David Balazic pointed out the lack of checks for a valid %XX code when

we unescape a string. We now check and decode only valid %XX strings.
This commit is contained in:
Daniel Stenberg 2003-05-21 15:53:59 +00:00
parent d78ec593fa
commit 2356325592
1 changed files with 20 additions and 7 deletions

View File

@ -79,6 +79,10 @@ char *curl_escape(const char *string, int length)
return ns;
}
#define ishex(in) ((in >= 'a' && in <= 'f') || \
(in >= 'A' && in <= 'F') || \
(in >= '0' && in <= '9'))
char *curl_unescape(const char *string, int length)
{
int alloc = (length?length:(int)strlen(string))+1;
@ -93,13 +97,19 @@ char *curl_unescape(const char *string, int length)
while(--alloc > 0) {
in = *string;
if('%' == in) {
/* encoded part */
if(sscanf(string+1, "%02X", &hex)) {
in = hex;
string+=2;
alloc-=2;
}
if(('%' == in) && ishex(string[1]) && ishex(string[2])) {
/* this is two hexadecimal digits following a '%' */
char hexstr[3];
char *ptr;
hexstr[0] = string[1];
hexstr[1] = string[2];
hexstr[2] = 0;
hex = strtol(hexstr, &ptr, 16);
in = hex;
string+=2;
alloc-=2;
}
ns[index++] = in;
@ -109,6 +119,9 @@ char *curl_unescape(const char *string, int length)
return ns;
}
/* For operating systems/environments that use different malloc/free
ssystems for the app and for this library, we provide a free that uses
the library's memory system */
void curl_free(void *p)
{
free(p);