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Subject[PATCH 03/22] KEYS: Provide missing asymmetric key subops for new key type ops
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Provide the missing asymmetric key subops for new key type ops.  This
include query, encrypt, decrypt and create signature. Verify signature
already exists. Also provided are accessor functions for this:

int query_asymmetric_key(const struct key *key,
struct kernel_pkey_query *info);

int encrypt_blob(struct kernel_pkey_params *params,
const void *data, void *enc);
int decrypt_blob(struct kernel_pkey_params *params,
const void *enc, void *data);
int create_signature(struct kernel_pkey_params *params,
const void *data, void *enc);

The public_key_signature struct gains an encoding field to carry the
encoding for verify_signature().

Signed-off-by: David Howells <dhowells@redhat.com>
---

Documentation/crypto/asymmetric-keys.txt | 24 ++++++--
crypto/asymmetric_keys/asymmetric_keys.h | 3 +
crypto/asymmetric_keys/asymmetric_type.c | 43 ++++++++++++++
crypto/asymmetric_keys/signature.c | 95 ++++++++++++++++++++++++++++++
include/crypto/public_key.h | 13 +++-
include/keys/asymmetric-subtype.h | 9 +++
6 files changed, 180 insertions(+), 7 deletions(-)

diff --git a/Documentation/crypto/asymmetric-keys.txt b/Documentation/crypto/asymmetric-keys.txt
index 5969bf42562a..deb656ef008b 100644
--- a/Documentation/crypto/asymmetric-keys.txt
+++ b/Documentation/crypto/asymmetric-keys.txt
@@ -183,6 +183,10 @@ and looks like the following:

void (*describe)(const struct key *key, struct seq_file *m);
void (*destroy)(void *payload);
+ int (*query)(const struct kernel_pkey_params *params,
+ struct kernel_pkey_query *info);
+ int (*eds_op)(struct kernel_pkey_params *params,
+ const void *in, void *out);
int (*verify_signature)(const struct key *key,
const struct public_key_signature *sig);
};
@@ -207,12 +211,22 @@ There are a number of operations defined by the subtype:
asymmetric key will look after freeing the fingerprint and releasing the
reference on the subtype module.

- (3) verify_signature().
+ (3) query().

- Optional. These are the entry points for the key usage operations.
- Currently there is only the one defined. If not set, the caller will be
- given -ENOTSUPP. The subtype may do anything it likes to implement an
- operation, including offloading to hardware.
+ Mandatory. This is a function for querying the capabilities of a key.
+
+ (4) eds_op().
+
+ Optional. This is the entry point for the encryption, decryption and
+ signature creation operations (which are distinguished by the operation ID
+ in the parameter struct). The subtype may do anything it likes to
+ implement an operation, including offloading to hardware.
+
+ (5) verify_signature().
+
+ Optional. This is the entry point for signature verification. The
+ subtype may do anything it likes to implement an operation, including
+ offloading to hardware.


==========================
diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h
index ca8e9ac34ce6..7be1ccf4fa9f 100644
--- a/crypto/asymmetric_keys/asymmetric_keys.h
+++ b/crypto/asymmetric_keys/asymmetric_keys.h
@@ -16,3 +16,6 @@ extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id);
extern int __asymmetric_key_hex_to_key_id(const char *id,
struct asymmetric_key_id *match_id,
size_t hexlen);
+
+extern int asymmetric_key_eds_op(struct kernel_pkey_params *params,
+ const void *in, void *out);
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 26539e9a8bda..69a0788a7de5 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -18,6 +18,7 @@
#include <linux/slab.h>
#include <linux/ctype.h>
#include <keys/system_keyring.h>
+#include <keys/user-type.h>
#include "asymmetric_keys.h"

MODULE_LICENSE("GPL");
@@ -538,6 +539,45 @@ static struct key_restriction *asymmetric_lookup_restriction(
return ret;
}

+int asymmetric_key_eds_op(struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ const struct asymmetric_key_subtype *subtype;
+ struct key *key = params->key;
+ int ret;
+
+ pr_devel("==>%s()\n", __func__);
+
+ if (key->type != &key_type_asymmetric)
+ return -EINVAL;
+ subtype = asymmetric_key_subtype(key);
+ if (!subtype ||
+ !key->payload.data[0])
+ return -EINVAL;
+ if (!subtype->eds_op)
+ return -ENOTSUPP;
+
+ ret = subtype->eds_op(params, in, out);
+
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+}
+
+static int asymmetric_key_verify_signature(struct kernel_pkey_params *params,
+ const void *in, const void *in2)
+{
+ struct public_key_signature sig = {
+ .s_size = params->in2_len,
+ .digest_size = params->in_len,
+ .encoding = params->encoding,
+ .hash_algo = params->hash_algo,
+ .digest = (void *)in,
+ .s = (void *)in2,
+ };
+
+ return verify_signature(params->key, &sig);
+}
+
struct key_type key_type_asymmetric = {
.name = "asymmetric",
.preparse = asymmetric_key_preparse,
@@ -548,6 +588,9 @@ struct key_type key_type_asymmetric = {
.destroy = asymmetric_key_destroy,
.describe = asymmetric_key_describe,
.lookup_restriction = asymmetric_lookup_restriction,
+ .asym_query = query_asymmetric_key,
+ .asym_eds_op = asymmetric_key_eds_op,
+ .asym_verify_signature = asymmetric_key_verify_signature,
};
EXPORT_SYMBOL_GPL(key_type_asymmetric);

diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c
index 28198314bc39..ad95a58c6642 100644
--- a/crypto/asymmetric_keys/signature.c
+++ b/crypto/asymmetric_keys/signature.c
@@ -16,7 +16,9 @@
#include <linux/export.h>
#include <linux/err.h>
#include <linux/slab.h>
+#include <linux/keyctl.h>
#include <crypto/public_key.h>
+#include <keys/user-type.h>
#include "asymmetric_keys.h"

/*
@@ -36,6 +38,99 @@ void public_key_signature_free(struct public_key_signature *sig)
}
EXPORT_SYMBOL_GPL(public_key_signature_free);

+/**
+ * query_asymmetric_key - Get information about an aymmetric key.
+ * @params: Various parameters.
+ * @info: Where to put the information.
+ */
+int query_asymmetric_key(const struct kernel_pkey_params *params,
+ struct kernel_pkey_query *info)
+{
+ const struct asymmetric_key_subtype *subtype;
+ struct key *key = params->key;
+ int ret;
+
+ pr_devel("==>%s()\n", __func__);
+
+ if (key->type != &key_type_asymmetric)
+ return -EINVAL;
+ subtype = asymmetric_key_subtype(key);
+ if (!subtype ||
+ !key->payload.data[0])
+ return -EINVAL;
+ if (!subtype->query)
+ return -ENOTSUPP;
+
+ ret = subtype->query(params, info);
+
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(query_asymmetric_key);
+
+/**
+ * encrypt_blob - Encrypt data using an asymmetric key
+ * @params: Various parameters
+ * @data: Data blob to be encrypted, length params->data_len
+ * @enc: Encrypted data buffer, length params->enc_len
+ *
+ * Encrypt the specified data blob using the private key specified by
+ * params->key. The encrypted data is wrapped in an encoding if
+ * params->encoding is specified (eg. "pkcs1").
+ *
+ * Returns the length of the data placed in the encrypted data buffer or an
+ * error.
+ */
+int encrypt_blob(struct kernel_pkey_params *params,
+ const void *data, void *enc)
+{
+ params->op = kernel_pkey_encrypt;
+ return asymmetric_key_eds_op(params, data, enc);
+}
+EXPORT_SYMBOL_GPL(encrypt_blob);
+
+/**
+ * decrypt_blob - Decrypt data using an asymmetric key
+ * @params: Various parameters
+ * @enc: Encrypted data to be decrypted, length params->enc_len
+ * @data: Decrypted data buffer, length params->data_len
+ *
+ * Decrypt the specified data blob using the private key specified by
+ * params->key. The decrypted data is wrapped in an encoding if
+ * params->encoding is specified (eg. "pkcs1").
+ *
+ * Returns the length of the data placed in the decrypted data buffer or an
+ * error.
+ */
+int decrypt_blob(struct kernel_pkey_params *params,
+ const void *enc, void *data)
+{
+ params->op = kernel_pkey_decrypt;
+ return asymmetric_key_eds_op(params, enc, data);
+}
+EXPORT_SYMBOL_GPL(decrypt_blob);
+
+/**
+ * create_signature - Sign some data using an asymmetric key
+ * @params: Various parameters
+ * @data: Data blob to be signed, length params->data_len
+ * @enc: Signature buffer, length params->enc_len
+ *
+ * Sign the specified data blob using the private key specified by params->key.
+ * The signature is wrapped in an encoding if params->encoding is specified
+ * (eg. "pkcs1"). If the encoding needs to know the digest type, this can be
+ * passed through params->hash_algo (eg. "sha1").
+ *
+ * Returns the length of the data placed in the signature buffer or an error.
+ */
+int create_signature(struct kernel_pkey_params *params,
+ const void *data, void *enc)
+{
+ params->op = kernel_pkey_sign;
+ return asymmetric_key_eds_op(params, data, enc);
+}
+EXPORT_SYMBOL_GPL(create_signature);
+
/**
* verify_signature - Initiate the use of an asymmetric key to verify a signature
* @key: The asymmetric key to verify against
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index e0b681a717ba..3a1047a0195c 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -14,6 +14,8 @@
#ifndef _LINUX_PUBLIC_KEY_H
#define _LINUX_PUBLIC_KEY_H

+#include <linux/keyctl.h>
+
/*
* Cryptographic data for the public-key subtype of the asymmetric key type.
*
@@ -40,6 +42,7 @@ struct public_key_signature {
u8 digest_size; /* Number of bytes in digest */
const char *pkey_algo;
const char *hash_algo;
+ const char *encoding;
};

extern void public_key_signature_free(struct public_key_signature *sig);
@@ -65,8 +68,14 @@ extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
const union key_payload *payload,
struct key *trusted);

-extern int verify_signature(const struct key *key,
- const struct public_key_signature *sig);
+extern int query_asymmetric_key(const struct kernel_pkey_params *,
+ struct kernel_pkey_query *);
+
+extern int encrypt_blob(struct kernel_pkey_params *, const void *, void *);
+extern int decrypt_blob(struct kernel_pkey_params *, const void *, void *);
+extern int create_signature(struct kernel_pkey_params *, const void *, void *);
+extern int verify_signature(const struct key *,
+ const struct public_key_signature *);

int public_key_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig);
diff --git a/include/keys/asymmetric-subtype.h b/include/keys/asymmetric-subtype.h
index e0a9c2368872..9ce2f0fae57e 100644
--- a/include/keys/asymmetric-subtype.h
+++ b/include/keys/asymmetric-subtype.h
@@ -17,6 +17,8 @@
#include <linux/seq_file.h>
#include <keys/asymmetric-type.h>

+struct kernel_pkey_query;
+struct kernel_pkey_params;
struct public_key_signature;

/*
@@ -34,6 +36,13 @@ struct asymmetric_key_subtype {
/* Destroy a key of this subtype */
void (*destroy)(void *payload_crypto, void *payload_auth);

+ int (*query)(const struct kernel_pkey_params *params,
+ struct kernel_pkey_query *info);
+
+ /* Encrypt/decrypt/sign data */
+ int (*eds_op)(struct kernel_pkey_params *params,
+ const void *in, void *out);
+
/* Verify the signature on a key of this subtype (optional) */
int (*verify_signature)(const struct key *key,
const struct public_key_signature *sig);
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