Re: SVN Merge
On 11-01-12 00:34, Peter Firmstone wrote: Simon IJskes - QCG wrote: On 10-01-12 12:54, Peter Firmstone wrote: At this point, the code's only been tested on sparc. If you give the SVN url, then i will run a QA on the apache build server. https://svn.apache.org/repos/asf/river/jtsk/skunk/peterConcurrentPolicy You can trigger a QA run with this link: https://builds.apache.org/job/River-trunk-QA-ubuntu-jdk7-skunk/build?delay=0sec Jenkins is restarting now, so i cannot start a run right now. Gr. Sim -- QCG, Software voor het MKB, 071-5890970, http://www.qcg.nl Quality Consultancy Group b.v., Leiderdorp, Kvk Den Haag: 28088397
Re: SVN Merge
On 11-01-12 09:26, Dan Creswell wrote: once we publish them we're stuck with them Why? Presumably we're stuck with them in the same way that Intel are stuck with continuing to support a huge legacy? Of course I don't subscribe to such an attitude - if they're broken, we fix them. Even internet API's behave this way in spite of all the good REST'ian things said about preserving URL's etc because nothing else is practical. We routinely see fork'ing of internet API's or versioning where an old API remains but in a run-down, no longer supported state whilst development goes on elsewhere. That's the equivalent of leaving an API in an old version of the River kit and replacing it in a newer version. Nothing is perfect at release, there's nothing wrong with trying to be as right as possible but there are limits and we need to recognise that rather than obsess over achieving the impossible. Dan. +10! -- QCG, Software voor het MKB, 071-5890970, http://www.qcg.nl Quality Consultancy Group b.v., Leiderdorp, Kvk Den Haag: 28088397
Re: SVN Merge
could use a hand to go over the new code to tidy up any loose ends, make sure any new public api looks right before we merge, so we can release quickly, once the merge is complete. At this point, the code's only been tested on sparc. Cheers, Peter. Dan Creswell wrote: Agreed, remember --dry-run will give you a preview of what's to come in a merge if you have concerns... On 10 January 2012 10:08, Tom Hobbs tvho...@googlemail.com wrote: Let SVN do the merge, your changes might be extensive but I doubt there has been much movement in those files since you checked them out. So the merge will probably be more of a replace. I'm hoping to get some coding done in the next few weeks - at last! So we might have enough changes soon for a release. Keep up the good work, Peter. Sent via mobile device, please forgive typos and spacing errors. On 10 Jan 2012 06:20, Peter j...@zeus.net.au wrote: The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. Not all of the code will be included, classes, like ConcurrentPermissions (and all policy cache associated classes), even though far better than Permissions, will be discarded, as recent developments (eliminating policy cache) have made them redundant. DelegatePermission is still there, designed to work with delegate wrapper classes that encapsulate sockets and and file handles, to enable removal of temporarily granted permissions. Example: A downloaded proxy is granted a SocketPermission to contact its server, if during deserialisation, the proxy modifies some public static fields (java.xml.* vulnerabilities ring a bell?) by replacing some platform classes with its own, it leaves some of its own proxy code on the stack context. The proxy after being downloaded is found to be untrusted and discarded. Every time the object the proxy has injected into the platform is accessed, it steals information and sends it back to its originating host. If a DelegatePermission(**SocketPermission p) is granted instead, the proxy recieves a socket that denies access when the permission is revoked, when trust can't be verified. The proxy could still perform a denial of service, by causing an out of memory error during deserialisation. DelegatePermission can also be used to grant temporary or limited access to Principals, eg after downloading 1GB, downloads are revoked and regranted at the next monthly cycle, something sililar could be used to limit writes to the file system. Obviously you'll need to buffer the input or output streams, to balance how often checks are performed, that is, if you choose to utilise it. A DelegateSocketFactory that can be used to encapsulate existing SocketFactory's will be released at a later date to enable DelegatePermission controlled streams and channels. Note any ProtectionDomains with SocketPermission will still have access to the same channel. DelegatePermission is intended to be a dynamically or runtime granted Permission. To function it requires a DelegateSecurityManager, each stack context domain must have permission either for the DelegatePermission or it's representative Permission. This was one motivation for a securitymanager cache, it needed to be as fast as possible and non blocking, unlike policy cache. Using delegates is of course optional. The other thing I was toying with was using deny as well as grant in policy files: Where denials would be checked first by the policy prior to checking grants: So you could deny a proxy access to the local network, whilst granting it access to the entire internet, with two simple policy statements. Or you could allow access to a directory, but deny access to a user policy file contained in that directory, for principal based grants. The syntax would be identical to a grant statement in policy files, except deny replaces grant. But then I realised despite the advantages, it adds complexity, because the deny statement could have unintended scope narrowing / widening consequences and Permissions like SocketPermission don't work as well as intended, it would be simpler to dynamically grant Permissions on an as needed basis. So any last remaining traces of deny must be removed. Instead of using deny in policy grants, I figure that proxy's can optionally include permissions.perms files under META-INF in their jar files as a hint to clients. By using the least priviledge model and limiting the GrantPermissions given to Principals administrators can limit Permissions users can grant to proxy's. The proxy developers would need to be aware they might not be granted all the permissions they'd like and offer reduced functionality by catching SecurityException. Regards
Re: SVN Merge
Thanks Sim. Simon IJskes - QCG wrote: On 11-01-12 00:34, Peter Firmstone wrote: Simon IJskes - QCG wrote: On 10-01-12 12:54, Peter Firmstone wrote: At this point, the code's only been tested on sparc. If you give the SVN url, then i will run a QA on the apache build server. https://svn.apache.org/repos/asf/river/jtsk/skunk/peterConcurrentPolicy You can trigger a QA run with this link: https://builds.apache.org/job/River-trunk-QA-ubuntu-jdk7-skunk/build?delay=0sec Jenkins is restarting now, so i cannot start a run right now. Gr. Sim
Re: SVN Merge
Hey Sim, Can you fire that test up for me? I don't seem to have a valid login on Jenkins. Thanks, Peter. Peter Firmstone wrote: Thanks Sim. Simon IJskes - QCG wrote: On 11-01-12 00:34, Peter Firmstone wrote: Simon IJskes - QCG wrote: On 10-01-12 12:54, Peter Firmstone wrote: At this point, the code's only been tested on sparc. If you give the SVN url, then i will run a QA on the apache build server. https://svn.apache.org/repos/asf/river/jtsk/skunk/peterConcurrentPolicy You can trigger a QA run with this link: https://builds.apache.org/job/River-trunk-QA-ubuntu-jdk7-skunk/build?delay=0sec Jenkins is restarting now, so i cannot start a run right now. Gr. Sim
Re: SVN Merge
On 11-01-12 13:30, Peter Firmstone wrote: Hey Sim, Can you fire that test up for me? I don't seem to have a valid login on Jenkins. I did alreayd, before your last commit. A apache committer id should be fine. -- QCG, Software voor het MKB, 071-5890970, http://www.qcg.nl Quality Consultancy Group b.v., Leiderdorp, Kvk Den Haag: 28088397
Re: SVN Merge
Let SVN do the merge, your changes might be extensive but I doubt there has been much movement in those files since you checked them out. So the merge will probably be more of a replace. I'm hoping to get some coding done in the next few weeks - at last! So we might have enough changes soon for a release. Keep up the good work, Peter. Sent via mobile device, please forgive typos and spacing errors. On 10 Jan 2012 06:20, Peter j...@zeus.net.au wrote: The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. Not all of the code will be included, classes, like ConcurrentPermissions (and all policy cache associated classes), even though far better than Permissions, will be discarded, as recent developments (eliminating policy cache) have made them redundant. DelegatePermission is still there, designed to work with delegate wrapper classes that encapsulate sockets and and file handles, to enable removal of temporarily granted permissions. Example: A downloaded proxy is granted a SocketPermission to contact its server, if during deserialisation, the proxy modifies some public static fields (java.xml.* vulnerabilities ring a bell?) by replacing some platform classes with its own, it leaves some of its own proxy code on the stack context. The proxy after being downloaded is found to be untrusted and discarded. Every time the object the proxy has injected into the platform is accessed, it steals information and sends it back to its originating host. If a DelegatePermission(SocketPermission p) is granted instead, the proxy recieves a socket that denies access when the permission is revoked, when trust can't be verified. The proxy could still perform a denial of service, by causing an out of memory error during deserialisation. DelegatePermission can also be used to grant temporary or limited access to Principals, eg after downloading 1GB, downloads are revoked and regranted at the next monthly cycle, something sililar could be used to limit writes to the file system. Obviously you'll need to buffer the input or output streams, to balance how often checks are performed, that is, if you choose to utilise it. A DelegateSocketFactory that can be used to encapsulate existing SocketFactory's will be released at a later date to enable DelegatePermission controlled streams and channels. Note any ProtectionDomains with SocketPermission will still have access to the same channel. DelegatePermission is intended to be a dynamically or runtime granted Permission. To function it requires a DelegateSecurityManager, each stack context domain must have permission either for the DelegatePermission or it's representative Permission. This was one motivation for a securitymanager cache, it needed to be as fast as possible and non blocking, unlike policy cache. Using delegates is of course optional. The other thing I was toying with was using deny as well as grant in policy files: Where denials would be checked first by the policy prior to checking grants: So you could deny a proxy access to the local network, whilst granting it access to the entire internet, with two simple policy statements. Or you could allow access to a directory, but deny access to a user policy file contained in that directory, for principal based grants. The syntax would be identical to a grant statement in policy files, except deny replaces grant. But then I realised despite the advantages, it adds complexity, because the deny statement could have unintended scope narrowing / widening consequences and Permissions like SocketPermission don't work as well as intended, it would be simpler to dynamically grant Permissions on an as needed basis. So any last remaining traces of deny must be removed. Instead of using deny in policy grants, I figure that proxy's can optionally include permissions.perms files under META-INF in their jar files as a hint to clients. By using the least priviledge model and limiting the GrantPermissions given to Principals administrators can limit Permissions users can grant to proxy's. The proxy developers would need to be aware they might not be granted all the permissions they'd like and offer reduced functionality by catching SecurityException. Regards, Peter.
Re: SVN Merge
Agreed, remember --dry-run will give you a preview of what's to come in a merge if you have concerns... On 10 January 2012 10:08, Tom Hobbs tvho...@googlemail.com wrote: Let SVN do the merge, your changes might be extensive but I doubt there has been much movement in those files since you checked them out. So the merge will probably be more of a replace. I'm hoping to get some coding done in the next few weeks - at last! So we might have enough changes soon for a release. Keep up the good work, Peter. Sent via mobile device, please forgive typos and spacing errors. On 10 Jan 2012 06:20, Peter j...@zeus.net.au wrote: The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. Not all of the code will be included, classes, like ConcurrentPermissions (and all policy cache associated classes), even though far better than Permissions, will be discarded, as recent developments (eliminating policy cache) have made them redundant. DelegatePermission is still there, designed to work with delegate wrapper classes that encapsulate sockets and and file handles, to enable removal of temporarily granted permissions. Example: A downloaded proxy is granted a SocketPermission to contact its server, if during deserialisation, the proxy modifies some public static fields (java.xml.* vulnerabilities ring a bell?) by replacing some platform classes with its own, it leaves some of its own proxy code on the stack context. The proxy after being downloaded is found to be untrusted and discarded. Every time the object the proxy has injected into the platform is accessed, it steals information and sends it back to its originating host. If a DelegatePermission(SocketPermission p) is granted instead, the proxy recieves a socket that denies access when the permission is revoked, when trust can't be verified. The proxy could still perform a denial of service, by causing an out of memory error during deserialisation. DelegatePermission can also be used to grant temporary or limited access to Principals, eg after downloading 1GB, downloads are revoked and regranted at the next monthly cycle, something sililar could be used to limit writes to the file system. Obviously you'll need to buffer the input or output streams, to balance how often checks are performed, that is, if you choose to utilise it. A DelegateSocketFactory that can be used to encapsulate existing SocketFactory's will be released at a later date to enable DelegatePermission controlled streams and channels. Note any ProtectionDomains with SocketPermission will still have access to the same channel. DelegatePermission is intended to be a dynamically or runtime granted Permission. To function it requires a DelegateSecurityManager, each stack context domain must have permission either for the DelegatePermission or it's representative Permission. This was one motivation for a securitymanager cache, it needed to be as fast as possible and non blocking, unlike policy cache. Using delegates is of course optional. The other thing I was toying with was using deny as well as grant in policy files: Where denials would be checked first by the policy prior to checking grants: So you could deny a proxy access to the local network, whilst granting it access to the entire internet, with two simple policy statements. Or you could allow access to a directory, but deny access to a user policy file contained in that directory, for principal based grants. The syntax would be identical to a grant statement in policy files, except deny replaces grant. But then I realised despite the advantages, it adds complexity, because the deny statement could have unintended scope narrowing / widening consequences and Permissions like SocketPermission don't work as well as intended, it would be simpler to dynamically grant Permissions on an as needed basis. So any last remaining traces of deny must be removed. Instead of using deny in policy grants, I figure that proxy's can optionally include permissions.perms files under META-INF in their jar files as a hint to clients. By using the least priviledge model and limiting the GrantPermissions given to Principals administrators can limit Permissions users can grant to proxy's. The proxy developers would need to be aware they might not be granted all the permissions they'd like and offer reduced functionality by catching SecurityException. Regards, Peter.
Re: SVN Merge
Tom Dan, thanks for the support, we're probably looking at a dry run by the weekend, right now I'm running the tests again, this run is expected to pass, I'm just checking for any regressions (same code in svn). I'll clean out all the redundant code, followed by some refactoring to move new public utility classes into package private where possible. I've you've got some time, I could use a hand to go over the new code to tidy up any loose ends, make sure any new public api looks right before we merge, so we can release quickly, once the merge is complete. At this point, the code's only been tested on sparc. Cheers, Peter. Dan Creswell wrote: Agreed, remember --dry-run will give you a preview of what's to come in a merge if you have concerns... On 10 January 2012 10:08, Tom Hobbs tvho...@googlemail.com wrote: Let SVN do the merge, your changes might be extensive but I doubt there has been much movement in those files since you checked them out. So the merge will probably be more of a replace. I'm hoping to get some coding done in the next few weeks - at last! So we might have enough changes soon for a release. Keep up the good work, Peter. Sent via mobile device, please forgive typos and spacing errors. On 10 Jan 2012 06:20, Peter j...@zeus.net.au wrote: The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. Not all of the code will be included, classes, like ConcurrentPermissions (and all policy cache associated classes), even though far better than Permissions, will be discarded, as recent developments (eliminating policy cache) have made them redundant. DelegatePermission is still there, designed to work with delegate wrapper classes that encapsulate sockets and and file handles, to enable removal of temporarily granted permissions. Example: A downloaded proxy is granted a SocketPermission to contact its server, if during deserialisation, the proxy modifies some public static fields (java.xml.* vulnerabilities ring a bell?) by replacing some platform classes with its own, it leaves some of its own proxy code on the stack context. The proxy after being downloaded is found to be untrusted and discarded. Every time the object the proxy has injected into the platform is accessed, it steals information and sends it back to its originating host. If a DelegatePermission(SocketPermission p) is granted instead, the proxy recieves a socket that denies access when the permission is revoked, when trust can't be verified. The proxy could still perform a denial of service, by causing an out of memory error during deserialisation. DelegatePermission can also be used to grant temporary or limited access to Principals, eg after downloading 1GB, downloads are revoked and regranted at the next monthly cycle, something sililar could be used to limit writes to the file system. Obviously you'll need to buffer the input or output streams, to balance how often checks are performed, that is, if you choose to utilise it. A DelegateSocketFactory that can be used to encapsulate existing SocketFactory's will be released at a later date to enable DelegatePermission controlled streams and channels. Note any ProtectionDomains with SocketPermission will still have access to the same channel. DelegatePermission is intended to be a dynamically or runtime granted Permission. To function it requires a DelegateSecurityManager, each stack context domain must have permission either for the DelegatePermission or it's representative Permission. This was one motivation for a securitymanager cache, it needed to be as fast as possible and non blocking, unlike policy cache. Using delegates is of course optional. The other thing I was toying with was using deny as well as grant in policy files: Where denials would be checked first by the policy prior to checking grants: So you could deny a proxy access to the local network, whilst granting it access to the entire internet, with two simple policy statements. Or you could allow access to a directory, but deny access to a user policy file contained in that directory, for principal based grants. The syntax would be identical to a grant statement in policy files, except deny replaces grant. But then I realised despite the advantages, it adds complexity, because the deny statement could have unintended scope narrowing / widening consequences and Permissions like SocketPermission don't work as well as intended, it would be simpler to dynamically grant Permissions on an as needed basis. So any last remaining traces of deny must be removed. Instead of using deny in policy grants, I figure that proxy's can optionally include permissions.perms files under META-INF in their jar files as a hint to clients
Re: SVN Merge
I can try and find some time for you. Let me know what you need and I'll do my best. Sent via mobile device, please forgive typos and spacing errors. On 10 Jan 2012 12:17, Peter Firmstone j...@zeus.net.au wrote: Tom Dan, thanks for the support, we're probably looking at a dry run by the weekend, right now I'm running the tests again, this run is expected to pass, I'm just checking for any regressions (same code in svn). I'll clean out all the redundant code, followed by some refactoring to move new public utility classes into package private where possible. I've you've got some time, I could use a hand to go over the new code to tidy up any loose ends, make sure any new public api looks right before we merge, so we can release quickly, once the merge is complete. At this point, the code's only been tested on sparc. Cheers, Peter. Dan Creswell wrote: Agreed, remember --dry-run will give you a preview of what's to come in a merge if you have concerns... On 10 January 2012 10:08, Tom Hobbs tvho...@googlemail.com wrote: Let SVN do the merge, your changes might be extensive but I doubt there has been much movement in those files since you checked them out. So the merge will probably be more of a replace. I'm hoping to get some coding done in the next few weeks - at last! So we might have enough changes soon for a release. Keep up the good work, Peter. Sent via mobile device, please forgive typos and spacing errors. On 10 Jan 2012 06:20, Peter j...@zeus.net.au wrote: The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. Not all of the code will be included, classes, like ConcurrentPermissions (and all policy cache associated classes), even though far better than Permissions, will be discarded, as recent developments (eliminating policy cache) have made them redundant. DelegatePermission is still there, designed to work with delegate wrapper classes that encapsulate sockets and and file handles, to enable removal of temporarily granted permissions. Example: A downloaded proxy is granted a SocketPermission to contact its server, if during deserialisation, the proxy modifies some public static fields (java.xml.* vulnerabilities ring a bell?) by replacing some platform classes with its own, it leaves some of its own proxy code on the stack context. The proxy after being downloaded is found to be untrusted and discarded. Every time the object the proxy has injected into the platform is accessed, it steals information and sends it back to its originating host. If a DelegatePermission(**SocketPermission p) is granted instead, the proxy recieves a socket that denies access when the permission is revoked, when trust can't be verified. The proxy could still perform a denial of service, by causing an out of memory error during deserialisation. DelegatePermission can also be used to grant temporary or limited access to Principals, eg after downloading 1GB, downloads are revoked and regranted at the next monthly cycle, something sililar could be used to limit writes to the file system. Obviously you'll need to buffer the input or output streams, to balance how often checks are performed, that is, if you choose to utilise it. A DelegateSocketFactory that can be used to encapsulate existing SocketFactory's will be released at a later date to enable DelegatePermission controlled streams and channels. Note any ProtectionDomains with SocketPermission will still have access to the same channel. DelegatePermission is intended to be a dynamically or runtime granted Permission. To function it requires a DelegateSecurityManager, each stack context domain must have permission either for the DelegatePermission or it's representative Permission. This was one motivation for a securitymanager cache, it needed to be as fast as possible and non blocking, unlike policy cache. Using delegates is of course optional. The other thing I was toying with was using deny as well as grant in policy files: Where denials would be checked first by the policy prior to checking grants: So you could deny a proxy access to the local network, whilst granting it access to the entire internet, with two simple policy statements. Or you could allow access to a directory, but deny access to a user policy file contained in that directory, for principal based grants. The syntax would be identical to a grant statement in policy files, except deny replaces grant. But then I realised despite the advantages, it adds complexity, because the deny statement could have unintended scope narrowing / widening consequences and Permissions like SocketPermission don't work as well as intended
Re: SVN Merge
On 10-01-12 12:54, Peter Firmstone wrote: Tom Dan, thanks for the support, we're probably looking at a dry run by the weekend, right now I'm running the tests again, this run is expected to pass, I'm just checking for any regressions (same code in svn). I'll clean out all the redundant code, followed by some refactoring to move new public utility classes into package private where possible. I've you've got some time, I could use a hand to go over the new code to tidy up any loose ends, make sure any new public api looks right before we merge, so we can release quickly, once the merge is complete. At this point, the code's only been tested on sparc. If you give the SVN url, then i will run a QA on the apache build server. Gr. Sim -- QCG, Software voor het MKB, 071-5890970, http://www.qcg.nl Quality Consultancy Group b.v., Leiderdorp, Kvk Den Haag: 28088397
Re: SVN Merge
On Tue, 2012-01-10 at 01:24, Peter wrote: The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. I think you have that backwards - implementation classes should be org.apache.river.*. net.jini.* should be public API and core classes. Having said that, I see that DynamicPolicyProvider is in net.jini.security.policy, and by that logic if it had package-private classes then they would reasonably go into the net.jini.* namespace. However I'd argue that the security policy is not core Jini so much as runtime environemnt, so I'd leave them in the org.apache.river.* namespace. ...snip... Cheers, Greg.
SVN Merge
The new security manager and policies are almost ready to merge back into trunk. Any svn merge tips would be much appreciated. First, I'd like to move some policy implementation classes that are at present public in org.apache.river.*, into package private net.jini.* namespaces, to reduce the public api. Not all of the code will be included, classes, like ConcurrentPermissions (and all policy cache associated classes), even though far better than Permissions, will be discarded, as recent developments (eliminating policy cache) have made them redundant. DelegatePermission is still there, designed to work with delegate wrapper classes that encapsulate sockets and and file handles, to enable removal of temporarily granted permissions. Example: A downloaded proxy is granted a SocketPermission to contact its server, if during deserialisation, the proxy modifies some public static fields (java.xml.* vulnerabilities ring a bell?) by replacing some platform classes with its own, it leaves some of its own proxy code on the stack context. The proxy after being downloaded is found to be untrusted and discarded. Every time the object the proxy has injected into the platform is accessed, it steals information and sends it back to its originating host. If a DelegatePermission(SocketPermission p) is granted instead, the proxy recieves a socket that denies access when the permission is revoked, when trust can't be verified. The proxy could still perform a denial of service, by causing an out of memory error during deserialisation. DelegatePermission can also be used to grant temporary or limited access to Principals, eg after downloading 1GB, downloads are revoked and regranted at the next monthly cycle, something sililar could be used to limit writes to the file system. Obviously you'll need to buffer the input or output streams, to balance how often checks are performed, that is, if you choose to utilise it. A DelegateSocketFactory that can be used to encapsulate existing SocketFactory's will be released at a later date to enable DelegatePermission controlled streams and channels. Note any ProtectionDomains with SocketPermission will still have access to the same channel. DelegatePermission is intended to be a dynamically or runtime granted Permission. To function it requires a DelegateSecurityManager, each stack context domain must have permission either for the DelegatePermission or it's representative Permission. This was one motivation for a securitymanager cache, it needed to be as fast as possible and non blocking, unlike policy cache. Using delegates is of course optional. The other thing I was toying with was using deny as well as grant in policy files: Where denials would be checked first by the policy prior to checking grants: So you could deny a proxy access to the local network, whilst granting it access to the entire internet, with two simple policy statements. Or you could allow access to a directory, but deny access to a user policy file contained in that directory, for principal based grants. The syntax would be identical to a grant statement in policy files, except deny replaces grant. But then I realised despite the advantages, it adds complexity, because the deny statement could have unintended scope narrowing / widening consequences and Permissions like SocketPermission don't work as well as intended, it would be simpler to dynamically grant Permissions on an as needed basis. So any last remaining traces of deny must be removed. Instead of using deny in policy grants, I figure that proxy's can optionally include permissions.perms files under META-INF in their jar files as a hint to clients. By using the least priviledge model and limiting the GrantPermissions given to Principals administrators can limit Permissions users can grant to proxy's. The proxy developers would need to be aware they might not be granted all the permissions they'd like and offer reduced functionality by catching SecurityException. Regards, Peter.
