From: Jarkko Sakkinen <jarkko@kernel.org>
To: Eric Snowberg <eric.snowberg@oracle.com>
Cc: zohar@linux.ibm.com, dhowells@redhat.com, dwmw2@infradead.org,
herbert@gondor.apana.org.au, davem@davemloft.net,
dmitry.kasatkin@gmail.com, paul@paul-moore.com,
jmorris@namei.org, serge@hallyn.com, pvorel@suse.cz,
tadeusz.struk@intel.com, kanth.ghatraju@oracle.com,
konrad.wilk@oracle.com, erpalmer@linux.vnet.ibm.com,
coxu@redhat.com, keyrings@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: Re: [PATCH v4 3/6] KEYS: X.509: Parse Basic Constraints for CA
Date: Fri, 10 Feb 2023 05:46:06 +0200 [thread overview]
Message-ID: <Y+W9/rzzfWhidjCU@kernel.org> (raw)
In-Reply-To: <20230207025958.974056-4-eric.snowberg@oracle.com>
On Mon, Feb 06, 2023 at 09:59:55PM -0500, Eric Snowberg wrote:
> Parse the X.509 Basic Constraints. The basic constraints extension
> identifies whether the subject of the certificate is a CA.
>
> BasicConstraints ::= SEQUENCE {
> cA BOOLEAN DEFAULT FALSE,
> pathLenConstraint INTEGER (0..MAX) OPTIONAL }
>
> If the CA is true, store it in the public_key. This will be used
> in a follow on patch that requires knowing if the public key is a CA.
>
> Link: https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.9
> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
> ---
> crypto/asymmetric_keys/x509_cert_parser.c | 22 ++++++++++++++++++++++
> include/crypto/public_key.h | 2 ++
> 2 files changed, 24 insertions(+)
>
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 7a9b084e2043..77547d4bd94d 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -586,6 +586,28 @@ int x509_process_extension(void *context, size_t hdrlen,
> return 0;
> }
>
> + if (ctx->last_oid == OID_basicConstraints) {
> + /*
> + * Get hold of the basicConstraints
> + * v[1] is the encoding size
> + * (Expect 0x2 or greater, making it 1 or more bytes)
> + * v[2] is the encoding type
> + * (Expect an ASN1_BOOL for the CA)
> + * v[3] is the contents of the ASN1_BOOL
> + * (Expect 1 if the CA is TRUE)
> + * vlen should match the entire extension size
> + */
> + if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ))
> + return -EBADMSG;
> + if (vlen < 2)
> + return -EBADMSG;
> + if (v[1] != vlen - 2)
> + return -EBADMSG;
> + if (vlen >= 4 && v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1)
> + ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_CA;
> + return 0;
> + }
> +
> return 0;
> }
>
> diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
> index 6d61695e1cde..c401762850f2 100644
> --- a/include/crypto/public_key.h
> +++ b/include/crypto/public_key.h
> @@ -28,6 +28,8 @@ struct public_key {
> bool key_is_private;
> const char *id_type;
> const char *pkey_algo;
> + unsigned long key_eflags; /* key extension flags */
> +#define KEY_EFLAG_CA 0 /* set if the CA basic constraints is set */
> };
>
> extern void public_key_free(struct public_key *key);
> --
> 2.27.0
>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
BR, Jarkko
next prev parent reply other threads:[~2023-02-10 3:46 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-07 2:59 [PATCH v4 0/6] Add CA enforcement keyring restrictions Eric Snowberg
2023-02-07 2:59 ` [PATCH v4 1/6] KEYS: Create static version of public_key_verify_signature Eric Snowberg
2023-02-10 3:39 ` Jarkko Sakkinen
2023-02-10 22:38 ` Eric Snowberg
2023-02-07 2:59 ` [PATCH v4 2/6] KEYS: Add missing function documentation Eric Snowberg
2023-02-08 21:48 ` Mimi Zohar
2023-02-10 3:40 ` Jarkko Sakkinen
2023-02-07 2:59 ` [PATCH v4 3/6] KEYS: X.509: Parse Basic Constraints for CA Eric Snowberg
2023-02-08 21:01 ` Mimi Zohar
2023-02-10 3:46 ` Jarkko Sakkinen [this message]
2023-02-07 2:59 ` [PATCH v4 4/6] KEYS: X.509: Parse Key Usage Eric Snowberg
2023-02-08 21:02 ` Mimi Zohar
2023-02-10 3:48 ` Jarkko Sakkinen
2023-02-10 22:39 ` Eric Snowberg
2023-02-07 2:59 ` [PATCH v4 5/6] KEYS: CA link restriction Eric Snowberg
2023-02-09 2:55 ` Mimi Zohar
2023-02-07 2:59 ` [PATCH v4 6/6] integrity: machine keyring CA configuration Eric Snowberg
2023-02-10 13:05 ` Mimi Zohar
2023-02-10 22:42 ` Eric Snowberg
2023-02-13 7:54 ` Jarkko Sakkinen
2023-02-14 21:24 ` Eric Snowberg
2023-02-08 12:38 ` [PATCH v4 0/6] Add CA enforcement keyring restrictions Mimi Zohar
2023-02-08 23:26 ` Eric Snowberg
2023-02-09 2:54 ` Mimi Zohar
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