lib: crypto: add x509 parser

Imported from linux kernel v5.3:
 x509.asn1 without changes
 x509_akid.asn1 without changes
 x509_parser.h without changes
 x509_cert_parser.c with changes marked as __UBOOT__
 x509_public_key.c with changes marked as __UBOOT__

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/lib/crypto/x509_parser.h b/lib/crypto/x509_parser.h
new file mode 100644
index 0000000..c233f13
--- /dev/null
+++ b/lib/crypto/x509_parser.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* X.509 certificate parser internal definitions
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/time.h>
+#include <crypto/public_key.h>
+#include <keys/asymmetric-type.h>
+
+struct x509_certificate {
+	struct x509_certificate *next;
+	struct x509_certificate *signer;	/* Certificate that signed this one */
+	struct public_key *pub;			/* Public key details */
+	struct public_key_signature *sig;	/* Signature parameters */
+	char		*issuer;		/* Name of certificate issuer */
+	char		*subject;		/* Name of certificate subject */
+	struct asymmetric_key_id *id;		/* Issuer + Serial number */
+	struct asymmetric_key_id *skid;		/* Subject + subjectKeyId (optional) */
+	time64_t	valid_from;
+	time64_t	valid_to;
+	const void	*tbs;			/* Signed data */
+	unsigned	tbs_size;		/* Size of signed data */
+	unsigned	raw_sig_size;		/* Size of sigature */
+	const void	*raw_sig;		/* Signature data */
+	const void	*raw_serial;		/* Raw serial number in ASN.1 */
+	unsigned	raw_serial_size;
+	unsigned	raw_issuer_size;
+	const void	*raw_issuer;		/* Raw issuer name in ASN.1 */
+	const void	*raw_subject;		/* Raw subject name in ASN.1 */
+	unsigned	raw_subject_size;
+	unsigned	raw_skid_size;
+	const void	*raw_skid;		/* Raw subjectKeyId in ASN.1 */
+	unsigned	index;
+	bool		seen;			/* Infinite recursion prevention */
+	bool		verified;
+	bool		self_signed;		/* T if self-signed (check unsupported_sig too) */
+	bool		unsupported_key;	/* T if key uses unsupported crypto */
+	bool		unsupported_sig;	/* T if signature uses unsupported crypto */
+	bool		blacklisted;
+};
+
+/*
+ * x509_cert_parser.c
+ */
+extern void x509_free_certificate(struct x509_certificate *cert);
+extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen);
+extern int x509_decode_time(time64_t *_t,  size_t hdrlen,
+			    unsigned char tag,
+			    const unsigned char *value, size_t vlen);
+
+/*
+ * x509_public_key.c
+ */
+extern int x509_get_sig_params(struct x509_certificate *cert);
+extern int x509_check_for_self_signed(struct x509_certificate *cert);