1/* 2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10#include <stdio.h> 11#include "internal/cryptlib.h" 12#include "internal/unicode.h" 13#include <openssl/asn1.h> 14 15/* UTF8 utilities */ 16 17/*- 18 * This parses a UTF8 string one character at a time. It is passed a pointer 19 * to the string and the length of the string. It sets 'value' to the value of 20 * the current character. It returns the number of characters read or a 21 * negative error code: 22 * -1 = string too short 23 * -2 = illegal character 24 * -3 = subsequent characters not of the form 10xxxxxx 25 * -4 = character encoded incorrectly (not minimal length). 26 */ 27 28int UTF8_getc(const unsigned char *str, int len, unsigned long *val) 29{ 30 const unsigned char *p; 31 unsigned long value; 32 int ret; 33 if (len <= 0) 34 return 0; 35 p = str; 36 37 /* Check syntax and work out the encoded value (if correct) */ 38 if ((*p & 0x80) == 0) { 39 value = *p++ & 0x7f; 40 ret = 1; 41 } else if ((*p & 0xe0) == 0xc0) { 42 if (len < 2) 43 return -1; 44 if ((p[1] & 0xc0) != 0x80) 45 return -3; 46 value = (*p++ & 0x1f) << 6; 47 value |= *p++ & 0x3f; 48 if (value < 0x80) 49 return -4; 50 ret = 2; 51 } else if ((*p & 0xf0) == 0xe0) { 52 if (len < 3) 53 return -1; 54 if (((p[1] & 0xc0) != 0x80) 55 || ((p[2] & 0xc0) != 0x80)) 56 return -3; 57 value = (*p++ & 0xf) << 12; 58 value |= (*p++ & 0x3f) << 6; 59 value |= *p++ & 0x3f; 60 if (value < 0x800) 61 return -4; 62 if (is_unicode_surrogate(value)) 63 return -2; 64 ret = 3; 65 } else if ((*p & 0xf8) == 0xf0) { 66 if (len < 4) 67 return -1; 68 if (((p[1] & 0xc0) != 0x80) 69 || ((p[2] & 0xc0) != 0x80) 70 || ((p[3] & 0xc0) != 0x80)) 71 return -3; 72 value = ((unsigned long)(*p++ & 0x7)) << 18; 73 value |= (*p++ & 0x3f) << 12; 74 value |= (*p++ & 0x3f) << 6; 75 value |= *p++ & 0x3f; 76 if (value < 0x10000) 77 return -4; 78 ret = 4; 79 } else 80 return -2; 81 *val = value; 82 return ret; 83} 84 85/* 86 * This takes a character 'value' and writes the UTF8 encoded value in 'str' 87 * where 'str' is a buffer containing 'len' characters. Returns the number of 88 * characters written, -1 if 'len' is too small or -2 if 'value' is out of 89 * range. 'str' can be set to NULL in which case it just returns the number of 90 * characters. It will need at most 4 characters. 91 */ 92 93int UTF8_putc(unsigned char *str, int len, unsigned long value) 94{ 95 if (!str) 96 len = 4; /* Maximum we will need */ 97 else if (len <= 0) 98 return -1; 99 if (value < 0x80) { 100 if (str) 101 *str = (unsigned char)value; 102 return 1; 103 } 104 if (value < 0x800) { 105 if (len < 2) 106 return -1; 107 if (str) { 108 *str++ = (unsigned char)(((value >> 6) & 0x1f) | 0xc0); 109 *str = (unsigned char)((value & 0x3f) | 0x80); 110 } 111 return 2; 112 } 113 if (value < 0x10000) { 114 if (is_unicode_surrogate(value)) 115 return -2; 116 if (len < 3) 117 return -1; 118 if (str) { 119 *str++ = (unsigned char)(((value >> 12) & 0xf) | 0xe0); 120 *str++ = (unsigned char)(((value >> 6) & 0x3f) | 0x80); 121 *str = (unsigned char)((value & 0x3f) | 0x80); 122 } 123 return 3; 124 } 125 if (value < UNICODE_LIMIT) { 126 if (len < 4) 127 return -1; 128 if (str) { 129 *str++ = (unsigned char)(((value >> 18) & 0x7) | 0xf0); 130 *str++ = (unsigned char)(((value >> 12) & 0x3f) | 0x80); 131 *str++ = (unsigned char)(((value >> 6) & 0x3f) | 0x80); 132 *str = (unsigned char)((value & 0x3f) | 0x80); 133 } 134 return 4; 135 } 136 return -2; 137} 138