crypto: sig - Introduce sig_alg backend

2024-10-05T05:22:04+00:00

Commit 6cb8815f41a9 ("crypto: sig - Add interface for sign/verify") began a transition of asymmetric sign/verify operations from crypto_akcipher to a new crypto_sig frontend. Internally, the crypto_sig frontend still uses akcipher_alg as backend, however: "The link between sig and akcipher is meant to be temporary. The plan is to create a new low-level API for sig and then migrate the signature code over to that from akcipher." https://lore.kernel.org/r/ZrG6w9wsb-iiLZIF@gondor.apana.org.au/ "having a separate alg for sig is definitely where we want to be since there is very little that the two types actually share." https://lore.kernel.org/r/ZrHlpz4qnre0zWJO@gondor.apana.org.au/ Take the next step of that migration and augment the crypto_sig frontend with a sig_alg backend to which all algorithms can be moved. During the migration, there will briefly be signature algorithms that are still based on crypto_akcipher, whilst others are already based on crypto_sig. Allow for that by building a fork into crypto_sig_*() API calls (i.e. crypto_sig_maxsize() and friends) such that one of the two backends is selected based on the transform's cra_type. Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu

crypto: sig - Add interface for sign/verify

2023-06-23T08:15:36+00:00

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

kernel/linux.git/include/crypto/internal/sig.h, branch v6.19.11

crypto: sig - Introduce sig_alg backend

crypto: sig - Add interface for sign/verify