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* KEYS: Keyring asymmetric key restrict method with chainingMat Martineau2017-04-041-0/+5
| | | | | | | | | | | | | Add a restrict_link_by_key_or_keyring_chain link restriction that searches for signing keys in the destination keyring in addition to the signing key or keyring designated when the destination keyring was created. Userspace enables this behavior by including the "chain" option in the keyring restriction: keyctl(KEYCTL_RESTRICT_KEYRING, keyring, "asymmetric", "key_or_keyring:<signing key>:chain"); Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
* KEYS: Restrict asymmetric key linkage using a specific keychainMat Martineau2017-04-041-0/+5
| | | | | | | | Adds restrict_link_by_signature_keyring(), which uses the restrict_key member of the provided destination_keyring data structure as the key or keyring to search for signing keys. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
* KEYS: Split role of the keyring pointer for keyring restrict functionsMat Martineau2017-04-031-2/+3
| | | | | | | | | | | | | | The first argument to the restrict_link_func_t functions was a keyring pointer. These functions are called by the key subsystem with this argument set to the destination keyring, but restrict_link_by_signature expects a pointer to the relevant trusted keyring. Restrict functions may need something other than a single struct key pointer to allow or reject key linkage, so the data used to make that decision (such as the trust keyring) is moved to a new, fourth argument. The first argument is now always the destination keyring. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
* KEYS: Move the point of trust determination to __key_link()David Howells2016-04-111-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Move x509_request_asymmetric_key() to asymmetric_type.cDavid Howells2016-04-111-6/+0
| | | | | | | Move x509_request_asymmetric_key() to asymmetric_type.c so that it can be generalised. Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Generalise system_verify_data() to provide access to internal contentDavid Howells2016-04-061-14/+0
| | | | | | | | | | | | | | | Generalise system_verify_data() to provide access to internal content through a callback. This allows all the PKCS#7 stuff to be hidden inside this function and removed from the PE file parser and the PKCS#7 test key. If external content is not required, NULL should be passed as data to the function. If the callback is not required, that can be set to NULL. The function is now called verify_pkcs7_signature() to contrast with verify_pefile_signature() and the definitions of both have been moved into linux/verification.h along with the key_being_used_for enum. Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Add identifier pointers to public_key_signature structDavid Howells2016-04-061-0/+1
| | | | | | | | Add key identifier pointers to public_key_signature struct so that they can be used to retain the identifier of the key to be used to verify the signature in both PKCS#7 and X.509. Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Allow authentication data to be stored in an asymmetric keyDavid Howells2016-04-061-1/+4
| | | | | | | | | 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>
* X.509: Make algo identifiers text instead of enumDavid Howells2016-03-031-26/+4
| | | | | | | | 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>
* akcipher: Move the RSA DER encoding check to the crypto layerDavid Howells2016-03-031-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* crypto: public_key: remove MPIs from public_key_signature structTadeusz Struk2016-02-181-13/+1
| | | | | | | | | After digsig_asymmetric.c is converted the MPIs can be now safely removed from the public_key_signature structure. 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>
* crypto: KEYS: convert public key and digsig asym to the akcipher apiTadeusz Struk2016-02-101-24/+10
| | | | | | | | 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>
* KEYS: Merge the type-specific data with the payload dataDavid Howells2015-10-211-1/+0
| | | | | | | | | | | | | | | | | 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
* PKCS#7: Appropriately restrict authenticated attributes and content typeDavid Howells2015-08-121-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A PKCS#7 or CMS message can have per-signature authenticated attributes that are digested as a lump and signed by the authorising key for that signature. If such attributes exist, the content digest isn't itself signed, but rather it is included in a special authattr which then contributes to the signature. Further, we already require the master message content type to be pkcs7_signedData - but there's also a separate content type for the data itself within the SignedData object and this must be repeated inside the authattrs for each signer [RFC2315 9.2, RFC5652 11.1]. We should really validate the authattrs if they exist or forbid them entirely as appropriate. To this end: (1) Alter the PKCS#7 parser to reject any message that has more than one signature where at least one signature has authattrs and at least one that does not. (2) Validate authattrs if they are present and strongly restrict them. Only the following authattrs are permitted and all others are rejected: (a) contentType. This is checked to be an OID that matches the content type in the SignedData object. (b) messageDigest. This must match the crypto digest of the data. (c) signingTime. If present, we check that this is a valid, parseable UTCTime or GeneralTime and that the date it encodes fits within the validity window of the matching X.509 cert. (d) S/MIME capabilities. We don't check the contents. (e) Authenticode SP Opus Info. We don't check the contents. (f) Authenticode Statement Type. We don't check the contents. The message is rejected if (a) or (b) are missing. If the message is an Authenticode type, the message is rejected if (e) is missing; if not Authenticode, the message is rejected if (d) - (f) are present. The S/MIME capabilities authattr (d) unfortunately has to be allowed to support kernels already signed by the pesign program. This only affects kexec. sign-file suppresses them (CMS_NOSMIMECAP). The message is also rejected if an authattr is given more than once or if it contains more than one element in its set of values. (3) Add a parameter to pkcs7_verify() to select one of the following restrictions and pass in the appropriate option from the callers: (*) VERIFYING_MODULE_SIGNATURE This requires that the SignedData content type be pkcs7-data and forbids authattrs. sign-file sets CMS_NOATTR. We could be more flexible and permit authattrs optionally, but only permit minimal content. (*) VERIFYING_FIRMWARE_SIGNATURE This requires that the SignedData content type be pkcs7-data and requires authattrs. In future, this will require an attribute holding the target firmware name in addition to the minimal set. (*) VERIFYING_UNSPECIFIED_SIGNATURE This requires that the SignedData content type be pkcs7-data but allows either no authattrs or only permits the minimal set. (*) VERIFYING_KEXEC_PE_SIGNATURE This only supports the Authenticode SPC_INDIRECT_DATA content type and requires at least an SpcSpOpusInfo authattr in addition to the minimal set. It also permits an SPC_STATEMENT_TYPE authattr (and an S/MIME capabilities authattr because the pesign program doesn't remove these). (*) VERIFYING_KEY_SIGNATURE (*) VERIFYING_KEY_SELF_SIGNATURE These are invalid in this context but are included for later use when limiting the use of X.509 certs. (4) The pkcs7_test key type is given a module parameter to select between the above options for testing purposes. For example: echo 1 >/sys/module/pkcs7_test_key/parameters/usage keyctl padd pkcs7_test foo @s </tmp/stuff.pkcs7 will attempt to check the signature on stuff.pkcs7 as if it contains a firmware blob (1 being VERIFYING_FIRMWARE_SIGNATURE). Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marcel Holtmann <marcel@holtmann.org> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
* MODSIGN: Provide a utility to append a PKCS#7 signature to a moduleDavid Howells2015-08-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a utility that: (1) Digests a module using the specified hash algorithm (typically sha256). [The digest can be dumped into a file by passing the '-d' flag] (2) Generates a PKCS#7 message that: (a) Has detached data (ie. the module content). (b) Is signed with the specified private key. (c) Refers to the specified X.509 certificate. (d) Has an empty X.509 certificate list. [The PKCS#7 message can be dumped into a file by passing the '-p' flag] (3) Generates a signed module by concatenating the old module, the PKCS#7 message, a descriptor and a magic string. The descriptor contains the size of the PKCS#7 message and indicates the id_type as PKEY_ID_PKCS7. (4) Either writes the signed module to the specified destination or renames it over the source module. This allows module signing to reuse the PKCS#7 handling code that was added for PE file parsing for signed kexec. Note that the utility is written in C and must be linked against the OpenSSL crypto library. Note further that I have temporarily dropped support for handling externally created signatures until we can work out the best way to do those. Hopefully, whoever creates the signature can give me a PKCS#7 certificate. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Vivek Goyal <vgoyal@redhat.com>
* X.509: Support X.509 lookup by Issuer+Serial form AuthorityKeyIdentifierDavid Howells2015-08-071-1/+2
| | | | | | | | | | | | | | | | | | | | If an X.509 certificate has an AuthorityKeyIdentifier extension that provides an issuer and serialNumber, then make it so that these are used in preference to the keyIdentifier field also held therein for searching for the signing certificate. If both the issuer+serialNumber and the keyIdentifier are supplied, then the certificate is looked up by the former but the latter is checked as well. If the latter doesn't match the subjectKeyIdentifier of the parent certificate, EKEYREJECTED is returned. This makes it possible to chain X.509 certificates based on the issuer and serialNumber fields rather than on subjectKeyIdentifier. This is necessary as we are having to deal with keys that are represented by X.509 certificates that lack a subjectKeyIdentifier. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Vivek Goyal <vgoyal@redhat.com>
* KEYS: Restore partial ID matching functionality for asymmetric keysDmitry Kasatkin2014-10-061-1/+2
| | | | | | | | | | | | Bring back the functionality whereby an asymmetric key can be matched with a partial match on one of its IDs. Whilst we're at it, allow for the possibility of having an increased number of IDs. Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Overhaul key identification when searching for asymmetric keysDavid Howells2014-09-161-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make use of the new match string preparsing to overhaul key identification when searching for asymmetric keys. The following changes are made: (1) Use the previously created asymmetric_key_id struct to hold the following key IDs derived from the X.509 certificate or PKCS#7 message: id: serial number + issuer skid: subjKeyId + subject authority: authKeyId + issuer (2) Replace the hex fingerprint attached to key->type_data[1] with an asymmetric_key_ids struct containing the id and the skid (if present). (3) Make the asymmetric_type match data preparse select one of two searches: (a) An iterative search for the key ID given if prefixed with "id:". The prefix is expected to be followed by a hex string giving the ID to search for. The criterion key ID is checked against all key IDs recorded on the key. (b) A direct search if the key ID is not prefixed with "id:". This will look for an exact match on the key description. (4) Make x509_request_asymmetric_key() take a key ID. This is then converted into "id:<hex>" and passed into keyring_search() where match preparsing will turn it back into a binary ID. (5) X.509 certificate verification then takes the authority key ID and looks up a key that matches it to find the public key for the certificate signature. (6) PKCS#7 certificate verification then takes the id key ID and looks up a key that matches it to find the public key for the signed information block signature. Additional changes: (1) Multiple subjKeyId and authKeyId values on an X.509 certificate cause the cert to be rejected with -EBADMSG. (2) The 'fingerprint' ID is gone. This was primarily intended to convey PGP public key fingerprints. If PGP is supported in future, this should generate a key ID that carries the fingerprint. (3) Th ca_keyid= kernel command line option is now converted to a key ID and used to match the authority key ID. Possibly this should only match the actual authKeyId part and not the issuer as well. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* PKCS#7: Use x509_request_asymmetric_key()David Howells2014-07-291-0/+4
| | | | | | | | | | | | | pkcs7_request_asymmetric_key() and x509_request_asymmetric_key() do the same thing, the latter being a copy of the former created by the IMA folks, so drop the PKCS#7 version as the X.509 location is more general. Whilst we're at it, rename the arguments of x509_request_asymmetric_key() to better reflect what the values being passed in are intended to match on an X.509 cert. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
* keys: change asymmetric keys to use common hash definitionsDmitry Kasatkin2013-10-251-14/+4
| | | | | | | | | | | | 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>
* KEYS: Store public key algo ID in public_key_signature structDavid Howells2013-09-251-0/+1
| | | | | | | | | | Store public key algorithm ID in public_key_signature struct for reference purposes. This allows a public_key_signature struct to be embedded in struct x509_certificate and other places more easily. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Josh Boyer <jwboyer@redhat.com>
* KEYS: Store public key algo ID in public_key structDavid Howells2013-09-251-0/+1
| | | | | | | | | | Store public key algo ID in public_key struct for reference purposes. This allows it to be removed from the x509_certificate struct and used to find a default in public_key_verify_signature(). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Josh Boyer <jwboyer@redhat.com>
* KEYS: Move the algorithm pointer array from x509 to public_key.cDavid Howells2013-09-251-0/+1
| | | | | | | | | | | | | | 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>
* KEYS: Rename public key parameter name arraysDavid Howells2013-09-251-3/+3
| | | | | | | | | 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>
* KEYS: Provide signature verification with an asymmetric keyDavid Howells2012-10-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide signature verification using an asymmetric-type key to indicate the public key to be used. The API is a single function that can be found in crypto/public_key.h: int verify_signature(const struct key *key, const struct public_key_signature *sig) The first argument is the appropriate key to be used and the second argument is the parsed signature data: struct public_key_signature { u8 *digest; u16 digest_size; enum pkey_hash_algo pkey_hash_algo : 8; union { MPI mpi[2]; struct { MPI s; /* m^d mod n */ } rsa; struct { MPI r; MPI s; } dsa; }; }; This should be filled in prior to calling the function. The hash algorithm should already have been called and the hash finalised and the output should be in a buffer pointed to by the 'digest' member. Any extra data to be added to the hash by the hash format (eg. PGP) should have been added by the caller prior to finalising the hash. It is assumed that the signature is made up of a number of MPI values. If an algorithm becomes available for which this is not the case, the above structure will have to change. It is also assumed that it will have been checked that the signature algorithm matches the key algorithm. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* KEYS: Asymmetric public-key algorithm crypto key subtypeDavid Howells2012-10-081-0/+104
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>