How to escape spaces in Apache SetEnvIf value

Question

I am trying to use SetEnvIf (Apache2, via a .htaccess file) to store an environment variable where the value to be assigned to the variable needs to contain spaces. For example, trying to set environment variable "AUTH_KEY" to have value "a b":

SetEnvIf Request_URI "^/example" AUTH_KEY="a\ b" 

No matter what I do, I have not been able to escape the space in the value - the space acts as a delimiter between env vars to be created (in the above AUTH_KEY is created with value '"a\' and a second env var is created called 'b"'). I have tried single-quotes too with no luck.

How do I escape the space character?

Answer 1

In the end I figured it out for myself…

SetEnvIf Request_URI "^/example" "AUTH_KEY=a b" 

… which looks odd, but works. It correctly sets AUTH_KEY to value a b

Hopefully this might save someone else's time in the future.

The details:- I am not a C programmer, but bumbling around on Google I found mod_setenvif.c listed at http://www.bvbcode.com/code/s6148jvr-385031

A function is called on line 405 (ap_getword_conf, for which I found detail at http://docstore.mik.ua/orelly/apache_mod/155.htm) which seems to parse strings, delimited by whitespace (but optionally encapsulated in quotes and accepting the use of escape characters).

I noticed that this happened before the sub-string returned by the function above being split by the '=' character (line 411, by function ap_getword). Thus quotes around the key=value pair, rather than just the value.

Answer 2

Try using instead SetEnvIf Request_URI "^/example" AUTH_KEY="a\sb". \s here represents the space.