wget: URL-decode user:password before base64-encoding it into auth hdr. Closes 3625.

function                                             old     new   delta
percent_decode_in_place                                -     152    +152
parse_url                                            304     317     +13
handle_incoming_and_exit                            2795    2798      +3
httpd_main                                           763     760      -3
decodeString                                         152       -    -152
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 2/1 up/down: 168/-155)           Total: 13 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/include/libbb.h b/include/libbb.h
index d0c7ace..21cbe1c 100644 (file)
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1578,6 +1578,15 @@ int starts_with_cpu(const char *str) FAST_FUNC;
 unsigned get_cpu_count(void) FAST_FUNC;
 
 
+/* Use strict=1 if you process input from untrusted source:
+ * it will return NULL on invalid %xx (bad hex chars)
+ * and str + 1 if decoded char is / or NUL.
+ * In non-strict mode, it always succeeds (returns str),
+ * and also it additionally decoded '+' to space.
+ */
+char *percent_decode_in_place(char *str, int strict) FAST_FUNC;
+
+
 extern const char bb_uuenc_tbl_base64[];
 extern const char bb_uuenc_tbl_std[];
 void bb_uuencode(char *store, const void *s, int length, const char *tbl) FAST_FUNC;

diff --git a/libbb/percent_decode.c b/libbb/percent_decode.c
new file mode 100644 (file)
index 0000000..9a9d80c
--- /dev/null
+++ b/libbb/percent_decode.c
@@ -0,0 +1,69 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//kbuild:lib-y += percent_decode.o
+
+#include "libbb.h"
+
+static unsigned hex_to_bin(unsigned char c)
+{
+       unsigned v;
+
+       v = c - '0';
+       if (v <= 9)
+               return v;
+       /* c | 0x20: letters to lower case, non-letters
+        * to (potentially different) non-letters */
+       v = (unsigned)(c | 0x20) - 'a';
+       if (v <= 5)
+               return v + 10;
+       return ~0;
+/* For testing:
+void t(char c) { printf("'%c'(%u) %u\n", c, c, hex_to_bin(c)); }
+int main() { t(0x10); t(0x20); t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
+t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
+*/
+}
+
+char* FAST_FUNC percent_decode_in_place(char *str, int strict)
+{
+       /* note that decoded string is always shorter than original */
+       char *src = str;
+       char *dst = str;
+       char c;
+
+       while ((c = *src++) != '\0') {
+               unsigned v;
+
+               if (!strict && c == '+') {
+                       *dst++ = ' ';
+                       continue;
+               }
+               if (c != '%') {
+                       *dst++ = c;
+                       continue;
+               }
+               v = hex_to_bin(src[0]);
+               if (v > 15) {
+ bad_hex:
+                       if (strict)
+                               return NULL;
+                       *dst++ = '%';
+                       continue;
+               }
+               v = (v * 16) | hex_to_bin(src[1]);
+               if (v > 255)
+                       goto bad_hex;
+               if (strict && (v == '/' || v == '\0')) {
+                       /* caller takes it as indication of invalid
+                        * (dangerous wrt exploits) chars */
+                       return str + 1;
+               }
+               *dst++ = v;
+               src += 2;
+       }
+       *dst = '\0';
+       return str;
+}

diff --git a/networking/httpd.c b/networking/httpd.c
index ba5eeba..24482fe 100644 (file)
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -820,78 +820,6 @@ static char *encodeString(const char *string)
 }
 #endif
 
-/*
- * Given a URL encoded string, convert it to plain ascii.
- * Since decoding always makes strings smaller, the decode is done in-place.
- * Thus, callers should xstrdup() the argument if they do not want the
- * argument modified.  The return is the original pointer, allowing this
- * function to be easily used as arguments to other functions.
- *
- * string    The first string to decode.
- * option_d  1 if called for httpd -d
- *
- * Returns a pointer to the decoded string (same as input).
- */
-static unsigned hex_to_bin(unsigned char c)
-{
-       unsigned v;
-
-       v = c - '0';
-       if (v <= 9)
-               return v;
-       /* c | 0x20: letters to lower case, non-letters
-        * to (potentially different) non-letters */
-       v = (unsigned)(c | 0x20) - 'a';
-       if (v <= 5)
-               return v + 10;
-       return ~0;
-/* For testing:
-void t(char c) { printf("'%c'(%u) %u\n", c, c, hex_to_bin(c)); }
-int main() { t(0x10); t(0x20); t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
-t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
-*/
-}
-static char *decodeString(char *orig, int option_d)
-{
-       /* note that decoded string is always shorter than original */
-       char *string = orig;
-       char *ptr = string;
-       char c;
-
-       while ((c = *ptr++) != '\0') {
-               unsigned v;
-
-               if (option_d && c == '+') {
-                       *string++ = ' ';
-                       continue;
-               }
-               if (c != '%') {
-                       *string++ = c;
-                       continue;
-               }
-               v = hex_to_bin(ptr[0]);
-               if (v > 15) {
- bad_hex:
-                       if (!option_d)
-                               return NULL;
-                       *string++ = '%';
-                       continue;
-               }
-               v = (v * 16) | hex_to_bin(ptr[1]);
-               if (v > 255)
-                       goto bad_hex;
-               if (!option_d && (v == '/' || v == '\0')) {
-                       /* caller takes it as indication of invalid
-                        * (dangerous wrt exploits) chars */
-                       return orig + 1;
-               }
-               *string++ = v;
-               ptr += 2;
-       }
-       *string = '\0';
-       return orig;
-}
-
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
 /*
  * Decode a base64 data stream as per rfc1521.
@@ -1949,7 +1877,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        }
 
        /* Decode URL escape sequences */
-       tptr = decodeString(urlcopy, 0);
+       tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
        if (tptr == NULL)
                send_headers_and_exit(HTTP_BAD_REQUEST);
        if (tptr == urlcopy + 1) {
@@ -2408,7 +2336,7 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
                        , &verbose
                );
        if (opt & OPT_DECODE_URL) {
-               fputs(decodeString(url_for_decode, 1), stdout);
+               fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
                return 0;
        }
 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR

diff --git a/networking/wget.c b/networking/wget.c
index 6443705..94a2f7c 100644 (file)
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -298,8 +298,13 @@ static void parse_url(const char *src_url, struct host_info *h)
 
        sp = strrchr(h->host, '@');
        if (sp != NULL) {
-               h->user = h->host;
+               // URL-decode "user:password" string before base64-encoding:
+               // wget http://test:my%20pass@example.com should send
+               // Authorization: Basic dGVzdDpteSBwYXNz
+               // which decodes to "test:my pass".
+               // Standard wget and curl do this too.
                *sp = '\0';
+               h->user = percent_decode_in_place(h->host, /*strict:*/ 0);
                h->host = sp + 1;
        }
 
@@ -660,12 +665,6 @@ static void download_one_url(const char *url)
 
 #if ENABLE_FEATURE_WGET_AUTHENTICATION
                if (target.user) {
-//TODO: URL-decode "user:password" string before base64-encoding:
-//wget http://test:my%20pass@example.com should send
-// Authorization: Basic dGVzdDpteSBwYXNz
-//which decodes to "test:my pass", instead of what we send now:
-// Authorization: Basic dGVzdDpteSUyMHBhc3M=
-//Can reuse decodeString() from httpd.c
                        fprintf(sfp, "Proxy-Authorization: Basic %s\r\n"+6,
                                base64enc(target.user));
                }