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authorDavid Howells <dhowells@redhat.com>2018-10-09 17:46:59 +0100
committerJames Morris <james.morris@microsoft.com>2018-10-26 09:30:46 +0100
commit00d60fd3b93219ea854220f0fd264b86398cbc53 (patch)
tree785d49e4c21db068d4aa4e1ec95bd8e095a3bd2e /security
parent70025f84e5b79627a6739533c4fe7cef5b605886 (diff)
downloadlinux-stericsson-00d60fd3b93219ea854220f0fd264b86398cbc53.tar.gz
KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]
Provide five keyctl functions that permit userspace to make use of the new key type ops for accessing and driving asymmetric keys. (*) Query an asymmetric key. long keyctl(KEYCTL_PKEY_QUERY, key_serial_t key, unsigned long reserved, struct keyctl_pkey_query *info); Get information about an asymmetric key. The information is returned in the keyctl_pkey_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_{ENCRYPT,DECRYPT,SIGN,VERIFY} __u32 key_size; The size in bits of the key. __u16 max_data_size; __u16 max_sig_size; __u16 max_enc_size; __u16 max_dec_size; The maximum sizes in bytes of a blob of data to be signed, a signature blob, a blob to be encrypted and a blob to be decrypted. reserved must be set to 0. This is intended for future use to hand over one or more passphrases needed unlock a key. If successful, 0 is returned. If the key is not an asymmetric key, EOPNOTSUPP is returned. (*) Encrypt, decrypt, sign or verify a blob using an asymmetric key. long keyctl(KEYCTL_PKEY_ENCRYPT, const struct keyctl_pkey_params *params, const char *info, const void *in, void *out); long keyctl(KEYCTL_PKEY_DECRYPT, const struct keyctl_pkey_params *params, const char *info, const void *in, void *out); long keyctl(KEYCTL_PKEY_SIGN, const struct keyctl_pkey_params *params, const char *info, const void *in, void *out); long keyctl(KEYCTL_PKEY_VERIFY, const struct keyctl_pkey_params *params, const char *info, const void *in, const void *in2); Use an asymmetric key to perform a public-key cryptographic operation a blob of data. The parameter block pointed to by params contains a number of integer values: __s32 key_id; __u32 in_len; __u32 out_len; __u32 in2_len; For a given operation, the in and out buffers are used as follows: Operation ID in,in_len out,out_len in2,in2_len ======================= =============== =============== =========== KEYCTL_PKEY_ENCRYPT Raw data Encrypted data - KEYCTL_PKEY_DECRYPT Encrypted data Raw data - KEYCTL_PKEY_SIGN Raw data Signature - KEYCTL_PKEY_VERIFY Raw data - Signature info is a string of key=value pairs that supply supplementary information. 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, encrypt, decrypt and sign all return the amount of data written into the output buffer. Verification returns 0 on success. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marcel Holtmann <marcel@holtmann.org> Reviewed-by: Marcel Holtmann <marcel@holtmann.org> Reviewed-by: Denis Kenzior <denkenz@gmail.com> Tested-by: Denis Kenzior <denkenz@gmail.com> Signed-off-by: James Morris <james.morris@microsoft.com>
Diffstat (limited to 'security')
-rw-r--r--security/keys/Makefile1
-rw-r--r--security/keys/compat.c18
-rw-r--r--security/keys/internal.h39
-rw-r--r--security/keys/keyctl.c24
-rw-r--r--security/keys/keyctl_pkey.c323
5 files changed, 405 insertions, 0 deletions
diff --git a/security/keys/Makefile b/security/keys/Makefile
index ef1581b337a3..9cef54064f60 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_PROC_FS) += proc.o
obj-$(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
#
# Key types
diff --git a/security/keys/compat.c b/security/keys/compat.c
index e87c89c0177c..9482df601dc3 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -141,6 +141,24 @@ COMPAT_SYSCALL_DEFINE5(keyctl, u32, option,
return keyctl_restrict_keyring(arg2, compat_ptr(arg3),
compat_ptr(arg4));
+ case KEYCTL_PKEY_QUERY:
+ if (arg3 != 0)
+ return -EINVAL;
+ return keyctl_pkey_query(arg2,
+ compat_ptr(arg4),
+ compat_ptr(arg5));
+
+ case KEYCTL_PKEY_ENCRYPT:
+ case KEYCTL_PKEY_DECRYPT:
+ case KEYCTL_PKEY_SIGN:
+ return keyctl_pkey_e_d_s(option,
+ compat_ptr(arg2), compat_ptr(arg3),
+ compat_ptr(arg4), compat_ptr(arg5));
+
+ case KEYCTL_PKEY_VERIFY:
+ return keyctl_pkey_verify(compat_ptr(arg2), compat_ptr(arg3),
+ compat_ptr(arg4), compat_ptr(arg5));
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 9f8208dc0e55..74cb0ff42fed 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -298,6 +298,45 @@ static inline long compat_keyctl_dh_compute(
#endif
#endif
+#ifdef CONFIG_ASYMMETRIC_KEY_TYPE
+extern long keyctl_pkey_query(key_serial_t,
+ const char __user *,
+ struct keyctl_pkey_query __user *);
+
+extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
+ const char __user *,
+ const void __user *, const void __user *);
+
+extern long keyctl_pkey_e_d_s(int,
+ const struct keyctl_pkey_params __user *,
+ const char __user *,
+ const void __user *, void __user *);
+#else
+static inline long keyctl_pkey_query(key_serial_t id,
+ const char __user *_info,
+ struct keyctl_pkey_query __user *_res)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
+ const char __user *_info,
+ const void __user *_in,
+ const void __user *_in2)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline long keyctl_pkey_e_d_s(int op,
+ const struct keyctl_pkey_params __user *params,
+ const char __user *_info,
+ const void __user *_in,
+ void __user *_out)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
/*
* Debugging key validation
*/
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 1ffe60bb2845..18619690ce77 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1747,6 +1747,30 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
(const char __user *) arg3,
(const char __user *) arg4);
+ case KEYCTL_PKEY_QUERY:
+ if (arg3 != 0)
+ return -EINVAL;
+ return keyctl_pkey_query((key_serial_t)arg2,
+ (const char __user *)arg4,
+ (struct keyctl_pkey_query *)arg5);
+
+ case KEYCTL_PKEY_ENCRYPT:
+ case KEYCTL_PKEY_DECRYPT:
+ case KEYCTL_PKEY_SIGN:
+ return keyctl_pkey_e_d_s(
+ option,
+ (const struct keyctl_pkey_params __user *)arg2,
+ (const char __user *)arg3,
+ (const void __user *)arg4,
+ (void __user *)arg5);
+
+ case KEYCTL_PKEY_VERIFY:
+ return keyctl_pkey_verify(
+ (const struct keyctl_pkey_params __user *)arg2,
+ (const char __user *)arg3,
+ (const void __user *)arg4,
+ (const void __user *)arg5);
+
default:
return -EOPNOTSUPP;
}
diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c
new file mode 100644
index 000000000000..783978842f13
--- /dev/null
+++ b/security/keys/keyctl_pkey.c
@@ -0,0 +1,323 @@
+/* Public-key operation keyctls
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/key.h>
+#include <linux/keyctl.h>
+#include <linux/parser.h>
+#include <linux/uaccess.h>
+#include <keys/user-type.h>
+#include "internal.h"
+
+static void keyctl_pkey_params_free(struct kernel_pkey_params *params)
+{
+ kfree(params->info);
+ key_put(params->key);
+}
+
+enum {
+ Opt_err = -1,
+ Opt_enc, /* "enc=<encoding>" eg. "enc=oaep" */
+ Opt_hash, /* "hash=<digest-name>" eg. "hash=sha1" */
+};
+
+static const match_table_t param_keys = {
+ { Opt_enc, "enc=%s" },
+ { Opt_hash, "hash=%s" },
+ { Opt_err, NULL }
+};
+
+/*
+ * Parse the information string which consists of key=val pairs.
+ */
+static int keyctl_pkey_params_parse(struct kernel_pkey_params *params)
+{
+ unsigned long token_mask = 0;
+ substring_t args[MAX_OPT_ARGS];
+ char *c = params->info, *p, *q;
+ int token;
+
+ while ((p = strsep(&c, " \t"))) {
+ if (*p == '\0' || *p == ' ' || *p == '\t')
+ continue;
+ token = match_token(p, param_keys, args);
+ if (__test_and_set_bit(token, &token_mask))
+ return -EINVAL;
+ q = args[0].from;
+ if (!q[0])
+ return -EINVAL;
+
+ switch (token) {
+ case Opt_enc:
+ params->encoding = q;
+ break;
+
+ case Opt_hash:
+ params->hash_algo = q;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Interpret parameters. Callers must always call the free function
+ * on params, even if an error is returned.
+ */
+static int keyctl_pkey_params_get(key_serial_t id,
+ const char __user *_info,
+ struct kernel_pkey_params *params)
+{
+ key_ref_t key_ref;
+ void *p;
+ int ret;
+
+ memset(params, 0, sizeof(*params));
+ params->encoding = "raw";
+
+ p = strndup_user(_info, PAGE_SIZE);
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+ params->info = p;
+
+ ret = keyctl_pkey_params_parse(params);
+ if (ret < 0)
+ return ret;
+
+ 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_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_pkey_params_get_2(const struct keyctl_pkey_params __user *_params,
+ const char __user *_info,
+ int op,
+ struct kernel_pkey_params *params)
+{
+ struct keyctl_pkey_params uparams;
+ struct kernel_pkey_query info;
+ int ret;
+
+ memset(params, 0, sizeof(*params));
+ params->encoding = "raw";
+
+ if (copy_from_user(&uparams, _params, sizeof(uparams)) != 0)
+ return -EFAULT;
+
+ ret = keyctl_pkey_params_get(uparams.key_id, _info, params);
+ if (ret < 0)
+ return ret;
+
+ ret = params->key->type->asym_query(params, &info);
+ if (ret < 0)
+ return ret;
+
+ switch (op) {
+ case KEYCTL_PKEY_ENCRYPT:
+ case KEYCTL_PKEY_DECRYPT:
+ if (uparams.in_len > info.max_enc_size ||
+ uparams.out_len > info.max_dec_size)
+ return -EINVAL;
+ break;
+ case KEYCTL_PKEY_SIGN:
+ case KEYCTL_PKEY_VERIFY:
+ if (uparams.in_len > info.max_sig_size ||
+ uparams.out_len > info.max_data_size)
+ return -EINVAL;
+ break;
+ default:
+ BUG();
+ }
+
+ params->in_len = uparams.in_len;
+ params->out_len = uparams.out_len;
+ return 0;
+}
+
+/*
+ * Query information about an asymmetric key.
+ */
+long keyctl_pkey_query(key_serial_t id,
+ const char __user *_info,
+ struct keyctl_pkey_query __user *_res)
+{
+ struct kernel_pkey_params params;
+ struct kernel_pkey_query res;
+ long ret;
+
+ memset(&params, 0, sizeof(params));
+
+ ret = keyctl_pkey_params_get(id, _info, &params);
+ if (ret < 0)
+ goto error;
+
+ ret = params.key->type->asym_query(&params, &res);
+ if (ret < 0)
+ goto error;
+
+ ret = -EFAULT;
+ if (copy_to_user(_res, &res, sizeof(res)) == 0 &&
+ clear_user(_res->__spare, sizeof(_res->__spare)) == 0)
+ ret = 0;
+
+error:
+ keyctl_pkey_params_free(&params);
+ return ret;
+}
+
+/*
+ * Encrypt/decrypt/sign
+ *
+ * Encrypt data, decrypt data or sign data using a public key.
+ *
+ * _info is a string of supplementary information in key=val format. For
+ * instance, it might contain:
+ *
+ * "enc=pkcs1 hash=sha256"
+ *
+ * where enc= specifies the encoding and hash= selects the OID to go in that
+ * particular encoding if required. If enc= isn't supplied, it's assumed that
+ * the caller is supplying raw values.
+ *
+ * If successful, the amount of data written into the output buffer is
+ * returned.
+ */
+long keyctl_pkey_e_d_s(int op,
+ const struct keyctl_pkey_params __user *_params,
+ const char __user *_info,
+ const void __user *_in,
+ void __user *_out)
+{
+ struct kernel_pkey_params params;
+ void *in, *out;
+ long ret;
+
+ ret = keyctl_pkey_params_get_2(_params, _info, op, &params);
+ if (ret < 0)
+ goto error_params;
+
+ ret = -EOPNOTSUPP;
+ if (!params.key->type->asym_eds_op)
+ goto error_params;
+
+ switch (op) {
+ case KEYCTL_PKEY_ENCRYPT:
+ params.op = kernel_pkey_encrypt;
+ break;
+ case KEYCTL_PKEY_DECRYPT:
+ params.op = kernel_pkey_decrypt;
+ break;
+ case KEYCTL_PKEY_SIGN:
+ params.op = kernel_pkey_sign;
+ break;
+ default:
+ BUG();
+ }
+
+ in = memdup_user(_in, params.in_len);
+ if (IS_ERR(in)) {
+ ret = PTR_ERR(in);
+ goto error_params;
+ }
+
+ ret = -ENOMEM;
+ out = kmalloc(params.out_len, GFP_KERNEL);
+ if (!out)
+ goto error_in;
+
+ ret = params.key->type->asym_eds_op(&params, in, out);
+ if (ret < 0)
+ goto error_out;
+
+ if (copy_to_user(_out, out, ret) != 0)
+ ret = -EFAULT;
+
+error_out:
+ kfree(out);
+error_in:
+ kfree(in);
+error_params:
+ keyctl_pkey_params_free(&params);
+ return ret;
+}
+
+/*
+ * Verify a signature.
+ *
+ * Verify a public key signature using the given key, or if not given, search
+ * for a matching key.
+ *
+ * _info is a string of supplementary information in key=val format. For
+ * instance, it might contain:
+ *
+ * "enc=pkcs1 hash=sha256"
+ *
+ * where enc= specifies the signature blob encoding and hash= selects the OID
+ * to go in that particular encoding. If enc= isn't supplied, it's assumed
+ * that the caller is supplying raw values.
+ *
+ * If successful, 0 is returned.
+ */
+long keyctl_pkey_verify(const struct keyctl_pkey_params __user *_params,
+ const char __user *_info,
+ const void __user *_in,
+ const void __user *_in2)
+{
+ struct kernel_pkey_params params;
+ void *in, *in2;
+ long ret;
+
+ ret = keyctl_pkey_params_get_2(_params, _info, KEYCTL_PKEY_VERIFY,
+ &params);
+ if (ret < 0)
+ goto error_params;
+
+ ret = -EOPNOTSUPP;
+ if (!params.key->type->asym_verify_signature)
+ goto error_params;
+
+ in = memdup_user(_in, params.in_len);
+ if (IS_ERR(in)) {
+ ret = PTR_ERR(in);
+ goto error_params;
+ }
+
+ in2 = memdup_user(_in2, params.in2_len);
+ if (IS_ERR(in2)) {
+ ret = PTR_ERR(in2);
+ goto error_in;
+ }
+
+ params.op = kernel_pkey_verify;
+ ret = params.key->type->asym_verify_signature(&params, in, in2);
+
+ kfree(in2);
+error_in:
+ kfree(in);
+error_params:
+ keyctl_pkey_params_free(&params);
+ return ret;
+}