/*
    File: ConfigurationAuthority.c

    Abstract: Interface to system security framework that manages access
    to protected resources like system configuration preferences.

    Copyright: (c) Copyright 2005 Apple Computer, Inc. All rights reserved.

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    Change History (most recent first):

$Log: ConfigurationAuthority.c,v $
Revision 1.2  2005/08/07 22:48:05  mkrochma
<rdar://problem/4204003> Bonjour Pref Pane returns -927 when "system.preferences" is not shared

Revision 1.1  2005/02/05 02:28:22  cheshire
Add Preference Pane to facilitate testing of DDNS & wide-area features

*/

#include "ConfigurationAuthority.h"
#include "ConfigurationRights.h"

#include <AssertMacros.h>


static AuthorizationRef	gAuthRef = 0;

static AuthorizationItem	gAuthorizations[] = {	{ UPDATE_SC_RIGHT, 0, NULL, 0 }, 
													{ EDIT_SYS_KEYCHAIN_RIGHT, 0, NULL, 0 }};
static AuthorizationRights	gAuthSet = { sizeof gAuthorizations / sizeof gAuthorizations[0], gAuthorizations };

static CFDictionaryRef	CreateRightsDict( CFStringRef prompt)
/* Create a CFDictionary decribing an auth right. See /etc/authorization for examples. */
/* Specifies that the right requires admin authentication, which persists for 5 minutes. */
{
	CFMutableDictionaryRef	dict = NULL, tmpDict;
	CFMutableArrayRef		mechanisms;
	CFNumberRef				timeout;
	int						val;
	
	tmpDict = CFDictionaryCreateMutable( (CFAllocatorRef) NULL, 0, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
	require( tmpDict != NULL, MakeDictFailed);

	CFDictionaryAddValue(tmpDict, CFSTR("class"), CFSTR("user"));
	CFDictionaryAddValue(tmpDict, CFSTR("comment"), prompt);
	CFDictionaryAddValue(tmpDict, CFSTR("group"), CFSTR("admin"));

	mechanisms = CFArrayCreateMutable((CFAllocatorRef) NULL, 1, &kCFTypeArrayCallBacks);
	require( mechanisms != NULL, MakeArrayFailed);
	CFArrayAppendValue( mechanisms, CFSTR("builtin:authenticate"));
	CFDictionaryAddValue( tmpDict, CFSTR("mechanisms"), mechanisms);

	val = 300;	// seconds
	timeout = CFNumberCreate((CFAllocatorRef) NULL, kCFNumberIntType, &val);
	require( timeout != NULL, MakeIntFailed);
	CFDictionaryAddValue( tmpDict, CFSTR("timeout"), timeout);
	CFDictionaryAddValue( tmpDict, CFSTR("shared"), kCFBooleanTrue);

	dict = tmpDict;
	tmpDict = NULL;

	CFRelease( timeout);
MakeIntFailed:
	CFRelease( mechanisms);
MakeArrayFailed:
	if ( tmpDict)
		CFRelease( tmpDict);
MakeDictFailed:
	return dict;
}

OSStatus InitConfigAuthority(void)
/* Initialize the authorization record-keeping */
{
	OSStatus        err;
	CFDictionaryRef dict;
	CFStringRef		rightInfo;

	err = AuthorizationCreate((AuthorizationRights*) NULL, (AuthorizationEnvironment*) NULL,
								(AuthorizationFlags) 0, &gAuthRef);
	require_noerr( err, NewAuthFailed);

	err = AuthorizationRightGet( UPDATE_SC_RIGHT, (CFDictionaryRef*) NULL);
	if( err == errAuthorizationDenied)
	{
		rightInfo = CFCopyLocalizedString(CFSTR("Authentication required to set Dynamic DNS preferences."), 
						CFSTR("Describes operation that requires user authorization"));
		require_action( rightInfo != NULL, GetStrFailed, err=coreFoundationUnknownErr;);
		dict = CreateRightsDict(rightInfo);
		require_action( dict != NULL, GetStrFailed, err=coreFoundationUnknownErr;);

		err = AuthorizationRightSet(gAuthRef, UPDATE_SC_RIGHT, dict, (CFStringRef) NULL, 
									(CFBundleRef) NULL, (CFStringRef) NULL);
		CFRelease(rightInfo);
		CFRelease(dict);
	}
	require_noerr( err, AuthSetFailed);

	err = AuthorizationRightGet( EDIT_SYS_KEYCHAIN_RIGHT, (CFDictionaryRef*) NULL);
	if( err == errAuthorizationDenied)
	{
		rightInfo = CFCopyLocalizedString( CFSTR("Authentication required to edit System Keychain."), 
						CFSTR("Describes operation that requires user authorization"));
		require_action( rightInfo != NULL, GetStrFailed, err=coreFoundationUnknownErr;);
		dict = CreateRightsDict( rightInfo);
		require_action( dict != NULL, GetStrFailed, err=coreFoundationUnknownErr;);

		err = AuthorizationRightSet(gAuthRef, EDIT_SYS_KEYCHAIN_RIGHT, dict, (CFStringRef) NULL, 
									(CFBundleRef) NULL, (CFStringRef) NULL);
		CFRelease( rightInfo);
		CFRelease( dict);
	}
	require_noerr( err, AuthSetFailed);

AuthSetFailed:
GetStrFailed:
NewAuthFailed:
	return err;
}

OSStatus	AttemptAcquireAuthority( Boolean allowUI)
/* Try to get permission for privileged ops, either implicitly or by asking the user for */
/* authority to perform operations (if necessary) */
{
	AuthorizationFlags	allowFlag = allowUI ? kAuthorizationFlagInteractionAllowed : 0;
	OSStatus			err;

	err = AuthorizationCopyRights( gAuthRef, &gAuthSet, (AuthorizationEnvironment*) NULL,
									kAuthorizationFlagExtendRights | kAuthorizationFlagPreAuthorize |
									allowFlag,
									(AuthorizationRights**) NULL);
	return err;
}

OSStatus ReleaseAuthority(void)
/* Discard authority to perform operations */
{
	(void) AuthorizationFree( gAuthRef, kAuthorizationFlagDestroyRights);
	gAuthRef = 0;
	return AuthorizationCreate( (AuthorizationRights*) NULL, (AuthorizationEnvironment*) NULL,
								(AuthorizationFlags) 0, &gAuthRef);
}

Boolean	CurrentlyAuthorized(void)
{
	OSStatus err = AttemptAcquireAuthority(true);
	return err == noErr;
}


OSStatus ExternalizeAuthority(AuthorizationExternalForm *pAuth)
/* Package up current authorizations for transfer to another process */
{
	return AuthorizationMakeExternalForm(gAuthRef, pAuth);
}
