How to digitally sign an xml document through the client's browser?

When I visit a site which requires a client-side certificate the browser automatically opens a popup asking me which personal certificate I would like to use to connect.

Is there any similar provision to sign an xml document using HTML5 or Flash? Otherwise (installing an appl开发者_高级运维ication on the client machine) is a Java applet the only cross-browser way to do it?

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At the moment you need to create your client-side module that will somehow request the document (or just the hash of the document) from the site, sign it and send it back to the server. The problem (besides writing your own module) is guaranteeing that the user signs what he sees and not the data some MITM attacker has pushed to the client.

We are currently finalizing our solution for distributed signing of various data with a set of reusable client-side module. This solution will be available in May as part of version 9 of our SecureBlackbox product.

Update: the beta version of SecureBlackbox 9 is available and it includes this distributed signing modules.