.\" $OpenBSD: ASN1_STRING_length.3,v 1.29 2021/12/14 19:36:18 schwarze Exp $ .\" full merge up to: OpenSSL 24a535ea Sep 22 13:14:20 2020 +0100 .\" .\" This file is a derived work. .\" The changes are covered by the following Copyright and license: .\" .\" Copyright (c) 2018, 2019, 2021 Ingo Schwarze .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. 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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. .\" .Dd $Mdocdate: December 14 2021 $ .Dt ASN1_STRING_LENGTH 3 .Os .Sh NAME .Nm ASN1_STRING_cmp , .Nm ASN1_OCTET_STRING_cmp , .Nm ASN1_STRING_data , .Nm ASN1_STRING_dup , .Nm ASN1_OCTET_STRING_dup , .Nm ASN1_STRING_get0_data , .Nm ASN1_STRING_length , .Nm ASN1_STRING_length_set , .Nm ASN1_STRING_set0 , .Nm ASN1_STRING_set , .Nm ASN1_OCTET_STRING_set , .Nm ASN1_STRING_copy , .Nm ASN1_STRING_to_UTF8 , .Nm ASN1_STRING_type .\" deprecated aliases, intentionally undocumented: .\" M_ASN1_STRING_data, M_ASN1_STRING_length .Nd ASN1_STRING utility functions .Sh SYNOPSIS .In openssl/asn1.h .Ft int .Fo ASN1_STRING_cmp .Fa "const ASN1_STRING *a" .Fa "const ASN1_STRING *b" .Fc .Ft int .Fo ASN1_OCTET_STRING_cmp .Fa "const ASN1_OCTET_STRING *a" .Fa "const ASN1_OCTET_STRING *b" .Fc .Ft unsigned char * .Fo ASN1_STRING_data .Fa "ASN1_STRING *x" .Fc .Ft ASN1_STRING * .Fo ASN1_STRING_dup .Fa "const ASN1_STRING *a" .Fc .Ft ASN1_OCTET_STRING * .Fo ASN1_OCTET_STRING_dup .Fa "const ASN1_OCTET_STRING *a" .Fc .Ft const unsigned char * .Fo ASN1_STRING_get0_data .Fa "const ASN1_STRING *x" .Fc .Ft int .Fo ASN1_STRING_length .Fa "const ASN1_STRING *x" .Fc .Ft void .Fo ASN1_STRING_length_set .Fa "ASN1_STRING *x" .Fa "int len" .Fc .Ft void .Fo ASN1_STRING_set0 .Fa "ASN1_STRING *str" .Fa "void *data" .Fa "int len" .Fc .Ft int .Fo ASN1_STRING_set .Fa "ASN1_STRING *str" .Fa "const void *data" .Fa "int len" .Fc .Ft int .Fo ASN1_OCTET_STRING_set .Fa "ASN1_OCTET_STRING *str" .Fa "const unsigned char *data" .Fa "int len" .Fc .Ft int .Fo ASN1_STRING_copy .Fa "ASN1_STRING *dst" .Fa "const ASN1_STRING *src" .Fc .Ft int .Fo ASN1_STRING_to_UTF8 .Fa "unsigned char **out" .Fa "const ASN1_STRING *in" .Fc .Ft int .Fo ASN1_STRING_type .Fa "const ASN1_STRING *x" .Fc .Sh DESCRIPTION These functions manipulate .Vt ASN1_STRING structures. .Pp .Fn ASN1_STRING_cmp compares the type, the length, and the content of .Fa a and .Fa b . .Pp .Fn ASN1_OCTET_STRING_cmp does exactly the same as .Fn ASN1_STRING_cmp without providing any type safety. .Pp .Fn ASN1_STRING_data is similar to .Fn ASN1_STRING_get0_data except that the returned value is not constant. This function is deprecated. Applications should use .Fn ASN1_STRING_get0_data instead. .Pp .Fn ASN1_STRING_dup allocates a new .Vt ASN1_STRING object and copies the type, length, data, and flags from .Fa a into it. .Pp .Fn ASN1_OCTET_STRING_dup does exactly the same as .Fn ASN1_STRING_dup without providing any type safety. .Pp .Fn ASN1_STRING_get0_data returns an internal pointer to the data of .Fa x . It should not be freed or modified in any way. .Pp .Fn ASN1_STRING_length returns the length attribute of .Fa x , measured in bytes. .Pp .Fn ASN1_STRING_length_set sets the length attribute of .Fa x to .Fa len . It may put .Fa x into an inconsistent internal state. .Pp .Fn ASN1_STRING_set0 frees any data stored in .Fa str , sets the length attribute to .Fa len bytes, and sets the data attribute to .Fa data , transferring ownership, without doing any validation. .Pp .Fn ASN1_STRING_set sets the length attribute of .Fa str to .Fa len and copies that number of bytes from .Fa data into .Fa str , overwriting any previous data. If .Fa len is \-1, then .Fn strlen data is used instead of .Fa len . If .Fa data is .Dv NULL , the content of .Fa str remains uninitialized; that is not considered an error unless .Fa len is negative. .Pp .Fn ASN1_OCTET_STRING_set does exactly the same as .Fn ASN1_STRING_set without providing any type safety. .Pp .Fn ASN1_STRING_copy copies the length and data of .Fa src into .Fa dst using .Fn ASN1_STRING_set and changes the type and flags of .Fa dst to match the type and flags of .Fa src . .Pp .Fn ASN1_STRING_to_UTF8 converts the string .Fa in to UTF-8 format. The converted data is copied into a newly allocated buffer .Pf * Fa out . The buffer .Pf * Fa out should be freed using .Xr free 3 . .Pp .Fn ASN1_STRING_type returns the type of .Fa x . If the bit .Dv V_ASN1_NEG is set in the return value, .Fa x is an ASN.1 INTEGER or ENUMERATED object with a negative value. .Pp Almost all ASN.1 types are represented as .Vt ASN1_STRING structures. Other types such as .Vt ASN1_OCTET_STRING are simply typedefed to .Vt ASN1_STRING and the functions call the .Vt ASN1_STRING equivalents. .Vt ASN1_STRING is also used for some CHOICE types which consist entirely of primitive string types such as .Vt DirectoryString and .Vt Time . .Pp These functions should .Em not be used to examine or modify .Vt ASN1_INTEGER or .Vt ASN1_ENUMERATED types: the relevant INTEGER or ENUMERATED utility functions should be used instead. .Pp In general it cannot be assumed that the data returned by .Fn ASN1_STRING_get0_data and .Fn ASN1_STRING_data is NUL terminated, and it may contain embedded NUL characters. The format of the data depends on the string type: for example for an .Vt IA5String the data contains ASCII characters, for a .Vt BMPString two bytes per character in big endian format, and for a .Vt UTF8String UTF-8 characters. .Pp Similar care should be taken to ensure the data is in the correct format when calling .Fn ASN1_STRING_set or .Fn ASN1_STRING_set0 . .Sh RETURN VALUES .Fn ASN1_STRING_cmp and .Fn ASN1_OCTET_STRING_cmp return 0 if the type, the length, and the content of .Fa a and .Fa b agree, or a non-zero value otherwise. In contrast to .Xr strcmp 3 , the sign of the return value does not indicate lexicographical ordering. .Pp .Fn ASN1_STRING_data and .Fn ASN1_STRING_get0_data return an internal pointer to the data of .Fa x . .Pp .Fn ASN1_STRING_dup and .Fn ASN1_OCTET_STRING_dup return a pointer to a newly allocated .Vt ASN1_STRING structure or .Dv NULL if an error occurred. .Pp .Fn ASN1_STRING_length returns a number of bytes. .Pp .Fn ASN1_STRING_set , .Fn ASN1_OCTET_STRING_set , and .Fn ASN1_STRING_copy return 1 on success or 0 on failure. They fail if memory allocation fails. .Fn ASN1_STRING_set and .Fn ASN1_OCTET_STRING_set also fail if .Fa data is .Dv NULL and .Fa len is \-1 in the same call. .Fn ASN1_STRING_copy also fails if .Fa src is .Dv NULL . .Pp .Fn ASN1_STRING_to_UTF8 returns the number of bytes in the output buffer .Pf * Fa out , or a negative number if an error occurred. .Pp .Fn ASN1_STRING_type returns an integer constant, for example .Dv V_ASN1_OCTET_STRING or .Dv V_ASN1_NEG_INTEGER . .Pp In some cases of failure of .Fn ASN1_STRING_dup , .Fn ASN1_STRING_set , and .Fn ASN1_STRING_to_UTF8 , the reason can be determined with .Xr ERR_get_error 3 . .Sh SEE ALSO .Xr ASN1_BIT_STRING_set 3 , .Xr ASN1_mbstring_copy 3 , .Xr ASN1_PRINTABLE_type 3 , .Xr ASN1_STRING_new 3 , .Xr ASN1_UNIVERSALSTRING_to_string 3 .Sh HISTORY .Fn ASN1_STRING_cmp , .Fn ASN1_STRING_dup , .Fn ASN1_STRING_set , and .Fn ASN1_OCTET_STRING_set first appeared in SSLeay 0.6.5. .Fn ASN1_OCTET_STRING_cmp , .Fn ASN1_STRING_data , .Fn ASN1_OCTET_STRING_dup , and .Fn ASN1_STRING_type first appeared in SSLeay 0.8.0. .Fn ASN1_STRING_length first appeared in SSLeay 0.9.0. All these functions have been available since .Ox 2.4 . .Pp .Fn ASN1_STRING_length_set first appeared in OpenSSL 0.9.5 and has been available since .Ox 2.7 . .Pp .Fn ASN1_STRING_to_UTF8 first appeared in OpenSSL 0.9.6 and has been available since .Ox 2.9 . .Pp .Fn ASN1_STRING_set0 first appeared in OpenSSL 0.9.8h and has been available since .Ox 4.5 . .Pp .Fn ASN1_STRING_copy first appeared in OpenSSL 1.0.0 and has been available since .Ox 4.9 . .Pp .Fn ASN1_STRING_get0_data first appeared in OpenSSL 1.1.0 and has been available since .Ox 6.3 . .Sh BUGS .Fn ASN1_OCTET_STRING_cmp , .Fn ASN1_OCTET_STRING_dup , and .Fn ASN1_OCTET_STRING_set do not check whether their arguments are really of the type .Dv V_ASN1_OCTET_STRING . They may report success even if their arguments are of a wrong type. Consequently, even in case of success, the return value of .Fn ASN1_OCTET_STRING_dup is not guaranteed to be of the type .Dv V_ASN1_OCTET_STRING either.