crypto: sig - Add interface for sign/verify

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>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/crypto/internal/sig.h b/include/crypto/internal/sig.h
new file mode 100644
index 000000000000..97cb26ef8115
--- /dev/null
+++ b/include/crypto/internal/sig.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Public Key Signature Algorithm
+ *
+ * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#ifndef _CRYPTO_INTERNAL_SIG_H
+#define _CRYPTO_INTERNAL_SIG_H
+
+#include <crypto/algapi.h>
+#include <crypto/sig.h>
+
+static inline void *crypto_sig_ctx(struct crypto_sig *tfm)
+{
+	return crypto_tfm_ctx(&tfm->base);
+}
+#endif