diff options
Diffstat (limited to 'src/utf8.c')
| -rw-r--r-- | src/utf8.c | 65 |
1 files changed, 62 insertions, 3 deletions
@@ -28,7 +28,7 @@ static void encode_unknown(strbuf *buf) strbuf_put(buf, repl, 3); } -int utf8proc_charlen(const uint8_t *str, int str_len) +static int utf8proc_charlen(const uint8_t *str, int str_len) { int length, i; @@ -51,6 +51,64 @@ int utf8proc_charlen(const uint8_t *str, int str_len) return length; } +// Validate a single UTF-8 character according to RFC 3629. +static int utf8proc_valid(const uint8_t *str, int str_len) +{ + int length = utf8proc_charlen(str, str_len); + + if (length <= 0) + return length; + + switch (length) { + case 1: + if (str[0] == 0x00) { + // ASCII NUL is technically valid but rejected + // for security reasons. + return -length; + } + break; + + case 2: + if (str[0] < 0xC2) { + // Overlong + return -length; + } + break; + + case 3: + if (str[0] == 0xE0) { + if (str[1] < 0xA0) { + // Overlong + return -length; + } + } + else if (str[0] == 0xED) { + if (str[1] >= 0xA0) { + // Surrogate + return -length; + } + } + break; + + case 4: + if (str[0] == 0xF0) { + if (str[1] < 0x90) { + // Overlong + return -length; + } + } + else if (str[0] >= 0xF4) { + if (str[0] > 0xF4 || str[1] >= 0x90) { + // Above 0x10FFFF + return -length; + } + } + break; + } + + return length; +} + void utf8proc_detab(strbuf *ob, const uint8_t *line, size_t size) { static const uint8_t whitespace[] = " "; @@ -60,7 +118,8 @@ void utf8proc_detab(strbuf *ob, const uint8_t *line, size_t size) while (i < size) { size_t org = i; - while (i < size && line[i] != '\t' && line[i] <= 0x80) { + while (i < size && line[i] != '\t' && line[i] != '\0' + && line[i] < 0x80) { i++; tab++; } @@ -76,7 +135,7 @@ void utf8proc_detab(strbuf *ob, const uint8_t *line, size_t size) i += 1; tab += numspaces; } else { - int charlen = utf8proc_charlen(line + i, size - i); + int charlen = utf8proc_valid(line + i, size - i); if (charlen >= 0) { strbuf_put(ob, line + i, charlen); |