avformat/http: escape unsafe URL path in HTTP request

This avoids generating invalid HTTP requests if the path contains space or
other special characters.

Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Marton Balint 2020-02-08 01:44:30 +01:00
parent 86b2fe9411
commit 6a7b5226e1
1 changed files with 35 additions and 1 deletions

View File

@ -1179,6 +1179,37 @@ static int http_read_header(URLContext *h, int *new_location)
return err;
}
/**
* Escape unsafe characters in path in order to pass them safely to the HTTP
* request. Insipred by the algorithm in GNU wget:
* - escape "%" characters not followed by two hex digits
* - escape all "unsafe" characters except which are also "reserved"
* - pass through everything else
*/
static void bprint_escaped_path(AVBPrint *bp, const char *path)
{
#define NEEDS_ESCAPE(ch) \
((ch) <= ' ' || (ch) >= '\x7f' || \
(ch) == '"' || (ch) == '%' || (ch) == '<' || (ch) == '>' || (ch) == '\\' || \
(ch) == '^' || (ch) == '`' || (ch) == '{' || (ch) == '}' || (ch) == '|')
while (*path) {
char buf[1024];
char *q = buf;
while (*path && q - buf < sizeof(buf) - 4) {
if (path[0] == '%' && av_isxdigit(path[1]) && av_isxdigit(path[2])) {
*q++ = *path++;
*q++ = *path++;
*q++ = *path++;
} else if (NEEDS_ESCAPE(*path)) {
q += snprintf(q, 4, "%%%02X", (uint8_t)*path++);
} else {
*q++ = *path++;
}
}
av_bprint_append_data(bp, buf, q - buf);
}
}
static int http_connect(URLContext *h, const char *path, const char *local_path,
const char *hoststr, const char *auth,
const char *proxyauth, int *new_location)
@ -1235,7 +1266,10 @@ static int http_connect(URLContext *h, const char *path, const char *local_path,
}
#endif
av_bprintf(&request, "%s %s HTTP/1.1\r\n", method, path);
av_bprintf(&request, "%s ", method);
bprint_escaped_path(&request, path);
av_bprintf(&request, " HTTP/1.1\r\n");
if (post && s->chunked_post)
av_bprintf(&request, "Transfer-Encoding: chunked\r\n");
/* set default headers if needed */