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>
This commit is contained in:
Denys Vlasenko
parent
5126cf9a15
commit
dd1061b6a7
@ -1578,6 +1578,15 @@ int starts_with_cpu(const char *str) FAST_FUNC;
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unsigned get_cpu_count(void) FAST_FUNC;
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/* Use strict=1 if you process input from untrusted source:
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* it will return NULL on invalid %xx (bad hex chars)
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* and str + 1 if decoded char is / or NUL.
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* In non-strict mode, it always succeeds (returns str),
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* and also it additionally decoded '+' to space.
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*/
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char *percent_decode_in_place(char *str, int strict) FAST_FUNC;
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extern const char bb_uuenc_tbl_base64[];
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extern const char bb_uuenc_tbl_std[];
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void bb_uuencode(char *store, const void *s, int length, const char *tbl) FAST_FUNC;
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69
libbb/percent_decode.c
Normal file
69
libbb/percent_decode.c
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@ -0,0 +1,69 @@
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/* vi: set sw=4 ts=4: */
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/*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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//kbuild:lib-y += percent_decode.o
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#include "libbb.h"
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static unsigned hex_to_bin(unsigned char c)
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{
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unsigned v;
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v = c - '0';
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if (v <= 9)
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return v;
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/* c | 0x20: letters to lower case, non-letters
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* to (potentially different) non-letters */
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v = (unsigned)(c | 0x20) - 'a';
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if (v <= 5)
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return v + 10;
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return ~0;
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/* For testing:
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void t(char c) { printf("'%c'(%u) %u\n", c, c, hex_to_bin(c)); }
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int main() { t(0x10); t(0x20); t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
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t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
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*/
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}
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char* FAST_FUNC percent_decode_in_place(char *str, int strict)
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{
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/* note that decoded string is always shorter than original */
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char *src = str;
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char *dst = str;
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char c;
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while ((c = *src++) != '\0') {
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unsigned v;
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if (!strict && c == '+') {
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*dst++ = ' ';
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continue;
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}
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if (c != '%') {
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*dst++ = c;
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continue;
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}
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v = hex_to_bin(src[0]);
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if (v > 15) {
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bad_hex:
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if (strict)
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return NULL;
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*dst++ = '%';
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continue;
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}
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v = (v * 16) | hex_to_bin(src[1]);
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if (v > 255)
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goto bad_hex;
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if (strict && (v == '/' || v == '\0')) {
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/* caller takes it as indication of invalid
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* (dangerous wrt exploits) chars */
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return str + 1;
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}
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*dst++ = v;
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src += 2;
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}
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*dst = '\0';
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return str;
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}
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@ -820,78 +820,6 @@ static char *encodeString(const char *string)
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}
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#endif
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/*
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* Given a URL encoded string, convert it to plain ascii.
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* Since decoding always makes strings smaller, the decode is done in-place.
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* Thus, callers should xstrdup() the argument if they do not want the
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* argument modified. The return is the original pointer, allowing this
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* function to be easily used as arguments to other functions.
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*
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* string The first string to decode.
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* option_d 1 if called for httpd -d
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*
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* Returns a pointer to the decoded string (same as input).
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*/
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static unsigned hex_to_bin(unsigned char c)
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{
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unsigned v;
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v = c - '0';
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if (v <= 9)
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return v;
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/* c | 0x20: letters to lower case, non-letters
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* to (potentially different) non-letters */
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v = (unsigned)(c | 0x20) - 'a';
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if (v <= 5)
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return v + 10;
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return ~0;
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/* For testing:
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void t(char c) { printf("'%c'(%u) %u\n", c, c, hex_to_bin(c)); }
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int main() { t(0x10); t(0x20); t('0'); t('9'); t('A'); t('F'); t('a'); t('f');
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t('0'-1); t('9'+1); t('A'-1); t('F'+1); t('a'-1); t('f'+1); return 0; }
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*/
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}
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static char *decodeString(char *orig, int option_d)
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{
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/* note that decoded string is always shorter than original */
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char *string = orig;
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char *ptr = string;
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char c;
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while ((c = *ptr++) != '\0') {
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unsigned v;
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if (option_d && c == '+') {
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*string++ = ' ';
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continue;
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}
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if (c != '%') {
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*string++ = c;
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continue;
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}
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v = hex_to_bin(ptr[0]);
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if (v > 15) {
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bad_hex:
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if (!option_d)
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return NULL;
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*string++ = '%';
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continue;
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}
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v = (v * 16) | hex_to_bin(ptr[1]);
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if (v > 255)
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goto bad_hex;
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if (!option_d && (v == '/' || v == '\0')) {
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/* caller takes it as indication of invalid
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* (dangerous wrt exploits) chars */
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return orig + 1;
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}
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*string++ = v;
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ptr += 2;
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}
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*string = '\0';
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return orig;
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}
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#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
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/*
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* Decode a base64 data stream as per rfc1521.
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@ -1949,7 +1877,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
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}
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/* Decode URL escape sequences */
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tptr = decodeString(urlcopy, 0);
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tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
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if (tptr == NULL)
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send_headers_and_exit(HTTP_BAD_REQUEST);
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if (tptr == urlcopy + 1) {
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@ -2408,7 +2336,7 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
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, &verbose
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);
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if (opt & OPT_DECODE_URL) {
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fputs(decodeString(url_for_decode, 1), stdout);
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fputs(percent_decode_in_place(url_for_decode, /*strict:*/ 0), stdout);
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return 0;
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}
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#if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
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@ -298,8 +298,13 @@ static void parse_url(const char *src_url, struct host_info *h)
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sp = strrchr(h->host, '@');
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if (sp != NULL) {
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h->user = h->host;
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// URL-decode "user:password" string before base64-encoding:
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// wget http://test:my%20pass@example.com should send
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// Authorization: Basic dGVzdDpteSBwYXNz
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// which decodes to "test:my pass".
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// Standard wget and curl do this too.
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*sp = '\0';
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h->user = percent_decode_in_place(h->host, /*strict:*/ 0);
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h->host = sp + 1;
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}
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@ -660,12 +665,6 @@ static void download_one_url(const char *url)
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#if ENABLE_FEATURE_WGET_AUTHENTICATION
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if (target.user) {
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//TODO: URL-decode "user:password" string before base64-encoding:
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//wget http://test:my%20pass@example.com should send
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// Authorization: Basic dGVzdDpteSBwYXNz
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//which decodes to "test:my pass", instead of what we send now:
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// Authorization: Basic dGVzdDpteSUyMHBhc3M=
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//Can reuse decodeString() from httpd.c
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fprintf(sfp, "Proxy-Authorization: Basic %s\r\n"+6,
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base64enc(target.user));
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}
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