/*

 * Copyright 2003-2026 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/e_os.h"

#include <string.h>

#include <limits.h>

#include <openssl/crypto.h>

#include "crypto/ctype.h"

#include "internal/cryptlib.h"

#include "internal/thread_once.h"

#include "internal/to_hex.h"

#define DEFAULT_SEPARATOR ':'

#define CH_ZERO '\0'

char *CRYPTO_strdup(const char *str, const char *file, int line)

{

    char *ret;

    size_t len;

    if (str == NULL)

        return NULL;

    len = strlen(str) + 1;

    ret = CRYPTO_malloc(len, file, line);

    if (ret != NULL)

        memcpy(ret, str, len);

    return ret;

}

char *CRYPTO_strndup(const char *str, size_t s, const char *file, int line)

{

    size_t maxlen;

    char *ret;

    if (str == NULL)

        return NULL;

    maxlen = OPENSSL_strnlen(str, s);

    ret = CRYPTO_malloc(maxlen + 1, file, line);

    if (ret) {

        memcpy(ret, str, maxlen);

        ret[maxlen] = CH_ZERO;

    }

    return ret;

}

void *CRYPTO_memdup(const void *data, size_t siz, const char *file, int line)

{

    void *ret;

    if (data == NULL || siz >= INT_MAX)

        return NULL;

    ret = CRYPTO_malloc(siz, file, line);

    if (ret == NULL)

        return NULL;

    return memcpy(ret, data, siz);

}

size_t OPENSSL_strnlen(const char *str, size_t maxlen)

{

    const char *p;

    for (p = str; maxlen-- != 0 && *p != CH_ZERO; ++p)

        ;

    return p - str;

}

size_t OPENSSL_strlcpy(char *dst, const char *src, size_t size)

{

    size_t l = 0;

    for (; size > 1 && *src; size--) {

        *dst++ = *src++;

        l++;

    }

    if (size)

        *dst = CH_ZERO;

    return l + strlen(src);

}

size_t OPENSSL_strlcat(char *dst, const char *src, size_t size)

{

    size_t l = 0;

    for (; size > 0 && *dst; size--, dst++)

        l++;

    return l + OPENSSL_strlcpy(dst, src, size);

}

/**

 * @brief Converts a string to an unsigned long integer.

 *

 * This function attempts to convert a string representation of a number

 * to an unsigned long integer, given a specified base. It also provides

 * error checking and reports whether the conversion was successful.

 * This function is just a wrapper around the POSIX strtoul function with

 * additional error checking.  This implies that errno for the caller is set

 * on calls to this function.

 *

 * @param str The string containing the representation of the number.

 * @param endptr A pointer to a pointer to character. If not NULL, it is set

 *               to the character immediately following the number in the

 *               string.

 * @param base The base to use for the conversion, which must be between 2,

 *             and 36 inclusive, or be the special value 0. If the base is 0,

 *             the actual base is determined by the format of the initial

 *             characters of the string.

 * @param num A pointer to an unsigned long where the result of the

 *            conversion is stored.

 *

 * @return 1 if the conversion was successful, 0 otherwise. Conversion is

 *         considered unsuccessful if no digits were consumed or if an error

 *         occurred during conversion.

 *

 * @note It is the caller's responsibility to check if the conversion is

 *       correct based on the expected consumption of the string as reported

 *       by endptr.

 */

int OPENSSL_strtoul(const char *str, char **endptr, int base,

    unsigned long *num)

{

    char *tmp_endptr;

    char **internal_endptr = endptr == NULL ? &tmp_endptr : endptr;

    errno = 0;

    *internal_endptr = (char *)str;

    if (num == NULL)

        return 0;

    if (str == NULL)

        return 0;

    /* Fail on negative input */

    if (*str == '-')

        return 0;

    *num = strtoul(str, internal_endptr, base);

    /*

     * We return error from this function under the following conditions

     * 1) If strtoul itself returned an error in translation

     * 2) If the caller didn't pass in an endptr value, and **internal_endptr

     *    doesn't point to '\0'.  The implication here is that if the caller

     *    doesn't care how much of a string is consumed, they expect the entire

     *    string to be consumed.  As such, no pointing to the NULL terminator

     *    means there was some part of the string left over after translation

     * 3) If no bytes of the string were consumed

     */

    if (errno != 0 || (endptr == NULL && **internal_endptr != '\0') || (str == *internal_endptr))

        return 0;

    return 1;

}

int OPENSSL_hexchar2int(unsigned char c)

{

#ifdef CHARSET_EBCDIC

    c = os_toebcdic[c];

#endif

    switch (c) {

    case '0':

        return 0;

    case '1':

        return 1;

    case '2':

        return 2;

    case '3':

        return 3;

    case '4':

        return 4;

    case '5':

        return 5;

    case '6':

        return 6;

    case '7':

        return 7;

    case '8':

        return 8;

    case '9':

        return 9;

    case 'a':

    case 'A':

        return 0x0A;

    case 'b':

    case 'B':

        return 0x0B;

    case 'c':

    case 'C':

        return 0x0C;

    case 'd':

    case 'D':

        return 0x0D;

    case 'e':

    case 'E':

        return 0x0E;

    case 'f':

    case 'F':

        return 0x0F;

    }

    return -1;

}

static int hexstr2buf_sep(unsigned char *buf, size_t buf_n, size_t *buflen,

    const char *str, const char sep)

{

    unsigned char *q;

    unsigned char ch, cl;

    int chi, cli;

    const unsigned char *p;

    size_t cnt;

    for (p = (const unsigned char *)str, q = buf, cnt = 0; *p;) {

        ch = *p++;

        /* A separator of CH_ZERO means there is no separator */

        if (ch == sep && sep != CH_ZERO)

            continue;

        cl = *p++;

        if (!cl) {

            ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_ODD_NUMBER_OF_DIGITS);

            return 0;

        }

        cli = OPENSSL_hexchar2int(cl);

        chi = OPENSSL_hexchar2int(ch);

        if (cli < 0 || chi < 0) {

            ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_ILLEGAL_HEX_DIGIT);

            return 0;

        }

        cnt++;

        if (q != NULL) {

            if (cnt > buf_n) {

                ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_SMALL_BUFFER);

                return 0;

            }

            *q++ = (unsigned char)((chi << 4) | cli);

        }

    }

    if (buflen != NULL)

        *buflen = cnt;

    return 1;

}

/*

 * Given a string of hex digits convert to a buffer

 */

int OPENSSL_hexstr2buf_ex(unsigned char *buf, size_t buf_n, size_t *buflen,

    const char *str, const char sep)

{

    return hexstr2buf_sep(buf, buf_n, buflen, str, sep);

}

unsigned char *ossl_hexstr2buf_sep(const char *str, long *buflen,

    const char sep)

{

    unsigned char *buf;

    size_t buf_n, tmp_buflen;

    buf_n = strlen(str);

    if (buf_n <= 1) {

        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_HEX_STRING_TOO_SHORT);

        return NULL;

    }

    buf_n /= 2;

    if ((buf = OPENSSL_malloc(buf_n)) == NULL)

        return NULL;

    if (buflen != NULL)

        *buflen = 0;

    tmp_buflen = 0;

    if (hexstr2buf_sep(buf, buf_n, &tmp_buflen, str, sep)) {

        if (buflen != NULL)

            *buflen = (long)tmp_buflen;

        return buf;

    }

    OPENSSL_free(buf);

    return NULL;

}

unsigned char *OPENSSL_hexstr2buf(const char *str, long *buflen)

{

    return ossl_hexstr2buf_sep(str, buflen, DEFAULT_SEPARATOR);

}

static int buf2hexstr_sep(char *str, size_t str_n, size_t *strlength,

    const unsigned char *buf, size_t buflen,

    const char sep)

{

    char *q;

    int has_sep = (sep != CH_ZERO);

    size_t i, len = has_sep ? buflen * 3 : 1 + buflen * 2;

    if (buflen > (has_sep ? SIZE_MAX / 3 : (SIZE_MAX - 1) / 2)) {

        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_MANY_BYTES);

        return 0;

    }

    if (len == 0)

        ++len;

    if (strlength != NULL)

        *strlength = len;

    if (str == NULL)

        return 1;

    if (str_n < len) {

        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_SMALL_BUFFER);

        return 0;

    }

    q = str;

    for (i = 0; i < buflen; i++) {

        q += ossl_to_hex(q, buf[i]);

        if (has_sep)

            *q++ = sep;

    }

    if (has_sep && buflen > 0)

        --q;

    *q = CH_ZERO;

#ifdef CHARSET_EBCDIC

    ebcdic2ascii(str, str, q - str);

#endif

    return 1;

}

int OPENSSL_buf2hexstr_ex(char *str, size_t str_n, size_t *strlength,

    const unsigned char *buf, size_t buflen,

    const char sep)

{

    return buf2hexstr_sep(str, str_n, strlength, buf, buflen, sep);

}

char *ossl_buf2hexstr_sep(const unsigned char *buf, long buflen, char sep)

{

    char *tmp;

    size_t tmp_n;

    if (buflen == 0)

        return OPENSSL_zalloc(1);

    if ((sep != CH_ZERO && (size_t)buflen > SIZE_MAX / 3)

        || (sep == CH_ZERO && (size_t)buflen > (SIZE_MAX - 1) / 2)) {

        ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_MANY_BYTES);

        return NULL;

    }

    tmp_n = (sep != CH_ZERO) ? (size_t)buflen * 3 : 1 + (size_t)buflen * 2;

    if ((tmp = OPENSSL_malloc(tmp_n)) == NULL)

        return NULL;

    if (buf2hexstr_sep(tmp, tmp_n, NULL, buf, buflen, sep))

        return tmp;

    OPENSSL_free(tmp);

    return NULL;

}

/*

 * Given a buffer of length 'buflen' return a OPENSSL_malloc'ed string with

 * its hex representation @@@ (Contents of buffer are always kept in ASCII,

 * also on EBCDIC machines)

 */

char *OPENSSL_buf2hexstr(const unsigned char *buf, long buflen)

{

    return ossl_buf2hexstr_sep(buf, buflen, DEFAULT_SEPARATOR);

}

int openssl_strerror_r(int errnum, char *buf, size_t buflen)

{

#if defined(_MSC_VER) && _MSC_VER >= 1400 && !defined(_WIN32_WCE)

    return !strerror_s(buf, buflen, errnum);

#elif defined(_GNU_SOURCE)

    char *err;

    /*

     * GNU strerror_r may not actually set buf.

     * It can return a pointer to some (immutable) static string in which case

     * buf is left unused.

     */

    err = strerror_r(errnum, buf, buflen);

    if (err == NULL || buflen == 0)

        return 0;

    /*

     * If err is statically allocated, err != buf and we need to copy the data.

     * If err points somewhere inside buf, OPENSSL_strlcpy can handle this,

     * since src and dest are not annotated with __restrict and the function

     * reads src byte for byte and writes to dest.

     * If err == buf we do not have to copy anything.

     */

    if (err != buf)

        OPENSSL_strlcpy(buf, err, buflen);

    return 1;

#elif (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L) || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 600)

    /*

     * We can use "real" strerror_r. The OpenSSL version differs in that it

     * gives 1 on success and 0 on failure for consistency with other OpenSSL

     * functions. Real strerror_r does it the other way around

     */

    return !strerror_r(errnum, buf, buflen);

#else

    char *err;

    /* Fall back to non-thread safe strerror()...its all we can do */

    if (buflen < 2)

        return 0;

    err = strerror(errnum);

    /* Can this ever happen? */

    if (err == NULL)

        return 0;

    OPENSSL_strlcpy(buf, err, buflen);

    return 1;

#endif

}

int OPENSSL_strcasecmp(const char *s1, const char *s2)

{

    int t;

    while ((t = ossl_tolower(*s1) - ossl_tolower(*s2++)) == 0)

        if (*s1++ == '\0')

            return 0;

    return t;

}

int OPENSSL_strncasecmp(const char *s1, const char *s2, size_t n)

{

    int t;

    size_t i;

    for (i = 0; i < n; i++)

        if ((t = ossl_tolower(*s1) - ossl_tolower(*s2++)) != 0)

            return t;

        else if (*s1++ == '\0')

            return 0;

    return 0;

}

size_t ossl_to_hex(char *buf, uint8_t n)

{

    static const char hexdig[] = "0123456789ABCDEF";

    return to_hex(buf, n, hexdig);

}