Provide three keyctl functions that permit userspace to make use of the new
key type ops for accessing and driving asymmetric kpp keys.
(*) Query an asymmetric kpp key.
long keyctl(KEYCTL_KPP_QUERY,
key_serial_t key, struct keyctl_kpp_query *res);
Get information about an asymmetric kpp key. The information is
returned in the keyctl_kpp_query struct:
__u32 supported_ops;
A bit mask of flags indicating which ops are supported. This
is constructed from a bitwise-OR of:
KEYCTL_SUPPORTS_{GEN_PUBKEY, COMPUTE_SS}
__u32 max_size;
The maximum size in bytes of the key.
__spare must be set to 0. This is intended for future use to hand
over one or more passphrases needed to unlock a key.
If successful, 0 is returned. If the key is not an asymmetric kpp key,
EOPNOTSUPP is returned.
(*) Generate the public key or compute the shared secret using an
asymmetric kpp key.
long keyctl(KEYCTL_KPP_GEN_PUBKEY,
const struct keyctl_kpp_params *params,
void *out);
long keyctl(KEYCTL_KPP_GEN_PUBKEY,
const struct keyctl_kpp_params *params,
const void *in, void *out);
The parameter block pointed by params contains a number of integer
values:
__s32 key_id;
__u32 in_len;
__u32 out_len;
For a given operation, the in and out buffers are used as follows:
Operation ID in,in_len out,out_len
======================= =================== ========================
KEYCTL_KPP_GEN_PUBKEY - Corresponding public key
KEYCTL_KPP_COMPUTE_SS Pair's public key Shared Secret
The __spare space in the parameter block must be set to 0. This is
intended, amongst other things, to allow the passing of passphrases
required to unlock a key.
If successful, the public key generation and the shared secret computation
will return the amount of data written into the output buffer.
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
---
Documentation/security/keys/core.rst | 59 ++++++++++
include/uapi/linux/keyctl.h | 16 +++
security/keys/Makefile | 1 +
security/keys/compat.c | 10 ++
security/keys/internal.h | 28 +++++
security/keys/keyctl.c | 13 +++
security/keys/keyctl_kpp.c | 205 +++++++++++++++++++++++++++++++++++
7 files changed, 332 insertions(+)
create mode 100644 security/keys/keyctl_kpp.c
diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst
index 9b69a1f..31b9501 100644
--- a/Documentation/security/keys/core.rst
+++ b/Documentation/security/keys/core.rst
@@ -994,6 +994,65 @@ The keyctl syscall functions are:
If successful, encrypt, decrypt and sign all return the amount of data
written into the output buffer. Verification returns 0 on success.
+ * Query an asymmetric kpp key::
+
+ long keyctl(KEYCTL_KPP_QUERY,
+ key_serial_t key, struct keyctl_kpp_query *res);
+
+ Get information about an asymmetric kpp key. The information is
+ returned in the keyctl_kpp_query struct::
+
+ struct keyctl_kpp_query {
+ __u32 supported_ops; /* Which ops are supported */
+ __u32 max_size; /* Maximum size of the output buffer in bytes */
+ __u32 __spare[10];
+ };
+
+ ``__u32 supported_ops;`` is a bit mask of flags indicating which ops are
+ supported. This is constructed from a bitwise-OR of::
+
+ KEYCTL_SUPPORTS_{GEN_PUBKEY, COMPUTE_SS}
+
+ ``__spare`` must be set to 0. This is intended for future use to hand
+ over one or more passphrases needed to unlock a key.
+
+ If successful, 0 is returned. If the key is not an asymmetric kpp key,
+ EOPNOTSUPP is returned.
+
+ * Generate the public key or compute the shared secret using an asymmetric
+ kpp key::
+
+ long keyctl(KEYCTL_KPP_GEN_PUBKEY,
+ const struct keyctl_kpp_params *params,
+ void *out);
+
+ long keyctl(KEYCTL_KPP_GEN_PUBKEY,
+ const struct keyctl_kpp_params *params,
+ const void *in, void *out);
+
+ The parameter block pointed by params contains a number of integer
+ values::
+ __s32 key_id;
+ __u32 in_len;
+ __u32 out_len;
+
+ ``key_id`` is the key tp be used and ``in_len`` and ``out_len`` are the
+ lengths in bytes of the input and output buffers.
+
+ For a given operation, the in and out buffers are used as follows::
+
+ Operation ID in,in_len out,out_len
+ ======================= =================== ========================
+ KEYCTL_KPP_GEN_PUBKEY - Corresponding public key
+ KEYCTL_KPP_COMPUTE_SS Pair's public key Shared Secret
+
+ The __spare space in the parameter block must be set to 0. This is
+ intended, amongst other things, to allow the passing of passphrases
+ required to unlock a key.
+
+ If successful, the public key generation and the shared secret computation
+ will return the amount of data written into the output buffer.
+
Kernel Services
===============
diff --git a/include/uapi/linux/keyctl.h b/include/uapi/linux/keyctl.h
index 98b79f8..dcee74c 100644
--- a/include/uapi/linux/keyctl.h
+++ b/include/uapi/linux/keyctl.h
@@ -67,6 +67,9 @@
#define KEYCTL_PKEY_DECRYPT 26 /* Decrypt a blob using a public key */
#define KEYCTL_PKEY_SIGN 27 /* Create a public key signature */
#define KEYCTL_PKEY_VERIFY 28 /* Verify a public key signature */
+#define KEYCTL_KPP_QUERY 30 /* Query KPP parameters */
+#define KEYCTL_KPP_GEN_PUBKEY 31 /* Generate public key */
+#define KEYCTL_KPP_COMPUTE_SS 32 /* Compute shared secret */
/* keyctl structures */
struct keyctl_dh_params {
@@ -110,4 +113,17 @@ struct keyctl_pkey_params {
#define KEYCTL_SUPPORTS_GEN_PUBKEY 0x0f
#define KEYCTL_SUPPORTS_COMPUTE_SS 0x10
+struct keyctl_kpp_query {
+ __u32 supported_ops; /* Which ops are supported */
+ __u32 max_size; /* Maximum size of the output buffer in bytes */
+ __u32 __spare[10];
+};
+
+struct keyctl_kpp_params {
+ __s32 key_id; /* Serial no. of private key to use */
+ __u32 in_len; /* Input data size */
+ __u32 out_len; /* Output buffer size */
+ __u32 __spare[7];
+};
+
#endif /* _LINUX_KEYCTL_H */
diff --git a/security/keys/Makefile b/security/keys/Makefile
index 9cef540..eb05d3c 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_SYSCTL) += sysctl.o
obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o
obj-$(CONFIG_KEY_DH_OPERATIONS) += dh.o
obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += keyctl_pkey.o
+obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += keyctl_kpp.o
#
# Key types
diff --git a/security/keys/compat.c b/security/keys/compat.c
index 9482df6..0909715 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -159,6 +159,16 @@ COMPAT_SYSCALL_DEFINE5(keyctl, u32, option,
return keyctl_pkey_verify(compat_ptr(arg2), compat_ptr(arg3),
compat_ptr(arg4), compat_ptr(arg5));
+ case KEYCTL_KPP_QUERY:
+ return keyctl_kpp_query(arg2, compat_ptr(arg5));
+
+ case KEYCTL_KPP_GEN_PUBKEY:
+ return keyctl_kpp_gen_pubkey(compat_ptr(arg2), compat_ptr(arg5);
+
+ case KEYCTL_KPP_COMPUTE_SS:
+ return keyctl_kpp_compute_ss(compat_ptr(arg2), compat_ptr(arg4),
+ compat_ptr(arg5));
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 74cb0ff..bacfda5 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -311,6 +311,14 @@ extern long keyctl_pkey_e_d_s(int,
const struct keyctl_pkey_params __user *,
const char __user *,
const void __user *, void __user *);
+
+extern long keyctl_kpp_query(key_serial_t, struct keyctl_kpp_query __user *);
+
+extern long keyctl_kpp_gen_pubkey(const struct keyctl_kpp_params __user *,
+ void __user *);
+
+extern long keyctl_kpp_compute_ss(const struct keyctl_kpp_params __user *,
+ const void __user *, void __user *);
#else
static inline long keyctl_pkey_query(key_serial_t id,
const char __user *_info,
@@ -335,6 +343,26 @@ static inline long keyctl_pkey_e_d_s(int op,
{
return -EOPNOTSUPP;
}
+
+static inline long keyctl_kpp_query(key_serial_t id,
+ struct keyctl_kpp_query __user *_res);
+{
+ return -EOPNOTSUPP;
+}
+
+static inline long keyctl_kpp_gen_pubkey(
+ const struct keyctl_kpp_params __user *params,
+ void __user *_out);
+{
+ return -EOPNOTSUPP;
+}
+
+static inline long keyctl_kpp_compute_ss(
+ const struct keyctl_kpp_params __user *params,
+ const void __user *in, void __user *_out);
+{
+ return -EOPNOTSUPP;
+}
#endif
/*
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 614b147bc..a9a47e6 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1775,6 +1775,19 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
(const void __user *)arg4,
(const void __user *)arg5);
+ case KEYCTL_KPP_QUERY:
+ return keyctl_kpp_query((key_serial_t)arg2,
+ (struct keyctl_kpp_query *)arg5);
+ case KEYCTL_KPP_GEN_PUBKEY:
+ return keyctl_kpp_gen_pubkey(
+ (const struct keyctl_kpp_params __user *)arg2,
+ (void __user *)arg5);
+ case KEYCTL_KPP_COMPUTE_SS:
+ return keyctl_kpp_compute_ss(
+ (const struct keyctl_kpp_params __user *)arg2,
+ (const void __user *)arg4,
+ (void __user *)arg5);
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/keyctl_kpp.c b/security/keys/keyctl_kpp.c
new file mode 100644
index 0000000..8b4f77a
--- /dev/null
+++ b/security/keys/keyctl_kpp.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/err.h>
+#include <linux/key.h>
+#include <linux/keyctl.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+
+enum kernel_kpp_operation {
+ kernel_kpp_gen_pubkey,
+ kernel_kpp_compute_ss,
+};
+
+static void keyctl_kpp_params_free(struct kernel_kpp_params *params)
+{
+ key_put(params->key);
+}
+
+/*
+ * Interpret parameters. Callers must always call the free function
+ * on params, even if an error is returned.
+ */
+static int keyctl_kpp_params_get(key_serial_t id,
+ struct kernel_kpp_params *params)
+{
+ key_ref_t key_ref;
+
+ key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
+ if (IS_ERR(key_ref))
+ return PTR_ERR(key_ref);
+ params->key = key_ref_to_ptr(key_ref);
+
+ if (!params->key->type->asym_kpp_query)
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+/*
+ * Get parameters from userspace. Callers must always call the free function
+ * on params, even if an error is returned.
+ */
+static int keyctl_kpp_params_get_2(
+ const struct keyctl_kpp_params __user *_params,
+ int operation,
+ struct kernel_kpp_params *params)
+{
+ struct keyctl_kpp_params uparams;
+ struct kernel_kpp_query res;
+ int ret;
+
+ if (copy_from_user(&uparams, _params, sizeof(uparams)) != 0)
+ return -EFAULT;
+
+ ret = keyctl_kpp_params_get(uparams.key_id, params);
+ if (ret < 0)
+ return ret;
+
+ ret = params->key->type->asym_kpp_query(params, &res);
+ if (ret < 0)
+ return ret;
+
+ switch (operation) {
+ case kernel_kpp_gen_pubkey:
+ if (uparams.out_len > res.max_size)
+ return -EINVAL;
+ break;
+ case kernel_kpp_compute_ss:
+ if (uparams.in_len > res.max_size ||
+ uparams.out_len > res.max_size)
+ return -EINVAL;
+ params->in_len = uparams.in_len;
+ break;
+ default:
+ return -EINVAL;
+ }
+ params->out_len = uparams.out_len;
+
+ return 0;
+}
+
+/*
+ * Query information about an asymmetric key.
+ */
+long keyctl_kpp_query(key_serial_t id, struct keyctl_kpp_query __user *_res)
+{
+ struct kernel_kpp_params params;
+ struct kernel_kpp_query res;
+ long ret;
+
+ memset(¶ms, 0, sizeof(params));
+
+ ret = keyctl_kpp_params_get(id, ¶ms);
+ if (ret < 0)
+ goto free_params;
+
+ ret = params.key->type->asym_kpp_query(¶ms, &res);
+ if (ret < 0)
+ goto free_params;
+
+ if (copy_to_user(_res, &res, sizeof(res)) ||
+ clear_user(_res->__spare, sizeof(_res->__spare)))
+ ret = -EFAULT;
+
+free_params:
+ keyctl_kpp_params_free(¶ms);
+ return ret;
+}
+
+/*
+ * Generate public key.
+ *
+ * If successful, the amount of data written into the output buffer is
+ * returned.
+ */
+long keyctl_kpp_gen_pubkey(const struct keyctl_kpp_params __user *_params,
+ void __user *_out)
+{
+ struct kernel_kpp_params params;
+ void *out;
+ long ret;
+
+ memset(¶ms, 0, sizeof(params));
+
+ ret = keyctl_kpp_params_get_2(_params, kernel_kpp_gen_pubkey, ¶ms);
+ if (ret < 0)
+ goto free_params;
+
+ if (!params.key->type->asym_kpp_gen_pubkey) {
+ ret = -EOPNOTSUPP;
+ goto free_params;
+ }
+
+ out = kmalloc(params.out_len, GFP_KERNEL);
+ if (!out) {
+ ret = -ENOMEM;
+ goto free_params;
+ }
+
+ ret = params.key->type->asym_kpp_gen_pubkey(¶ms, out);
+ if (ret < 0)
+ goto free_all;
+
+ if (copy_to_user(_out, out, ret) != 0)
+ ret = -EFAULT;
+
+free_all:
+ kfree(out);
+free_params:
+ keyctl_kpp_params_free(¶ms);
+ return ret;
+}
+
+/*
+ * Compute shared secret.
+ *
+ * If successful, the amount of data written into the output buffer is
+ * returned.
+ */
+long keyctl_kpp_compute_ss(const struct keyctl_kpp_params __user *_params,
+ const void __user *_in,
+ void __user *_out)
+{
+ struct kernel_kpp_params params;
+ void *in, *out;
+ long ret;
+
+ memset(¶ms, 0, sizeof(params));
+
+ ret = keyctl_kpp_params_get_2(_params, kernel_kpp_compute_ss, ¶ms);
+ if (ret < 0)
+ goto free_params;
+
+ if (!params.key->type->asym_kpp_compute_ss) {
+ ret = -EOPNOTSUPP;
+ goto free_params;
+ }
+
+ in = memdup_user(_in, params.in_len);
+ if (IS_ERR(in)) {
+ ret = PTR_ERR(in);
+ goto free_params;
+ }
+
+ out = kmalloc(params.out_len, GFP_KERNEL);
+ if (!out) {
+ ret = -ENOMEM;
+ goto free_in;
+ }
+
+ ret = params.key->type->asym_kpp_compute_ss(¶ms, in, out);
+ if (ret < 0)
+ goto free_all;
+
+ if (copy_to_user(_out, out, ret) != 0)
+ ret = -EFAULT;
+
+free_all:
+ kfree(out);
+free_in:
+ kfree(in);
+free_params:
+ keyctl_kpp_params_free(¶ms);
+ return ret;
+}
--
2.9.4
