Re: [Qemu-devel] [PATCH] io: ignore case when matching websockets HTTP headers

[Daniel P. Berrange]

On Mon, Feb 27, 2017 at 08:14:56PM +0000, Daniel P. Berrange wrote:
> According to RFC7230 Section 3.2, header field name is case-insensitive.
> Convert the header data into all lowercase before doing string matching
> on the headers.
> 
> Signed-off-by: Daniel P. Berrange <address@hidden>
> ---
>  io/channel-websock.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/io/channel-websock.c b/io/channel-websock.c
> index a06a4a8..32b7f37 100644
> --- a/io/channel-websock.c
> +++ b/io/channel-websock.c
> @@ -33,9 +33,9 @@
>  #define QIO_CHANNEL_WEBSOCK_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
>  #define QIO_CHANNEL_WEBSOCK_GUID_LEN strlen(QIO_CHANNEL_WEBSOCK_GUID)
>  
> -#define QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL "Sec-WebSocket-Protocol"
> -#define QIO_CHANNEL_WEBSOCK_HEADER_VERSION "Sec-WebSocket-Version"
> -#define QIO_CHANNEL_WEBSOCK_HEADER_KEY "Sec-WebSocket-Key"
> +#define QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL "sec-websocket-protocol"
> +#define QIO_CHANNEL_WEBSOCK_HEADER_VERSION "sec-websocket-version"
> +#define QIO_CHANNEL_WEBSOCK_HEADER_KEY "sec-websocket-key"
>  
>  #define QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY "binary"
>  
> @@ -223,7 +223,7 @@ static int 
> qio_channel_websock_handshake_process(QIOChannelWebsock *ioc,
>  static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc,
>                                                Error **errp)
>  {
> -    char *handshake_end;
> +    char *handshake_end, *tmp;
>      ssize_t ret;
>      /* Typical HTTP headers from novnc are 512 bytes, so limiting
>       * total header size to 4096 is easily enough. */
> @@ -249,9 +249,13 @@ static int 
> qio_channel_websock_handshake_read(QIOChannelWebsock *ioc,
>          }
>      }
>  
> +    for (tmp = (char *)ioc->encinput.buffer; tmp < handshake_end; tmp++) {
> +        *tmp = g_ascii_tolower(*tmp);
> +    }
> +

self-nack - this does not in fact work - while it is fine to lowercase
the header keys, we must not touch the header values as some data is
case-sensitive

Regards,
Daniel
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