/*

 * Copyright 2019-2023 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 "internal/namemap.h"

#include <openssl/lhash.h>

#include "crypto/lhash.h"      /* ossl_lh_strcasehash */

#include "internal/tsan_assist.h"

#include "internal/sizes.h"

#include "crypto/context.h"

/*-

 * The namenum entry

 * =================

 */

typedef struct {

    char *name;

    int number;

} NAMENUM_ENTRY;

DEFINE_LHASH_OF_EX(NAMENUM_ENTRY);

/*-

 * The namemap itself

 * ==================

 */

struct ossl_namemap_st {

    /* Flags */

    unsigned int stored:1; /* If 1, it's stored in a library context */

    CRYPTO_RWLOCK *lock;

    LHASH_OF(NAMENUM_ENTRY) *namenum;  /* Name->number mapping */

    TSAN_QUALIFIER int max_number;     /* Current max number */

};

/* LHASH callbacks */

static unsigned long namenum_hash(const NAMENUM_ENTRY *n)

{

    return ossl_lh_strcasehash(n->name);

}

static int namenum_cmp(const NAMENUM_ENTRY *a, const NAMENUM_ENTRY *b)

{

    return OPENSSL_strcasecmp(a->name, b->name);

}

static void namenum_free(NAMENUM_ENTRY *n)

{

    if (n != NULL)

        OPENSSL_free(n->name);

    OPENSSL_free(n);

}

/* OSSL_LIB_CTX_METHOD functions for a namemap stored in a library context */

void *ossl_stored_namemap_new(OSSL_LIB_CTX *libctx)

{

    OSSL_NAMEMAP *namemap = ossl_namemap_new();

    if (namemap != NULL)

        namemap->stored = 1;

    return namemap;

}

void ossl_stored_namemap_free(void *vnamemap)

{

    OSSL_NAMEMAP *namemap = vnamemap;

    if (namemap != NULL) {

        /* Pretend it isn't stored, or ossl_namemap_free() will do nothing */

        namemap->stored = 0;

        ossl_namemap_free(namemap);

    }

}

/*-

 * API functions

 * =============

 */

int ossl_namemap_empty(OSSL_NAMEMAP *namemap)

{

#ifdef TSAN_REQUIRES_LOCKING

    /* No TSAN support */

    int rv;

    if (namemap == NULL)

        return 1;

    if (!CRYPTO_THREAD_read_lock(namemap->lock))

        return -1;

    rv = namemap->max_number == 0;

    CRYPTO_THREAD_unlock(namemap->lock);

    return rv;

#else

    /* Have TSAN support */

    return namemap == NULL || tsan_load(&namemap->max_number) == 0;

#endif

}

typedef struct doall_names_data_st {

    int number;

    const char **names;

    int found;

} DOALL_NAMES_DATA;

static void do_name(const NAMENUM_ENTRY *namenum, DOALL_NAMES_DATA *data)

{

    if (namenum->number == data->number)

        data->names[data->found++] = namenum->name;

}

IMPLEMENT_LHASH_DOALL_ARG_CONST(NAMENUM_ENTRY, DOALL_NAMES_DATA);

/*

 * Call the callback for all names in the namemap with the given number.

 * A return value 1 means that the callback was called for all names. A

 * return value of 0 means that the callback was not called for any names.

 */

int ossl_namemap_doall_names(const OSSL_NAMEMAP *namemap, int number,

                             void (*fn)(const char *name, void *data),

                             void *data)

{

    DOALL_NAMES_DATA cbdata;

    size_t num_names;

    int i;

    cbdata.number = number;

    cbdata.found = 0;

    if (namemap == NULL)

        return 0;

    /*

     * We collect all the names first under a read lock. Subsequently we call

     * the user function, so that we're not holding the read lock when in user

     * code. This could lead to deadlocks.

     */

    if (!CRYPTO_THREAD_read_lock(namemap->lock))

        return 0;

    num_names = lh_NAMENUM_ENTRY_num_items(namemap->namenum);

    if (num_names == 0) {

        CRYPTO_THREAD_unlock(namemap->lock);

        return 0;

    }

    cbdata.names = OPENSSL_malloc(sizeof(*cbdata.names) * num_names);

    if (cbdata.names == NULL) {

        CRYPTO_THREAD_unlock(namemap->lock);

        return 0;

    }

    lh_NAMENUM_ENTRY_doall_DOALL_NAMES_DATA(namemap->namenum, do_name,

                                            &cbdata);

    CRYPTO_THREAD_unlock(namemap->lock);

    for (i = 0; i < cbdata.found; i++)

        fn(cbdata.names[i], data);

    OPENSSL_free(cbdata.names);

    return 1;

}

/* This function is not thread safe, the namemap must be locked */

static int namemap_name2num(const OSSL_NAMEMAP *namemap,

                            const char *name)

{

    NAMENUM_ENTRY *namenum_entry, namenum_tmpl;

    namenum_tmpl.name = (char *)name;

    namenum_tmpl.number = 0;

    namenum_entry =

        lh_NAMENUM_ENTRY_retrieve(namemap->namenum, &namenum_tmpl);

    return namenum_entry != NULL ? namenum_entry->number : 0;

}

int ossl_namemap_name2num(const OSSL_NAMEMAP *namemap, const char *name)

{

    int number;

#ifndef FIPS_MODULE

    if (namemap == NULL)

        namemap = ossl_namemap_stored(NULL);

#endif

    if (namemap == NULL)

        return 0;

    if (!CRYPTO_THREAD_read_lock(namemap->lock))

        return 0;

    number = namemap_name2num(namemap, name);

    CRYPTO_THREAD_unlock(namemap->lock);

    return number;

}

int ossl_namemap_name2num_n(const OSSL_NAMEMAP *namemap,

                            const char *name, size_t name_len)

{

    char *tmp;

    int ret;

    if (name == NULL || (tmp = OPENSSL_strndup(name, name_len)) == NULL)

        return 0;

    ret = ossl_namemap_name2num(namemap, tmp);

    OPENSSL_free(tmp);

    return ret;

}

struct num2name_data_st {

    size_t idx;                  /* Countdown */

    const char *name;            /* Result */

};

static void do_num2name(const char *name, void *vdata)

{

    struct num2name_data_st *data = vdata;

    if (data->idx > 0)

        data->idx--;

    else if (data->name == NULL)

        data->name = name;

}

const char *ossl_namemap_num2name(const OSSL_NAMEMAP *namemap, int number,

                                  size_t idx)

{

    struct num2name_data_st data;

    data.idx = idx;

    data.name = NULL;

    if (!ossl_namemap_doall_names(namemap, number, do_num2name, &data))

        return NULL;

    return data.name;

}

/* This function is not thread safe, the namemap must be locked */

static int namemap_add_name(OSSL_NAMEMAP *namemap, int number,

                            const char *name)

{

    NAMENUM_ENTRY *namenum = NULL;

    int tmp_number;

    /* If it already exists, we don't add it */

    if ((tmp_number = namemap_name2num(namemap, name)) != 0)

        return tmp_number;

    if ((namenum = OPENSSL_zalloc(sizeof(*namenum))) == NULL)

        return 0;

    if ((namenum->name = OPENSSL_strdup(name)) == NULL)

        goto err;

    /* The tsan_counter use here is safe since we're under lock */

    namenum->number =

        number != 0 ? number : 1 + tsan_counter(&namemap->max_number);

    (void)lh_NAMENUM_ENTRY_insert(namemap->namenum, namenum);

    if (lh_NAMENUM_ENTRY_error(namemap->namenum))

        goto err;

    return namenum->number;

 err:

    namenum_free(namenum);

    return 0;

}

int ossl_namemap_add_name(OSSL_NAMEMAP *namemap, int number,

                          const char *name)

{

    int tmp_number;

#ifndef FIPS_MODULE

    if (namemap == NULL)

        namemap = ossl_namemap_stored(NULL);

#endif

    if (name == NULL || *name == 0 || namemap == NULL)

        return 0;

    if (!CRYPTO_THREAD_write_lock(namemap->lock))

        return 0;

    tmp_number = namemap_add_name(namemap, number, name);

    CRYPTO_THREAD_unlock(namemap->lock);

    return tmp_number;

}

int ossl_namemap_add_names(OSSL_NAMEMAP *namemap, int number,

                           const char *names, const char separator)

{

    char *tmp, *p, *q, *endp;

    /* Check that we have a namemap */

    if (!ossl_assert(namemap != NULL)) {

        ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if ((tmp = OPENSSL_strdup(names)) == NULL)

        return 0;

    if (!CRYPTO_THREAD_write_lock(namemap->lock)) {

        OPENSSL_free(tmp);

        return 0;

    }

    /*

     * Check that no name is an empty string, and that all names have at

     * most one numeric identity together.

     */

    for (p = tmp; *p != '\0'; p = q) {

        int this_number;

        size_t l;

        if ((q = strchr(p, separator)) == NULL) {

            l = strlen(p);       /* offset to \0 */

            q = p + l;

        } else {

            l = q - p;           /* offset to the next separator */

            *q++ = '\0';

        }

        if (*p == '\0') {

            ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_BAD_ALGORITHM_NAME);

            number = 0;

            goto end;

        }

        this_number = namemap_name2num(namemap, p);

        if (number == 0) {

            number = this_number;

        } else if (this_number != 0 && this_number != number) {

            ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_CONFLICTING_NAMES,

                           "\"%s\" has an existing different identity %d (from \"%s\")",

                           p, this_number, names);

            number = 0;

            goto end;

        }

    }

    endp = p;

    /* Now that we have checked, register all names */

    for (p = tmp; p < endp; p = q) {

        int this_number;

        q = p + strlen(p) + 1;

        this_number = namemap_add_name(namemap, number, p);

        if (number == 0) {

            number = this_number;

        } else if (this_number != number) {

            ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR,

                           "Got number %d when expecting %d",

                           this_number, number);

            number = 0;

            goto end;

        }

    }

 end:

    CRYPTO_THREAD_unlock(namemap->lock);

    OPENSSL_free(tmp);

    return number;

}

/*-

 * Pre-population

 * ==============

 */

#ifndef FIPS_MODULE

#include <openssl/evp.h>

/* Creates an initial namemap with names found in the legacy method db */

static void get_legacy_evp_names(int base_nid, int nid, const char *pem_name,

                                 void *arg)

{

    int num = 0;

    ASN1_OBJECT *obj;

    if (base_nid != NID_undef) {

        num = ossl_namemap_add_name(arg, num, OBJ_nid2sn(base_nid));

        num = ossl_namemap_add_name(arg, num, OBJ_nid2ln(base_nid));

    }

    if (nid != NID_undef) {

        num = ossl_namemap_add_name(arg, num, OBJ_nid2sn(nid));

        num = ossl_namemap_add_name(arg, num, OBJ_nid2ln(nid));

        if ((obj = OBJ_nid2obj(nid)) != NULL) {

            char txtoid[OSSL_MAX_NAME_SIZE];

            if (OBJ_obj2txt(txtoid, sizeof(txtoid), obj, 1) > 0)

                num = ossl_namemap_add_name(arg, num, txtoid);

        }

    }

    if (pem_name != NULL)

        num = ossl_namemap_add_name(arg, num, pem_name);

}

static void get_legacy_cipher_names(const OBJ_NAME *on, void *arg)

{

    const EVP_CIPHER *cipher = (void *)OBJ_NAME_get(on->name, on->type);

    if (cipher != NULL)

        get_legacy_evp_names(NID_undef, EVP_CIPHER_get_type(cipher), NULL, arg);

}

static void get_legacy_md_names(const OBJ_NAME *on, void *arg)

{

    const EVP_MD *md = (void *)OBJ_NAME_get(on->name, on->type);

    if (md != NULL)

        get_legacy_evp_names(0, EVP_MD_get_type(md), NULL, arg);

}

static void get_legacy_pkey_meth_names(const EVP_PKEY_ASN1_METHOD *ameth,

                                       void *arg)

{

    int nid = 0, base_nid = 0, flags = 0;

    const char *pem_name = NULL;

    EVP_PKEY_asn1_get0_info(&nid, &base_nid, &flags, NULL, &pem_name, ameth);

    if (nid != NID_undef) {

        if ((flags & ASN1_PKEY_ALIAS) == 0) {

            switch (nid) {

            case EVP_PKEY_DHX:

                /* We know that the name "DHX" is used too */

                get_legacy_evp_names(0, nid, "DHX", arg);

                /* FALLTHRU */

            default:

                get_legacy_evp_names(0, nid, pem_name, arg);

            }

        } else {

            /*

             * Treat aliases carefully, some of them are undesirable, or

             * should not be treated as such for providers.

             */

            switch (nid) {

            case EVP_PKEY_SM2:

                /*

                 * SM2 is a separate keytype with providers, not an alias for

                 * EC.

                 */

                get_legacy_evp_names(0, nid, pem_name, arg);

                break;

            default:

                /* Use the short name of the base nid as the common reference */

                get_legacy_evp_names(base_nid, nid, pem_name, arg);

            }

        }

    }

}

#endif

/*-

 * Constructors / destructors

 * ==========================

 */

OSSL_NAMEMAP *ossl_namemap_stored(OSSL_LIB_CTX *libctx)

{

#ifndef FIPS_MODULE

    int nms;

#endif

    OSSL_NAMEMAP *namemap =

        ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_NAMEMAP_INDEX);

    if (namemap == NULL)

        return NULL;

#ifndef FIPS_MODULE

    nms = ossl_namemap_empty(namemap);

    if (nms < 0) {

        /*

         * Could not get lock to make the count, so maybe internal objects

         * weren't added. This seems safest.

         */

        return NULL;

    }

    if (nms == 1) {

        int i, end;

        /* Before pilfering, we make sure the legacy database is populated */

        OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS

                            | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);

        OBJ_NAME_do_all(OBJ_NAME_TYPE_CIPHER_METH,

                        get_legacy_cipher_names, namemap);

        OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH,

                        get_legacy_md_names, namemap);

        /* We also pilfer data from the legacy EVP_PKEY_ASN1_METHODs */

        for (i = 0, end = EVP_PKEY_asn1_get_count(); i < end; i++)

            get_legacy_pkey_meth_names(EVP_PKEY_asn1_get0(i), namemap);

    }

#endif

    return namemap;

}

OSSL_NAMEMAP *ossl_namemap_new(void)

{

    OSSL_NAMEMAP *namemap;

    if ((namemap = OPENSSL_zalloc(sizeof(*namemap))) != NULL

        && (namemap->lock = CRYPTO_THREAD_lock_new()) != NULL

        && (namemap->namenum =

            lh_NAMENUM_ENTRY_new(namenum_hash, namenum_cmp)) != NULL)

        return namemap;

    ossl_namemap_free(namemap);

    return NULL;

}

void ossl_namemap_free(OSSL_NAMEMAP *namemap)

{

    if (namemap == NULL || namemap->stored)

        return;

    lh_NAMENUM_ENTRY_doall(namemap->namenum, namenum_free);

    lh_NAMENUM_ENTRY_free(namemap->namenum);

    CRYPTO_THREAD_lock_free(namemap->lock);

    OPENSSL_free(namemap);

}