Kasatkin, Dmitry <dmitry.kasatkin@xxxxxxxxx> wrote: > It would also nice to have an API to supply pre-computed data hash. For > example IMA uses the same functionality to compute the hash of the file > content, and then, based on security.ima type decided either verify it using > just hash, or use digital signature. We could pass a hash as data. But may > be we do not want to have extra operation and compute hash over hash. If I understand you correctly, you'd like to have the option to do the hashing externally to this API? Would you supply the completed hash or just a hash with the data in it, and require this API to complete it (ie. chuck metadata into it)? I don't think it should be hard. I could add an alternative to verify_sig_add_data() perhaps. Either that or one function that does the lot and takes the precomputed hash as input. There would be no need for the split into four functions (begin, add_data, end, cancel) in such a case. The reason for the split is so that the caller can invoke add_data several times with non-contiguous bits of data. It might even make sense to expose the crypto hash object for direct access rather than use add_data - but that then makes it hard to use crypto hardware where you would just shovel the raw data into it and it does all the hashing and cryptography in a black box. David -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
