diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
commit | 1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5 (patch) | |
tree | 6cf8220b628ebd2ccfc1375dd6516c6996e9abcc /lib/crypto_backend/utf8.c | |
parent | Initial commit. (diff) | |
download | cryptsetup-1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5.tar.xz cryptsetup-1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5.zip |
Adding upstream version 2:2.6.1.upstream/2%2.6.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/crypto_backend/utf8.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/lib/crypto_backend/utf8.c b/lib/crypto_backend/utf8.c new file mode 100644 index 0000000..24e0d8d --- /dev/null +++ b/lib/crypto_backend/utf8.c @@ -0,0 +1,288 @@ +/* + * UTF8/16 helpers, copied and adapted from systemd project. + * + * Copyright (C) 2010 Lennart Poettering + * + * cryptsetup related changes + * Copyright (C) 2021-2023 Vojtech Trefny + + * Parts of the original systemd implementation are based on the GLIB utf8 + * validation functions. + * gutf8.c - Operations on UTF-8 strings. + * + * Copyright (C) 1999 Tom Tromey + * Copyright (C) 2000 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <errno.h> +#include <endian.h> + +#include "crypto_backend.h" + +static inline bool utf16_is_surrogate(char16_t c) +{ + return c >= 0xd800U && c <= 0xdfffU; +} + +static inline bool utf16_is_trailing_surrogate(char16_t c) +{ + return c >= 0xdc00U && c <= 0xdfffU; +} + +static inline char32_t utf16_surrogate_pair_to_unichar(char16_t lead, char16_t trail) +{ + return ((((char32_t) lead - 0xd800U) << 10) + ((char32_t) trail - 0xdc00U) + 0x10000U); +} + +/** + * utf8_encode_unichar() - Encode single UCS-4 character as UTF-8 + * @out_utf8: output buffer of at least 4 bytes or NULL + * @g: UCS-4 character to encode + * + * This encodes a single UCS-4 character as UTF-8 and writes it into @out_utf8. + * The length of the character is returned. It is not zero-terminated! If the + * output buffer is NULL, only the length is returned. + * + * Returns: The length in bytes that the UTF-8 representation does or would + * occupy. + */ +static size_t utf8_encode_unichar(char *out_utf8, char32_t g) +{ + if (g < (1 << 7)) { + if (out_utf8) + out_utf8[0] = g & 0x7f; + return 1; + } else if (g < (1 << 11)) { + if (out_utf8) { + out_utf8[0] = 0xc0 | ((g >> 6) & 0x1f); + out_utf8[1] = 0x80 | (g & 0x3f); + } + return 2; + } else if (g < (1 << 16)) { + if (out_utf8) { + out_utf8[0] = 0xe0 | ((g >> 12) & 0x0f); + out_utf8[1] = 0x80 | ((g >> 6) & 0x3f); + out_utf8[2] = 0x80 | (g & 0x3f); + } + return 3; + } else if (g < (1 << 21)) { + if (out_utf8) { + out_utf8[0] = 0xf0 | ((g >> 18) & 0x07); + out_utf8[1] = 0x80 | ((g >> 12) & 0x3f); + out_utf8[2] = 0x80 | ((g >> 6) & 0x3f); + out_utf8[3] = 0x80 | (g & 0x3f); + } + return 4; + } + + return 0; +} + +/** + * crypt_utf16_to_utf8() + * @out: output buffer, should be 2 * @length + 1 long + * @s: string to convert + * @length: length of @s in bytes + * + * Converts a UTF16LE encoded string to a UTF8 encoded string. + * + * Returns: 0 on success, negative errno otherwise + */ +int crypt_utf16_to_utf8(char **out, const char16_t *s, size_t length /* bytes! */) +{ + const uint8_t *f; + char *t; + + assert(s); + assert(out); + assert(*out); + + /* Input length is in bytes, i.e. the shortest possible character takes 2 bytes. Each unicode character may + * take up to 4 bytes in UTF-8. Let's also account for a trailing NUL byte. */ + if (length * 2 < length) + return -EOVERFLOW; /* overflow */ + + f = (const uint8_t*) s; + t = *out; + + while (f + 1 < (const uint8_t*) s + length) { + char16_t w1, w2; + + /* see RFC 2781 section 2.2 */ + + w1 = f[1] << 8 | f[0]; + f += 2; + + if (!utf16_is_surrogate(w1)) { + t += utf8_encode_unichar(t, w1); + continue; + } + + if (utf16_is_trailing_surrogate(w1)) + continue; /* spurious trailing surrogate, ignore */ + + if (f + 1 >= (const uint8_t*) s + length) + break; + + w2 = f[1] << 8 | f[0]; + f += 2; + + if (!utf16_is_trailing_surrogate(w2)) { + f -= 2; + continue; /* surrogate missing its trailing surrogate, ignore */ + } + + t += utf8_encode_unichar(t, utf16_surrogate_pair_to_unichar(w1, w2)); + } + + *t = 0; + return 0; +} + +/* count of characters used to encode one unicode char */ +static size_t utf8_encoded_expected_len(uint8_t c) +{ + if (c < 0x80) + return 1; + if ((c & 0xe0) == 0xc0) + return 2; + if ((c & 0xf0) == 0xe0) + return 3; + if ((c & 0xf8) == 0xf0) + return 4; + if ((c & 0xfc) == 0xf8) + return 5; + if ((c & 0xfe) == 0xfc) + return 6; + + return 0; +} + +/* decode one unicode char */ +static int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar) +{ + char32_t unichar; + size_t len, i; + + assert(str); + + len = utf8_encoded_expected_len(str[0]); + + switch (len) { + case 1: + *ret_unichar = (char32_t)str[0]; + return 0; + case 2: + unichar = str[0] & 0x1f; + break; + case 3: + unichar = (char32_t)str[0] & 0x0f; + break; + case 4: + unichar = (char32_t)str[0] & 0x07; + break; + case 5: + unichar = (char32_t)str[0] & 0x03; + break; + case 6: + unichar = (char32_t)str[0] & 0x01; + break; + default: + return -EINVAL; + } + + for (i = 1; i < len; i++) { + if (((char32_t)str[i] & 0xc0) != 0x80) + return -EINVAL; + + unichar <<= 6; + unichar |= (char32_t)str[i] & 0x3f; + } + + *ret_unichar = unichar; + + return 0; +} + +static size_t utf16_encode_unichar(char16_t *out, char32_t c) +{ + /* Note that this encodes as little-endian. */ + + switch (c) { + + case 0 ... 0xd7ffU: + case 0xe000U ... 0xffffU: + out[0] = htole16(c); + return 1; + + case 0x10000U ... 0x10ffffU: + c -= 0x10000U; + out[0] = htole16((c >> 10) + 0xd800U); + out[1] = htole16((c & 0x3ffU) + 0xdc00U); + return 2; + + default: /* A surrogate (invalid) */ + return 0; + } +} + +/** + * crypt_utf8_to_utf16() + * @out: output buffer, should be @length + 1 long + * @s: string to convert + * @length: length of @s in bytes + * + * Converts a UTF8 encoded string to a UTF16LE encoded string. + * + * Returns: 0 on success, negative errno otherwise + */ +int crypt_utf8_to_utf16(char16_t **out, const char *s, size_t length) +{ + char16_t *p; + size_t i; + int r; + + assert(s); + + p = *out; + + for (i = 0; i < length;) { + char32_t unichar; + size_t e; + + e = utf8_encoded_expected_len(s[i]); + if (e <= 1) /* Invalid and single byte characters are copied as they are */ + goto copy; + + if (i + e > length) /* sequence longer than input buffer, then copy as-is */ + goto copy; + + r = utf8_encoded_to_unichar(s + i, &unichar); + if (r < 0) /* sequence invalid, then copy as-is */ + goto copy; + + p += utf16_encode_unichar(p, unichar); + i += e; + continue; + + copy: + *(p++) = htole16(s[i++]); + } + + *p = 0; + return 0; +} |