/*

 * Copyright 2019-2024 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 "internal/tsan_assist.h"

#include "internal/hashtable.h"

#include "internal/sizes.h"

#include "crypto/context.h"

#define NAMEMAP_HT_BUCKETS 2048

HT_START_KEY_DEFN(namenum_key)

HT_DEF_KEY_FIELD_CHAR_ARRAY(name, 64)

HT_END_KEY_DEFN(NAMENUM_KEY)

/*-

 * The namemap itself

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

 */

typedef char STRING;

typedef STACK_OF(STRING) NAMES;

DEFINE_STACK_OF(STRING)

DEFINE_STACK_OF(NAMES)

struct ossl_namemap_st {

    /* Flags */

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

    HT *namenum_ht;        /* Name->number mapping */

    CRYPTO_RWLOCK *lock;

    STACK_OF(NAMES) *numnames;

    TSAN_QUALIFIER int max_number;     /* Current max number */

};

static void name_string_free(char *name)

{

    OPENSSL_free(name);

}

static void names_free(NAMES *n)

{

    sk_STRING_pop_free(n, name_string_free);

}

/* 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(libctx);

    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

}

/*

 * 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)

{

    int i;

    NAMES *names;

    if (namemap == NULL || number <= 0)

        return 0;

    /*

     * We duplicate the NAMES stack 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;

    names = sk_NAMES_value(namemap->numnames, number - 1);

    if (names != NULL)

        names = sk_STRING_dup(names);

    CRYPTO_THREAD_unlock(namemap->lock);

    if (names == NULL)

        return 0;

    for (i = 0; i < sk_STRING_num(names); i++)

        fn(sk_STRING_value(names, i), data);

    sk_STRING_free(names);

    return i > 0;

}

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

{

    int number = 0;

    HT_VALUE *val;

    NAMENUM_KEY key;

#ifndef FIPS_MODULE

    if (namemap == NULL)

        namemap = ossl_namemap_stored(NULL);

#endif

    if (namemap == NULL)

        return 0;

    HT_INIT_KEY(&key);

    HT_SET_KEY_STRING_CASE(&key, name, name);

    val = ossl_ht_get(namemap->namenum_ht, TO_HT_KEY(&key));

    if (val != NULL)

        /* We store a (small) int directly instead of a pointer to it. */

        number = (int)(intptr_t)val->value;

    return number;

}

/* TODO: Optimize to avoid strndup() */

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;

}

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

                                  size_t idx)

{

    NAMES *names;

    const char *ret = NULL;

    if (namemap == NULL || number <= 0)

        return NULL;

    if (!CRYPTO_THREAD_read_lock(namemap->lock))

        return NULL;

    names = sk_NAMES_value(namemap->numnames, number - 1);

    if (names != NULL)

        ret = sk_STRING_value(names, idx);

    CRYPTO_THREAD_unlock(namemap->lock);

    return ret;

}

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

static int numname_insert(OSSL_NAMEMAP *namemap, int number,

                          const char *name)

{

    NAMES *names;

    char *tmpname;

    if (number > 0) {

        names = sk_NAMES_value(namemap->numnames, number - 1);

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

            /* cannot happen */

            return 0;

        }

    } else {

        /* a completely new entry */

        names = sk_STRING_new_null();

        if (names == NULL)

            return 0;

    }

    if ((tmpname = OPENSSL_strdup(name)) == NULL)

        goto err;

    if (!sk_STRING_push(names, tmpname))

        goto err;

    if (number <= 0) {

        if (!sk_NAMES_push(namemap->numnames, names))

            goto err;

        number = sk_NAMES_num(namemap->numnames);

    }

    return number;

 err:

    if (number <= 0)

        sk_STRING_free(names);

    OPENSSL_free(tmpname);

    return 0;

}

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

static int namemap_add_name(OSSL_NAMEMAP *namemap, int number,

                            const char *name)

{

    int ret;

    HT_VALUE val = { 0 };

    NAMENUM_KEY key;

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

    if ((ret = ossl_namemap_name2num(namemap, name)) != 0)

        return ret;

    if ((number = numname_insert(namemap, number, name)) == 0)

        return 0;

    /* Using tsan_store alone here is safe since we're under lock */

    tsan_store(&namemap->max_number, number);

    HT_INIT_KEY(&key);

    HT_SET_KEY_STRING_CASE(&key, name, name);

    val.value = (void *)(intptr_t)number;

    ret = ossl_ht_insert(namemap->namenum_ht, TO_HT_KEY(&key), &val, NULL);

    if (!ossl_assert(ret != 0)) /* cannot happen as we are under write lock */

        return 0;

    if (ret < 1) {

        /* unable to insert due to too many collisions */

        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_MANY_NAMES);

        return 0;

    }

    return number;

}

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 = ossl_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(OSSL_LIB_CTX *libctx)

{

    OSSL_NAMEMAP *namemap;

    HT_CONFIG htconf = { NULL, NULL, NULL, NAMEMAP_HT_BUCKETS, 1, 1 };

    htconf.ctx = libctx;

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

        goto err;

    if ((namemap->lock = CRYPTO_THREAD_lock_new()) == NULL)

        goto err;

    if ((namemap->namenum_ht = ossl_ht_new(&htconf)) == NULL)

        goto err;

    if ((namemap->numnames = sk_NAMES_new_null()) == NULL)

        goto err;

    return namemap;

 err:

    ossl_namemap_free(namemap);

    return NULL;

}

void ossl_namemap_free(OSSL_NAMEMAP *namemap)

{

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

        return;

    sk_NAMES_pop_free(namemap->numnames, names_free);

    ossl_ht_free(namemap->namenum_ht);

    CRYPTO_THREAD_lock_free(namemap->lock);

    OPENSSL_free(namemap);

}