hi,
the solution is here.
https://developer.apple.com/library/ios/#featuredarticles/iPhoneConfigurationPro fileRef/RevisionHistory.html#//apple_ref/doc/uid/TP40010206-CH99-SW1
the process is:
1. create a profile and use specific keys for the proxy settings
2. sign it - can be done by importing it into apple configurator (available on the mac app store)
3. deploy it via email or using the configurator itself for supervised devices.
sample configuration is below. it includes forcing a pass key and also a separate global admin password for profile removal
it is also configured for automatic proxy pac configuration form a specific URL.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>HasRemovalPasscode</key>
<true/>
<key>PayloadContent</key>
<array>
<dict>
<key>PayloadDescription</key>
<string>Global HTTP Proxy</string>
<key>PayloadIdentifier</key>
<string>com.apple.proxy.http.global.91572CEC-6F2D-4D56-A17F-111771716412</strin g>
<key>PayloadUUID</key>
<string>91572CEC-6F2D-4D56-A17F-111771716412</string>
<key>PayloadVersion</key>
<real>1</real>
<key>PayloadType</key>
<string>com.apple.proxy.http.global</string>
<key>ProxyPACURL</key>
<string>https://corpproxy.com/pac</string>
<key>ProxyType</key>
<string>Auto</string>
</dict>
<dict>
<key>PayloadDescription</key>
<string>Configures passcode settings.</string>
<key>PayloadDisplayName</key>
<string>Passcode</string>
<key>PayloadIdentifier</key>
<string>com.apple.mobiledevice.passwordpolicy.A1D653A1-7AF7-447F-9C06-BBD890F3A 71B</string>
<key>PayloadType</key>
<string>com.apple.mobiledevice.passwordpolicy</string>
<key>PayloadUUID</key>
<string>A1D653A1-7AF7-447F-9C06-BBD890F3A71B</string>
<key>PayloadVersion</key>
<integer>1</integer>
<key>allowSimple</key>
<true/>
<key>forcePIN</key>
<true/>
<key>maxFailedAttempts</key>
<integer>10</integer>
<key>maxGracePeriod</key>
<integer>0</integer>
<key>minComplexChars</key>
<integer>0</integer>
<key>minLength</key>
<integer>0</integer>
<key>requireAlphanumeric</key>
<false/>
</dict>
<dict>
<key>PayloadDescription</key>
<string>Configures a password for profile removal</string>
<key>PayloadDisplayName</key>
<string>Profile Removal</string>
<key>PayloadIdentifier</key>
<string>com.apple.profileRemovalPassword.E0CE5E65-F7F2-4D2F-8F74-B169BE49EAB4</ string>
<key>PayloadType</key>
<string>com.apple.profileRemovalPassword</string>
<key>PayloadUUID</key>
<string>E0CE5E65-F7F2-4D2F-8F74-B169BE49EAB4</string>
<key>PayloadVersion</key>
<real>1</real>
<key>RemovalPassword</key>
<string>secret</string>
</dict>
</array>
<key>PayloadDisplayName</key>
<string>Development Phone test</string>
<key>PayloadIdentifier</key>
<string>my.machine</string>
<key>PayloadOrganization</key>
<string>Liad Bokovsky</string>
<key>PayloadRemovalDisallowed</key>
<true/>
<key>PayloadType</key>
<string>Configuration</string>
<key>PayloadUUID</key>
<string>A8860C59-BB90-49A6-99DF-2240766A1FD4</string>
<key>PayloadVersion</key>
<integer>1</integer>
</dict>
</plist>