Commit Graph

21 Commits

Author SHA1 Message Date
David Howells c08fed7371 KEYS: Implement encrypt, decrypt and sign for software asymmetric key [ver #2]
Implement the encrypt, decrypt and sign operations for the software
asymmetric key subtype.  This mostly involves offloading the call to the
crypto layer.

Note that the decrypt and sign operations require a private key to be
supplied.  Encrypt (and also verify) will work with either a public or a
private key.  A public key can be supplied with an X.509 certificate and a
private key can be supplied using a PKCS#8 blob:

	# j=`openssl pkcs8 -in ~/pkcs7/firmwarekey2.priv -topk8 -nocrypt -outform DER | keyctl padd asymmetric foo @s`
	# keyctl pkey_query $j - enc=pkcs1
	key_size=4096
	max_data_size=512
	max_sig_size=512
	max_enc_size=512
	max_dec_size=512
	encrypt=y
	decrypt=y
	sign=y
	verify=y
	# keyctl pkey_encrypt $j 0 data enc=pkcs1 >/tmp/enc
	# keyctl pkey_decrypt $j 0 /tmp/enc enc=pkcs1 >/tmp/dec
	# cmp data /tmp/dec
	# keyctl pkey_sign $j 0 data enc=pkcs1 hash=sha1 >/tmp/sig
	# keyctl pkey_verify $j 0 data /tmp/sig enc=pkcs1 hash=sha1
	#

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>
2018-10-26 09:30:46 +01:00
David Howells f7c4e06e06 KEYS: Allow the public_key struct to hold a private key [ver #2]
Put a flag in the public_key struct to indicate if the structure is holding
a private key.  The private key must be held ASN.1 encoded in the format
specified in RFC 3447 A.1.2.  This is the form required by crypto/rsa.c.

The software encryption subtype's verification and query functions then
need to select the appropriate crypto function to set the key.

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>
2018-10-26 09:30:46 +01:00
David Howells 82f94f2447 KEYS: Provide software public key query function [ver #2]
Provide a query function for the software public key implementation.  This
permits information about such a key to be obtained using
query_asymmetric_key() or KEYCTL_PKEY_QUERY.

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>
2018-10-26 09:30:46 +01:00
Eric Biggers 437499eea4 X.509: fix BUG_ON() when hash algorithm is unsupported
The X.509 parser mishandles the case where the certificate's signature's
hash algorithm is not available in the crypto API.  In this case,
x509_get_sig_params() doesn't allocate the cert->sig->digest buffer;
this part seems to be intentional.  However,
public_key_verify_signature() is still called via
x509_check_for_self_signed(), which triggers the 'BUG_ON(!sig->digest)'.

Fix this by making public_key_verify_signature() return -ENOPKG if the
hash buffer has not been allocated.

Reproducer when all the CONFIG_CRYPTO_SHA512* options are disabled:

    openssl req -new -sha512 -x509 -batch -nodes -outform der \
        | keyctl padd asymmetric desc @s

Fixes: 6c2dc5ae4a ("X.509: Extract signature digest and make self-signed cert checks earlier")
Reported-by: Paolo Valente <paolo.valente@linaro.org>
Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-22 14:38:33 +00:00
Eric Biggers 72f9a07b6b KEYS: be careful with error codes in public_key_verify_signature()
In public_key_verify_signature(), if akcipher_request_alloc() fails, we
return -ENOMEM.  But that error code was set 25 lines above, and by
accident someone could easily insert new code in between that assigns to
'ret', which would introduce a signature verification bypass.  Make the
code clearer by moving the -ENOMEM down to where it is used.

Additionally, the callers of public_key_verify_signature() only consider
a negative return value to be an error.  This means that if any positive
return value is accidentally introduced deeper in the call stack (e.g.
'return EBADMSG' instead of 'return -EBADMSG' somewhere in RSA),
signature verification will be bypassed.  Make things more robust by
having public_key_verify_signature() warn about positive errors and
translate them into -EINVAL.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-12-08 15:13:29 +00:00
David Howells 1e684d3820 pkcs7: Set the module licence to prevent tainting
Set the module licence to prevent the kernel from being tainted if loaded
as a module.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-15 16:38:45 +00:00
Gilad Ben-Yossef 0ca2a04ac3 crypto: move pub key to generic async completion
public_key_verify_signature() is starting an async crypto op and
waiting for it to complete. Move it over to generic code doing
the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-03 22:11:18 +08:00
Gilad Ben-Yossef e68368aed5 crypto: asymmetric_keys - handle EBUSY due to backlog correctly
public_key_verify_signature() was passing the CRYPTO_TFM_REQ_MAY_BACKLOG
flag to akcipher_request_set_callback() but was not handling correctly
the case where a -EBUSY error could be returned from the call to
crypto_akcipher_verify() if backlog was used, possibly casuing
data corruption due to use-after-free of buffers.

Resolve this by handling -EBUSY correctly.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-05-23 12:45:10 +08:00
Pan Bian fbb726302a crypto: asymmetric_keys - set error code on failure
In function public_key_verify_signature(), returns variable ret on
error paths. When the call to kmalloc() fails, the value of ret is 0,
and it is not set to an errno before returning. This patch fixes the
bug.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188891

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-12-14 18:33:13 +08:00
David Howells 3b76456317 KEYS: Allow authentication data to be stored in an asymmetric key
Allow authentication data to be stored in an asymmetric key in the 4th
element of the key payload and provide a way for it to be destroyed.

For the public key subtype, this will be a public_key_signature struct.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:33 +01:00
David Howells 4e8ae72a75 X.509: Make algo identifiers text instead of enum
Make the identifier public key and digest algorithm fields text instead of
enum.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00
David Howells d43de6c780 akcipher: Move the RSA DER encoding check to the crypto layer
Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key
subtype to the rsa crypto module's pkcs1pad template.  This means that the
public_key subtype no longer has any dependencies on public key type.

To make this work, the following changes have been made:

 (1) The rsa pkcs1pad template is now used for RSA keys.  This strips off the
     padding and returns just the message hash.

 (2) In a previous patch, the pkcs1pad template gained an optional second
     parameter that, if given, specifies the hash used.  We now give this,
     and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5
     encoding and verifies that the correct digest OID is present.

 (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to
     something that doesn't care about what the encryption actually does
     and and has been merged into public_key.c.

 (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone.  Module signing must set
     CONFIG_CRYPTO_RSA=y instead.

Thoughts:

 (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to
     the padding template?  Should there be multiple padding templates
     registered that share most of the code?

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00
Tadeusz Struk db6c43bd21 crypto: KEYS: convert public key and digsig asym to the akcipher api
This patch converts the module verification code to the new akcipher API.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-02-10 10:13:27 +00:00
David Howells 146aa8b145 KEYS: Merge the type-specific data with the payload data
Merge the type-specific data with the payload data into one four-word chunk
as it seems pointless to keep them separate.

Use user_key_payload() for accessing the payloads of overloaded
user-defined keys.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
cc: ecryptfs@vger.kernel.org
cc: linux-ext4@vger.kernel.org
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-ima-devel@lists.sourceforge.net
2015-10-21 15:18:36 +01:00
David Howells f29299b480 KEYS: Add a name for PKEY_ID_PKCS7
Add a name for PKEY_ID_PKCS7 into the pkey_id_type_name array.

Signed-off-by: David Howells <dhowells@redhat.com>
2015-08-12 17:01:01 +01:00
David Howells 876c6e3e02 KEYS: Fix public_key asymmetric key subtype name
The length of the name of an asymmetric key subtype must be stored in struct
asymmetric_key_subtype::name_len so that it can be matched by a search for
"<subkey_name>:<partial_fingerprint>".  Fix the public_key subtype to have
name_len set.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-09-03 10:27:28 +10:00
Dmitry Kasatkin 3fe78ca2fb keys: change asymmetric keys to use common hash definitions
This patch makes use of the newly defined common hash algorithm info,
replacing, for example, PKEY_HASH with HASH_ALGO.

Changelog:
- Lindent fixes - Mimi

CC: David Howells <dhowells@redhat.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:15:18 -04:00
David Howells 3d167d68e3 KEYS: Split public_key_verify_signature() and make available
Modify public_key_verify_signature() so that it now takes a public_key struct
rather than a key struct and supply a wrapper that takes a key struct.  The
wrapper is then used by the asymmetric key subtype and the modified function is
used by X.509 self-signature checking and can be used by other things also.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 17:17:00 +01:00
David Howells 206ce59a10 KEYS: Move the algorithm pointer array from x509 to public_key.c
Move the public-key algorithm pointer array from x509_public_key.c to
public_key.c as it isn't X.509 specific.

Note that to make this configure correctly, the public key part must be
dependent on the RSA module rather than the other way round.  This needs a
further patch to make use of the crypto module loading stuff rather than using
a fixed table.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 15:51:07 +01:00
David Howells 9abc4e66eb KEYS: Rename public key parameter name arrays
Rename the arrays of public key parameters (public key algorithm names, hash
algorithm names and ID type names) so that the array name ends in "_name".

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 15:51:07 +01:00
David Howells a9681bf3dd KEYS: Asymmetric public-key algorithm crypto key subtype
Add a subtype for supporting asymmetric public-key encryption algorithms such
as DSA (FIPS-186) and RSA (PKCS#1 / RFC1337).

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08 13:50:14 +10:30