The dst SG list needs to be set to NULL for verify calls. Do
this as otherwise the underlying algorithm may fail.
Furthermore the digest needs to be copied just like the source.
Fixes: 6cb8815f41 ("crypto: sig - Add interface for sign/verify")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Split out the sign/verify functionality from the existing akcipher
interface. Most algorithms in akcipher either support encryption
and decryption, or signing and verify. Only one supports both.
As a signature algorithm may not support encryption at all, these
two should be spearated.
For now sig is simply a wrapper around akcipher as all algorithms
remain unchanged. This is a first step and allows users to start
allocating sig instead of akcipher.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
