1 files changed, 265 insertions, 0 deletions
diff --git a/include/crypto/sig.h b/include/crypto/sig.h
new file mode 100644
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--- /dev/null
+++ b/include/crypto/sig.h
@@ -0,0 +1,265 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Public Key Signature Algorithm
+ *
+ * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#ifndef _CRYPTO_SIG_H
+#define _CRYPTO_SIG_H
+
+#include <linux/crypto.h>
+
+/**
+ * struct crypto_sig - user-instantiated objects which encapsulate
+ * algorithms and core processing logic
+ *
+ * @base:	Common crypto API algorithm data structure
+ */
+struct crypto_sig {
+	struct crypto_tfm base;
+};
+
+/**
+ * struct sig_alg - generic public key signature algorithm
+ *
+ * @sign:	Function performs a sign operation as defined by public key
+ *		algorithm. On success, the signature size is returned.
+ *		Optional.
+ * @verify:	Function performs a complete verify operation as defined by
+ *		public key algorithm, returning verification status. Optional.
+ * @set_pub_key: Function invokes the algorithm specific set public key
+ *		function, which knows how to decode and interpret
+ *		the BER encoded public key and parameters. Mandatory.
+ * @set_priv_key: Function invokes the algorithm specific set private key
+ *		function, which knows how to decode and interpret
+ *		the BER encoded private key and parameters. Optional.
+ * @key_size:	Function returns key size. Mandatory.
+ * @digest_size: Function returns maximum digest size. Optional.
+ * @max_size:	Function returns maximum signature size. Optional.
+ * @init:	Initialize the cryptographic transformation object.
+ *		This function is used to initialize the cryptographic
+ *		transformation object. This function is called only once at
+ *		the instantiation time, right after the transformation context
+ *		was allocated. In case the cryptographic hardware has some
+ *		special requirements which need to be handled by software, this
+ *		function shall check for the precise requirement of the
+ *		transformation and put any software fallbacks in place.
+ * @exit:	Deinitialize the cryptographic transformation object. This is a
+ *		counterpart to @init, used to remove various changes set in
+ *		@init.
+ *
+ * @base:	Common crypto API algorithm data structure
+ */
+struct sig_alg {
+	int (*sign)(struct crypto_sig *tfm,
+		    const void *src, unsigned int slen,
+		    void *dst, unsigned int dlen);
+	int (*verify)(struct crypto_sig *tfm,
+		      const void *src, unsigned int slen,
+		      const void *digest, unsigned int dlen);
+	int (*set_pub_key)(struct crypto_sig *tfm,
+			   const void *key, unsigned int keylen);
+	int (*set_priv_key)(struct crypto_sig *tfm,
+			    const void *key, unsigned int keylen);
+	unsigned int (*key_size)(struct crypto_sig *tfm);
+	unsigned int (*digest_size)(struct crypto_sig *tfm);
+	unsigned int (*max_size)(struct crypto_sig *tfm);
+	int (*init)(struct crypto_sig *tfm);
+	void (*exit)(struct crypto_sig *tfm);
+
+	struct crypto_alg base;
+};
+
+/**
+ * DOC: Generic Public Key Signature API
+ *
+ * The Public Key Signature API is used with the algorithms of type
+ * CRYPTO_ALG_TYPE_SIG (listed as type "sig" in /proc/crypto)
+ */
+
+/**
+ * crypto_alloc_sig() - allocate signature tfm handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	      signing algorithm e.g. "ecdsa"
+ * @type: specifies the type of the algorithm
+ * @mask: specifies the mask for the algorithm
+ *
+ * Allocate a handle for public key signature algorithm. The returned struct
+ * crypto_sig is the handle that is required for any subsequent
+ * API invocation for signature operations.
+ *
+ * Return: allocated handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask);
+
+static inline struct crypto_tfm *crypto_sig_tfm(struct crypto_sig *tfm)
+{
+	return &tfm->base;
+}
+
+static inline struct crypto_sig *__crypto_sig_tfm(struct crypto_tfm *tfm)
+{
+	return container_of(tfm, struct crypto_sig, base);
+}
+
+static inline struct sig_alg *__crypto_sig_alg(struct crypto_alg *alg)
+{
+	return container_of(alg, struct sig_alg, base);
+}
+
+static inline struct sig_alg *crypto_sig_alg(struct crypto_sig *tfm)
+{
+	return __crypto_sig_alg(crypto_sig_tfm(tfm)->__crt_alg);
+}
+
+/**
+ * crypto_free_sig() - free signature tfm handle
+ *
+ * @tfm: signature tfm handle allocated with crypto_alloc_sig()
+ *
+ * If @tfm is a NULL or error pointer, this function does nothing.
+ */
+static inline void crypto_free_sig(struct crypto_sig *tfm)
+{
+	crypto_destroy_tfm(tfm, crypto_sig_tfm(tfm));
+}
+
+/**
+ * crypto_sig_keysize() - Get key size
+ *
+ * Function returns the key size in bits.
+ * Function assumes that the key is already set in the transformation. If this
+ * function is called without a setkey or with a failed setkey, you may end up
+ * in a NULL dereference.
+ *
+ * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
+ */
+static inline unsigned int crypto_sig_keysize(struct crypto_sig *tfm)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->key_size(tfm);
+}
+
+/**
+ * crypto_sig_digestsize() - Get maximum digest size
+ *
+ * Function returns the maximum digest size in bytes.
+ * Function assumes that the key is already set in the transformation. If this
+ * function is called without a setkey or with a failed setkey, you may end up
+ * in a NULL dereference.
+ *
+ * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
+ */
+static inline unsigned int crypto_sig_digestsize(struct crypto_sig *tfm)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->digest_size(tfm);
+}
+
+/**
+ * crypto_sig_maxsize() - Get maximum signature size
+ *
+ * Function returns the maximum signature size in bytes.
+ * Function assumes that the key is already set in the transformation. If this
+ * function is called without a setkey or with a failed setkey, you may end up
+ * in a NULL dereference.
+ *
+ * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
+ */
+static inline unsigned int crypto_sig_maxsize(struct crypto_sig *tfm)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->max_size(tfm);
+}
+
+/**
+ * crypto_sig_sign() - Invoke signing operation
+ *
+ * Function invokes the specific signing operation for a given algorithm
+ *
+ * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
+ * @src:	source buffer
+ * @slen:	source length
+ * @dst:	destination obuffer
+ * @dlen:	destination length
+ *
+ * Return: signature size on success; error code in case of error
+ */
+static inline int crypto_sig_sign(struct crypto_sig *tfm,
+				  const void *src, unsigned int slen,
+				  void *dst, unsigned int dlen)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->sign(tfm, src, slen, dst, dlen);
+}
+
+/**
+ * crypto_sig_verify() - Invoke signature verification
+ *
+ * Function invokes the specific signature verification operation
+ * for a given algorithm.
+ *
+ * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
+ * @src:	source buffer
+ * @slen:	source length
+ * @digest:	digest
+ * @dlen:	digest length
+ *
+ * Return: zero on verification success; error code in case of error.
+ */
+static inline int crypto_sig_verify(struct crypto_sig *tfm,
+				    const void *src, unsigned int slen,
+				    const void *digest, unsigned int dlen)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->verify(tfm, src, slen, digest, dlen);
+}
+
+/**
+ * crypto_sig_set_pubkey() - Invoke set public key operation
+ *
+ * Function invokes the algorithm specific set key function, which knows
+ * how to decode and interpret the encoded key and parameters
+ *
+ * @tfm:	tfm handle
+ * @key:	BER encoded public key, algo OID, paramlen, BER encoded
+ *		parameters
+ * @keylen:	length of the key (not including other data)
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_sig_set_pubkey(struct crypto_sig *tfm,
+					const void *key, unsigned int keylen)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->set_pub_key(tfm, key, keylen);
+}
+
+/**
+ * crypto_sig_set_privkey() - Invoke set private key operation
+ *
+ * Function invokes the algorithm specific set key function, which knows
+ * how to decode and interpret the encoded key and parameters
+ *
+ * @tfm:	tfm handle
+ * @key:	BER encoded private key, algo OID, paramlen, BER encoded
+ *		parameters
+ * @keylen:	length of the key (not including other data)
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_sig_set_privkey(struct crypto_sig *tfm,
+					 const void *key, unsigned int keylen)
+{
+	struct sig_alg *alg = crypto_sig_alg(tfm);
+
+	return alg->set_priv_key(tfm, key, keylen);
+}
+#endif