summaryrefslogtreecommitdiffstats
path: root/Objects/unicodeobject.c
diff options
context:
space:
mode:
authorMarc-André Lemburg <mal@egenix.com>2002-04-10 20:36:13 (GMT)
committerMarc-André Lemburg <mal@egenix.com>2002-04-10 20:36:13 (GMT)
commit68e69338ae19c37bd3e69cb76e107bfa76231e06 (patch)
tree9050cb2fda190be071ca75d4728609d7f70a9ced /Objects/unicodeobject.c
parente3c764b6c288ff546e8b1c3513044c63558aad8b (diff)
downloadcpython-68e69338ae19c37bd3e69cb76e107bfa76231e06.zip
cpython-68e69338ae19c37bd3e69cb76e107bfa76231e06.tar.gz
cpython-68e69338ae19c37bd3e69cb76e107bfa76231e06.tar.bz2
Bug fix for UTF-8 encoding bug (buffer overrun) #541828.
Diffstat (limited to 'Objects/unicodeobject.c')
-rw-r--r--Objects/unicodeobject.c85
1 files changed, 46 insertions, 39 deletions
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 57c031f..52eb61d 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1172,85 +1172,92 @@ int utf8_encoding_error(const Py_UNICODE **source,
}
#endif
+/* Allocation strategy: we default to Latin-1, then do one resize
+ whenever we hit an order boundary. The assumption is that
+ characters from higher orders usually occur often enough to warrant
+ this.
+*/
+
PyObject *PyUnicode_EncodeUTF8(const Py_UNICODE *s,
int size,
const char *errors)
{
PyObject *v;
char *p;
- unsigned int cbAllocated = 2 * size;
- unsigned int cbWritten = 0;
int i = 0;
-
+ int overalloc = 2;
+ int len;
+
/* Short-cut for emtpy strings */
if (size == 0)
return PyString_FromStringAndSize(NULL, 0);
- /* We allocate 4 more bytes to have room for at least one full
- UTF-8 sequence; saves a few cycles in the loop below */
- v = PyString_FromStringAndSize(NULL, cbAllocated + 4);
+ v = PyString_FromStringAndSize(NULL, overalloc * size);
if (v == NULL)
return NULL;
p = PyString_AS_STRING(v);
+
while (i < size) {
Py_UCS4 ch = s[i++];
- if (ch < 0x80) {
+ if (ch < 0x80)
+ /* Encode ASCII */
*p++ = (char) ch;
- cbWritten++;
- }
else if (ch < 0x0800) {
+ /* Encode Latin-1 */
*p++ = (char)(0xc0 | (ch >> 6));
*p++ = (char)(0x80 | (ch & 0x3f));
- cbWritten += 2;
}
else {
-
- /* Assure that we have enough room for high order Unicode
- ordinals */
- if (cbWritten >= cbAllocated) {
- cbAllocated += 4 * 10;
- if (_PyString_Resize(&v, cbAllocated + 4))
- goto onError;
- p = PyString_AS_STRING(v) + cbWritten;
- }
-
+ /* Encode UCS2 Unicode ordinals */
if (ch < 0x10000) {
- /* Check for high surrogate */
+
+ /* Special case: check for high surrogate */
if (0xD800 <= ch && ch <= 0xDBFF && i != size) {
Py_UCS4 ch2 = s[i];
- /* Check for low surrogate */
+ /* Check for low surrogate and combine the two to
+ form a UCS4 value */
if (0xDC00 <= ch2 && ch2 <= 0xDFFF) {
- ch = ((ch - 0xD800) << 10 | (ch2 - 0xDC00)) + 0x00010000;
- *p++ = (char)(0xf0 | (ch >> 18));
- *p++ = (char)(0x80 | ((ch >> 12) & 0x3f));
- *p++ = (char)(0x80 | ((ch >> 6) & 0x3f));
- *p++ = (char)(0x80 | (ch & 0x3f));
- i++;
- cbWritten += 4;
- continue;
+ ch = ((ch - 0xD800) << 10 | (ch2 - 0xDC00)) + 0x10000;
+ i++;
+ goto encodeUCS4;
}
/* Fall through: handles isolated high surrogates */
}
+
+ if (overalloc < 3) {
+ len = (int)(p - PyString_AS_STRING(v));
+ overalloc = 3;
+ if (_PyString_Resize(&v, overalloc * size))
+ goto onError;
+ p = PyString_AS_STRING(v) + len;
+ }
*p++ = (char)(0xe0 | (ch >> 12));
*p++ = (char)(0x80 | ((ch >> 6) & 0x3f));
*p++ = (char)(0x80 | (ch & 0x3f));
- cbWritten += 3;
-
- } else {
- *p++ = (char)(0xf0 | (ch>>18));
- *p++ = (char)(0x80 | ((ch>>12) & 0x3f));
- *p++ = (char)(0x80 | ((ch>>6) & 0x3f));
- *p++ = (char)(0x80 | (ch & 0x3f));
- cbWritten += 4;
+ continue;
+ }
+
+ /* Encode UCS4 Unicode ordinals */
+ encodeUCS4:
+ if (overalloc < 4) {
+ len = (int)(p - PyString_AS_STRING(v));
+ overalloc = 4;
+ if (_PyString_Resize(&v, overalloc * size))
+ goto onError;
+ p = PyString_AS_STRING(v) + len;
}
+ *p++ = (char)(0xf0 | (ch >> 18));
+ *p++ = (char)(0x80 | ((ch >> 12) & 0x3f));
+ *p++ = (char)(0x80 | ((ch >> 6) & 0x3f));
+ *p++ = (char)(0x80 | (ch & 0x3f));
}
}
*p = '\0';
- if (_PyString_Resize(&v, cbWritten))
+ if (_PyString_Resize(&v, (int)(p - PyString_AS_STRING(v))))
goto onError;
return v;