de66514d93
In TPM 1.2 an authorization was a 20 byte number. The spec actually
recommended you to hash variable length passwords and use the sha1
hash as the authorization. Because the spec doesn't require this
hashing, the current authorization for trusted keys is a 40 digit hex
number. For TPM 2.0 the spec allows the passing in of variable length
passwords and passphrases directly, so we should allow that in trusted
keys for ease of use. Update the 'blobauth' parameter to take this
into account, so we can now use plain text passwords for the keys.
so before
keyctl add trusted kmk "new 32 blobauth=f572d396fae9206628714fb2ce00f72e94f2258fkeyhandle=81000001" @u
after we will accept both the old hex sha1 form as well as a new
directly supplied password:
keyctl add trusted kmk "new 32 blobauth=hello keyhandle=81000001" @u
Since a sha1 hex code must be exactly 40 bytes long and a direct
password must be 20 or less, we use the length as the discriminator
for which form is input.
Note this is both and enhancement and a potential bug fix. The TPM
2.0 spec requires us to strip leading zeros, meaning empyty
authorization is a zero length HMAC whereas we're currently passing in
20 bytes of zeros. A lot of TPMs simply accept this as OK, but the
Microsoft TPM emulator rejects it with TPM_RC_BAD_AUTH, so this patch
makes the Microsoft TPM emulator work with trusted keys.
Fixes: 0fe5480303 ("keys, trusted: seal/unseal with TPM 2.0 chips")
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
47 lines
1.0 KiB
C
47 lines
1.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2010 IBM Corporation
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* Author: David Safford <safford@us.ibm.com>
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*/
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#ifndef _KEYS_TRUSTED_TYPE_H
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#define _KEYS_TRUSTED_TYPE_H
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#include <linux/key.h>
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#include <linux/rcupdate.h>
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#include <linux/tpm.h>
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#define MIN_KEY_SIZE 32
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#define MAX_KEY_SIZE 128
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#define MAX_BLOB_SIZE 512
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#define MAX_PCRINFO_SIZE 64
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#define MAX_DIGEST_SIZE 64
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struct trusted_key_payload {
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struct rcu_head rcu;
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unsigned int key_len;
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unsigned int blob_len;
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unsigned char migratable;
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unsigned char key[MAX_KEY_SIZE + 1];
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unsigned char blob[MAX_BLOB_SIZE];
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};
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struct trusted_key_options {
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uint16_t keytype;
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uint32_t keyhandle;
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unsigned char keyauth[TPM_DIGEST_SIZE];
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uint32_t blobauth_len;
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unsigned char blobauth[TPM_DIGEST_SIZE];
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uint32_t pcrinfo_len;
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unsigned char pcrinfo[MAX_PCRINFO_SIZE];
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int pcrlock;
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uint32_t hash;
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uint32_t policydigest_len;
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unsigned char policydigest[MAX_DIGEST_SIZE];
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uint32_t policyhandle;
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};
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extern struct key_type key_type_trusted;
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#endif /* _KEYS_TRUSTED_TYPE_H */
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