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path: root/crypto/asymmetric_keys/x509_parser.h
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2016-04-11KEYS: Move the point of trust determination to __key_link()David Howells
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>
2016-04-11X.509: Move the trust validation code out to its own fileDavid Howells
Move the X.509 trust validation code out to its own file so that it can be generalised. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06PKCS#7: Make trust determination dependent on contents of trust keyringDavid Howells
Make the determination of the trustworthiness of a key dependent on whether a key that can verify it is present in the supplied ring of trusted keys rather than whether or not the verifying key has KEY_FLAG_TRUSTED set. verify_pkcs7_signature() will return -ENOKEY if the PKCS#7 message trust chain cannot be verified. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06X.509: Extract signature digest and make self-signed cert checks earlierDavid Howells
Extract the signature digest for an X.509 certificate earlier, at the end of x509_cert_parse() rather than leaving it to the callers thereof since it has to be called anyway. Further, immediately after that, check the signature on self-signed certificates, also rather in the callers of x509_cert_parse(). We note in the x509_certificate struct the following bits of information: (1) Whether the signature is self-signed (even if we can't check the signature due to missing crypto). (2) Whether the key held in the certificate needs unsupported crypto to be used. We may get a PKCS#7 message with X.509 certs that we can't make use of - we just ignore them and give ENOPKG at the end it we couldn't verify anything if at least one of these unusable certs are in the chain of trust. (3) Whether the signature held in the certificate needs unsupported crypto to be checked. We can still use the key held in this certificate, even if we can't check the signature on it - if it is held in the system trusted keyring, for instance. We just can't add it to a ring of trusted keys or follow it further up the chain of trust. Making these checks earlier allows x509_check_signature() to be removed and replaced with direct calls to public_key_verify_signature(). Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06X.509: Retain the key verification dataDavid Howells
Retain the key verification data (ie. the struct public_key_signature) including the digest and the key identifiers. Note that this means that we need to take a separate copy of the digest in x509_get_sig_params() rather than lumping it in with the crypto layer data. Signed-off-by: David Howells <dhowells@redhat.com>
2015-10-21KEYS: Merge the type-specific data with the payload dataDavid Howells
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
2015-08-12PKCS#7: Improve and export the X.509 ASN.1 time object decoderDavid Howells
Make the X.509 ASN.1 time object decoder fill in a time64_t rather than a struct tm to make comparison easier (unfortunately, this makes readable display less easy) and export it so that it can be used by the PKCS#7 code too. Further, tighten up its parsing to reject invalid dates (eg. weird characters, non-existent hour numbers) and unsupported dates (eg. timezones other than 'Z' or dates earlier than 1970). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
2015-08-07X.509: Extract both parts of the AuthorityKeyIdentifierDavid Howells
Extract both parts of the AuthorityKeyIdentifier, not just the keyIdentifier, as the second part can be used to match X.509 certificates by issuer and serialNumber. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Vivek Goyal <vgoyal@redhat.com>
2014-10-06KEYS: use swapped SKID for performing partial matchingDmitry Kasatkin
Earlier KEYS code used pure subject key identifiers (fingerprint) for searching keys. Latest merged code removed that and broke compatibility with integrity subsytem signatures and original format of module signatures. This patch returns back partial matching on SKID. 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>
2014-10-03X.509: If available, use the raw subjKeyId to form the key descriptionDavid Howells
Module signing matches keys by comparing against the key description exactly. However, the way the key description gets constructed got changed to be composed of the subject name plus the certificate serial number instead of the subject name and the subjectKeyId. I changed this to avoid problems with certificates that don't *have* a subjectKeyId. Instead, if available, use the raw subjectKeyId to form the key description and only use the serial number if the subjectKeyId doesn't exist. Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: David Howells <dhowells@redhat.com>
2014-09-16PKCS#7: Better handling of unsupported cryptoDavid Howells
Provide better handling of unsupported crypto when verifying a PKCS#7 message. If we can't bridge the gap between a pair of X.509 certs or between a signed info block and an X.509 cert because it involves some crypto we don't support, that's not necessarily the end of the world as there may be other ways points at which we can intersect with a ring of trusted keys. Instead, only produce ENOPKG immediately if all the signed info blocks in a PKCS#7 message require unsupported crypto to bridge to the first X.509 cert. Otherwise, we defer the generation of ENOPKG until we get ENOKEY during trust validation. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16KEYS: Overhaul key identification when searching for asymmetric keysDavid Howells
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>
2014-07-01X.509: Add bits needed for PKCS#7David Howells
PKCS#7 validation requires access to the serial number and the raw names in an X.509 certificate. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-10-25ima: provide support for arbitrary hash algorithmsDmitry Kasatkin
In preparation of supporting more hash algorithms with larger hash sizes needed for signature verification, this patch replaces the 20 byte sized digest, with a more flexible structure. The new structure includes the hash algorithm, digest size, and digest. Changelog: - recalculate filedata hash for the measurement list, if the signature hash digest size is greater than 20 bytes. - use generic HASH_ALGO_ - make ima_calc_file_hash static - scripts lindent and checkpatch fixes Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25keys: change asymmetric keys to use common hash definitionsDmitry Kasatkin
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>
2013-09-25X.509: Embed public_key_signature struct and create filler functionDavid Howells
Embed a public_key_signature struct in struct x509_certificate, eliminating now unnecessary fields, and split x509_check_signature() to create a filler function for it that attaches a digest of the signed data and an MPI that represents the signature data. x509_free_certificate() is then modified to deal with these. Whilst we're at it, export both x509_check_signature() and the new x509_get_sig_params(). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25X.509: struct x509_certificate needs struct tm declaringDavid Howells
struct x509_certificate needs struct tm declaring by #inclusion of linux/time.h prior to its definition. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25KEYS: Store public key algo ID in public_key structDavid Howells
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>
2012-10-10MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checkingDavid Howells
The current choice of lifetime for the autogenerated X.509 of 100 years, putting the validTo date in 2112, causes problems on 32-bit systems where a 32-bit time_t wraps in 2106. 64-bit x86_64 systems seem to be unaffected. This can result in something like: Loading module verification certificates X.509: Cert 6e03943da0f3b015ba6ed7f5e0cac4fe48680994 has expired MODSIGN: Problem loading in-kernel X.509 certificate (-127) Or: X.509: Cert 6e03943da0f3b015ba6ed7f5e0cac4fe48680994 is not yet valid MODSIGN: Problem loading in-kernel X.509 certificate (-129) Instead of turning the dates into time_t values and comparing, turn the system clock and the ASN.1 dates into tm structs and compare those piecemeal instead. Reported-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Josh Boyer <jwboyer@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08X.509: Add a crypto key parser for binary (DER) X.509 certificatesDavid Howells
Add a crypto key parser for binary (DER) encoded X.509 certificates. The certificate is parsed and, if possible, the signature is verified. An X.509 key can be added like this: # keyctl padd crypto bar @s </tmp/x509.cert 15768135 and displayed like this: # cat /proc/keys 00f09a47 I--Q--- 1 perm 39390000 0 0 asymmetri bar: X509.RSA e9fd6d08 [] Note that this only works with binary certificates. PEM encoded certificates are ignored by the parser. Note also that the X.509 key ID is not congruent with the PGP key ID, but for the moment, they will match. If a NULL or "" name is given to add_key(), then the parser will generate a key description from the CertificateSerialNumber and Name fields of the TBSCertificate: 00aefc4e I--Q--- 1 perm 39390000 0 0 asymmetri bfbc0cd76d050ea4:/C=GB/L=Cambridge/O=Red Hat/CN=kernel key: X509.RSA 0c688c7b [] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>