Add key-agreement protocol primitives (kpp) API which allows to
implement primitives required by protocols such as DH and ECDH.
The API is composed mainly by the following functions
* set_params() - It allows the user to set the parameters known to
both parties involved in the key-agreement session
* set_secret() - It allows the user to set his secret, also
referred to as his private key
* generate_public_key() - It generates the public key to be sent to
the other counterpart involved in the key-agreement session. The
function has to be called after set_params() and set_secret()
* generate_secret() - It generates the shared secret for the session
Other functions such as init() and exit() are provided for allowing
cryptographic hardware to be inizialized properly before use
Signed-off-by: Salvatore Benedetto <salvatore.benedetto@xxxxxxxxx>
---
crypto/Kconfig | 10 ++
crypto/Makefile | 1 +
crypto/crypto_user.c | 20 +++
crypto/kpp.c | 123 +++++++++++++++
include/crypto/internal/kpp.h | 64 ++++++++
include/crypto/kpp.h | 333 ++++++++++++++++++++++++++++++++++++++++
include/linux/crypto.h | 1 +
include/uapi/linux/cryptouser.h | 5 +
8 files changed, 557 insertions(+)
create mode 100644 crypto/kpp.c
create mode 100644 include/crypto/internal/kpp.h
create mode 100644 include/crypto/kpp.h
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 93a1fdc..31bf962 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -93,6 +93,15 @@ config CRYPTO_AKCIPHER
select CRYPTO_AKCIPHER2
select CRYPTO_ALGAPI
+config CRYPTO_KPP2
+ tristate
+ select CRYPTO_ALGAPI2
+
+config CRYPTO_KPP
+ tristate
+ select CRYPTO_ALGAPI
+ select CRYPTO_KPP2
+
config CRYPTO_RSA
tristate "RSA algorithm"
select CRYPTO_AKCIPHER
@@ -114,6 +123,7 @@ config CRYPTO_MANAGER2
select CRYPTO_HASH2
select CRYPTO_BLKCIPHER2
select CRYPTO_AKCIPHER2
+ select CRYPTO_KPP2
config CRYPTO_USER
tristate "Userspace cryptographic algorithm configuration"
diff --git a/crypto/Makefile b/crypto/Makefile
index 4f4ef7e..5b60890 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -30,6 +30,7 @@ crypto_hash-y += shash.o
obj-$(CONFIG_CRYPTO_HASH2) += crypto_hash.o
obj-$(CONFIG_CRYPTO_AKCIPHER2) += akcipher.o
+obj-$(CONFIG_CRYPTO_KPP2) += kpp.o
$(obj)/rsapubkey-asn1.o: $(obj)/rsapubkey-asn1.c $(obj)/rsapubkey-asn1.h
$(obj)/rsaprivkey-asn1.o: $(obj)/rsaprivkey-asn1.c $(obj)/rsaprivkey-asn1.h
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index 43fe85f..d28513fb 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -28,6 +28,7 @@
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
+#include <crypto/kpp.h>
#include "internal.h"
@@ -126,6 +127,21 @@ nla_put_failure:
return -EMSGSIZE;
}
+static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg)
+{
+ struct crypto_report_kpp rkpp;
+
+ strncpy(rkpp.type, "kpp", sizeof(rkpp.type));
+
+ if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
+ sizeof(struct crypto_report_kpp), &rkpp))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
static int crypto_report_one(struct crypto_alg *alg,
struct crypto_user_alg *ualg, struct sk_buff *skb)
{
@@ -176,6 +192,10 @@ static int crypto_report_one(struct crypto_alg *alg,
goto nla_put_failure;
break;
+ case CRYPTO_ALG_TYPE_KPP:
+ if (crypto_report_kpp(skb, alg))
+ goto nla_put_failure;
+ break;
}
out:
diff --git a/crypto/kpp.c b/crypto/kpp.c
new file mode 100644
index 0000000..d36ce05
--- /dev/null
+++ b/crypto/kpp.c
@@ -0,0 +1,123 @@
+/*
+ * Key-agreement Protocol Primitives (KPP)
+ *
+ * Copyright (c) 2016, Intel Corporation
+ * Authors: Salvatore Benedetto <salvatore.benedetto@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <crypto/algapi.h>
+#include <linux/cryptouser.h>
+#include <net/netlink.h>
+#include <crypto/kpp.h>
+#include <crypto/internal/kpp.h>
+#include "internal.h"
+
+#ifdef CONFIG_NET
+static int crypto_kpp_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+ struct crypto_report_kpp rkpp;
+
+ strncpy(rkpp.type, "kpp", sizeof(rkpp.type));
+
+ if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
+ sizeof(struct crypto_report_kpp), &rkpp))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+#else
+static int crypto_kpp_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+ return -ENOSYS;
+}
+#endif
+
+static void crypto_kpp_show(struct seq_file *m, struct crypto_alg *alg)
+ __attribute__ ((unused));
+
+static void crypto_kpp_show(struct seq_file *m, struct crypto_alg *alg)
+{
+ seq_puts(m, "type : kpp\n");
+}
+
+static void crypto_kpp_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_kpp *kpp = __crypto_kpp_tfm(tfm);
+ struct kpp_alg *alg = crypto_kpp_alg(kpp);
+
+ alg->exit(kpp);
+}
+
+static int crypto_kpp_init_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_kpp *kpp = __crypto_kpp_tfm(tfm);
+ struct kpp_alg *alg = crypto_kpp_alg(kpp);
+
+ if (alg->exit)
+ kpp->base.exit = crypto_kpp_exit_tfm;
+
+ if (alg->init)
+ return alg->init(kpp);
+
+ return 0;
+}
+
+static const struct crypto_type crypto_kpp_type = {
+ .extsize = crypto_alg_extsize,
+ .init_tfm = crypto_kpp_init_tfm,
+#ifdef CONFIG_PROC_FS
+ .show = crypto_kpp_show,
+#endif
+ .report = crypto_kpp_report,
+ .maskclear = ~CRYPTO_ALG_TYPE_MASK,
+ .maskset = CRYPTO_ALG_TYPE_MASK,
+ .type = CRYPTO_ALG_TYPE_KPP,
+ .tfmsize = offsetof(struct crypto_kpp, base),
+};
+
+struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask)
+{
+ return crypto_alloc_tfm(alg_name, &crypto_kpp_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_kpp);
+
+static void kpp_prepare_alg(struct kpp_alg *alg)
+{
+ struct crypto_alg *base = &alg->base;
+
+ base->cra_type = &crypto_kpp_type;
+ base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
+ base->cra_flags |= CRYPTO_ALG_TYPE_KPP;
+}
+
+int crypto_register_kpp(struct kpp_alg *alg)
+{
+ struct crypto_alg *base = &alg->base;
+
+ kpp_prepare_alg(alg);
+ return crypto_register_alg(base);
+}
+EXPORT_SYMBOL_GPL(crypto_register_kpp);
+
+void crypto_unregister_kpp(struct kpp_alg *alg)
+{
+ crypto_unregister_alg(&alg->base);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_kpp);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Key-agreement Protocol Primitives");
diff --git a/include/crypto/internal/kpp.h b/include/crypto/internal/kpp.h
new file mode 100644
index 0000000..ad3acf3
--- /dev/null
+++ b/include/crypto/internal/kpp.h
@@ -0,0 +1,64 @@
+/*
+ * Key-agreement Protocol Primitives (KPP)
+ *
+ * Copyright (c) 2016, Intel Corporation
+ * Authors: Salvatore Benedetto <salvatore.benedetto@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#ifndef _CRYPTO_KPP_INT_H
+#define _CRYPTO_KPP_INT_H
+#include <crypto/kpp.h>
+#include <crypto/algapi.h>
+
+/*
+ * Transform internal helpers.
+ */
+static inline void *kpp_request_ctx(struct kpp_request *req)
+{
+ return req->__ctx;
+}
+
+static inline void *kpp_tfm_ctx(struct crypto_kpp *tfm)
+{
+ return tfm->base.__crt_ctx;
+}
+
+static inline void kpp_request_complete(struct kpp_request *req, int err)
+{
+ req->base.complete(&req->base, err);
+}
+
+static inline const char *kpp_alg_name(struct crypto_kpp *tfm)
+{
+ return crypto_kpp_tfm(tfm)->__crt_alg->cra_name;
+}
+
+/**
+ * crypto_register_kpp() -- Register key-agreement protocol primitives algorithm
+ *
+ * Function registers an implementation of a key-agreement protocol primitive
+ * algorithm
+ *
+ * @alg: algorithm definition
+ *
+ * Return: zero on success; error code in case of error
+ */
+int crypto_register_kpp(struct kpp_alg *alg);
+
+/**
+ * crypto_unregister_kpp() -- Unregister key-agreement protocol primitive
+ * algorithm
+ *
+ * Function unregisters an implementation of a key-agreement protocol primitive
+ * algorithm
+ *
+ * @alg: algorithm definition
+ */
+void crypto_unregister_kpp(struct kpp_alg *alg);
+
+#endif
diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h
new file mode 100644
index 0000000..8eb14a6
--- /dev/null
+++ b/include/crypto/kpp.h
@@ -0,0 +1,333 @@
+/*
+ * Key-agreement Protocol Primitives (KPP)
+ *
+ * Copyright (c) 2016, Intel Corporation
+ * Authors: Salvatore Benedetto <salvatore.benedetto@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _CRYPTO_KPP_
+#define _CRYPTO_KPP_
+#include <linux/crypto.h>
+
+/**
+ * struct kpp_request
+ *
+ * @base: Common attributes for async crypto requests
+ * @src: Source data
+ * @dst: Destination data
+ * @src_len: Size of the input buffer
+ * @dst_len: Size of the output buffer. It needs to be at least
+ * as big as the expected result depending on the operation
+ * After operation it will be updated with the actual size of the
+ * result. In case of error where the dst sgl size was insufficient,
+ * it will be updated to the size required for the operation.
+ * @__ctx: Start of private context data
+ */
+struct kpp_request {
+ struct crypto_async_request base;
+ struct scatterlist *src;
+ struct scatterlist *dst;
+ unsigned int src_len;
+ unsigned int dst_len;
+ void *__ctx[] CRYPTO_MINALIGN_ATTR;
+};
+
+/**
+ * struct crypto_kpp - user-instantiated object which encapsulate
+ * algorithms and core processing logic
+ *
+ * @base: Common crypto API algorithm data structure
+ */
+struct crypto_kpp {
+ struct crypto_tfm base;
+};
+
+/**
+ * struct kpp_alg - generic key-agreement protocol primitives
+ *
+ * @set_params: Function invokes the protocol specific function
+ * which knows how to decode and interpret the buffer
+ * @set_secret: Function invokes the protocol specific function to
+ * store the secret private key. The implementation knows
+ * how to decode the buffer
+ * @generate_public_key: Function generate the public key to be sent to the
+ * counterpart. In case of error, where output is not big
+ * enough req->dst_len will be updated to the size
+ * required
+ * @compute_shared_secret: Function compute the shared secret as defined by
+ * the algorithm. The result is given back to the user.
+ * In case of error, where output is not big enough,
+ * req->dst_len will be updated to the size required
+ * @max_size: Function returns the size of the output buffer
+ * @init: Initialize the object. This is called only once at
+ * instantiation time. In case the cryptographic hardware
+ * needs to be initialized. Software fallback should be
+ * put in place here.
+ * @exit: Undo everything @init did.
+ *
+ * @reqsize: Request context size required by algorithm
+ * implementation
+ * @base Common crypto API algorithm data structure
+ */
+struct kpp_alg {
+ int (*set_params)(struct crypto_kpp *tfm, void *buffer,
+ unsigned int len);
+ int (*set_secret)(struct crypto_kpp *tfm, void *buffer,
+ unsigned int len);
+ int (*generate_public_key)(struct kpp_request *req);
+ int (*compute_shared_secret)(struct kpp_request *req);
+
+ int (*max_size)(struct crypto_kpp *tfm);
+
+ int (*init)(struct crypto_kpp *tfm);
+ void (*exit)(struct crypto_kpp *tfm);
+
+ unsigned int reqsize;
+ struct crypto_alg base;
+};
+
+/**
+ * DOC: Generic Key-agreement Protocol Primitevs API
+ *
+ * The KPP API is used with the algorithm type
+ * CRYPTO_ALG_TYPE_KPP (listed as type "kpp" in /proc/crypto)
+ */
+
+/**
+ * crypto_alloc_kpp() - allocate KPP tfm handle
+ * @alg_name: is the name of the kpp algorithm (e.g. "dh", "ecdh")
+ * @type: specifies the type of the algorithm
+ * @mask: specifies the mask for the algorithm
+ *
+ * Allocate a handle for kpp algorithm. The returned struct crypto_kpp
+ * is requeried for any following API invocation
+ *
+ * Return: allocated handle in case of success; IS_ERR() is true in case of
+ * an error, PTR_ERR() returns the error code.
+ */
+struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask);
+
+static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm)
+{
+ return &tfm->base;
+}
+
+static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg)
+{
+ return container_of(alg, struct kpp_alg, base);
+}
+
+static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm)
+{
+ return container_of(tfm, struct crypto_kpp, base);
+}
+
+static inline struct kpp_alg *crypto_kpp_alg(struct crypto_kpp *tfm)
+{
+ return __crypto_kpp_alg(crypto_kpp_tfm(tfm)->__crt_alg);
+}
+
+static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm)
+{
+ return crypto_kpp_alg(tfm)->reqsize;
+}
+
+static inline void kpp_request_set_tfm(struct kpp_request *req,
+ struct crypto_kpp *tfm)
+{
+ req->base.tfm = crypto_kpp_tfm(tfm);
+}
+
+static inline struct crypto_kpp *crypto_kpp_reqtfm(struct kpp_request *req)
+{
+ return __crypto_kpp_tfm(req->base.tfm);
+}
+
+/**
+ * crypto_free_kpp() - free KPP tfm handle
+ *
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
+ */
+static inline void crypto_free_kpp(struct crypto_kpp *tfm)
+{
+ crypto_destroy_tfm(tfm, crypto_kpp_tfm(tfm));
+}
+
+/**
+ * kpp_request_alloc() - allocates kpp request
+ *
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
+ * @gfp: allocation flags
+ *
+ * Return: allocated handle in case of success or NULL in case of an error.
+ */
+static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm,
+ gfp_t gfp)
+{
+ struct kpp_request *req;
+
+ req = kmalloc(sizeof(*req) + crypto_kpp_reqsize(tfm), gfp);
+ if (likely(req))
+ kpp_request_set_tfm(req, tfm);
+
+ return req;
+}
+
+/**
+ * kpp_request_free() - zeroize and free kpp request
+ *
+ * @req: request to free
+ */
+static inline void kpp_request_free(struct kpp_request *req)
+{
+ kzfree(req);
+}
+
+/**
+ * kpp_request_set_callback() - Sets an asynchronous callback.
+ *
+ * Callback will be called when an asynchronous operation on a given
+ * request is finished.
+ *
+ * @req: request that the callback will be set for
+ * @flgs: specify for instance if the operation may backlog
+ * @cmpl: callback which will be called
+ * @data: private data used by the caller
+ */
+static inline void kpp_request_set_callback(struct kpp_request *req,
+ u32 flgs,
+ crypto_completion_t cmpl,
+ void *data)
+{
+ req->base.complete = cmpl;
+ req->base.data = data;
+ req->base.flags = flgs;
+}
+
+/**
+ * kpp_request_set_input() - Sets input buffer
+ *
+ * Sets parameters required by generate_public_key
+ *
+ * @req: kpp request
+ * @input: ptr to input scatter list
+ * @input_len: size of the input scatter list
+ */
+static inline void kpp_request_set_input(struct kpp_request *req,
+ struct scatterlist *input,
+ unsigned int input_len)
+{
+ req->src = input;
+ req->src_len = input_len;
+}
+
+/**
+ * kpp_request_set_output() - Sets output buffer
+ *
+ * Sets parameters required by kpp operation
+ *
+ * @req: kpp request
+ * @output: ptr to output scatter list
+ * @output_len: size of the output scatter list
+ */
+static inline void kpp_request_set_output(struct kpp_request *req,
+ struct scatterlist *output,
+ unsigned int output_len)
+{
+ req->dst = output;
+ req->dst_len = output_len;
+}
+
+/**
+ * crypto_kpp_set_params() - Invoke kpp operation
+ *
+ * Function invokes the specific kpp operation for a given alg
+ *
+ * @tfm: tfm handle
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_kpp_set_params(struct crypto_kpp *tfm,
+ void *buffer, unsigned int len)
+{
+ struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+ return alg->set_params(tfm, buffer, len);
+}
+
+/**
+ * crypto_kpp_set_secret() - Invoke kpp operation
+ *
+ * Function invokes the specific kpp operation for a given alg.
+ *
+ * @tfm: tfm handle
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm, void *buffer,
+ unsigned int len)
+{
+ struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+ return alg->set_secret(tfm, buffer, len);
+}
+
+/**
+ * crypto_kpp_generate_public_key() - Invoke kpp operation
+ *
+ * Function invokes the specific kpp operation for generating the public part
+ * for a given kpp algorithm
+ *
+ * @req: kpp key request
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_kpp_generate_public_key(struct kpp_request *req)
+{
+ struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
+ struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+ return alg->generate_public_key(req);
+}
+
+/**
+ * crypto_kpp_compute_shared_secret() - Invoke kpp operation
+ *
+ * Function invokes the specific kpp operation for computing the shared secret
+ * for a given kpp algorithm.
+ *
+ * @req: kpp key request
+ *
+ * Return: zero on success; error code in case of error
+ */
+static inline int crypto_kpp_compute_shared_secret(struct kpp_request *req)
+{
+ struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
+ struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+ return alg->compute_shared_secret(req);
+}
+
+/**
+ * crypto_kpp_maxsize() - Get len for output buffer
+ *
+ * Function returns the output buffer size required
+ *
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
+ *
+ * Return: minimum len for output buffer or error code if key hasn't been set
+ */
+static inline int crypto_kpp_maxsize(struct crypto_kpp *tfm)
+{
+ struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+ return alg->max_size(tfm);
+}
+
+#endif
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 99c9489..18f5cd2 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -54,6 +54,7 @@
#define CRYPTO_ALG_TYPE_AHASH 0x0000000a
#define CRYPTO_ALG_TYPE_RNG 0x0000000c
#define CRYPTO_ALG_TYPE_AKCIPHER 0x0000000d
+#define CRYPTO_ALG_TYPE_KPP 0x0000000e
#define CRYPTO_ALG_TYPE_HASH_MASK 0x0000000e
#define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000c
diff --git a/include/uapi/linux/cryptouser.h b/include/uapi/linux/cryptouser.h
index 2e67bb6..79b5ded 100644
--- a/include/uapi/linux/cryptouser.h
+++ b/include/uapi/linux/cryptouser.h
@@ -45,6 +45,7 @@ enum crypto_attr_type_t {
CRYPTOCFGA_REPORT_RNG, /* struct crypto_report_rng */
CRYPTOCFGA_REPORT_CIPHER, /* struct crypto_report_cipher */
CRYPTOCFGA_REPORT_AKCIPHER, /* struct crypto_report_akcipher */
+ CRYPTOCFGA_REPORT_KPP, /* struct crypto_report_kpp */
__CRYPTOCFGA_MAX
#define CRYPTOCFGA_MAX (__CRYPTOCFGA_MAX - 1)
@@ -107,5 +108,9 @@ struct crypto_report_akcipher {
char type[CRYPTO_MAX_NAME];
};
+struct crypto_report_kpp {
+ char type[CRYPTO_MAX_NAME];
+};
+
#define CRYPTO_REPORT_MAXSIZE (sizeof(struct crypto_user_alg) + \
sizeof(struct crypto_report_blkcipher))
--
1.9.1
--
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