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authorEric Snowberg <eric.snowberg@oracle.com>2023-03-02 11:46:49 -0500
committerJarkko Sakkinen <jarkko@kernel.org>2023-04-24 16:15:53 +0300
commit4e4a89b2224e29d59d6d9cefa66041dd36c1d596 (patch)
treed9b7dfcd041c18bbe28d2bc7a0236be99eff5f1d /crypto/asymmetric_keys/x509_cert_parser.c
parenta2bb96ca05091240892a34519b8570d0b3dedfc8 (diff)
downloadlinux-crypto-4e4a89b2224e29d59d6d9cefa66041dd36c1d596.tar.gz
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KEYS: X.509: Parse Basic Constraints for CA
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> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Tested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to '')
-rw-r--r--crypto/asymmetric_keys/x509_cert_parser.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 7a9b084e..77547d4b 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;
}