#include <assert.h> #include <stdio.h> #include <string.h> #include "buffer.h" #include "houdini.h" #include "utf8.h" #include "entities.inc" /* Binary tree lookup code for entities added by JGM */ static const unsigned char *S_lookup(int i, int low, int hi, const unsigned char *s, int len) { int j; int cmp = strncmp((const char *)s, (const char *)cmark_entities[i].entity, len); if (cmp == 0 && cmark_entities[i].entity[len] == 0) { return (const unsigned char *)cmark_entities[i].bytes; } else if (cmp < 0 && i > low) { j = i - ((i - low) / 2); if (j == i) j -= 1; return S_lookup(j, low, i - 1, s, len); } else if (cmp > 0 && i < hi) { j = i + ((hi - i) / 2); if (j == i) j += 1; return S_lookup(j, i + 1, hi, s, len); } else { return NULL; } } static const unsigned char *S_lookup_entity(const unsigned char *s, int len) { return S_lookup(CMARK_NUM_ENTITIES / 2, 0, CMARK_NUM_ENTITIES - 1, s, len); } bufsize_t houdini_unescape_ent(cmark_strbuf *ob, const uint8_t *src, bufsize_t size) { bufsize_t i = 0; if (size >= 3 && src[0] == '#') { int codepoint = 0; int num_digits = 0; if (_isdigit(src[1])) { for (i = 1; i < size && _isdigit(src[i]); ++i) { codepoint = (codepoint * 10) + (src[i] - '0'); if (codepoint >= 0x110000) { // Keep counting digits but // avoid integer overflow. codepoint = 0x110000; } } num_digits = i - 1; } else if (src[1] == 'x' || src[1] == 'X') { for (i = 2; i < size && _isxdigit(src[i]); ++i) { codepoint = (codepoint * 16) + ((src[i] | 32) % 39 - 9); if (codepoint >= 0x110000) { // Keep counting digits but // avoid integer overflow. codepoint = 0x110000; } } num_digits = i - 2; } if (num_digits >= 1 && num_digits <= 8 && i < size && src[i] == ';') { if (codepoint == 0 || (codepoint >= 0xD800 && codepoint < 0xE000) || codepoint >= 0x110000) { codepoint = 0xFFFD; } cmark_utf8proc_encode_char(codepoint, ob); return i + 1; } } else { if (size > CMARK_ENTITY_MAX_LENGTH) size = CMARK_ENTITY_MAX_LENGTH; for (i = CMARK_ENTITY_MIN_LENGTH; i < size; ++i) { if (src[i] == ' ') break; if (src[i] == ';') { const unsigned char *entity = S_lookup_entity(src, i); if (entity != NULL) { cmark_strbuf_puts(ob, (const char *)entity); return i + 1; } break; } } } return 0; } int houdini_unescape_html(cmark_strbuf *ob, const uint8_t *src, bufsize_t size) { bufsize_t i = 0, org, ent; while (i < size) { org = i; while (i < size && src[i] != '&') i++; if (likely(i > org)) { if (unlikely(org == 0)) { if (i >= size) return 0; cmark_strbuf_grow(ob, HOUDINI_UNESCAPED_SIZE(size)); } cmark_strbuf_put(ob, src + org, i - org); } /* escaping */ if (i >= size) break; i++; ent = houdini_unescape_ent(ob, src + i, size - i); i += ent; /* not really an entity */ if (ent == 0) cmark_strbuf_putc(ob, '&'); } return 1; } void houdini_unescape_html_f(cmark_strbuf *ob, const uint8_t *src, bufsize_t size) { if (!houdini_unescape_html(ob, src, size)) cmark_strbuf_put(ob, src, size); }