/* crypto/err/err.c */
/* 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.]
 */
/* ====================================================================
 * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
 *
 * 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 above 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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "cryptlib.h"
#include <openssl/lhash.h>
#include <openssl/crypto.h>
#include <openssl/buffer.h>
#include <openssl/bio.h>
#include <openssl/err.h>

DECLARE_LHASH_OF(ERR_STRING_DATA);
DECLARE_LHASH_OF(ERR_STATE);

static void err_load_strings(int lib, ERR_STRING_DATA *str);

static void ERR_STATE_free(ERR_STATE *s);
#ifndef OPENSSL_NO_ERR
static ERR_STRING_DATA ERR_str_libraries[] = {
    {ERR_PACK(ERR_LIB_NONE, 0, 0), "unknown library"},
    {ERR_PACK(ERR_LIB_SYS, 0, 0), "system library"},
    {ERR_PACK(ERR_LIB_BN, 0, 0), "bignum routines"},
    {ERR_PACK(ERR_LIB_RSA, 0, 0), "rsa routines"},
    {ERR_PACK(ERR_LIB_DH, 0, 0), "Diffie-Hellman routines"},
    {ERR_PACK(ERR_LIB_EVP, 0, 0), "digital envelope routines"},
    {ERR_PACK(ERR_LIB_BUF, 0, 0), "memory buffer routines"},
    {ERR_PACK(ERR_LIB_OBJ, 0, 0), "object identifier routines"},
    {ERR_PACK(ERR_LIB_PEM, 0, 0), "PEM routines"},
    {ERR_PACK(ERR_LIB_DSA, 0, 0), "dsa routines"},
    {ERR_PACK(ERR_LIB_X509, 0, 0), "x509 certificate routines"},
    {ERR_PACK(ERR_LIB_ASN1, 0, 0), "asn1 encoding routines"},
    {ERR_PACK(ERR_LIB_CONF, 0, 0), "configuration file routines"},
    {ERR_PACK(ERR_LIB_CRYPTO, 0, 0), "common libcrypto routines"},
    {ERR_PACK(ERR_LIB_EC, 0, 0), "elliptic curve routines"},
    {ERR_PACK(ERR_LIB_SSL, 0, 0), "SSL routines"},
    {ERR_PACK(ERR_LIB_BIO, 0, 0), "BIO routines"},
    {ERR_PACK(ERR_LIB_PKCS7, 0, 0), "PKCS7 routines"},
    {ERR_PACK(ERR_LIB_X509V3, 0, 0), "X509 V3 routines"},
    {ERR_PACK(ERR_LIB_PKCS12, 0, 0), "PKCS12 routines"},
    {ERR_PACK(ERR_LIB_RAND, 0, 0), "random number generator"},
    {ERR_PACK(ERR_LIB_DSO, 0, 0), "DSO support routines"},
    {ERR_PACK(ERR_LIB_TS, 0, 0), "time stamp routines"},
    {ERR_PACK(ERR_LIB_ENGINE, 0, 0), "engine routines"},
    {ERR_PACK(ERR_LIB_OCSP, 0, 0), "OCSP routines"},
    {ERR_PACK(ERR_LIB_FIPS, 0, 0), "FIPS routines"},
    {ERR_PACK(ERR_LIB_CMS, 0, 0), "CMS routines"},
    {ERR_PACK(ERR_LIB_HMAC, 0, 0), "HMAC routines"},
    {0, NULL},
};

static ERR_STRING_DATA ERR_str_functs[] = {
    {ERR_PACK(0, SYS_F_FOPEN, 0), "fopen"},
    {ERR_PACK(0, SYS_F_CONNECT, 0), "connect"},
    {ERR_PACK(0, SYS_F_GETSERVBYNAME, 0), "getservbyname"},
    {ERR_PACK(0, SYS_F_SOCKET, 0), "socket"},
    {ERR_PACK(0, SYS_F_IOCTLSOCKET, 0), "ioctlsocket"},
    {ERR_PACK(0, SYS_F_BIND, 0), "bind"},
    {ERR_PACK(0, SYS_F_LISTEN, 0), "listen"},
    {ERR_PACK(0, SYS_F_ACCEPT, 0), "accept"},
# ifdef OPENSSL_SYS_WINDOWS
    {ERR_PACK(0, SYS_F_WSASTARTUP, 0), "WSAstartup"},
# endif
    {ERR_PACK(0, SYS_F_OPENDIR, 0), "opendir"},
    {ERR_PACK(0, SYS_F_FREAD, 0), "fread"},
    {0, NULL},
};

static ERR_STRING_DATA ERR_str_reasons[] = {
    {ERR_R_SYS_LIB, "system lib"},
    {ERR_R_BN_LIB, "BN lib"},
    {ERR_R_RSA_LIB, "RSA lib"},
    {ERR_R_DH_LIB, "DH lib"},
    {ERR_R_EVP_LIB, "EVP lib"},
    {ERR_R_BUF_LIB, "BUF lib"},
    {ERR_R_OBJ_LIB, "OBJ lib"},
    {ERR_R_PEM_LIB, "PEM lib"},
    {ERR_R_DSA_LIB, "DSA lib"},
    {ERR_R_X509_LIB, "X509 lib"},
    {ERR_R_ASN1_LIB, "ASN1 lib"},
    {ERR_R_CONF_LIB, "CONF lib"},
    {ERR_R_CRYPTO_LIB, "CRYPTO lib"},
    {ERR_R_EC_LIB, "EC lib"},
    {ERR_R_SSL_LIB, "SSL lib"},
    {ERR_R_BIO_LIB, "BIO lib"},
    {ERR_R_PKCS7_LIB, "PKCS7 lib"},
    {ERR_R_X509V3_LIB, "X509V3 lib"},
    {ERR_R_PKCS12_LIB, "PKCS12 lib"},
    {ERR_R_RAND_LIB, "RAND lib"},
    {ERR_R_DSO_LIB, "DSO lib"},
    {ERR_R_ENGINE_LIB, "ENGINE lib"},
    {ERR_R_OCSP_LIB, "OCSP lib"},
    {ERR_R_TS_LIB, "TS lib"},

    {ERR_R_NESTED_ASN1_ERROR, "nested asn1 error"},
    {ERR_R_BAD_ASN1_OBJECT_HEADER, "bad asn1 object header"},
    {ERR_R_BAD_GET_ASN1_OBJECT_CALL, "bad get asn1 object call"},
    {ERR_R_EXPECTING_AN_ASN1_SEQUENCE, "expecting an asn1 sequence"},
    {ERR_R_ASN1_LENGTH_MISMATCH, "asn1 length mismatch"},
    {ERR_R_MISSING_ASN1_EOS, "missing asn1 eos"},

    {ERR_R_FATAL, "fatal"},
    {ERR_R_MALLOC_FAILURE, "malloc failure"},
    {ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED,
     "called a function you should not call"},
    {ERR_R_PASSED_NULL_PARAMETER, "passed a null parameter"},
    {ERR_R_INTERNAL_ERROR, "internal error"},
    {ERR_R_DISABLED, "called a function that was disabled at compile-time"},

    {0, NULL},
};
#endif

/* Define the predeclared (but externally opaque) "ERR_FNS" type */
struct st_ERR_FNS {
    /* Works on the "error_hash" string table */
    LHASH_OF(ERR_STRING_DATA) *(*cb_err_get) (int create);
    void (*cb_err_del) (void);
    ERR_STRING_DATA *(*cb_err_get_item) (const ERR_STRING_DATA *);
    ERR_STRING_DATA *(*cb_err_set_item) (ERR_STRING_DATA *);
    ERR_STRING_DATA *(*cb_err_del_item) (ERR_STRING_DATA *);
    /* Works on the "thread_hash" error-state table */
    LHASH_OF(ERR_STATE) *(*cb_thread_get) (int create);
    void (*cb_thread_release) (LHASH_OF(ERR_STATE) **hash);
    ERR_STATE *(*cb_thread_get_item) (const ERR_STATE *);
    ERR_STATE *(*cb_thread_set_item) (ERR_STATE *);
    void (*cb_thread_del_item) (const ERR_STATE *);
    /* Returns the next available error "library" numbers */
    int (*cb_get_next_lib) (void);
};

/* Predeclarations of the "err_defaults" functions */
static LHASH_OF(ERR_STRING_DATA) *int_err_get(int create);
static void int_err_del(void);
static ERR_STRING_DATA *int_err_get_item(const ERR_STRING_DATA *);
static ERR_STRING_DATA *int_err_set_item(ERR_STRING_DATA *);
static ERR_STRING_DATA *int_err_del_item(ERR_STRING_DATA *);
static LHASH_OF(ERR_STATE) *int_thread_get(int create);
static void int_thread_release(LHASH_OF(ERR_STATE) **hash);
static ERR_STATE *int_thread_get_item(const ERR_STATE *);
static ERR_STATE *int_thread_set_item(ERR_STATE *);
static void int_thread_del_item(const ERR_STATE *);
static int int_err_get_next_lib(void);
/* The static ERR_FNS table using these defaults functions */
static const ERR_FNS err_defaults = {
    int_err_get,
    int_err_del,
    int_err_get_item,
    int_err_set_item,
    int_err_del_item,
    int_thread_get,
    int_thread_release,
    int_thread_get_item,
    int_thread_set_item,
    int_thread_del_item,
    int_err_get_next_lib
};

/* The replacable table of ERR_FNS functions we use at run-time */
static const ERR_FNS *err_fns = NULL;

/* Eg. rather than using "err_get()", use "ERRFN(err_get)()". */
#define ERRFN(a) err_fns->cb_##a

/*
 * The internal state used by "err_defaults" - as such, the setting, reading,
 * creating, and deleting of this data should only be permitted via the
 * "err_defaults" functions. This way, a linked module can completely defer
 * all ERR state operation (together with requisite locking) to the
 * implementations and state in the loading application.
 */
static LHASH_OF(ERR_STRING_DATA) *int_error_hash = NULL;
static LHASH_OF(ERR_STATE) *int_thread_hash = NULL;
static int int_thread_hash_references = 0;
static int int_err_library_number = ERR_LIB_USER;

/*
 * Internal function that checks whether "err_fns" is set and if not, sets it
 * to the defaults.
 */
static void err_fns_check(void)
{
    if (err_fns)
        return;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    if (!err_fns)
        err_fns = &err_defaults;
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
}

/* API functions to get or set the underlying ERR functions. */

const ERR_FNS *ERR_get_implementation(void)
{
    err_fns_check();
    return err_fns;
}

int ERR_set_implementation(const ERR_FNS *fns)
{
    int ret = 0;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    /*
     * It's too late if 'err_fns' is non-NULL. BTW: not much point setting an
     * error is there?!
     */
    if (!err_fns) {
        err_fns = fns;
        ret = 1;
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
    return ret;
}

/*
 * These are the callbacks provided to "lh_new()" when creating the LHASH
 * tables internal to the "err_defaults" implementation.
 */

static unsigned long get_error_values(int inc, int top, const char **file,
                                      int *line, const char **data,
                                      int *flags);

/* The internal functions used in the "err_defaults" implementation */

static unsigned long err_string_data_hash(const ERR_STRING_DATA *a)
{
    unsigned long ret, l;

    l = a->error;
    ret = l ^ ERR_GET_LIB(l) ^ ERR_GET_FUNC(l);
    return (ret ^ ret % 19 * 13);
}

static IMPLEMENT_LHASH_HASH_FN(err_string_data, ERR_STRING_DATA)

static int err_string_data_cmp(const ERR_STRING_DATA *a,
                               const ERR_STRING_DATA *b)
{
    return (int)(a->error - b->error);
}

static IMPLEMENT_LHASH_COMP_FN(err_string_data, ERR_STRING_DATA)

static LHASH_OF(ERR_STRING_DATA) *int_err_get(int create)
{
    LHASH_OF(ERR_STRING_DATA) *ret = NULL;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    if (!int_error_hash && create) {
        CRYPTO_push_info("int_err_get (err.c)");
        int_error_hash = lh_ERR_STRING_DATA_new();
        CRYPTO_pop_info();
    }
    if (int_error_hash)
        ret = int_error_hash;
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);

    return ret;
}

static void int_err_del(void)
{
    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    if (int_error_hash) {
        lh_ERR_STRING_DATA_free(int_error_hash);
        int_error_hash = NULL;
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
}

static ERR_STRING_DATA *int_err_get_item(const ERR_STRING_DATA *d)
{
    ERR_STRING_DATA *p;
    LHASH_OF(ERR_STRING_DATA) *hash;

    err_fns_check();
    hash = ERRFN(err_get) (0);
    if (!hash)
        return NULL;

    CRYPTO_r_lock(CRYPTO_LOCK_ERR);
    p = lh_ERR_STRING_DATA_retrieve(hash, d);
    CRYPTO_r_unlock(CRYPTO_LOCK_ERR);

    return p;
}

static ERR_STRING_DATA *int_err_set_item(ERR_STRING_DATA *d)
{
    ERR_STRING_DATA *p;
    LHASH_OF(ERR_STRING_DATA) *hash;

    err_fns_check();
    hash = ERRFN(err_get) (1);
    if (!hash)
        return NULL;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    p = lh_ERR_STRING_DATA_insert(hash, d);
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);

    return p;
}

static ERR_STRING_DATA *int_err_del_item(ERR_STRING_DATA *d)
{
    ERR_STRING_DATA *p;
    LHASH_OF(ERR_STRING_DATA) *hash;

    err_fns_check();
    hash = ERRFN(err_get) (0);
    if (!hash)
        return NULL;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    p = lh_ERR_STRING_DATA_delete(hash, d);
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);

    return p;
}

static unsigned long err_state_hash(const ERR_STATE *a)
{
    return CRYPTO_THREADID_hash(&a->tid) * 13;
}

static IMPLEMENT_LHASH_HASH_FN(err_state, ERR_STATE)

static int err_state_cmp(const ERR_STATE *a, const ERR_STATE *b)
{
    return CRYPTO_THREADID_cmp(&a->tid, &b->tid);
}

static IMPLEMENT_LHASH_COMP_FN(err_state, ERR_STATE)

static LHASH_OF(ERR_STATE) *int_thread_get(int create)
{
    LHASH_OF(ERR_STATE) *ret = NULL;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    if (!int_thread_hash && create) {
        CRYPTO_push_info("int_thread_get (err.c)");
        int_thread_hash = lh_ERR_STATE_new();
        CRYPTO_pop_info();
    }
    if (int_thread_hash) {
        int_thread_hash_references++;
        ret = int_thread_hash;
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
    return ret;
}

static void int_thread_release(LHASH_OF(ERR_STATE) **hash)
{
    int i;

    if (hash == NULL || *hash == NULL)
        return;

    i = CRYPTO_add(&int_thread_hash_references, -1, CRYPTO_LOCK_ERR);

#ifdef REF_PRINT
    fprintf(stderr, "%4d:%s\n", int_thread_hash_references, "ERR");
#endif
    if (i > 0)
        return;
#ifdef REF_CHECK
    if (i < 0) {
        fprintf(stderr, "int_thread_release, bad reference count\n");
        abort();                /* ok */
    }
#endif
    *hash = NULL;
}

static ERR_STATE *int_thread_get_item(const ERR_STATE *d)
{
    ERR_STATE *p;
    LHASH_OF(ERR_STATE) *hash;

    err_fns_check();
    hash = ERRFN(thread_get) (0);
    if (!hash)
        return NULL;

    CRYPTO_r_lock(CRYPTO_LOCK_ERR);
    p = lh_ERR_STATE_retrieve(hash, d);
    CRYPTO_r_unlock(CRYPTO_LOCK_ERR);

    ERRFN(thread_release) (&hash);
    return p;
}

static ERR_STATE *int_thread_set_item(ERR_STATE *d)
{
    ERR_STATE *p;
    LHASH_OF(ERR_STATE) *hash;

    err_fns_check();
    hash = ERRFN(thread_get) (1);
    if (!hash)
        return NULL;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    p = lh_ERR_STATE_insert(hash, d);
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);

    ERRFN(thread_release) (&hash);
    return p;
}

static void int_thread_del_item(const ERR_STATE *d)
{
    ERR_STATE *p;
    LHASH_OF(ERR_STATE) *hash;

    err_fns_check();
    hash = ERRFN(thread_get) (0);
    if (!hash)
        return;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    p = lh_ERR_STATE_delete(hash, d);
    /* make sure we don't leak memory */
    if (int_thread_hash_references == 1
        && int_thread_hash && lh_ERR_STATE_num_items(int_thread_hash) == 0) {
        lh_ERR_STATE_free(int_thread_hash);
        int_thread_hash = NULL;
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);

    ERRFN(thread_release) (&hash);
    if (p)
        ERR_STATE_free(p);
}

static int int_err_get_next_lib(void)
{
    int ret;

    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    ret = int_err_library_number++;
    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);

    return ret;
}

#ifndef OPENSSL_NO_ERR
# define NUM_SYS_STR_REASONS 127
# define LEN_SYS_STR_REASON 32

static ERR_STRING_DATA SYS_str_reasons[NUM_SYS_STR_REASONS + 1];
/*
 * SYS_str_reasons is filled with copies of strerror() results at
 * initialization. 'errno' values up to 127 should cover all usual errors,
 * others will be displayed numerically by ERR_error_string. It is crucial
 * that we have something for each reason code that occurs in
 * ERR_str_reasons, or bogus reason strings will be returned for SYSerr(),
 * which always gets an errno value and never one of those 'standard' reason
 * codes.
 */

static void build_SYS_str_reasons(void)
{
    /* OPENSSL_malloc cannot be used here, use static storage instead */
    static char strerror_tab[NUM_SYS_STR_REASONS][LEN_SYS_STR_REASON];
    int i;
    static int init = 1;

    CRYPTO_r_lock(CRYPTO_LOCK_ERR);
    if (!init) {
        CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
        return;
    }

    CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
    CRYPTO_w_lock(CRYPTO_LOCK_ERR);
    if (!init) {
        CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
        return;
    }

    for (i = 1; i <= NUM_SYS_STR_REASONS; i++) {
        ERR_STRING_DATA *str = &SYS_str_reasons[i - 1];

        str->error = (unsigned long)i;
        if (str->string == NULL) {
            char (*dest)[LEN_SYS_STR_REASON] = &(strerror_tab[i - 1]);
            char *src = strerror(i);
            if (src != NULL) {
                strncpy(*dest, src, sizeof *dest);
                (*dest)[sizeof *dest - 1] = '\0';
                str->string = *dest;
            }
        }
        if (str->string == NULL)
            str->string = "unknown";
    }

    /*
     * Now we still have SYS_str_reasons[NUM_SYS_STR_REASONS] = {0, NULL}, as
     * required by ERR_load_strings.
     */

    init = 0;

    CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
}
#endif

#define err_clear_data(p,i) \
        do { \
        if (((p)->err_data[i] != NULL) && \
                (p)->err_data_flags[i] & ERR_TXT_MALLOCED) \
                {  \
                OPENSSL_free((p)->err_data[i]); \
                (p)->err_data[i]=NULL; \
                } \
        (p)->err_data_flags[i]=0; \
        } while(0)

#define err_clear(p,i) \
        do { \
        (p)->err_flags[i]=0; \
        (p)->err_buffer[i]=0; \
        err_clear_data(p,i); \
        (p)->err_file[i]=NULL; \
        (p)->err_line[i]= -1; \
        } while(0)

static void ERR_STATE_free(ERR_STATE *s)
{
    int i;

    if (s == NULL)
        return;

    for (i = 0; i < ERR_NUM_ERRORS; i++) {
        err_clear_data(s, i);
    }
    OPENSSL_free(s);
}

void ERR_load_ERR_strings(void)
{
    err_fns_check();
#ifndef OPENSSL_NO_ERR
    err_load_strings(0, ERR_str_libraries);
    err_load_strings(0, ERR_str_reasons);
    err_load_strings(ERR_LIB_SYS, ERR_str_functs);
    build_SYS_str_reasons();
    err_load_strings(ERR_LIB_SYS, SYS_str_reasons);
#endif
}

static void err_load_strings(int lib, ERR_STRING_DATA *str)
{
    while (str->error) {
        if (lib)
            str->error |= ERR_PACK(lib, 0, 0);
        ERRFN(err_set_item) (str);
        str++;
    }
}

void ERR_load_strings(int lib, ERR_STRING_DATA *str)
{
    ERR_load_ERR_strings();
    err_load_strings(lib, str);
}

void ERR_unload_strings(int lib, ERR_STRING_DATA *str)
{
    while (str->error) {
        if (lib)
            str->error |= ERR_PACK(lib, 0, 0);
        ERRFN(err_del_item) (str);
        str++;
    }
}

void ERR_free_strings(void)
{
    err_fns_check();
    ERRFN(err_del) ();
}

/********************************************************/

void ERR_put_error(int lib, int func, int reason, const char *file, int line)
{
    ERR_STATE *es;

#ifdef _OSD_POSIX
    /*
     * In the BS2000-OSD POSIX subsystem, the compiler generates path names
     * in the form "*POSIX(/etc/passwd)". This dirty hack strips them to
     * something sensible. @@@ We shouldn't modify a const string, though.
     */
    if (strncmp(file, "*POSIX(", sizeof("*POSIX(") - 1) == 0) {
        char *end;

        /* Skip the "*POSIX(" prefix */
        file += sizeof("*POSIX(") - 1;
        end = &file[strlen(file) - 1];
        if (*end == ')')
            *end = '\0';
        /* Optional: use the basename of the path only. */
        if ((end = strrchr(file, '/')) != NULL)
            file = &end[1];
    }
#endif
    es = ERR_get_state();

    es->top = (es->top + 1) % ERR_NUM_ERRORS;
    if (es->top == es->bottom)
        es->bottom = (es->bottom + 1) % ERR_NUM_ERRORS;
    es->err_flags[es->top] = 0;
    es->err_buffer[es->top] = ERR_PACK(lib, func, reason);
    es->err_file[es->top] = file;
    es->err_line[es->top] = line;
    err_clear_data(es, es->top);
}

void ERR_clear_error(void)
{
    int i;
    ERR_STATE *es;

    es = ERR_get_state();

    for (i = 0; i < ERR_NUM_ERRORS; i++) {
        err_clear(es, i);
    }
    es->top = es->bottom = 0;
}

unsigned long ERR_get_error(void)
{
    return (get_error_values(1, 0, NULL, NULL, NULL, NULL));
}

unsigned long ERR_get_error_line(const char **file, int *line)
{
    return (get_error_values(1, 0, file, line, NULL, NULL));
}

unsigned long ERR_get_error_line_data(const char **file, int *line,
                                      const char **data, int *flags)
{
    return (get_error_values(1, 0, file, line, data, flags));
}

unsigned long ERR_peek_error(void)
{
    return (get_error_values(0, 0, NULL, NULL, NULL, NULL));
}

unsigned long ERR_peek_error_line(const char **file, int *line)
{
    return (get_error_values(0, 0, file, line, NULL, NULL));
}

unsigned long ERR_peek_error_line_data(const char **file, int *line,
                                       const char **data, int *flags)
{
    return (get_error_values(0, 0, file, line, data, flags));
}

unsigned long ERR_peek_last_error(void)
{
    return (get_error_values(0, 1, NULL, NULL, NULL, NULL));
}

unsigned long ERR_peek_last_error_line(const char **file, int *line)
{
    return (get_error_values(0, 1, file, line, NULL, NULL));
}

unsigned long ERR_peek_last_error_line_data(const char **file, int *line,
                                            const char **data, int *flags)
{
    return (get_error_values(0, 1, file, line, data, flags));
}

static unsigned long get_error_values(int inc, int top, const char **file,
                                      int *line, const char **data,
                                      int *flags)
{
    int i = 0;
    ERR_STATE *es;
    unsigned long ret;

    es = ERR_get_state();

    if (inc && top) {
        if (file)
            *file = "";
        if (line)
            *line = 0;
        if (data)
            *data = "";
        if (flags)
            *flags = 0;

        return ERR_R_INTERNAL_ERROR;
    }

    if (es->bottom == es->top)
        return 0;
    if (top)
        i = es->top;            /* last error */
    else
        i = (es->bottom + 1) % ERR_NUM_ERRORS; /* first error */

    ret = es->err_buffer[i];
    if (inc) {
        es->bottom = i;
        es->err_buffer[i] = 0;
    }

    if ((file != NULL) && (line != NULL)) {
        if (es->err_file[i] == NULL) {
            *file = "NA";
            if (line != NULL)
                *line = 0;
        } else {
            *file = es->err_file[i];
            if (line != NULL)
                *line = es->err_line[i];
        }
    }

    if (data == NULL) {
        if (inc) {
            err_clear_data(es, i);
        }
    } else {
        if (es->err_data[i] == NULL) {
            *data = "";
            if (flags != NULL)
                *flags = 0;
        } else {
            *data = es->err_data[i];
            if (flags != NULL)
                *flags = es->err_data_flags[i];
        }
    }
    return ret;
}

void ERR_error_string_n(unsigned long e, char *buf, size_t len)
{
    char lsbuf[64], fsbuf[64], rsbuf[64];
    const char *ls, *fs, *rs;
    unsigned long l, f, r;

    l = ERR_GET_LIB(e);
    f = ERR_GET_FUNC(e);
    r = ERR_GET_REASON(e);

    ls = ERR_lib_error_string(e);
    fs = ERR_func_error_string(e);
    rs = ERR_reason_error_string(e);

    if (ls == NULL)
        BIO_snprintf(lsbuf, sizeof(lsbuf), "lib(%lu)", l);
    if (fs == NULL)
        BIO_snprintf(fsbuf, sizeof(fsbuf), "func(%lu)", f);
    if (rs == NULL)
        BIO_snprintf(rsbuf, sizeof(rsbuf), "reason(%lu)", r);

    BIO_snprintf(buf, len, "error:%08lX:%s:%s:%s", e, ls ? ls : lsbuf,
                 fs ? fs : fsbuf, rs ? rs : rsbuf);
    if (strlen(buf) == len - 1) {
        /*
         * output may be truncated; make sure we always have 5
         * colon-separated fields, i.e. 4 colons ...
         */
#define NUM_COLONS 4
        if (len > NUM_COLONS) { /* ... if possible */
            int i;
            char *s = buf;

            for (i = 0; i < NUM_COLONS; i++) {
                char *colon = strchr(s, ':');
                if (colon == NULL || colon > &buf[len - 1] - NUM_COLONS + i) {
                    /*
                     * set colon no. i at last possible position (buf[len-1]
                     * is the terminating 0)
                     */
                    colon = &buf[len - 1] - NUM_COLONS + i;
                    *colon = ':';
                }
                s = colon + 1;
            }
        }
    }
}

/* BAD for multi-threading: uses a local buffer if ret == NULL */
/*
 * ERR_error_string_n should be used instead for ret != NULL as
 * ERR_error_string cannot know how large the buffer is
 */
char *ERR_error_string(unsigned long e, char *ret)
{
    static char buf[256];

    if (ret == NULL)
        ret = buf;
    ERR_error_string_n(e, ret, 256);

    return ret;
}

LHASH_OF(ERR_STRING_DATA) *ERR_get_string_table(void)
{
    err_fns_check();
    return ERRFN(err_get) (0);
}

LHASH_OF(ERR_STATE) *ERR_get_err_state_table(void)
{
    err_fns_check();
    return ERRFN(thread_get) (0);
}

void ERR_release_err_state_table(LHASH_OF(ERR_STATE) **hash)
{
    err_fns_check();
    ERRFN(thread_release) (hash);
}

const char *ERR_lib_error_string(unsigned long e)
{
    ERR_STRING_DATA d, *p;
    unsigned long l;

    err_fns_check();
    l = ERR_GET_LIB(e);
    d.error = ERR_PACK(l, 0, 0);
    p = ERRFN(err_get_item) (&d);
    return ((p == NULL) ? NULL : p->string);
}

const char *ERR_func_error_string(unsigned long e)
{
    ERR_STRING_DATA d, *p;
    unsigned long l, f;

    err_fns_check();
    l = ERR_GET_LIB(e);
    f = ERR_GET_FUNC(e);
    d.error = ERR_PACK(l, f, 0);
    p = ERRFN(err_get_item) (&d);
    return ((p == NULL) ? NULL : p->string);
}

const char *ERR_reason_error_string(unsigned long e)
{
    ERR_STRING_DATA d, *p = NULL;
    unsigned long l, r;

    err_fns_check();
    l = ERR_GET_LIB(e);
    r = ERR_GET_REASON(e);
    d.error = ERR_PACK(l, 0, r);
    p = ERRFN(err_get_item) (&d);
    if (!p) {
        d.error = ERR_PACK(0, 0, r);
        p = ERRFN(err_get_item) (&d);
    }
    return ((p == NULL) ? NULL : p->string);
}

void ERR_remove_thread_state(const CRYPTO_THREADID *id)
{
    ERR_STATE tmp;

    if (id)
        CRYPTO_THREADID_cpy(&tmp.tid, id);
    else
        CRYPTO_THREADID_current(&tmp.tid);
    err_fns_check();
    /*
     * thread_del_item automatically destroys the LHASH if the number of
     * items reaches zero.
     */
    ERRFN(thread_del_item) (&tmp);
}

#ifndef OPENSSL_NO_DEPRECATED
void ERR_remove_state(unsigned long pid)
{
    ERR_remove_thread_state(NULL);
}
#endif

ERR_STATE *ERR_get_state(void)
{
    static ERR_STATE fallback;
    ERR_STATE *ret, tmp, *tmpp = NULL;
    int i;
    CRYPTO_THREADID tid;

    err_fns_check();
    CRYPTO_THREADID_current(&tid);
    CRYPTO_THREADID_cpy(&tmp.tid, &tid);
    ret = ERRFN(thread_get_item) (&tmp);

    /* ret == the error state, if NULL, make a new one */
    if (ret == NULL) {
        ret = (ERR_STATE *)OPENSSL_malloc(sizeof(ERR_STATE));
        if (ret == NULL)
            return (&fallback);
        CRYPTO_THREADID_cpy(&ret->tid, &tid);
        ret->top = 0;
        ret->bottom = 0;
        for (i = 0; i < ERR_NUM_ERRORS; i++) {
            ret->err_data[i] = NULL;
            ret->err_data_flags[i] = 0;
        }
        tmpp = ERRFN(thread_set_item) (ret);
        /* To check if insertion failed, do a get. */
        if (ERRFN(thread_get_item) (ret) != ret) {
            ERR_STATE_free(ret); /* could not insert it */
            return (&fallback);
        }
        /*
         * If a race occured in this function and we came second, tmpp is the
         * first one that we just replaced.
         */
        if (tmpp)
            ERR_STATE_free(tmpp);
    }
    return ret;
}

int ERR_get_next_error_library(void)
{
    err_fns_check();
    return ERRFN(get_next_lib) ();
}

void ERR_set_error_data(char *data, int flags)
{
    ERR_STATE *es;
    int i;

    es = ERR_get_state();

    i = es->top;
    if (i == 0)
        i = ERR_NUM_ERRORS - 1;

    err_clear_data(es, i);
    es->err_data[i] = data;
    es->err_data_flags[i] = flags;
}

void ERR_add_error_data(int num, ...)
{
    va_list args;
    va_start(args, num);
    ERR_add_error_vdata(num, args);
    va_end(args);
}

void ERR_add_error_vdata(int num, va_list args)
{
    int i, n, s;
    char *str, *p, *a;

    s = 80;
    str = OPENSSL_malloc(s + 1);
    if (str == NULL)
        return;
    str[0] = '\0';

    n = 0;
    for (i = 0; i < num; i++) {
        a = va_arg(args, char *);
        /* ignore NULLs, thanks to Bob Beck <beck@obtuse.com> */
        if (a != NULL) {
            n += strlen(a);
            if (n > s) {
                s = n + 20;
                p = OPENSSL_realloc(str, s + 1);
                if (p == NULL) {
                    OPENSSL_free(str);
                    return;
                } else
                    str = p;
            }
            BUF_strlcat(str, a, (size_t)s + 1);
        }
    }
    ERR_set_error_data(str, ERR_TXT_MALLOCED | ERR_TXT_STRING);
}

int ERR_set_mark(void)
{
    ERR_STATE *es;

    es = ERR_get_state();

    if (es->bottom == es->top)
        return 0;
    es->err_flags[es->top] |= ERR_FLAG_MARK;
    return 1;
}

int ERR_pop_to_mark(void)
{
    ERR_STATE *es;

    es = ERR_get_state();

    while (es->bottom != es->top
           && (es->err_flags[es->top] & ERR_FLAG_MARK) == 0) {
        err_clear(es, es->top);
        es->top -= 1;
        if (es->top == -1)
            es->top = ERR_NUM_ERRORS - 1;
    }

    if (es->bottom == es->top)
        return 0;
    es->err_flags[es->top] &= ~ERR_FLAG_MARK;
    return 1;
}
