Understanding Tolerant HTTP Request Parsing
By default, the ProxySG blocks malformed HTTP requests, returning a 400 Invalid Request error. The
tolerant HTTP request parsing flag causes certain types of malformed requests to be processed instead
of being rejected.
By default, a header line not beginning with a <Tab> or space character must consist of a header name
(which contains no <Tab> or space characters), followed by a colon, followed by an optional value, or
an error is reported. With tolerant request parsing enabled, a request header name is allowed to
contain <Tab> or space characters, and if the request header line does not contain a colon, then the
entire line is taken as the header name.
A header containing one or more <Tab> or space characters, and nothing else, is considered
ambiguous. Blue Coat does not know if this is a blank continuation line or if it is the blank line that
signals the end of the header section. By default, an ambiguous blank line is illegal, and an error is
reported. With tolerant request parsing enabled, an ambiguous blank line is treated as the blank line
that signals the end of the header section.
To Enable the HTTP Tolerant Request Parsing Flag through the CLI
From the (config) prompt, enter the following command to enable tolerant HTTP request parsing (the default is disabled):
SGOS#(config) http tolerant-request-parsing
To disable HTTP tolerant request parsing, enter the following command:
SGOS#(config) http no tolerant-request-parsing