Coverage Report

Created: 2024-11-21 07:03

/src/boringssl/crypto/bytestring/unicode.c
Line
Count
Source (jump to first uncovered line)
1
/* Copyright (c) 2018, Google Inc.
2
 *
3
 * Permission to use, copy, modify, and/or distribute this software for any
4
 * purpose with or without fee is hereby granted, provided that the above
5
 * copyright notice and this permission notice appear in all copies.
6
 *
7
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15
#include <openssl/bytestring.h>
16
17
#include "internal.h"
18
19
20
0
static int is_valid_code_point(uint32_t v) {
21
  // References in the following are to Unicode 15.0.0.
22
0
  if (// The Unicode space runs from zero to 0x10ffff (3.4 D9).
23
0
      v > 0x10ffff ||
24
      // Values 0x...fffe, 0x...ffff, and 0xfdd0-0xfdef are permanently reserved
25
      // as noncharacters (3.4 D14). See also 23.7. As our APIs are intended for
26
      // "open interchange", such as ASN.1, we reject them.
27
0
      (v & 0xfffe) == 0xfffe ||
28
0
      (v >= 0xfdd0 && v <= 0xfdef) ||
29
      // Surrogate code points are invalid (3.2 C1).
30
0
      (v >= 0xd800 && v <= 0xdfff)) {
31
0
    return 0;
32
0
  }
33
0
  return 1;
34
0
}
35
36
// BOTTOM_BITS returns a byte with the bottom |n| bits set.
37
0
#define BOTTOM_BITS(n) (uint8_t)((1u << (n)) - 1)
38
39
// TOP_BITS returns a byte with the top |n| bits set.
40
0
#define TOP_BITS(n) ((uint8_t)~BOTTOM_BITS(8 - (n)))
41
42
0
int CBS_get_utf8(CBS *cbs, uint32_t *out) {
43
0
  uint8_t c;
44
0
  if (!CBS_get_u8(cbs, &c)) {
45
0
    return 0;
46
0
  }
47
0
  if (c <= 0x7f) {
48
0
    *out = c;
49
0
    return 1;
50
0
  }
51
0
  uint32_t v, lower_bound;
52
0
  size_t len;
53
0
  if ((c & TOP_BITS(3)) == TOP_BITS(2)) {
54
0
    v = c & BOTTOM_BITS(5);
55
0
    len = 1;
56
0
    lower_bound = 0x80;
57
0
  } else if ((c & TOP_BITS(4)) == TOP_BITS(3)) {
58
0
    v = c & BOTTOM_BITS(4);
59
0
    len = 2;
60
0
    lower_bound = 0x800;
61
0
  } else if ((c & TOP_BITS(5)) == TOP_BITS(4)) {
62
0
    v = c & BOTTOM_BITS(3);
63
0
    len = 3;
64
0
    lower_bound = 0x10000;
65
0
  } else {
66
0
    return 0;
67
0
  }
68
0
  for (size_t i = 0; i < len; i++) {
69
0
    if (!CBS_get_u8(cbs, &c) ||
70
0
        (c & TOP_BITS(2)) != TOP_BITS(1)) {
71
0
      return 0;
72
0
    }
73
0
    v <<= 6;
74
0
    v |= c & BOTTOM_BITS(6);
75
0
  }
76
0
  if (!is_valid_code_point(v) ||
77
0
      v < lower_bound) {
78
0
    return 0;
79
0
  }
80
0
  *out = v;
81
0
  return 1;
82
0
}
83
84
0
int CBS_get_latin1(CBS *cbs, uint32_t *out) {
85
0
  uint8_t c;
86
0
  if (!CBS_get_u8(cbs, &c)) {
87
0
    return 0;
88
0
  }
89
0
  *out = c;
90
0
  return 1;
91
0
}
92
93
0
int CBS_get_ucs2_be(CBS *cbs, uint32_t *out) {
94
  // Note UCS-2 (used by BMPString) does not support surrogates.
95
0
  uint16_t c;
96
0
  if (!CBS_get_u16(cbs, &c) ||
97
0
      !is_valid_code_point(c)) {
98
0
    return 0;
99
0
  }
100
0
  *out = c;
101
0
  return 1;
102
0
}
103
104
0
int CBS_get_utf32_be(CBS *cbs, uint32_t *out) {
105
0
  return CBS_get_u32(cbs, out) && is_valid_code_point(*out);
106
0
}
107
108
0
size_t CBB_get_utf8_len(uint32_t u) {
109
0
  if (u <= 0x7f) {
110
0
    return 1;
111
0
  }
112
0
  if (u <= 0x7ff) {
113
0
    return 2;
114
0
  }
115
0
  if (u <= 0xffff) {
116
0
    return 3;
117
0
  }
118
0
  return 4;
119
0
}
120
121
0
int CBB_add_utf8(CBB *cbb, uint32_t u) {
122
0
  if (!is_valid_code_point(u)) {
123
0
    return 0;
124
0
  }
125
0
  if (u <= 0x7f) {
126
0
    return CBB_add_u8(cbb, (uint8_t)u);
127
0
  }
128
0
  if (u <= 0x7ff) {
129
0
    return CBB_add_u8(cbb, TOP_BITS(2) | (u >> 6)) &&
130
0
           CBB_add_u8(cbb, TOP_BITS(1) | (u & BOTTOM_BITS(6)));
131
0
  }
132
0
  if (u <= 0xffff) {
133
0
    return CBB_add_u8(cbb, TOP_BITS(3) | (u >> 12)) &&
134
0
           CBB_add_u8(cbb, TOP_BITS(1) | ((u >> 6) & BOTTOM_BITS(6))) &&
135
0
           CBB_add_u8(cbb, TOP_BITS(1) | (u & BOTTOM_BITS(6)));
136
0
  }
137
0
  if (u <= 0x10ffff) {
138
0
    return CBB_add_u8(cbb, TOP_BITS(4) | (u >> 18)) &&
139
0
           CBB_add_u8(cbb, TOP_BITS(1) | ((u >> 12) & BOTTOM_BITS(6))) &&
140
0
           CBB_add_u8(cbb, TOP_BITS(1) | ((u >> 6) & BOTTOM_BITS(6))) &&
141
0
           CBB_add_u8(cbb, TOP_BITS(1) | (u & BOTTOM_BITS(6)));
142
0
  }
143
0
  return 0;
144
0
}
145
146
0
int CBB_add_latin1(CBB *cbb, uint32_t u) {
147
0
  return u <= 0xff && CBB_add_u8(cbb, (uint8_t)u);
148
0
}
149
150
0
int CBB_add_ucs2_be(CBB *cbb, uint32_t u) {
151
0
  return u <= 0xffff && is_valid_code_point(u) && CBB_add_u16(cbb, (uint16_t)u);
152
0
}
153
154
0
int CBB_add_utf32_be(CBB *cbb, uint32_t u) {
155
0
  return is_valid_code_point(u) && CBB_add_u32(cbb, u);
156
0
}