/*
 * Copyright 2006-2022 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License"). You may not use
 * this file except in compliance with the License. You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#include <openssl/objects.h>
#include "obj_xref.h"
#include "internal/nelem.h"
#include "internal/thread_once.h"
#include <openssl/err.h>

static STACK_OF(nid_triple) *sig_app, *sigx_app;
static CRYPTO_RWLOCK *sig_lock;

static int sig_cmp(const nid_triple *a, const nid_triple *b)
{
 return a->sign_id - b->sign_id;
}

DECLARE_OBJ_BSEARCH_CMP_FN(nid_triple, nid_triple, sig);
IMPLEMENT_OBJ_BSEARCH_CMP_FN(nid_triple, nid_triple, sig);

static int sig_sk_cmp(const nid_triple *const *a, const nid_triple *const *b)
{
 return (*a)->sign_id - (*b)->sign_id;
}

DECLARE_OBJ_BSEARCH_CMP_FN(const nid_triple *, const nid_triple *, sigx);

static int sigx_cmp(const nid_triple *const *a, const nid_triple *const *b)
{
 int ret;

 ret = (*a)->hash_id - (*b)->hash_id;
 /* The "b" side of the comparison carries the algorithms already
 * registered. A NID_undef for 'hash_id' there means that the
 * signature algorithm doesn't need a digest to operate OK. In
 * such case, any hash_id/digest algorithm on the test side (a),
 * incl. NID_undef, is acceptable. signature algorithm NID
 * (pkey_id) must match in any case.
 */
 if ((ret != 0) && ((*b)->hash_id != NID_undef))
 return ret;
 return (*a)->pkey_id - (*b)->pkey_id;
}

IMPLEMENT_OBJ_BSEARCH_CMP_FN(const nid_triple *, const nid_triple *, sigx);

static CRYPTO_ONCE sig_init = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(o_sig_init)
{
 sig_lock = CRYPTO_THREAD_lock_new();
 return sig_lock != NULL;
}

static ossl_inline int obj_sig_init(void)
{
 return RUN_ONCE(&sig_init, o_sig_init);
}

static int ossl_obj_find_sigid_algs(int signid, int *pdig_nid, int *ppkey_nid,
 int lock)
{
 nid_triple tmp;
 const nid_triple *rv;
 int idx;

 if (signid == NID_undef)
 return 0;

 tmp.sign_id = signid;
 rv = OBJ_bsearch_sig(&tmp, sigoid_srt, OSSL_NELEM(sigoid_srt));
 if (rv == NULL) {
 if (!obj_sig_init())
 return 0;
 if (lock && !CRYPTO_THREAD_read_lock(sig_lock)) {
 ERR_raise(ERR_LIB_OBJ, ERR_R_UNABLE_TO_GET_READ_LOCK);
 return 0;
 }
 if (sig_app != NULL) {
 idx = sk_nid_triple_find(sig_app, &tmp);
 if (idx >= 0)
 rv = sk_nid_triple_value(sig_app, idx);
 }
 if (lock)
 CRYPTO_THREAD_unlock(sig_lock);
 if (rv == NULL)
 return 0;
 }

 if (pdig_nid != NULL)
 *pdig_nid = rv->hash_id;
 if (ppkey_nid != NULL)
 *ppkey_nid = rv->pkey_id;
 return 1;
}

int OBJ_find_sigid_algs(int signid, int *pdig_nid, int *ppkey_nid)
{
 return ossl_obj_find_sigid_algs(signid, pdig_nid, ppkey_nid, 1);
}

int OBJ_find_sigid_by_algs(int *psignid, int dig_nid, int pkey_nid)
{
 nid_triple tmp;
 const nid_triple *t = &tmp;
 const nid_triple **rv;
 int idx;

 /* permitting searches for sig algs without digest: */
 if (pkey_nid == NID_undef)
 return 0;

 tmp.hash_id = dig_nid;
 tmp.pkey_id = pkey_nid;

 rv = OBJ_bsearch_sigx(&t, sigoid_srt_xref, OSSL_NELEM(sigoid_srt_xref));
 if (rv == NULL) {
 if (!obj_sig_init())
 return 0;
 if (!CRYPTO_THREAD_read_lock(sig_lock)) {
 ERR_raise(ERR_LIB_OBJ, ERR_R_UNABLE_TO_GET_READ_LOCK);
 return 0;
 }
 if (sigx_app != NULL) {
 idx = sk_nid_triple_find(sigx_app, &tmp);
 if (idx >= 0) {
 t = sk_nid_triple_value(sigx_app, idx);
 rv = &t;
 }
 }
 CRYPTO_THREAD_unlock(sig_lock);
 if (rv == NULL)
 return 0;
 }

 if (psignid != NULL)
 *psignid = (*rv)->sign_id;
 return 1;
}

int OBJ_add_sigid(int signid, int dig_id, int pkey_id)
{
 nid_triple *ntr;
 int dnid = NID_undef, pnid = NID_undef, ret = 0;

 if (signid == NID_undef || pkey_id == NID_undef)
 return 0;

 if (!obj_sig_init())
 return 0;

 if ((ntr = OPENSSL_malloc(sizeof(*ntr))) == NULL)
 return 0;
 ntr->sign_id = signid;
 ntr->hash_id = dig_id;
 ntr->pkey_id = pkey_id;

 if (!CRYPTO_THREAD_write_lock(sig_lock)) {
 ERR_raise(ERR_LIB_OBJ, ERR_R_UNABLE_TO_GET_WRITE_LOCK);
 OPENSSL_free(ntr);
 return 0;
 }

 /* Check that the entry doesn't exist or exists as desired */
 if (ossl_obj_find_sigid_algs(signid, &dnid, &pnid, 0)) {
 ret = dnid == dig_id && pnid == pkey_id;
 goto err;
 }

 if (sig_app == NULL) {
 sig_app = sk_nid_triple_new(sig_sk_cmp);
 if (sig_app == NULL)
 goto err;
 }
 if (sigx_app == NULL) {
 sigx_app = sk_nid_triple_new(sigx_cmp);
 if (sigx_app == NULL)
 goto err;
 }

 /*
 * Better might be to find where to insert the element and insert it there.
 * This would avoid the sorting steps below.
 */
 if (!sk_nid_triple_push(sig_app, ntr))
 goto err;
 if (!sk_nid_triple_push(sigx_app, ntr)) {
 ntr = NULL; /* This is referenced by sig_app still */
 goto err;
 }

 sk_nid_triple_sort(sig_app);
 sk_nid_triple_sort(sigx_app);

 ntr = NULL;
 ret = 1;
 err:
 OPENSSL_free(ntr);
 CRYPTO_THREAD_unlock(sig_lock);
 return ret;
}

static void sid_free(nid_triple *tt)
{
 OPENSSL_free(tt);
}

void OBJ_sigid_free(void)
{
 sk_nid_triple_pop_free(sig_app, sid_free);
 sk_nid_triple_free(sigx_app);
 CRYPTO_THREAD_lock_free(sig_lock);
 sig_app = NULL;
 sigx_app = NULL;
 sig_lock = NULL;
}