[git commit] wget: URL-decode user:password before base64-encoding it into auth hdr. Closes 3625.
Denys Vlasenko
vda.linux at googlemail.com
Sun Sep 11 19:04:02 UTC 2011
commit: http://git.busybox.net/busybox/commit/?id=dd1061b6a79b0161597799e825bfefc27993ace5
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
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 at googlemail.com>
---
include/libbb.h | 9 ++++++
libbb/percent_decode.c | 69 +++++++++++++++++++++++++++++++++++++++++++
networking/httpd.c | 76 +----------------------------------------------
networking/wget.c | 13 ++++----
4 files changed, 86 insertions(+), 81 deletions(-)
create mode 100644 libbb/percent_decode.c
diff --git a/include/libbb.h b/include/libbb.h
index d0c7ace..21cbe1c 100644
--- 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
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
--- 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
--- 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));
}
--
1.7.3.4
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