diff options
Diffstat (limited to 'libmisc/utf8.c')
| -rw-r--r-- | libmisc/utf8.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/libmisc/utf8.c b/libmisc/utf8.c index 5f91021..28357f0 100644 --- a/libmisc/utf8.c +++ b/libmisc/utf8.c @@ -9,17 +9,21 @@ void utf8_decode_codepoint(const uint8_t *str, size_t len, uint32_t *ret_ch, uint8_t *ret_chlen) { uint32_t ch; uint8_t chlen; - if ((str[0] & 0b10000000) == 0b00000000) { ch = str[0] & 0b01111111; chlen = 1; } - else if ((str[0] & 0b11100000) == 0b11000000) { ch = str[0] & 0b00011111; chlen = 2; } - else if ((str[0] & 0b11110000) == 0b11100000) { ch = str[0] & 0b00001111; chlen = 3; } - else if ((str[0] & 0b11111000) == 0b11110000) { ch = str[0] & 0b00000111; chlen = 4; } + uint32_t chmin; + if ((str[0] & 0b10000000) == 0b00000000) { ch = str[0] & 0b01111111; chlen = 1; chmin = 0; } /* bits=7+(0*6)= 7 */ + else if ((str[0] & 0b11100000) == 0b11000000) { ch = str[0] & 0b00011111; chlen = 2; chmin = UINT32_C(1)<< 7; } /* bits=5+(1*6)=11 */ + else if ((str[0] & 0b11110000) == 0b11100000) { ch = str[0] & 0b00001111; chlen = 3; chmin = UINT32_C(1)<<11; } /* bits=4+(2*6)=16 */ + else if ((str[0] & 0b11111000) == 0b11110000) { ch = str[0] & 0b00000111; chlen = 4; chmin = UINT32_C(1)<<16; } /* bits=3+(3*6)=21 */ else goto invalid; - if ((ch == 0 && chlen != 1) || chlen > len) goto invalid; + if (chlen > len) + goto invalid; for (uint8_t i = 1; i < chlen; i++) { - if ((str[i] & 0b11000000) != 0b10000000) goto invalid; + if ((str[i] & 0b11000000) != 0b10000000) + goto invalid; ch = (ch << 6) | (str[i] & 0b00111111); } - if (ch > 0x10FFFF) goto invalid; + if (ch > 0x10FFFF || ch < chmin) + goto invalid; *ret_ch = ch; *ret_chlen = chlen; return; |