/*
 *  Copyright 2014-2026 The GmSSL Project. All Rights Reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the License);
 *  you may not use this file except in compliance with the License.
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 */


#ifndef GMSSL_SCT_H
#define GMSSL_SCT_H


#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <gmssl/digest.h>
#include <gmssl/x509_key.h>


#ifdef __cplusplus
extern "C" {
#endif


enum {
	SCT_version_v1 = 0,
};

enum {
	SCT_signature_type_certificate_timestamp = 0,
	SCT_signature_type_tree_hash = 1,
};

enum {
	SCT_log_entry_type_x509_entry = 0,
	SCT_log_entry_type_precert_entry = 1,
};

#define SCT_LOG_ID_SIZE	32
#define SCT_ISSUER_KEY_HASH_SIZE	32
#define SCT_MAX_SIGNED_DATA_SIZE	65536

/*
struct {
	Version sct_version;
	SignatureType signature_type = certificate_timestamp;
	uint64 timestamp;
	LogEntryType entry_type;
	select(entry_type) {
	case x509_entry: ASN.1Cert;
	case precert_entry: PreCert;
	} signed_entry;
	CtExtensions extensions;
} digitally_signed;

ASN.1Cert ::= opaque <1..2^24-1>;

PreCert ::= struct {
	opaque issuer_key_hash[32];
	TBSCertificate tbs_certificate;
}

TBSCertificate ::= opaque <1..2^24-1>;

CtExtensions ::= opaque <0..2^16-1>;
*/
int sct_signed_data_to_bytes(int version, uint64_t timestamp, int entry_type,
	const uint8_t issuer_key_hash[SCT_ISSUER_KEY_HASH_SIZE],
	const uint8_t *entry, size_t entry_len,
	const uint8_t *exts, size_t extslen,
	uint8_t **out, size_t *outlen);
int sct_signed_data_construct(const uint8_t *sct, size_t sct_len,
	int entry_type, const uint8_t issuer_key_hash[SCT_ISSUER_KEY_HASH_SIZE],
	const uint8_t *entry, size_t entry_len,
	uint8_t **out, size_t *outlen);

/*
DigitallySigned ::= struct {
	uint16 sig_algorithm;
	opaque signature<0..2^16-1>;
}
*/
int signed_certificate_timestamp_signature_to_bytes(
	int sig_alg, const uint8_t *sig, size_t siglen,
	uint8_t **out, size_t *outlen);
int signed_certificate_timestamp_signature_from_bytes(
	int *sig_alg, const uint8_t **sig, size_t *siglen,
	const uint8_t **in, size_t *inlen);
int signed_certificate_timestamp_signature_print(FILE *fp, int fmt, int ind,
	const char *label, const uint8_t *d, size_t dlen);


/*
SignedCertificateTimestamp ::= struct {
	Version sct_version;
	LogID id;
	uint64 timestamp;
	CtExtensions extensions;
	DigitallySigned signature;
}

Version ::= enum { v1(0), (255) }

LogID ::= opaque key_id[32];

CtExtensions ::= opaque <0..2^16-1>;
*/
int signed_certificate_timestamp_to_bytes(int version,
	const uint8_t log_id[SCT_LOG_ID_SIZE], uint64_t timestamp,
	const uint8_t *exts, size_t extslen,
	int sig_alg, const uint8_t *sig, size_t siglen,
	uint8_t **out, size_t *outlen);
int signed_certificate_timestamp_from_bytes(int *version,
	const uint8_t **log_id, uint64_t *timestamp,
	const uint8_t **exts, size_t *extslen,
	int *sig_alg, const uint8_t **sig, size_t *siglen,
	const uint8_t **in, size_t *inlen);
int signed_certificate_timestamp_print(FILE *fp, int fmt, int ind,
	const char *label, const uint8_t *d, size_t dlen);
int signed_certificate_timestamp_verify(const uint8_t *sct, size_t sct_len,
	const uint8_t *signed_data, size_t signed_data_len,
	X509_KEY *key, const DIGEST *digest);


typedef struct {
	X509_KEY log_key;
	uint8_t log_id[32];
	const char *log_name;
	const char *log_url;
	const char *log_dns_domain;
} CT_LOG_INFO;

int sct_list_verify(const uint8_t *sct_list, size_t sct_list_len,
	int entry_type, const uint8_t issuer_key_hash[SCT_ISSUER_KEY_HASH_SIZE],
	const uint8_t *entry, size_t entry_len,
	const CT_LOG_INFO *ct_logs, size_t ct_logs_cnt,
	size_t at_least);



#ifdef __cplusplus
}
#endif
#endif