diff mbox series

[v5,3/6] security: keys: trusted fix tpm2 authorizations

Message ID 20200130101812.6271-4-James.Bottomley@HansenPartnership.com
State New
Headers show
Series TPM 2.0 trusted keys with attached policy | expand

Commit Message

James Bottomley Jan. 30, 2020, 10:18 a.m. UTC
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=f572d396fae9206628714fb2ce00f72e94f2258f"

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"

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.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
 include/keys/trusted-type.h               |  1 +
 security/keys/trusted-keys/trusted_tpm1.c | 26 +++++++++++++++++++++-----
 security/keys/trusted-keys/trusted_tpm2.c | 10 ++++++----
 3 files changed, 28 insertions(+), 9 deletions(-)

Comments

Jarkko Sakkinen Feb. 25, 2020, 4:48 p.m. UTC | #1
On Thu, Jan 30, 2020 at 11:18:09AM +0100, James Bottomley wrote:
> 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=f572d396fae9206628714fb2ce00f72e94f2258f"
> 
> 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"
> 
> 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.
> 
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Should have a fixes tag.

> ---
>  include/keys/trusted-type.h               |  1 +
>  security/keys/trusted-keys/trusted_tpm1.c | 26 +++++++++++++++++++++-----
>  security/keys/trusted-keys/trusted_tpm2.c | 10 ++++++----
>  3 files changed, 28 insertions(+), 9 deletions(-)
> 
> diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
> index a94c03a61d8f..b2ed3481c6a0 100644
> --- a/include/keys/trusted-type.h
> +++ b/include/keys/trusted-type.h
> @@ -30,6 +30,7 @@ struct trusted_key_options {
>  	uint16_t keytype;
>  	uint32_t keyhandle;
>  	unsigned char keyauth[TPM_DIGEST_SIZE];
> +	uint32_t blobauth_len;
>  	unsigned char blobauth[TPM_DIGEST_SIZE];
>  	uint32_t pcrinfo_len;
>  	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
> diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
> index d2c5ec1e040b..3f33d3f74d3c 100644
> --- a/security/keys/trusted-keys/trusted_tpm1.c
> +++ b/security/keys/trusted-keys/trusted_tpm1.c
> @@ -781,12 +781,28 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
>  				return -EINVAL;
>  			break;
>  		case Opt_blobauth:
> -			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
> -				return -EINVAL;
> -			res = hex2bin(opt->blobauth, args[0].from,
> -				      SHA1_DIGEST_SIZE);
> -			if (res < 0)
> +			/*
> +			 * TPM 1.2 authorizations are sha1 hashes
> +			 * passed in as hex strings.  TPM 2.0
> +			 * authorizations are simple passwords
> +			 * (although it can take a hash as well)

Justify to the 80 character line length.

> +			 */
> +			opt->blobauth_len = strlen(args[0].from);
> +			if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
> +				res = hex2bin(opt->blobauth, args[0].from,
> +					      TPM_DIGEST_SIZE);
> +				if (res < 0)
> +					return -EINVAL;
> +
> +				opt->blobauth_len = TPM_DIGEST_SIZE;
> +			} else if (tpm2 &&
> +				   opt->blobauth_len <= sizeof(opt->blobauth)) {
> +				memcpy(opt->blobauth, args[0].from,
> +				       opt->blobauth_len);
> +			} else {
>  				return -EINVAL;
> +			}

This starts to be unnecessarily complicated.

This is what I would suggest:

opt->blobauth_len = strlen(args[0].from);
if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
	res = hex2bin(opt->blobauth, args[0].from,
		      TPM_DIGEST_SIZE);
	if (res < 0)
		return -EINVAL;

	opt->blobauth_len = TPM_DIGEST_SIZE;
	return 0;
}

if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
	memcpy(opt->blobauth, args[0].from,
	       opt->blobauth_len);
	return 0;
}

return -EINVAL;

Easier to see quickly "when happens what".

/Jarkko
Jarkko Sakkinen Feb. 26, 2020, 3:15 p.m. UTC | #2
On Tue, Feb 25, 2020 at 06:48:50PM +0200, Jarkko Sakkinen wrote:
> On Thu, Jan 30, 2020 at 11:18:09AM +0100, James Bottomley wrote:
> > 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=f572d396fae9206628714fb2ce00f72e94f2258f"
> > 
> > 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"
> > 
> > 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.
> > 
> > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> 
> Should have a fixes tag.
> 
> > ---
> >  include/keys/trusted-type.h               |  1 +
> >  security/keys/trusted-keys/trusted_tpm1.c | 26 +++++++++++++++++++++-----
> >  security/keys/trusted-keys/trusted_tpm2.c | 10 ++++++----
> >  3 files changed, 28 insertions(+), 9 deletions(-)
> > 
> > diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
> > index a94c03a61d8f..b2ed3481c6a0 100644
> > --- a/include/keys/trusted-type.h
> > +++ b/include/keys/trusted-type.h
> > @@ -30,6 +30,7 @@ struct trusted_key_options {
> >  	uint16_t keytype;
> >  	uint32_t keyhandle;
> >  	unsigned char keyauth[TPM_DIGEST_SIZE];
> > +	uint32_t blobauth_len;
> >  	unsigned char blobauth[TPM_DIGEST_SIZE];
> >  	uint32_t pcrinfo_len;
> >  	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
> > diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
> > index d2c5ec1e040b..3f33d3f74d3c 100644
> > --- a/security/keys/trusted-keys/trusted_tpm1.c
> > +++ b/security/keys/trusted-keys/trusted_tpm1.c
> > @@ -781,12 +781,28 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
> >  				return -EINVAL;
> >  			break;
> >  		case Opt_blobauth:
> > -			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
> > -				return -EINVAL;
> > -			res = hex2bin(opt->blobauth, args[0].from,
> > -				      SHA1_DIGEST_SIZE);
> > -			if (res < 0)
> > +			/*
> > +			 * TPM 1.2 authorizations are sha1 hashes
> > +			 * passed in as hex strings.  TPM 2.0
> > +			 * authorizations are simple passwords
> > +			 * (although it can take a hash as well)
> 
> Justify to the 80 character line length.
> 
> > +			 */
> > +			opt->blobauth_len = strlen(args[0].from);
> > +			if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
> > +				res = hex2bin(opt->blobauth, args[0].from,
> > +					      TPM_DIGEST_SIZE);
> > +				if (res < 0)
> > +					return -EINVAL;
> > +
> > +				opt->blobauth_len = TPM_DIGEST_SIZE;
> > +			} else if (tpm2 &&
> > +				   opt->blobauth_len <= sizeof(opt->blobauth)) {
> > +				memcpy(opt->blobauth, args[0].from,
> > +				       opt->blobauth_len);
> > +			} else {
> >  				return -EINVAL;
> > +			}
> 
> This starts to be unnecessarily complicated.
> 
> This is what I would suggest:
> 
> opt->blobauth_len = strlen(args[0].from);
> if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
> 	res = hex2bin(opt->blobauth, args[0].from,
> 		      TPM_DIGEST_SIZE);
> 	if (res < 0)
> 		return -EINVAL;
> 
> 	opt->blobauth_len = TPM_DIGEST_SIZE;
> 	return 0;
> }
> 
> if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
> 	memcpy(opt->blobauth, args[0].from,
> 	       opt->blobauth_len);
> 	return 0;
> }
> 
> return -EINVAL;
> 
> Easier to see quickly "when happens what".
> 
> /Jarkko

And in short summary "TPM2" instead of tpm2.

/Jarkko
James Bottomley Feb. 27, 2020, 12:58 a.m. UTC | #3
On Tue, 2020-02-25 at 18:48 +0200, Jarkko Sakkinen wrote:
> On Thu, Jan 30, 2020 at 11:18:09AM +0100, James Bottomley wrote:
> > 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=f572d396fae9206628714fb2ce00f72e94f2258f"
> > 
> > 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"
> > 
> > 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.
> > 
> > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.c
> > om>
> 
> Should have a fixes tag.

I made all the other changes, but I'm not sure what to identify in the
fixes tag.  The problem is the code I updated was simply carried over
unaltered from TPM 1.2

You could certainly argue that commit

commit 0fe5480303a1657b328a0a389f8d99249d9961f5
Author: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Date:   Fri Jun 26 22:28:26 2015 +0300

    keys, trusted: seal/unseal with TPM 2.0 chips

Should have updated the blobauth handling ... is that the one you'd
like fixes: to identify?

James
Jarkko Sakkinen Feb. 27, 2020, 4:19 p.m. UTC | #4
On Wed, Feb 26, 2020 at 04:58:11PM -0800, James Bottomley wrote:
> On Tue, 2020-02-25 at 18:48 +0200, Jarkko Sakkinen wrote:
> > On Thu, Jan 30, 2020 at 11:18:09AM +0100, James Bottomley wrote:
> > > 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=f572d396fae9206628714fb2ce00f72e94f2258f"
> > > 
> > > 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"
> > > 
> > > 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.
> > > 
> > > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.c
> > > om>
> > 
> > Should have a fixes tag.
> 
> I made all the other changes, but I'm not sure what to identify in the
> fixes tag.  The problem is the code I updated was simply carried over
> unaltered from TPM 1.2
> 
> You could certainly argue that commit
> 
> commit 0fe5480303a1657b328a0a389f8d99249d9961f5
> Author: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Date:   Fri Jun 26 22:28:26 2015 +0300
> 
>     keys, trusted: seal/unseal with TPM 2.0 chips
> 
> Should have updated the blobauth handling ... is that the one you'd
> like fixes: to identify?

What I'm thinking is to have fixes tag w/o cc to stable. I'm not
sure at this point whether we want to backport this but it still
makes sense to tag it.

/Jarkko
James Bottomley Feb. 27, 2020, 4:21 p.m. UTC | #5
On Thu, 2020-02-27 at 18:19 +0200, Jarkko Sakkinen wrote:
> On Wed, Feb 26, 2020 at 04:58:11PM -0800, James Bottomley wrote:
> > On Tue, 2020-02-25 at 18:48 +0200, Jarkko Sakkinen wrote:
> > > On Thu, Jan 30, 2020 at 11:18:09AM +0100, James Bottomley wrote:
> > > > 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=f572d396fae9206628714fb2ce00f72e94f2258f"
> > > > 
> > > > 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"
> > > > 
> > > > 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.
> > > > 
> > > > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnersh
> > > > ip.c
> > > > om>
> > > 
> > > Should have a fixes tag.
> > 
> > I made all the other changes, but I'm not sure what to identify in
> > the
> > fixes tag.  The problem is the code I updated was simply carried
> > over
> > unaltered from TPM 1.2
> > 
> > You could certainly argue that commit
> > 
> > commit 0fe5480303a1657b328a0a389f8d99249d9961f5
> > Author: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > Date:   Fri Jun 26 22:28:26 2015 +0300
> > 
> >     keys, trusted: seal/unseal with TPM 2.0 chips
> > 
> > Should have updated the blobauth handling ... is that the one you'd
> > like fixes: to identify?
> 
> What I'm thinking is to have fixes tag w/o cc to stable. I'm not
> sure at this point whether we want to backport this but it still
> makes sense to tag it.

Ok, I'll add that commit as the fixes; it certainly makes no sense to
backport this change before the above commit.

James
James Bottomley Feb. 27, 2020, 5:49 p.m. UTC | #6
On Thu, 2020-02-27 at 08:21 -0800, James Bottomley wrote:
> On Thu, 2020-02-27 at 18:19 +0200, Jarkko Sakkinen wrote:
[...]
> Ok, I'll add that commit as the fixes; it certainly makes no sense to
> backport this change before the above commit.

This is what I currently have.  Do you want me to resend the whole
series?

James

----8>8>8>-----

From: James Bottomley <James.Bottomley@HansenPartnership.com>
Subject: [PATCH v6 3/6] security: keys: trusted: fix TPM2 authorizations

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=f572d396fae9206628714fb2ce00f72e94f2258f"

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"

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.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Fixes: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 chips")

---

v6: change comment, eliminate else clauses and add fixes tag

diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index a94c03a61d8f..b2ed3481c6a0 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -30,6 +30,7 @@ struct trusted_key_options {
 	uint16_t keytype;
 	uint32_t keyhandle;
 	unsigned char keyauth[TPM_DIGEST_SIZE];
+	uint32_t blobauth_len;
 	unsigned char blobauth[TPM_DIGEST_SIZE];
 	uint32_t pcrinfo_len;
 	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
index d2c5ec1e040b..add9f071d818 100644
--- a/security/keys/trusted-keys/trusted_tpm1.c
+++ b/security/keys/trusted-keys/trusted_tpm1.c
@@ -781,13 +781,33 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
 				return -EINVAL;
 			break;
 		case Opt_blobauth:
-			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
-				return -EINVAL;
-			res = hex2bin(opt->blobauth, args[0].from,
-				      SHA1_DIGEST_SIZE);
-			if (res < 0)
-				return -EINVAL;
+			/*
+			 * TPM 1.2 authorizations are sha1 hashes passed in as
+			 * hex strings.  TPM 2.0 authorizations are simple
+			 * passwords (although it can take a hash as well)
+			 */
+			opt->blobauth_len = strlen(args[0].from);
+
+			if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
+				res = hex2bin(opt->blobauth, args[0].from,
+					      TPM_DIGEST_SIZE);
+				if (res < 0)
+					return -EINVAL;
+
+				opt->blobauth_len = TPM_DIGEST_SIZE;
+				return 0;
+			}
+
+			if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
+				memcpy(opt->blobauth, args[0].from,
+				       opt->blobauth_len);
+				return 0;
+			}
+
+			return -EINVAL;
+
 			break;
+
 		case Opt_migratable:
 			if (*args[0].from == '0')
 				pay->migratable = 0;
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 08ec7f48f01d..b4a5058107c2 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -91,10 +91,12 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 			     TPM_DIGEST_SIZE);
 
 	/* sensitive */
-	tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
+	tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len + 1);
+
+	tpm_buf_append_u16(&buf, options->blobauth_len);
+	if (options->blobauth_len)
+		tpm_buf_append(&buf, options->blobauth, options->blobauth_len);
 
-	tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
-	tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
 	tpm_buf_append_u16(&buf, payload->key_len + 1);
 	tpm_buf_append(&buf, payload->key, payload->key_len);
 	tpm_buf_append_u8(&buf, payload->migratable);
@@ -258,7 +260,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
 			     NULL /* nonce */, 0,
 			     TPM2_SA_CONTINUE_SESSION,
 			     options->blobauth /* hmac */,
-			     TPM_DIGEST_SIZE);
+			     options->blobauth_len);
 
 	rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
 	if (rc > 0)
Jarkko Sakkinen March 2, 2020, 11:08 a.m. UTC | #7
On Thu, Feb 27, 2020 at 09:49:29AM -0800, James Bottomley wrote:
> On Thu, 2020-02-27 at 08:21 -0800, James Bottomley wrote:
> > On Thu, 2020-02-27 at 18:19 +0200, Jarkko Sakkinen wrote:
> [...]
> > Ok, I'll add that commit as the fixes; it certainly makes no sense to
> > backport this change before the above commit.
> 
> This is what I currently have.  Do you want me to resend the whole
> series?

I prefer to review full snapshots of the series.

/Jarkko
diff mbox series

Patch

diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index a94c03a61d8f..b2ed3481c6a0 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -30,6 +30,7 @@  struct trusted_key_options {
 	uint16_t keytype;
 	uint32_t keyhandle;
 	unsigned char keyauth[TPM_DIGEST_SIZE];
+	uint32_t blobauth_len;
 	unsigned char blobauth[TPM_DIGEST_SIZE];
 	uint32_t pcrinfo_len;
 	unsigned char pcrinfo[MAX_PCRINFO_SIZE];
diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
index d2c5ec1e040b..3f33d3f74d3c 100644
--- a/security/keys/trusted-keys/trusted_tpm1.c
+++ b/security/keys/trusted-keys/trusted_tpm1.c
@@ -781,12 +781,28 @@  static int getoptions(char *c, struct trusted_key_payload *pay,
 				return -EINVAL;
 			break;
 		case Opt_blobauth:
-			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
-				return -EINVAL;
-			res = hex2bin(opt->blobauth, args[0].from,
-				      SHA1_DIGEST_SIZE);
-			if (res < 0)
+			/*
+			 * TPM 1.2 authorizations are sha1 hashes
+			 * passed in as hex strings.  TPM 2.0
+			 * authorizations are simple passwords
+			 * (although it can take a hash as well)
+			 */
+			opt->blobauth_len = strlen(args[0].from);
+			if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
+				res = hex2bin(opt->blobauth, args[0].from,
+					      TPM_DIGEST_SIZE);
+				if (res < 0)
+					return -EINVAL;
+
+				opt->blobauth_len = TPM_DIGEST_SIZE;
+			} else if (tpm2 &&
+				   opt->blobauth_len <= sizeof(opt->blobauth)) {
+				memcpy(opt->blobauth, args[0].from,
+				       opt->blobauth_len);
+			} else {
 				return -EINVAL;
+			}
+
 			break;
 		case Opt_migratable:
 			if (*args[0].from == '0')
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 08ec7f48f01d..b4a5058107c2 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -91,10 +91,12 @@  int tpm2_seal_trusted(struct tpm_chip *chip,
 			     TPM_DIGEST_SIZE);
 
 	/* sensitive */
-	tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
+	tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len + 1);
+
+	tpm_buf_append_u16(&buf, options->blobauth_len);
+	if (options->blobauth_len)
+		tpm_buf_append(&buf, options->blobauth, options->blobauth_len);
 
-	tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
-	tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
 	tpm_buf_append_u16(&buf, payload->key_len + 1);
 	tpm_buf_append(&buf, payload->key, payload->key_len);
 	tpm_buf_append_u8(&buf, payload->migratable);
@@ -258,7 +260,7 @@  static int tpm2_unseal_cmd(struct tpm_chip *chip,
 			     NULL /* nonce */, 0,
 			     TPM2_SA_CONTINUE_SESSION,
 			     options->blobauth /* hmac */,
-			     TPM_DIGEST_SIZE);
+			     options->blobauth_len);
 
 	rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
 	if (rc > 0)