Le decadi 20 ventôse, an CCXXIII, Nicolas George a écrit : > I will try to propose another patch for pure validation.
See the attached patches. Regards, -- Nicolas George
From cef95aaec223b6644db6e52f9c6452d7aa01648b Mon Sep 17 00:00:00 2001
From: Nicolas George <geo...@nsup.org>
Date: Tue, 10 Mar 2015 13:43:17 +0100
Subject: [PATCH 1/2] lavf/http: full validation of headers option string.
Signed-off-by: Nicolas George <geo...@nsup.org>
---
libavformat/http.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 52 insertions(+), 6 deletions(-)
diff --git a/libavformat/http.c b/libavformat/http.c
index 55dcb6e..2d8f5dc 100644
--- a/libavformat/http.c
+++ b/libavformat/http.c
@@ -25,6 +25,7 @@
#include <zlib.h>
#endif /* CONFIG_ZLIB */
+#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
@@ -292,6 +293,55 @@ int ff_http_averror(int status_code, int default_averror)
return default_averror;
}
+static void validate_headers_option(void *log, unsigned char *header)
+{
+ unsigned char *p = header;
+ const char *error = NULL;
+ int tag;
+
+ /* *( header-field CRLF ) */
+ while (*p) {
+ /* header-field = field-name ":" OWS field-value OWS
+ field-name = token = 1*tchar */
+ tag = 0;
+ while ((unsigned)((*p | 32) - 'a') < 26 || (unsigned)(*p - '0') < 10 ||
+ *p == '!' || *p == '#' || *p == '$' || *p == '%' || *p == '&' ||
+ *p =='\'' || *p == '*' || *p == '+' || *p == '-' || *p == '.' ||
+ *p == '^' || *p == '_' || *p == '`' || *p == '|' || *p == '~') {
+ p++;
+ tag = 1;
+ }
+ if (!tag || *p != ':') {
+ error = "no valid field name";
+ goto fail;
+ }
+ /* field-value = *( field-content / obs-fold )
+ field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+ field-vchar = VCHAR / obs-text
+ VCHAR = visible USASCII character
+ obs-text = %x80-FF
+ obs-fold = CRLF 1*( SP / HTAB ) */
+ while (*p) {
+ while (*p >= 32 || *p == '\t')
+ p++;
+ if (p[0] != '\r' || p[1] != '\n') {
+ error = *p ? "invalid character in vield value" :
+ "missing trailing CRLF";
+ goto fail;
+ }
+ p += 2;
+ if (*p != ' ' && *p != '\t')
+ break;
+ p++;
+ }
+ }
+ return;
+
+fail:
+ av_log(log, AV_LOG_WARNING, "Invalid HTTP header at offset %u: %s\n",
+ (unsigned)(p - header), error);
+}
+
static int http_open(URLContext *h, const char *uri, int flags,
AVDictionary **options)
{
@@ -310,12 +360,8 @@ static int http_open(URLContext *h, const char *uri, int flags,
if (options)
av_dict_copy(&s->chained_options, *options, 0);
- if (s->headers) {
- int len = strlen(s->headers);
- if (len < 2 || strcmp("\r\n", s->headers + len - 2))
- av_log(h, AV_LOG_WARNING,
- "No trailing CRLF found in HTTP header.\n");
- }
+ if (s->headers)
+ validate_headers_option(s, s->headers);
ret = http_open_cnx(h, options);
if (ret < 0)
--
2.1.4
From 68591d1dc097cae158eb8bcb08abc884dc414a3d Mon Sep 17 00:00:00 2001 From: Nicolas George <geo...@nsup.org> Date: Wed, 11 Mar 2015 11:50:21 +0100 Subject: [PATCH 2/2] doc/protocols: insist on HTTP headers syntax. Signed-off-by: Nicolas George <geo...@nsup.org> --- doc/protocols.texi | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/doc/protocols.texi b/doc/protocols.texi index 5f6dfa8..b46a36d 100644 --- a/doc/protocols.texi +++ b/doc/protocols.texi @@ -230,7 +230,8 @@ Set a specific content type for the POST messages. @item headers Set custom HTTP headers, can override built in default headers. The -value must be a string encoding the headers. +value must be a string encoding the headers, with lines terminated by CRLF, +including the final one. @item multiple_requests Use persistent connections if set to 1, default is 0. -- 2.1.4
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