, &tag_byte)) {
return 0;
}
// ITU-T X.690 section 8.1.2.3 specifies the format for identifiers with a tag
// number no greater than 30.
//
// If the number portion is 31 (0x1f, the largest value that fits in the
// allotted bits), then the tag is more than one byte long and the
// continuation bytes contain the tag number.
CBS_ASN1_TAG tag = ((CBS_ASN1_TAG)tag_byte & 0xe0) << CBS_ASN1_TAG_SHIFT;
CBS_ASN1_TAG tag_number = tag_byte & 0x1f;
if (tag_number == 0x1f) {
uint64_t v;
if (!parse_base128_integer(cbs, &v) ||
// Check the tag number is within our supported bounds.
v > CBS_ASN1_TAG_NUMBER_MASK ||
// Small tag numbers should have used low tag number form, even in BER.
v < 0x1f) {
return 0;
}
tag_number = (CBS_ASN1_TAG)v;
}
tag |= tag_number;
// Tag [UNIVERSAL 0] is reserved for use by the encoding. Reject it here to
// avoid some ambiguity around ANY values and BER indefinite-length EOCs. See
// https://crbug.com/boringssl/455.
if ((tag & ~CBS_ASN1_CONSTRUCTED) == 0) {
return 0;
}
*out = tag;
return 1;
}
static int cbs_get_any_asn1_element(CBS *cbs, CBS *out, CBS_ASN1_TAG *out_tag,
size_t *out_header_len, int *out_ber_found,
int *out_indefinite, int ber_ok) {
CBS header = *cbs;
CBS throwaway;
if (out == NULL) {
out = &throwaway;
}
if (ber_ok) {
*out_ber_found = 0;
*out_indefinite = 0;
} else {
assert(out_ber_found == NULL);
assert(out_indefinite == NULL);
}
CBS_ASN1_TAG tag;
if (!parse_asn1_tag(&header, &tag)) {
return 0;
}
if (out_tag != NULL) {
*out_tag = tag;
}
uint8_t length_byte;
if (!CBS_get_u8(&header, &length_byte)) {
return 0;
}
size_t header_len = CBS_len(cbs) - CBS_len(&header);
size_t len;
// The format for the length encoding is specified in ITU-T X.690 section
// 8.1.3.
if ((length_byte & 0x80) == 0) {
// Short form length.
len = ((size_t) length_byte) + header_len;
if (out_header_len != NULL) {
*out_header_len = header_len;
}
} else {
// The high bit indicate that this is the long form, while the next 7 bits
// encode the number of subsequent octets used to encode the length (ITU-T
// X.690 clause 8.1.3.5.b).
const size_t num_bytes = length_byte & 0x7f;
uint64_t len64;
if (ber_ok && (tag & CBS_ASN1_CONSTRUCTED) != 0 && num_bytes == 0) {
// indefinite length
if (out_header_len != NULL) {
*out_header_len = header_len;
}
*out_ber_found = 1;
*out_indefinite = 1;
return CBS_get_bytes(cbs, out, header_len);
}
// ITU-T X.690 clause 8.1.3.5.c specifies that the value 0xff shall not be
// used as the first byte of the length. If this parser encounters that
// value, num_bytes will be parsed as 127, which will fail this check.
if (num_bytes == 0 || num_bytes > 4) {
return 0;
}
if (!cbs_get_u(&header, &len64, num_bytes)) {
return 0;
}
// ITU-T X.690 section 10.1 (DER length forms) requires encoding the
// length with the minimum number of octets. BER could, technically, have
// 125 superfluous zero bytes. We do not attempt to handle that and still
// require that the length fit in a |uint32_t| for BER.
if (len64 < 128) {
// Length should have used short-form encoding.
if (ber_ok) {
*out_ber_found = 1;
} else {
return 0;
}
}
if ((len64 >> ((num_bytes - 1) * 8)) == 0) {
// Length should have been at least one byte shorter.
if (ber_ok) {
*out_ber_found = 1;
} else {
return 0;
}
}
len = len64;
if (len + header_len + num_bytes < len) {
// Overflow.
return 0;
}
len += header_len + num_bytes;
if (out_header_len != NULL) {
*out_header_len = header_len + num_bytes;
}
}
return CBS_get_bytes(cbs, out, len);
}
int CBS_get_any_asn1(CBS *cbs, CBS *out, CBS_ASN1_TAG *out_tag) {
size_t header_len;
if (!CBS_get_any_asn1_element(cbs, out, out_tag, &header_len)) {
return 0;
}
if (!CBS_skip(out, header_len)) {
assert(0);
return 0;
}
return 1;
}
int CBS_get_any_asn1_element(CBS *cbs, CBS *out, CBS_ASN1_TAG *out_tag,
size_t *out_header_len) {
return cbs_get_any_asn1_element(cbs, out, out_tag, out_header_len, NULL, NULL,
/*ber_ok=*/0);
}
int CBS_get_any_ber_asn1_element(CBS *cbs, CBS *out, CBS_ASN1_TAG *out_tag,
size_t *out_header_len, int *out_ber_found,
int *out_indefinite) {
int ber_found_temp;
return cbs_get_any_asn1_element(
cbs, out, out_tag, out_header_len,
out_ber_found ? out_ber_found : &ber_found_temp, out_indefinite,
/*ber_ok=*/1);
}
static int cbs_get_asn1(CBS *cbs, CBS *out, CBS_ASN1_TAG tag_value,
int skip_header) {
size_t header_len;
CBS_ASN1_TAG tag;
CBS throwaway;
if (out == NULL) {
out = &throwaway;
}
if (!CBS_get_any_asn1_element(cbs, out, &tag, &header_len) ||
tag != tag_value) {
return 0;
}
if (skip_header && !CBS_skip(out, header_len)) {
assert(0);
return 0;
}
return 1;
}
int CBS_get_asn1(CBS *cbs, CBS *out, CBS_ASN1_TAG tag_value) {
return cbs_get_asn1(cbs, out, tag_value, 1 /* skip header */);
}
int CBS_get_asn1_element(CBS *cbs, CBS *out, CBS_ASN1_TAG tag_value) {
return cbs_get_asn1(cbs, out, tag_value, 0 /* include header */);
}
int CBS_peek_asn1_tag(const CBS *cbs, CBS_ASN1_TAG tag_value) {
CBS copy = *cbs;
CBS_ASN1_TAG actual_tag;
return parse_asn1_tag(©, &actual_tag) && tag_value == actual_tag;
}
int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out) {
CBS bytes;
if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_INTEGER) ||
!CBS_is_unsigned_asn1_integer(&bytes)) {
return 0;
}
*out = 0;
const uint8_t *data = CBS_data(&bytes);
size_t len = CBS_len(&bytes);
for (size_t i = 0; i < len; i++) {
if ((*out >> 56) != 0) {
// Too large to represent as a uint64_t.
return 0;
}
*out <<= 8;
*out |= data[i];
}
return 1;
}
int CBS_get_asn1_int64(CBS *cbs, int64_t *out) {
int is_negative;
CBS bytes;
if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_INTEGER) ||
!CBS_is_valid_asn1_integer(&bytes, &is_negative)) {
return 0;
}
const uint8_t *data = CBS_data(&bytes);
const size_t len = CBS_len(&bytes);
if (len > sizeof(int64_t)) {
return 0;
}
uint8_t sign_extend[sizeof(int64_t)];
OPENSSL_memset(sign_extend, is_negative ? 0xff : 0, sizeof(sign_extend));
OPENSSL_memcpy(sign_extend + sizeof(int64_t) - len, data, len);
*out = CRYPTO_load_u64_be(sign_extend);
return 1;
}
int CBS_get_asn1_bool(CBS *cbs, int *out) {
CBS bytes;
if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_BOOLEAN) ||
CBS_len(&bytes) != 1) {
return 0;
}
const uint8_t value = *CBS_data(&bytes);
if (value != 0 && value != 0xff) {
return 0;
}
*out = !!value;
return 1;
}
int CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, CBS_ASN1_TAG tag) {
int present = 0;
if (CBS_peek_asn1_tag(cbs, tag)) {
if (!CBS_get_asn1(cbs, out, tag)) {
return 0;
}
present = 1;
}
if (out_present != NULL) {
*out_present = present;
}
return 1;
}
int CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, int *out_present,
CBS_ASN1_TAG tag) {
CBS child;
int present;
if (!CBS_get_optional_asn1(cbs, &child, &present, tag)) {
return 0;
}
if (present) {
assert(out);
if (!CBS_get_asn1(&child, out, CBS_ASN1_OCTETSTRING) ||
CBS_len(&child) != 0) {
return 0;
}
} else {
CBS_init(out, NULL, 0);
}
if (out_present) {
*out_present = present;
}
return 1;
}
int CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, CBS_ASN1_TAG tag,
uint64_t default_value) {
CBS child;
int present;
if (!CBS_get_optional_asn1(cbs, &child, &present, tag)) {
return 0;
}
if (present) {
if (!CBS_get_asn1_uint64(&child, out) ||
CBS_len(&child) != 0) {
return 0;
}
} else {
*out = default_value;
}
return 1;
}
int CBS_get_optional_asn1_bool(CBS *cbs, int *out, CBS_ASN1_TAG tag,
int default_value) {
CBS child, child2;
int present;
if (!CBS_get_optional_asn1(cbs, &child, &present, tag)) {
return 0;
}
if (present) {
uint8_t boolean;
if (!CBS_get_asn1(&child, &child2, CBS_ASN1_BOOLEAN) ||
CBS_len(&child2) != 1 ||
CBS_len(&child) != 0) {
return 0;
}
boolean = CBS_data(&child2)[0];
if (boolean == 0) {
*out = 0;
} else if (boolean == 0xff) {
*out = 1;
} else {
return 0;
}
} else {
*out = default_value;
}
return 1;
}
int CBS_is_valid_asn1_bitstring(const CBS *cbs) {
CBS in = *cbs;
uint8_t num_unused_bits;
if (!CBS_get_u8(&in, &num_unused_bits) ||
num_unused_bits > 7) {
return 0;
}
if (num_unused_bits == 0) {
return 1;
}
// All num_unused_bits bits must exist and be zeros.
uint8_t last;
if (!CBS_get_last_u8(&in, &last) ||
(last & ((1 << num_unused_bits) - 1)) != 0) {
return 0;
}
return 1;
}
int CBS_asn1_bitstring_has_bit(const CBS *cbs, unsigned bit) {
if (!CBS_is_valid_asn1_bitstring(cbs)) {
return 0;
}
const unsigned byte_num = (bit >> 3) + 1;
const unsigned bit_num = 7 - (bit & 7);
// Unused bits are zero, and this function does not distinguish between
// missing and unset bits. Thus it is sufficient to do a byte-level length
// check.
return byte_num < CBS_len(cbs) &&
(CBS_data(cbs)[byte_num] & (1 << bit_num)) != 0;
}
int CBS_is_valid_asn1_integer(const CBS *cbs, int *out_is_negative) {
CBS copy = *cbs;
uint8_t first_byte, second_byte;
if (!CBS_get_u8(©, &first_byte)) {
return 0; // INTEGERs may not be empty.
}
if (out_is_negative != NULL) {
*out_is_negative = (first_byte & 0x80) != 0;
}
if (!CBS_get_u8(©, &second_byte)) {
return 1; // One byte INTEGERs are always minimal.
}
if ((first_byte == 0x00 && (second_byte & 0x80) == 0) ||
(first_byte == 0xff && (second_byte & 0x80) != 0)) {
return 0; // The value is minimal iff the first 9 bits are not all equal.
}
return 1;
}
int CBS_is_unsigned_asn1_integer(const CBS *cbs) {
int is_negative;
return CBS_is_valid_asn1_integer(cbs, &is_negative) && !is_negative;
}
static int add_decimal(CBB *out, uint64_t v) {
char buf[DECIMAL_SIZE(uint64_t) + 1];
snprintf(buf, sizeof(buf), "%" PRIu64, v);
return CBB_add_bytes(out, (const uint8_t *)buf, strlen(buf));
}
int CBS_is_valid_asn1_oid(const CBS *cbs) {
if (CBS_len(cbs) == 0) {
return 0; // OID encodings cannot be empty.
}
CBS copy = *cbs;
uint8_t v, prev = 0;
while (CBS_get_u8(©, &v)) {
// OID encodings are a sequence of minimally-encoded base-128 integers (see
// |parse_base128_integer|). If |prev|'s MSB was clear, it was the last byte
// of an integer (or |v| is the first byte). |v| is then the first byte of
// the next integer. If first byte of an integer is 0x80, it is not
// minimally-encoded.
if ((prev & 0x80) == 0 && v == 0x80) {
return 0;
}
prev = v;
}
// The last byte should must end an integer encoding.
return (prev & 0x80) == 0;
}
char *CBS_asn1_oid_to_text(const CBS *cbs) {
CBB cbb;
if (!CBB_init(&cbb, 32)) {
goto err;
}
CBS copy = *cbs;
// The first component is 40 * value1 + value2, where value1 is 0, 1, or 2.
uint64_t v;
if (!parse_base128_integer(©, &v)) {
goto err;
}
if (v >= 80) {
if (!CBB_add_bytes(&cbb, (const uint8_t *)"2.", 2) ||
!add_decimal(&cbb, v - 80)) {
goto err;
}
} else if (!add_decimal(&cbb, v / 40) ||
!CBB_add_u8(&cbb, '.') ||
!add_decimal(&cbb, v % 40)) {
goto err;
}
while (CBS_len(©) != 0) {
if (!parse_base128_integer(©, &v) ||
!CBB_add_u8(&cbb, '.') ||
!add_decimal(&cbb, v)) {
goto err;
}
}
uint8_t *txt;
size_t txt_len;
if (!CBB_add_u8(&cbb, '\0') ||
!CBB_finish(&cbb, &txt, &txt_len)) {
goto err;
}
return (char *)txt;
err:
CBB_cleanup(&cbb);
return NULL;
}
static int cbs_get_two_digits(CBS *cbs, int *out) {
uint8_t first_digit, second_digit;
if (!CBS_get_u8(cbs, &first_digit)) {
return 0;
}
if (!OPENSSL_isdigit(first_digit)) {
return 0;
}
if (!CBS_get_u8(cbs, &second_digit)) {
return 0;
}
if (!OPENSSL_isdigit(second_digit)) {
return 0;
}
*out = (first_digit - '0') * 10 + (second_digit - '0');
return 1;
}
static int is_valid_day(int year, int month, int day) {
if (day < 1) {
return 0;
}
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
return day <= 31;
case 4:
case 6:
case 9:
case 11:
return day <= 30;
case 2:
if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {
return day <= 29;
} else {
return day <= 28;
}
default:
return 0;
}
}
static int CBS_parse_rfc5280_time_internal(const CBS *cbs, int is_gentime,
int allow_timezone_offset,
struct tm *out_tm) {
int year, month, day, hour, min, sec, tmp;
CBS copy = *cbs;
uint8_t tz;
if (is_gentime) {
if (!cbs_get_two_digits(©, &tmp)) {
return 0;
}
year = tmp * 100;
if (!cbs_get_two_digits(©, &tmp)) {
return 0;
}
year += tmp;
} else {
year = 1900;
if (!cbs_get_two_digits(©, &tmp)) {
return 0;
}
year += tmp;
if (year < 1950) {
year += 100;
}
if (year >= 2050) {
return 0; // A Generalized time must be used.
}
}
if (!cbs_get_two_digits(©, &month) || month < 1 ||
month > 12 || // Reject invalid months.
!cbs_get_two_digits(©, &day) ||
!is_valid_day(year, month, day) || // Reject invalid days.
!cbs_get_two_digits(©, &hour) ||
hour > 23 || // Reject invalid hours.
!cbs_get_two_digits(©, &min) ||
min > 59 || // Reject invalid minutes.
!cbs_get_two_digits(©, &sec) || sec > 59 || !CBS_get_u8(©, &tz)) {
return 0;
}
int offset_sign = 0;
switch (tz) {
case 'Z':
break; // We correctly have 'Z' on the end as per spec.
case '+':
offset_sign = 1;
break; // Should not be allowed per RFC 5280.
case '-':
offset_sign = -1;
break; // Should not be allowed per RFC 5280.
default:
return 0; // Reject anything else after the time.
}
// If allow_timezone_offset is non-zero, allow for a four digit timezone
// offset to be specified even though this is not allowed by RFC 5280. We are
// permissive of this for UTCTimes due to the unfortunate existence of
// artisinally rolled long lived certificates that were baked into places that
// are now difficult to change. These certificates were generated with the
// 'openssl' command that permissively allowed the creation of certificates
// with notBefore and notAfter times specified as strings for direct
// certificate inclusion on the command line. For context see cl/237068815.
//
// TODO(bbe): This has been expunged from public web-pki as the ecosystem has
// managed to encourage CA compliance with standards. We should find a way to
// get rid of this or make it off by default.
int offset_seconds = 0;
if (offset_sign != 0) {
if (!allow_timezone_offset) {
return 0;
}
int offset_hours, offset_minutes;
if (!cbs_get_two_digits(©, &offset_hours) ||
offset_hours > 23 || // Reject invalid hours.
!cbs_get_two_digits(©, &offset_minutes) ||
offset_minutes > 59) { // Reject invalid minutes.
return 0;
}
offset_seconds = offset_sign * (offset_hours * 3600 + offset_minutes * 60);
}
if (CBS_len(©) != 0) {
return 0; // Reject invalid lengths.
}
if (out_tm != NULL) {
// Fill in the tm fields corresponding to what we validated.
out_tm->tm_year = year - 1900;
out_tm->tm_mon = month - 1;
out_tm->tm_mday = day;
out_tm->tm_hour = hour;
out_tm->tm_min = min;
out_tm->tm_sec = sec;
if (offset_seconds && !OPENSSL_gmtime_adj(out_tm, 0, offset_seconds)) {
return 0;
}
}
return 1;
}
int CBS_parse_generalized_time(const CBS *cbs, struct tm *out_tm,
int allow_timezone_offset) {
return CBS_parse_rfc5280_time_internal(cbs, 1, allow_timezone_offset, out_tm);
}
int CBS_parse_utc_time(const CBS *cbs, struct tm *out_tm,
int allow_timezone_offset) {
return CBS_parse_rfc5280_time_internal(cbs, 0, allow_timezone_offset, out_tm);
}