In Linux Kernel 2.6.19, major changes have taken place in the security hashing infrastructure. Hence, a patch is required to upgrade the older digsig module to current kernel interfaces. digsig supported only kernels till 2.6.16. The patch has all the required changes for switching between crypto_digest to crypto_hash infrastructure. And it gets compiled and works fine with the 2.6.19 and above kernels.
The patch applies to digsig-1.5 package.