/* $OpenBSD: by_dir.c,v 1.48 2024/08/31 10:19:17 tb Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <openssl/opensslconf.h>

#include <openssl/err.h>
#include <openssl/x509.h>

#include "x509_local.h"

typedef struct lookup_dir_hashes_st {
	unsigned long hash;
	int suffix;
} BY_DIR_HASH;

typedef struct lookup_dir_entry_st {
	char *dir;
	int dir_type;
	STACK_OF(BY_DIR_HASH) *hashes;
} BY_DIR_ENTRY;

typedef struct lookup_dir_st {
	BUF_MEM *buffer;
	STACK_OF(BY_DIR_ENTRY) *dirs;
} BY_DIR;

DECLARE_STACK_OF(BY_DIR_HASH)
DECLARE_STACK_OF(BY_DIR_ENTRY)

static int dir_ctrl(X509_LOOKUP *ctx, int cmd, const char *argp, long argl,
    char **ret);
static int new_dir(X509_LOOKUP *lu);
static void free_dir(X509_LOOKUP *lu);
static int add_cert_dir(BY_DIR *ctx, const char *dir, int type);
static int get_cert_by_subject(X509_LOOKUP *xl, int type, X509_NAME *name,
    X509_OBJECT *ret);

static const X509_LOOKUP_METHOD x509_dir_lookup = {
	.name = "Load certs from files in a directory",
	.new_item = new_dir,
	.free = free_dir,
	.ctrl = dir_ctrl,
	.get_by_subject = get_cert_by_subject,
};

const X509_LOOKUP_METHOD *
X509_LOOKUP_hash_dir(void)
{
	return &x509_dir_lookup;
}
LCRYPTO_ALIAS(X509_LOOKUP_hash_dir);

static int
dir_ctrl(X509_LOOKUP *ctx, int cmd, const char *argp, long argl,
    char **retp)
{
	BY_DIR *ld = ctx->method_data;
	int ret = 0;

	switch (cmd) {
	case X509_L_ADD_DIR:
		if (argl == X509_FILETYPE_DEFAULT) {
			ret = add_cert_dir(ld, X509_get_default_cert_dir(),
			    X509_FILETYPE_PEM);
			if (!ret) {
				X509error(X509_R_LOADING_CERT_DIR);
			}
		} else
			ret = add_cert_dir(ld, argp, (int)argl);
		break;
	}
	return ret;
}

static int
new_dir(X509_LOOKUP *lu)
{
	BY_DIR *a;

	if ((a = malloc(sizeof(*a))) == NULL) {
		X509error(ERR_R_MALLOC_FAILURE);
		return 0;
	}
	if ((a->buffer = BUF_MEM_new()) == NULL) {
		X509error(ERR_R_MALLOC_FAILURE);
		free(a);
		return 0;
	}
	a->dirs = NULL;
	lu->method_data = a;
	return 1;
}

static void
by_dir_hash_free(BY_DIR_HASH *hash)
{
	free(hash);
}

static int
by_dir_hash_cmp(const BY_DIR_HASH * const *a,
    const BY_DIR_HASH * const *b)
{
	if ((*a)->hash > (*b)->hash)
		return 1;
	if ((*a)->hash < (*b)->hash)
		return -1;
	return 0;
}

static void
by_dir_entry_free(BY_DIR_ENTRY *ent)
{
	free(ent->dir);
	sk_BY_DIR_HASH_pop_free(ent->hashes, by_dir_hash_free);
	free(ent);
}

static void
free_dir(X509_LOOKUP *lu)
{
	BY_DIR *a;

	a = lu->method_data;
	sk_BY_DIR_ENTRY_pop_free(a->dirs, by_dir_entry_free);
	BUF_MEM_free(a->buffer);
	free(a);
}

static int
add_cert_dir(BY_DIR *ctx, const char *dir, int type)
{
	int j;
	const char *s, *ss, *p;
	ptrdiff_t len;

	if (dir == NULL || !*dir) {
		X509error(X509_R_INVALID_DIRECTORY);
		return 0;
	}

	s = dir;
	p = s;
	do {
		if ((*p == ':') || (*p == '\0')) {
			BY_DIR_ENTRY *ent;

			ss = s;
			s = p + 1;
			len = p - ss;
			if (len == 0)
				continue;
			for (j = 0; j < sk_BY_DIR_ENTRY_num(ctx->dirs); j++) {
				ent = sk_BY_DIR_ENTRY_value(ctx->dirs, j);
				if (strlen(ent->dir) == (size_t)len &&
				    strncmp(ent->dir, ss, (size_t)len) == 0)
					break;
			}
			if (j < sk_BY_DIR_ENTRY_num(ctx->dirs))
				continue;
			if (ctx->dirs == NULL) {
				ctx->dirs = sk_BY_DIR_ENTRY_new_null();
				if (ctx->dirs == NULL) {
					X509error(ERR_R_MALLOC_FAILURE);
					return 0;
				}
			}
			ent = malloc(sizeof(*ent));
			if (ent == NULL) {
				X509error(ERR_R_MALLOC_FAILURE);
				return 0;
			}
			ent->dir_type = type;
			ent->hashes = sk_BY_DIR_HASH_new(by_dir_hash_cmp);
			ent->dir = strndup(ss, (size_t)len);
			if (ent->dir == NULL || ent->hashes == NULL) {
				X509error(ERR_R_MALLOC_FAILURE);
				by_dir_entry_free(ent);
				return 0;
			}
			if (!sk_BY_DIR_ENTRY_push(ctx->dirs, ent)) {
				X509error(ERR_R_MALLOC_FAILURE);
				by_dir_entry_free(ent);
				return 0;
			}
		}
	} while (*p++ != '\0');
	return 1;
}

static int
get_cert_by_subject(X509_LOOKUP *xl, int type, X509_NAME *name,
    X509_OBJECT *ret)
{
	BY_DIR *ctx;
	union	{
		struct	{
			X509 st_x509;
			X509_CINF st_x509_cinf;
		} x509;
		struct	{
			X509_CRL st_crl;
			X509_CRL_INFO st_crl_info;
		} crl;
	} data;
	int ok = 0;
	int i, j, k;
	unsigned long h;
	BUF_MEM *b = NULL;
	X509_OBJECT stmp, *tmp;
	const char *postfix="";

	if (name == NULL)
		return 0;

	stmp.type = type;
	if (type == X509_LU_X509) {
		data.x509.st_x509.cert_info = &data.x509.st_x509_cinf;
		data.x509.st_x509_cinf.subject = name;
		stmp.data.x509 = &data.x509.st_x509;
		postfix="";
	} else if (type == X509_LU_CRL) {
		data.crl.st_crl.crl = &data.crl.st_crl_info;
		data.crl.st_crl_info.issuer = name;
		stmp.data.crl = &data.crl.st_crl;
		postfix="r";
	} else {
		X509error(X509_R_WRONG_LOOKUP_TYPE);
		goto finish;
	}

	if ((b = BUF_MEM_new()) == NULL) {
		X509error(ERR_R_BUF_LIB);
		goto finish;
	}

	ctx = xl->method_data;

	h = X509_NAME_hash(name);
	for (i = 0; i < sk_BY_DIR_ENTRY_num(ctx->dirs); i++) {
		BY_DIR_ENTRY *ent;
		int idx;
		BY_DIR_HASH htmp, *hent;

		ent = sk_BY_DIR_ENTRY_value(ctx->dirs, i);
		j = strlen(ent->dir) + 1 + 8 + 6 + 1 + 1;
		if (!BUF_MEM_grow(b, j)) {
			X509error(ERR_R_MALLOC_FAILURE);
			goto finish;
		}
		if (type == X509_LU_CRL) {
			htmp.hash = h;
			CRYPTO_r_lock(CRYPTO_LOCK_X509_STORE);
			idx = sk_BY_DIR_HASH_find(ent->hashes, &htmp);
			if (idx >= 0) {
				hent = sk_BY_DIR_HASH_value(ent->hashes, idx);
				k = hent->suffix;
			} else {
				hent = NULL;
				k = 0;
			}
			CRYPTO_r_unlock(CRYPTO_LOCK_X509_STORE);
		} else {
			k = 0;
			hent = NULL;
		}
		for (;;) {
			(void) snprintf(b->data, b->max, "%s/%08lx.%s%d",
			    ent->dir, h, postfix, k);
			/*
			 * Found one. Attempt to load it. This could fail for
			 * any number of reasons from the file can't be opened,
			 * the file contains garbage, etc. Clear the error stack
			 * to avoid exposing the lower level error. These all
			 * boil down to "we could not find CA/CRL".
			 */
			if (type == X509_LU_X509) {
				if ((X509_load_cert_file(xl, b->data,
				    ent->dir_type)) == 0) {
					ERR_clear_error();
					break;
				}
			} else if (type == X509_LU_CRL) {
				if ((X509_load_crl_file(xl, b->data,
				    ent->dir_type)) == 0) {
					ERR_clear_error();
					break;
				}
			}
			/* The lack of a CA or CRL will be caught higher up. */
			k++;
		}

		/* we have added it to the cache so now pull it out again */
		CRYPTO_w_lock(CRYPTO_LOCK_X509_STORE);
		j = sk_X509_OBJECT_find(xl->store_ctx->objs, &stmp);
		tmp = sk_X509_OBJECT_value(xl->store_ctx->objs, j);
		CRYPTO_w_unlock(CRYPTO_LOCK_X509_STORE);

		/* If a CRL, update the last file suffix added for this */
		if (type == X509_LU_CRL) {
			CRYPTO_w_lock(CRYPTO_LOCK_X509_STORE);
			/*
			 * Look for entry again in case another thread added
			 * an entry first.
			 */
			if (hent == NULL) {
				htmp.hash = h;
				idx = sk_BY_DIR_HASH_find(ent->hashes, &htmp);
				hent = sk_BY_DIR_HASH_value(ent->hashes, idx);
			}
			if (hent == NULL) {
				hent = malloc(sizeof(*hent));
				if (hent == NULL) {
					X509error(ERR_R_MALLOC_FAILURE);
					CRYPTO_w_unlock(CRYPTO_LOCK_X509_STORE);
					ok = 0;
					goto finish;
				}
				hent->hash = h;
				hent->suffix = k;
				if (!sk_BY_DIR_HASH_push(ent->hashes, hent)) {
					X509error(ERR_R_MALLOC_FAILURE);
					CRYPTO_w_unlock(CRYPTO_LOCK_X509_STORE);
					free(hent);
					ok = 0;
					goto finish;
				}
			} else if (hent->suffix < k)
				hent->suffix = k;

			CRYPTO_w_unlock(CRYPTO_LOCK_X509_STORE);

		}

		if (tmp != NULL) {
			ok = 1;
			ret->type = tmp->type;
			memcpy(&ret->data, &tmp->data, sizeof(ret->data));
			goto finish;
		}
	}
finish:
	BUF_MEM_free(b);
	return ok;
}