Created attachment 519154 [details]
NCSA Auth Configuration Squid

Hi,
 I come a cross the same problem on RHEL6.1.
 yum-rhn-plugin-0.9.1-26.el6_1.1.noarch

 I have set two testing HTTP Proxy Squid configurations with Authentication:
    NCSA Authentication 
    PAM  Authentication

I have tested with those User names and Passwords.

PROXY_USER="proxy_user_${RANDOM}"
PROXY_PASS='proxy_password'
NCSA PASS
PAM  PASS

PROXY_USER="proxy_user_${RANDOM}"
PROXY_PASS='#proxypassword'
NCSA - FAIL 
PAM  - FAIL

PROXY_USER="proxy_user_${RANDOM}"
PROXY_PASS='proxy#password'
NCSA - FAIL
PAM  - FAIL

I have just noticed one weird  scenario:

1. Register to  rhn.errata.stage.redhat.com
2. Sqiud Configuration /etc/squid/squid.conf -- See attachment
3. Restart Squid: service squid restart
4. Configure yum - /etc/sysconfig/rhn/up2date
   enableProxy=1
   httpProxy=localhost:3128
   enableProxyAuth=1

htpasswd -cb /etc/squid/passwd  proxy_1      'ddddddd#' 
yum remove zsh -y
sed -i.bak 's|^\(proxyPassword=\).*|\1ddddddd#|;s|^\(proxyUser=\).*|\1proxy_1|'
/etc/sysconfig/rhn/up2date;
diff /etc/sysconfig/rhn/up2date{.bak,}
yum install zsh -y
FAIL
---
htpasswd -cb /etc/squid/passwd  proxy_2    'dddddddd#' 
yum remove zsh -y
sed -i.bak
's|^\(proxyPassword=\).*|\1dddddddd#|;s|^\(proxyUser=\).*|\1proxy_2|'
/etc/sysconfig/rhn/up2date;
diff /etc/sysconfig/rhn/up2date{.bak,}
yum install zsh -y 
PASS

It seems it is somehow depends on the Password length.
If the password length is more than 8 it passes.
I think the problem could be in "htpasswd".

satellite.git CLIENT-RHEL-6: d1a16251bbd171ed0db1fb07dc2eab81267abc57

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1664.html