Handle %xx encoding in querystring

Convert valid %xx expressions in querystring to ascii, ignore invalid
expressions (i.e. eat the three characters %xx).

Signed-off-by: Lars Hjemli <larsh@hal-2004.(none)>

3 files changed, 36 insertions, 0 deletions

diff --git a/cgit.h b/cgit.h
index 249650e..eb8f08c 100644
--- a/cgit.h
+++ b/cgit.h
@@ -67,6 +67,8 @@ extern void cgit_global_config_cb(const char *name, const char *value);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 extern void cgit_querystring_cb(const char *name, const char *value);
 
+extern int hextoint(char c);
+
 extern void *cgit_free_commitinfo(struct commitinfo *info);
 
 extern char *fmt(const char *format,...);
diff --git a/parsing.c b/parsing.c
index 1b22fcf..4173dd4 100644
--- a/parsing.c
+++ b/parsing.c
@@ -79,6 +79,25 @@ int cgit_read_config(const char *filename, configfn fn)
         return ret;
 }
 
+char *convert_query_hexchar(char *txt)
+{
+        int d1, d2;
+        if (strlen(txt) < 3) {
+                *txt = '\0';
+                return txt-1;
+        }
+        d1 = hextoint(*(txt+1));
+        d2 = hextoint(*(txt+2));
+        if (d1<0 || d2<0) {
+                strcpy(txt, txt+3);
+                return txt-1;
+        } else {
+                *txt = d1 * 16 + d2;
+                strcpy(txt+1, txt+3);
+                return txt;
+        }
+}
+
 int cgit_parse_query(char *txt, configfn fn)
 {
         char *t, *value = NULL, c;
@@ -94,6 +113,8 @@ int cgit_parse_query(char *txt, configfn fn)
                         value = t+1;
                 } else if (c=='+') {
                         *t = ' ';
+                } else if (c=='%') {
+                        t = convert_query_hexchar(t);
                 } else if (c=='&') {
                         *t = '\0';
                         (*fn)(txt, value);
diff --git a/shared.c b/shared.c
index 7def51a..e4595fa 100644
--- a/shared.c
+++ b/shared.c
@@ -113,3 +113,16 @@ void *cgit_free_commitinfo(struct commitinfo *info)
         free(info);
         return NULL;
 }
+
+int hextoint(char c)
+{
+        if (c >= 'a' && c <= 'f')
+                return 10 + c - 'a';
+        else if (c >= 'A' && c <= 'F')
+                return 10 + c - 'A';
+        else if (c >= '0' && c <= '9')
+                return c - '0';
+        else
+                return -1;
+}
+