1 files changed, 108 insertions, 0 deletions
diff --git a/src/core/ngx_string.c b/src/core/ngx_string.c
index a236654d7..fc3738234 100644
--- a/src/core/ngx_string.c
+++ b/src/core/ngx_string.c
@@ -928,3 +928,111 @@ ngx_escape_uri(u_char *dst, u_char *src, size_t size, ngx_uint_t type)
 
     return (uintptr_t) dst;
 }
+
+
+void
+ngx_unescape_uri(u_char **dst, u_char **src, size_t size)
+{
+    u_char  *d, *s, ch, c, decoded;
+    enum {
+        sw_usual = 0,
+        sw_quoted,
+        sw_quoted_second
+    } state;
+
+    d = *dst;
+    s = *src;
+
+    state = 0;
+    decoded = 0;
+
+    while (size--) {
+
+        ch = *s++;
+
+        switch (state) {
+        case sw_usual:
+            if (ch == '?') {
+                *d++ = ch;
+                goto done;
+            }
+
+            if (ch == '%') {
+                state = sw_quoted;
+                break;
+            }
+
+            *d++ = ch;
+            break;
+
+        case sw_quoted:
+
+            if (ch >= '0' && ch <= '9') {
+                decoded = (u_char) (ch - '0');
+                state = sw_quoted_second;
+                break;
+            }
+
+            c = (u_char) (ch | 0x20);
+            if (c >= 'a' && c <= 'f') {
+                decoded = (u_char) (c - 'a' + 10);
+                state = sw_quoted_second;
+                break;
+            }
+
+            /* skip the invalid quoted character */
+
+            s++;
+            size--;
+
+            break;
+
+        case sw_quoted_second:
+
+            if (ch >= '0' && ch <= '9') {
+                ch = (u_char) ((decoded << 4) + ch - '0');
+
+                state = sw_usual;
+
+                if (ch > '%' && ch < 0x7f) {
+                    *d++ = ch;
+                    break;
+                }
+
+                *d++ = '%'; *d++ = *(s - 2); *d++ = *(s - 1);
+
+                break;
+            }
+
+            c = (u_char) (ch | 0x20);
+            if (c >= 'a' && c <= 'f') {
+                ch = (u_char) ((decoded << 4) + c - 'a' + 10);
+
+                if (ch == '?') {
+                    *d++ = ch;
+                    goto done;
+                }
+
+                state = sw_usual;
+
+                if (ch > '%' && ch < 0x7f) {
+                    *d++ = ch;
+                    break;
+                }
+
+                *d++ = '%'; *d++ = *(s - 2); *d++ = *(s - 1);
+
+                break;
+            }
+
+            /* skip the invalid quoted character */
+
+            break;
+        }
+    }
+
+done:
+
+    *dst = d;
+    *src = s;
+}