/* Copyright (c) 2018, 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/bytestring.h> #include "internal.h" static int is_valid_code_point(uint32_t v) { // References in the following are to Unicode 9.0.0. if (// The Unicode space runs from zero to 0x10ffff (3.4 D9). v > 0x10ffff || // Values 0x...fffe, 0x...ffff, and 0xfdd0-0xfdef are permanently reserved // (3.4 D14) (v & 0xfffe) == 0xfffe || (v >= 0xfdd0 && v <= 0xfdef) || // Surrogate code points are invalid (3.2 C1). (v >= 0xd800 && v <= 0xdfff)) { return 0; } return 1; } // BOTTOM_BITS returns a byte with the bottom |n| bits set. #define BOTTOM_BITS(n) (uint8_t)((1u << (n)) - 1) // TOP_BITS returns a byte with the top |n| bits set. #define TOP_BITS(n) ((uint8_t)~BOTTOM_BITS(8 - (n))) int cbs_get_utf8(CBS *cbs, uint32_t *out) { uint8_t c; if (!CBS_get_u8(cbs, &c)) { return 0; } if (c <= 0x7f) { *out = c; return 1; } uint32_t v, lower_bound; size_t len; if ((c & TOP_BITS(3)) == TOP_BITS(2)) { v = c & BOTTOM_BITS(5); len = 1; lower_bound = 0x80; } else if ((c & TOP_BITS(4)) == TOP_BITS(3)) { v = c & BOTTOM_BITS(4); len = 2; lower_bound = 0x800; } else if ((c & TOP_BITS(5)) == TOP_BITS(4)) { v = c & BOTTOM_BITS(3); len = 3; lower_bound = 0x10000; } else { return 0; } for (size_t i = 0; i < len; i++) { if (!CBS_get_u8(cbs, &c) || (c & TOP_BITS(2)) != TOP_BITS(1)) { return 0; } v <<= 6; v |= c & BOTTOM_BITS(6); } if (!is_valid_code_point(v) || v < lower_bound) { return 0; } *out = v; return 1; } int cbs_get_latin1(CBS *cbs, uint32_t *out) { uint8_t c; if (!CBS_get_u8(cbs, &c)) { return 0; } *out = c; return 1; } int cbs_get_ucs2_be(CBS *cbs, uint32_t *out) { // Note UCS-2 (used by BMPString) does not support surrogates. uint16_t c; if (!CBS_get_u16(cbs, &c) || !is_valid_code_point(c)) { return 0; } *out = c; return 1; } int cbs_get_utf32_be(CBS *cbs, uint32_t *out) { return CBS_get_u32(cbs, out) && is_valid_code_point(*out); } size_t cbb_get_utf8_len(uint32_t u) { if (u <= 0x7f) { return 1; } if (u <= 0x7ff) { return 2; } if (u <= 0xffff) { return 3; } return 4; } int cbb_add_utf8(CBB *cbb, uint32_t u) { if (!is_valid_code_point(u)) { return 0; } if (u <= 0x7f) { return CBB_add_u8(cbb, (uint8_t)u); } if (u <= 0x7ff) { return CBB_add_u8(cbb, TOP_BITS(2) | (u >> 6)) && CBB_add_u8(cbb, TOP_BITS(1) | (u & BOTTOM_BITS(6))); } if (u <= 0xffff) { return CBB_add_u8(cbb, TOP_BITS(3) | (u >> 12)) && CBB_add_u8(cbb, TOP_BITS(1) | ((u >> 6) & BOTTOM_BITS(6))) && CBB_add_u8(cbb, TOP_BITS(1) | (u & BOTTOM_BITS(6))); } if (u <= 0x10ffff) { return CBB_add_u8(cbb, TOP_BITS(4) | (u >> 18)) && CBB_add_u8(cbb, TOP_BITS(1) | ((u >> 12) & BOTTOM_BITS(6))) && CBB_add_u8(cbb, TOP_BITS(1) | ((u >> 6) & BOTTOM_BITS(6))) && CBB_add_u8(cbb, TOP_BITS(1) | (u & BOTTOM_BITS(6))); } return 0; } int cbb_add_latin1(CBB *cbb, uint32_t u) { return u <= 0xff && CBB_add_u8(cbb, (uint8_t)u); } int cbb_add_ucs2_be(CBB *cbb, uint32_t u) { return u <= 0xffff && is_valid_code_point(u) && CBB_add_u16(cbb, (uint16_t)u); } int cbb_add_utf32_be(CBB *cbb, uint32_t u) { return is_valid_code_point(u) && CBB_add_u32(cbb, u); }