KEYS: fix length validation in keyctl_pkey_params_get_2()

In many cases, keyctl_pkey_params_get_2() is validating the user buffer
lengths against the wrong algorithm properties. Fix it to check against
the correct properties.

Probably this wasn't noticed before because for all asymmetric keys of
the "public_key" subtype, max_data_size == max_sig_size == max_enc_size
== max_dec_size. However, this isn't necessarily true for the
"asym_tpm" subtype (it should be, but it's not strictly validated). Of
course, future key types could have different values as well.

Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

KEYS: remove redundant memset

Reviewing use of memset in keyctl_pkey.c

keyctl_pkey_params_get prologue code to set params up

memset(params, 0, sizeof(*params));
params->encoding = "raw";

keyctl_pkey_query has the same prologue
and calls keyctl_pkey_params_get.

So remove the prologue.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ben Boeckel <mathstuf@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36

Based on 1 normalized pattern(s):

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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 114 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

KEYS: fix parsing invalid pkey info string

We need to check the return value of match_token() for Opt_err before
doing anything with it.

[ Not only did the old "-1" value for Opt_err cause problems for the
__test_and_set_bit(), as fixed in commit 94c13f66e13c ("security:
don't use a negative Opt_err token index"), but accessing
"args[0].from" is invalid for the Opt_err case, as pointed out by Eric
later. - Linus ]

Reported-by: syzbot+a22e0dc07567662c50bc@syzkaller.appspotmail.com
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@kernel.org # 4.20
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security: don't use a negative Opt_err token index

The code uses a bitmap to check for duplicate tokens during parsing, and
that doesn't work at all for the negative Opt_err token case.

There is absolutely no reason to make Opt_err be negative, and in fact
it only confuses things, since some of the affected functions actually
return a positive Opt_xyz enum _or_ a regular negative error code (eg
-EINVAL), and using -1 for Opt_err makes no sense.

There are similar problems in ima_policy.c and key encryption, but they
don't have the immediate bug wrt bitmap handing, and ima_policy.c in
particular needs a different patch to make the enum values match the
token array index. Mimi is sending that separately.

Reported-by: syzbot+a22e0dc07567662c50bc@syzkaller.appspotmail.com
Reported-by: Eric Biggers <ebiggers@kernel.org>
Fixes: 5208cc83423d ("keys, trusted: fix: *do not* allow duplicate key options")
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Cc: James Morris James Morris <jmorris@namei.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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>