| /* 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" |
| |
| |
| void CBS_init(CBS *cbs, const uint8_t *data, size_t len) { |
| cbs->data = data; |
| cbs->len = len; |
| } |
| |
| 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); |
| } |
| |
| const uint8_t *CBS_data(const CBS *cbs) { |
| return cbs->data; |
| } |
| |
| size_t CBS_len(const CBS *cbs) { |
| return cbs->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 = 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 = 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)); |
| } |
| |
| // 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, unsigned *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. |
| unsigned tag = ((unsigned)tag_byte & 0xe0) << CBS_ASN1_TAG_SHIFT; |
| unsigned 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 = (unsigned)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, unsigned *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); |
| } |
| |
| unsigned 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, unsigned *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, unsigned *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, unsigned *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, unsigned tag_value, |
| int skip_header) { |
| size_t header_len; |
| unsigned 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, unsigned tag_value) { |
| return cbs_get_asn1(cbs, out, tag_value, 1 /* skip header */); |
| } |
| |
| int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value) { |
| return cbs_get_asn1(cbs, out, tag_value, 0 /* include header */); |
| } |
| |
| int CBS_peek_asn1_tag(const CBS *cbs, unsigned tag_value) { |
| if (CBS_len(cbs) < 1) { |
| return 0; |
| } |
| |
| CBS copy = *cbs; |
| unsigned 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)]; |
| memset(sign_extend, is_negative ? 0xff : 0, sizeof(sign_extend)); |
| for (size_t i = 0; i < len; i++) { |
| sign_extend[i] = data[len - i - 1]; |
| } |
| memcpy(out, sign_extend, sizeof(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, unsigned 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, |
| unsigned 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, unsigned 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, unsigned 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]; |
| BIO_snprintf(buf, sizeof(buf), "%" PRIu64, v); |
| return CBB_add_bytes(out, (const uint8_t *)buf, strlen(buf)); |
| } |
| |
| 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 (!isdigit(first_digit)) { |
| return 0; |
| } |
| if (!CBS_get_u8(cbs, &second_digit)) { |
| return 0; |
| } |
| if (!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); |
| } |