crypto/asn1/asn1_lib.c - third_party/openssl - Git at Google

 /*
  * Copyright 1995-2021 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 <stdio.h>
 #include <limits.h>
 #include "internal/cryptlib.h"
 #include <openssl/asn1.h>
 #include "asn1_local.h"

 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl,
                            long max);
 static void asn1_put_length(unsigned char **pp, int length);

 static int _asn1_check_infinite_end(const unsigned char **p, long len)
 {
     /*
      * If there is 0 or 1 byte left, the length check should pick things up
      */
     if (len <= 0) {
         return 1;
     } else {
         if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) {
             (*p) += 2;
             return 1;
         }
     }
     return 0;
 }

 int ASN1_check_infinite_end(unsigned char **p, long len)
 {
     return _asn1_check_infinite_end((const unsigned char **)p, len);
 }

 int ASN1_const_check_infinite_end(const unsigned char **p, long len)
 {
     return _asn1_check_infinite_end(p, len);
 }

 int ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
                     int *pclass, long omax)
 {
     int i, ret;
     long len;
     const unsigned char *p = *pp;
     int tag, xclass, inf;
     long max = omax;

     if (omax <= 0) {
         ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_SMALL);
         return 0x80;
     }
     ret = (*p & V_ASN1_CONSTRUCTED);
     xclass = (*p & V_ASN1_PRIVATE);
     i = *p & V_ASN1_PRIMITIVE_TAG;
     if (i == V_ASN1_PRIMITIVE_TAG) { /* high-tag */
         p++;
         if (--max == 0)
             goto err;
         len = 0;
         while (*p & 0x80) {
             len <<= 7L;
             len |= *(p++) & 0x7f;
             if (--max == 0)
                 goto err;
             if (len > (INT_MAX >> 7L))
                 goto err;
         }
         len <<= 7L;
         len |= *(p++) & 0x7f;
         tag = (int)len;
         if (--max == 0)
             goto err;
     } else {
         tag = i;
         p++;
         if (--max == 0)
             goto err;
     }
     *ptag = tag;
     *pclass = xclass;
     if (!asn1_get_length(&p, &inf, plength, max))
         goto err;

     if (inf && !(ret & V_ASN1_CONSTRUCTED))
         goto err;

     if (*plength > (omax - (p - *pp))) {
         ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);
         /*
          * Set this so that even if things are not long enough the values are
          * set correctly
          */
         ret |= 0x80;
     }
     *pp = p;
     return ret | inf;
  err:
     ERR_raise(ERR_LIB_ASN1, ASN1_R_HEADER_TOO_LONG);
     return 0x80;
 }

 /*
  * Decode a length field.
  * The short form is a single byte defining a length 0 - 127.
  * The long form is a byte 0 - 127 with the top bit set and this indicates
  * the number of following octets that contain the length.  These octets
  * are stored most significant digit first.
  */
 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl,
                            long max)
 {
     const unsigned char *p = *pp;
     unsigned long ret = 0;
     int i;

     if (max-- < 1)
         return 0;
     if (*p == 0x80) {
         *inf = 1;
         p++;
     } else {
         *inf = 0;
         i = *p & 0x7f;
         if (*p++ & 0x80) {
             if (max < i + 1)
                 return 0;
             /* Skip leading zeroes */
             while (i > 0 && *p == 0) {
                 p++;
                 i--;
             }
             if (i > (int)sizeof(long))
                 return 0;
             while (i > 0) {
                 ret <<= 8;
                 ret |= *p++;
                 i--;
             }
             if (ret > LONG_MAX)
                 return 0;
         } else {
             ret = i;
         }
     }
     *pp = p;
     *rl = (long)ret;
     return 1;
 }

 /*
  * constructed == 2 for indefinite length constructed
  */
 void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
                      int xclass)
 {
     unsigned char *p = *pp;
     int i, ttag;

     i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
     i |= (xclass & V_ASN1_PRIVATE);
     if (tag < 31) {
         *(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
     } else {
         *(p++) = i | V_ASN1_PRIMITIVE_TAG;
         for (i = 0, ttag = tag; ttag > 0; i++)
             ttag >>= 7;
         ttag = i;
         while (i-- > 0) {
             p[i] = tag & 0x7f;
             if (i != (ttag - 1))
                 p[i] |= 0x80;
             tag >>= 7;
         }
         p += ttag;
     }
     if (constructed == 2)
         *(p++) = 0x80;
     else
         asn1_put_length(&p, length);
     *pp = p;
 }

 int ASN1_put_eoc(unsigned char **pp)
 {
     unsigned char *p = *pp;

     *p++ = 0;
     *p++ = 0;
     *pp = p;
     return 2;
 }

 static void asn1_put_length(unsigned char **pp, int length)
 {
     unsigned char *p = *pp;
     int i, len;

     if (length <= 127) {
         *(p++) = (unsigned char)length;
     } else {
         len = length;
         for (i = 0; len > 0; i++)
             len >>= 8;
         *(p++) = i | 0x80;
         len = i;
         while (i-- > 0) {
             p[i] = length & 0xff;
             length >>= 8;
         }
         p += len;
     }
     *pp = p;
 }

 int ASN1_object_size(int constructed, int length, int tag)
 {
     int ret = 1;

     if (length < 0)
         return -1;
     if (tag >= 31) {
         while (tag > 0) {
             tag >>= 7;
             ret++;
         }
     }
     if (constructed == 2) {
         ret += 3;
     } else {
         ret++;
         if (length > 127) {
             int tmplen = length;
             while (tmplen > 0) {
                 tmplen >>= 8;
                 ret++;
             }
         }
     }
     if (ret >= INT_MAX - length)
         return -1;
     return ret + length;
 }

 int ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str)
 {
     if (str == NULL)
         return 0;
     dst->type = str->type;
     if (!ASN1_STRING_set(dst, str->data, str->length))
         return 0;
     /* Copy flags but preserve embed value */
     dst->flags &= ASN1_STRING_FLAG_EMBED;
     dst->flags |= str->flags & ~ASN1_STRING_FLAG_EMBED;
     return 1;
 }

 ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *str)
 {
     ASN1_STRING *ret;

     if (!str)
         return NULL;
     ret = ASN1_STRING_new();
     if (ret == NULL)
         return NULL;
     if (!ASN1_STRING_copy(ret, str)) {
         ASN1_STRING_free(ret);
         return NULL;
     }
     return ret;
 }

 int ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len_in)
 {
     unsigned char *c;
     const char *data = _data;
     size_t len;

     if (len_in < 0) {
         if (data == NULL)
             return 0;
         len = strlen(data);
     } else {
         len = (size_t)len_in;
     }
     /*
      * Verify that the length fits within an integer for assignment to
      * str->length below.  The additional 1 is subtracted to allow for the
      * '\0' terminator even though this isn't strictly necessary.
      */
     if (len > INT_MAX - 1) {
         ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LARGE);
         return 0;
     }
     if ((size_t)str->length <= len || str->data == NULL) {
         c = str->data;
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
         /* No NUL terminator in fuzzing builds */
         str->data = OPENSSL_realloc(c, len != 0 ? len : 1);
 #else
         str->data = OPENSSL_realloc(c, len + 1);
 #endif
         if (str->data == NULL) {
             ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
             str->data = c;
             return 0;
         }
     }
     str->length = len;
     if (data != NULL) {
         memcpy(str->data, data, len);
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
         /* Set the unused byte to something non NUL and printable. */
         if (len == 0)
             str->data[len] = '~';
 #else
         /*
          * Add a NUL terminator. This should not be necessary - but we add it as
          * a safety precaution
          */
         str->data[len] = '\0';
 #endif
     }
     return 1;
 }

 void ASN1_STRING_set0(ASN1_STRING *str, void *data, int len)
 {
     OPENSSL_free(str->data);
     str->data = data;
     str->length = len;
 }

 ASN1_STRING *ASN1_STRING_new(void)
 {
     return ASN1_STRING_type_new(V_ASN1_OCTET_STRING);
 }

 ASN1_STRING *ASN1_STRING_type_new(int type)
 {
     ASN1_STRING *ret;

     ret = OPENSSL_zalloc(sizeof(*ret));
     if (ret == NULL) {
         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
         return NULL;
     }
     ret->type = type;
     return ret;
 }

 void ossl_asn1_string_embed_free(ASN1_STRING *a, int embed)
 {
     if (a == NULL)
         return;
     if (!(a->flags & ASN1_STRING_FLAG_NDEF))
         OPENSSL_free(a->data);
     if (embed == 0)
         OPENSSL_free(a);
 }

 void ASN1_STRING_free(ASN1_STRING *a)
 {
     if (a == NULL)
         return;
     ossl_asn1_string_embed_free(a, a->flags & ASN1_STRING_FLAG_EMBED);
 }

 void ASN1_STRING_clear_free(ASN1_STRING *a)
 {
     if (a == NULL)
         return;
     if (a->data && !(a->flags & ASN1_STRING_FLAG_NDEF))
         OPENSSL_cleanse(a->data, a->length);
     ASN1_STRING_free(a);
 }

 int ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b)
 {
     int i;

     i = (a->length - b->length);
     if (i == 0) {
         if (a->length != 0)
             i = memcmp(a->data, b->data, a->length);
         if (i == 0)
             return a->type - b->type;
         else
             return i;
     } else {
         return i;
     }
 }

 int ASN1_STRING_length(const ASN1_STRING *x)
 {
     return x->length;
 }

 #ifndef OPENSSL_NO_DEPRECATED_3_0
 void ASN1_STRING_length_set(ASN1_STRING *x, int len)
 {
     x->length = len;
 }
 #endif

 int ASN1_STRING_type(const ASN1_STRING *x)
 {
     return x->type;
 }

 const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *x)
 {
     return x->data;
 }

 #ifndef OPENSSL_NO_DEPRECATED_1_1_0
 unsigned char *ASN1_STRING_data(ASN1_STRING *x)
 {
     return x->data;
 }
 #endif

 /* |max_len| excludes NUL terminator and may be 0 to indicate no restriction */
 char *ossl_sk_ASN1_UTF8STRING2text(STACK_OF(ASN1_UTF8STRING) *text,
                                    const char *sep, size_t max_len)
 {
     int i;
     ASN1_UTF8STRING *current;
     size_t length = 0, sep_len;
     char *result = NULL;
     char *p;

     if (sep == NULL)
         sep = "";
     sep_len = strlen(sep);

     for (i = 0; i < sk_ASN1_UTF8STRING_num(text); i++) {
         current = sk_ASN1_UTF8STRING_value(text, i);
         if (i > 0)
             length += sep_len;
         length += ASN1_STRING_length(current);
         if (max_len != 0 && length > max_len)
             return NULL;
     }
     if ((result = OPENSSL_malloc(length + 1)) == NULL)
         return NULL;

     p = result;
     for (i = 0; i < sk_ASN1_UTF8STRING_num(text); i++) {
         current = sk_ASN1_UTF8STRING_value(text, i);
         length = ASN1_STRING_length(current);
         if (i > 0 && sep_len > 0) {
             strncpy(p, sep, sep_len + 1); /* using + 1 to silence gcc warning */
             p += sep_len;
         }
         strncpy(p, (const char *)ASN1_STRING_get0_data(current), length);
         p += length;
     }
     *p = '\0';

     return result;
 }
	/*
	* Copyright 1995-2021 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 <stdio.h>
	#include <limits.h>
	#include "internal/cryptlib.h"
	#include <openssl/asn1.h>
	#include "asn1_local.h"

	static int asn1_get_length(const unsigned char *pp, int inf, long *rl,
	long max);
	static void asn1_put_length(unsigned char **pp, int length);

	static int _asn1_check_infinite_end(const unsigned char **p, long len)
	{
	/*
	* If there is 0 or 1 byte left, the length check should pick things up
	*/
	if (len <= 0) {
	return 1;
	} else {
	if ((len >= 2) && ((p)[0] == 0) && ((p)[1] == 0)) {
	(*p) += 2;
	return 1;
	}
	}
	return 0;
	}

	int ASN1_check_infinite_end(unsigned char **p, long len)
	{
	return _asn1_check_infinite_end((const unsigned char **)p, len);
	}

	int ASN1_const_check_infinite_end(const unsigned char **p, long len)
	{
	return _asn1_check_infinite_end(p, len);
	}

	int ASN1_get_object(const unsigned char *pp, long plength, int *ptag,
	int *pclass, long omax)
	{
	int i, ret;
	long len;
	const unsigned char p = pp;
	int tag, xclass, inf;
	long max = omax;

	if (omax <= 0) {
	ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_SMALL);
	return 0x80;
	}
	ret = (*p & V_ASN1_CONSTRUCTED);
	xclass = (*p & V_ASN1_PRIVATE);
	i = *p & V_ASN1_PRIMITIVE_TAG;
	if (i == V_ASN1_PRIMITIVE_TAG) { /* high-tag */
	p++;
	if (--max == 0)
	goto err;
	len = 0;
	while (*p & 0x80) {
	len <<= 7L;
	len \|= *(p++) & 0x7f;
	if (--max == 0)
	goto err;
	if (len > (INT_MAX >> 7L))
	goto err;
	}
	len <<= 7L;
	len \|= *(p++) & 0x7f;
	tag = (int)len;
	if (--max == 0)
	goto err;
	} else {
	tag = i;
	p++;
	if (--max == 0)
	goto err;
	}
	*ptag = tag;
	*pclass = xclass;
	if (!asn1_get_length(&p, &inf, plength, max))
	goto err;

	if (inf && !(ret & V_ASN1_CONSTRUCTED))
	goto err;

	if (plength > (omax - (p - pp))) {
	ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);
	/*
	* Set this so that even if things are not long enough the values are
	* set correctly
	*/
	ret \|= 0x80;
	}
	*pp = p;
	return ret \| inf;
	err:
	ERR_raise(ERR_LIB_ASN1, ASN1_R_HEADER_TOO_LONG);
	return 0x80;
	}

	/*
	* Decode a length field.
	* The short form is a single byte defining a length 0 - 127.
	* The long form is a byte 0 - 127 with the top bit set and this indicates
	* the number of following octets that contain the length. These octets
	* are stored most significant digit first.
	*/
	static int asn1_get_length(const unsigned char *pp, int inf, long *rl,
	long max)
	{
	const unsigned char p = pp;
	unsigned long ret = 0;
	int i;

	if (max-- < 1)
	return 0;
	if (*p == 0x80) {
	*inf = 1;
	p++;
	} else {
	*inf = 0;
	i = *p & 0x7f;
	if (*p++ & 0x80) {
	if (max < i + 1)
	return 0;
	/* Skip leading zeroes */
	while (i > 0 && *p == 0) {
	p++;
	i--;
	}
	if (i > (int)sizeof(long))
	return 0;
	while (i > 0) {
	ret <<= 8;
	ret \|= *p++;
	i--;
	}
	if (ret > LONG_MAX)
	return 0;
	} else {
	ret = i;
	}
	}
	*pp = p;
	*rl = (long)ret;
	return 1;
	}

	/*
	* constructed == 2 for indefinite length constructed
	*/
	void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
	int xclass)
	{
	unsigned char p = pp;
	int i, ttag;

	i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
	i \|= (xclass & V_ASN1_PRIVATE);
	if (tag < 31) {
	*(p++) = i \| (tag & V_ASN1_PRIMITIVE_TAG);
	} else {
	*(p++) = i \| V_ASN1_PRIMITIVE_TAG;
	for (i = 0, ttag = tag; ttag > 0; i++)
	ttag >>= 7;
	ttag = i;
	while (i-- > 0) {
	p[i] = tag & 0x7f;
	if (i != (ttag - 1))
	p[i] \|= 0x80;
	tag >>= 7;
	}
	p += ttag;
	}
	if (constructed == 2)
	*(p++) = 0x80;
	else
	asn1_put_length(&p, length);
	*pp = p;
	}

	int ASN1_put_eoc(unsigned char **pp)
	{
	unsigned char p = pp;

	*p++ = 0;
	*p++ = 0;
	*pp = p;
	return 2;
	}

	static void asn1_put_length(unsigned char **pp, int length)
	{
	unsigned char p = pp;
	int i, len;

	if (length <= 127) {
	*(p++) = (unsigned char)length;
	} else {
	len = length;
	for (i = 0; len > 0; i++)
	len >>= 8;
	*(p++) = i \| 0x80;
	len = i;
	while (i-- > 0) {
	p[i] = length & 0xff;
	length >>= 8;
	}
	p += len;
	}
	*pp = p;
	}

	int ASN1_object_size(int constructed, int length, int tag)
	{
	int ret = 1;

	if (length < 0)
	return -1;
	if (tag >= 31) {
	while (tag > 0) {
	tag >>= 7;
	ret++;
	}
	}
	if (constructed == 2) {
	ret += 3;
	} else {
	ret++;
	if (length > 127) {
	int tmplen = length;
	while (tmplen > 0) {
	tmplen >>= 8;
	ret++;
	}
	}
	}
	if (ret >= INT_MAX - length)
	return -1;
	return ret + length;
	}

	int ASN1_STRING_copy(ASN1_STRING dst, const ASN1_STRING str)
	{
	if (str == NULL)
	return 0;
	dst->type = str->type;
	if (!ASN1_STRING_set(dst, str->data, str->length))
	return 0;
	/* Copy flags but preserve embed value */
	dst->flags &= ASN1_STRING_FLAG_EMBED;
	dst->flags \|= str->flags & ~ASN1_STRING_FLAG_EMBED;
	return 1;
	}

	ASN1_STRING ASN1_STRING_dup(const ASN1_STRING str)
	{
	ASN1_STRING *ret;

	if (!str)
	return NULL;
	ret = ASN1_STRING_new();
	if (ret == NULL)
	return NULL;
	if (!ASN1_STRING_copy(ret, str)) {
	ASN1_STRING_free(ret);
	return NULL;
	}
	return ret;
	}

	int ASN1_STRING_set(ASN1_STRING str, const void _data, int len_in)
	{
	unsigned char *c;
	const char *data = _data;
	size_t len;

	if (len_in < 0) {
	if (data == NULL)
	return 0;
	len = strlen(data);
	} else {
	len = (size_t)len_in;
	}
	/*
	* Verify that the length fits within an integer for assignment to
	* str->length below. The additional 1 is subtracted to allow for the
	* '\0' terminator even though this isn't strictly necessary.
	*/
	if (len > INT_MAX - 1) {
	ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LARGE);
	return 0;
	}
	if ((size_t)str->length <= len \|\| str->data == NULL) {
	c = str->data;
	#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
	/* No NUL terminator in fuzzing builds */
	str->data = OPENSSL_realloc(c, len != 0 ? len : 1);
	#else
	str->data = OPENSSL_realloc(c, len + 1);
	#endif
	if (str->data == NULL) {
	ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
	str->data = c;
	return 0;
	}
	}
	str->length = len;
	if (data != NULL) {
	memcpy(str->data, data, len);
	#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
	/* Set the unused byte to something non NUL and printable. */
	if (len == 0)
	str->data[len] = '~';
	#else
	/*
	* Add a NUL terminator. This should not be necessary - but we add it as
	* a safety precaution
	*/
	str->data[len] = '\0';
	#endif
	}
	return 1;
	}

	void ASN1_STRING_set0(ASN1_STRING str, void data, int len)
	{
	OPENSSL_free(str->data);
	str->data = data;
	str->length = len;
	}

	ASN1_STRING *ASN1_STRING_new(void)
	{
	return ASN1_STRING_type_new(V_ASN1_OCTET_STRING);
	}

	ASN1_STRING *ASN1_STRING_type_new(int type)
	{
	ASN1_STRING *ret;

	ret = OPENSSL_zalloc(sizeof(*ret));
	if (ret == NULL) {
	ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
	return NULL;
	}
	ret->type = type;
	return ret;
	}

	void ossl_asn1_string_embed_free(ASN1_STRING *a, int embed)
	{
	if (a == NULL)
	return;
	if (!(a->flags & ASN1_STRING_FLAG_NDEF))
	OPENSSL_free(a->data);
	if (embed == 0)
	OPENSSL_free(a);
	}

	void ASN1_STRING_free(ASN1_STRING *a)
	{
	if (a == NULL)
	return;
	ossl_asn1_string_embed_free(a, a->flags & ASN1_STRING_FLAG_EMBED);
	}

	void ASN1_STRING_clear_free(ASN1_STRING *a)
	{
	if (a == NULL)
	return;
	if (a->data && !(a->flags & ASN1_STRING_FLAG_NDEF))
	OPENSSL_cleanse(a->data, a->length);
	ASN1_STRING_free(a);
	}

	int ASN1_STRING_cmp(const ASN1_STRING a, const ASN1_STRING b)
	{
	int i;

	i = (a->length - b->length);
	if (i == 0) {
	if (a->length != 0)
	i = memcmp(a->data, b->data, a->length);
	if (i == 0)
	return a->type - b->type;
	else
	return i;
	} else {
	return i;
	}
	}

	int ASN1_STRING_length(const ASN1_STRING *x)
	{
	return x->length;
	}

	#ifndef OPENSSL_NO_DEPRECATED_3_0
	void ASN1_STRING_length_set(ASN1_STRING *x, int len)
	{
	x->length = len;
	}
	#endif

	int ASN1_STRING_type(const ASN1_STRING *x)
	{
	return x->type;
	}

	const unsigned char ASN1_STRING_get0_data(const ASN1_STRING x)
	{
	return x->data;
	}

	#ifndef OPENSSL_NO_DEPRECATED_1_1_0
	unsigned char ASN1_STRING_data(ASN1_STRING x)
	{
	return x->data;
	}
	#endif

	/* \|max_len\| excludes NUL terminator and may be 0 to indicate no restriction */
	char ossl_sk_ASN1_UTF8STRING2text(STACK_OF(ASN1_UTF8STRING) text,
	const char *sep, size_t max_len)
	{
	int i;
	ASN1_UTF8STRING *current;
	size_t length = 0, sep_len;
	char *result = NULL;
	char *p;

	if (sep == NULL)
	sep = "";
	sep_len = strlen(sep);

	for (i = 0; i < sk_ASN1_UTF8STRING_num(text); i++) {
	current = sk_ASN1_UTF8STRING_value(text, i);
	if (i > 0)
	length += sep_len;
	length += ASN1_STRING_length(current);
	if (max_len != 0 && length > max_len)
	return NULL;
	}
	if ((result = OPENSSL_malloc(length + 1)) == NULL)
	return NULL;

	p = result;
	for (i = 0; i < sk_ASN1_UTF8STRING_num(text); i++) {
	current = sk_ASN1_UTF8STRING_value(text, i);
	length = ASN1_STRING_length(current);
	if (i > 0 && sep_len > 0) {
	strncpy(p, sep, sep_len + 1); /* using + 1 to silence gcc warning */
	p += sep_len;
	}
	strncpy(p, (const char *)ASN1_STRING_get0_data(current), length);
	p += length;
	}
	*p = '\0';

	return result;
	}