.\" $OpenBSD: ASN1_TYPE_get.3,v 1.19 2023/10/09 16:06:01 tb Exp $ .\" selective merge up to: OpenSSL 6328d367 Jul 4 21:58:30 2020 +0200 .\" .\" This file is a derived work. .\" The changes are covered by the following Copyright and license: .\" .\" Copyright (c) 2017, 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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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: October 9 2023 $ .Dt ASN1_TYPE_GET 3 .Os .Sh NAME .Nm ASN1_TYPE_new , .Nm ASN1_TYPE_free , .Nm ASN1_TYPE_get , .Nm ASN1_TYPE_set , .Nm ASN1_TYPE_set1 , .Nm ASN1_TYPE_set_octetstring , .Nm ASN1_TYPE_get_octetstring , .Nm ASN1_TYPE_set_int_octetstring , .Nm ASN1_TYPE_get_int_octetstring , .Nm ASN1_TYPE_cmp .Nd ASN.1 objects of arbitrary type .Sh SYNOPSIS .In openssl/asn1.h .Ft ASN1_TYPE * .Fn ASN1_TYPE_new void .Ft void .Fn ASN1_TYPE_free "ASN1_TYPE *a" .Ft int .Fo ASN1_TYPE_get .Fa "const ASN1_TYPE *a" .Fc .Ft void .Fo ASN1_TYPE_set .Fa "ASN1_TYPE *a" .Fa "int type" .Fa "void *value" .Fc .Ft int .Fo ASN1_TYPE_set1 .Fa "ASN1_TYPE *a" .Fa "int type" .Fa "const void *value" .Fc .Ft int .Fo ASN1_TYPE_set_octetstring .Fa "ASN1_TYPE *a" .Fa "const unsigned char *data" .Fa "int len" .Fc .Ft int .Fo ASN1_TYPE_get_octetstring .Fa "const ASN1_TYPE *a" .Fa "unsigned char *buffer" .Fa "int buflen" .Fc .Ft int .Fo ASN1_TYPE_set_int_octetstring .Fa "ASN1_TYPE *a" .Fa "long num" .Fa "const unsigned char *data" .Fa "int len" .Fc .Ft int .Fo ASN1_TYPE_get_int_octetstring .Fa "const ASN1_TYPE *a", .Fa "long *num" .Fa "unsigned char *buffer", .Fa "int buflen" .Fc .Ft int .Fo ASN1_TYPE_cmp .Fa "const ASN1_TYPE *a" .Fa "const ASN1_TYPE *b" .Fc .Sh DESCRIPTION The .Vt ASN1_TYPE data type and the .Dv V_ASN1_ANY type identifier constant represent the ASN.1 ANY type. An .Vt ASN1_TYPE object can store an ASN.1 value of arbitrary type, including constructed types such as a SEQUENCE. It also remembers internally which type it currently holds. .Pp .Fn ASN1_TYPE_new allocates and initializes an empty .Vt ASN1_TYPE object of type .Dv V_ASN1_UNDEF . .Pp .Fn ASN1_TYPE_free frees .Fa a including the value stored in it, if any. If .Fa a is a .Dv NULL pointer, no action occurs. .Pp .Fn ASN1_TYPE_get returns the type currently held by .Fa a , represented by one of the .Dv V_ASN1_* constants defined in .In openssl/asn1.h . .Pp .Fn ASN1_TYPE_set frees the value contained in .Fa a , if any, and sets the .Fa value and .Fa type now held in .Fa a . This function uses the pointer .Fa value internally so it must .Sy not be freed up after the call. .Pp .Fn ASN1_TYPE_set1 sets the type held by .Fa a to .Fa type and its value to a copy of .Fa value . If copying succeeds, the previous value that was contained in .Fa a is freed. If copying fails, .Fa a remains unchanged. .Pp The type and meaning of the .Fa value argument of .Fn ASN1_TYPE_set and .Fn ASN1_TYPE_set1 is determined by the .Fa type argument. If .Fa type is .Dv V_ASN1_NULL , .Fa value is ignored. If .Fa type is .Dv V_ASN1_BOOLEAN , then the boolean is set to TRUE if .Fa value is not .Dv NULL . If .Fa type is .Dv V_ASN1_OBJECT , then .Fa value is an .Vt ASN1_OBJECT structure. Otherwise .Fa type is an .Vt ASN1_STRING structure. If .Fa type corresponds to a primitive type or a string type, then the contents of the .Vt ASN1_STRING contains the content octets of the type. If .Fa type corresponds to a constructed type or a tagged type .Pq Dv V_ASN1_SEQUENCE , V_ASN1_SET , No or Dv V_ASN1_OTHER , then the .Vt ASN1_STRING contains the entire ASN.1 encoding verbatim, including tag and length octets. .Pp .Fn ASN1_TYPE_set_octetstring allocates a new .Vt ASN1_OCTET_STRING object, copies .Fa len bytes of .Fa data into it using .Xr ASN1_STRING_set 3 , and replaces the value of .Fa a with it by calling .Fn ASN1_TYPE_set with a type of .Dv V_ASN1_OCTET_STRING . .Pp .Fn ASN1_TYPE_get_octetstring copies the contents of the .Vt ASN1_OCTET_STRING object contained in .Fa a , but not more than .Fa buflen bytes, into the .Fa buffer provided by the caller. .Pp .Fn ASN1_TYPE_set_int_octetstring frees the value contained in .Fa a , if any, sets its type to .Dv V_ASN1_SEQUENCE , and sets its value to a two-element ASN.1 sequence consisting of an ASN.1 INTEGER object with the value .Fa num and an ASN.1 OCTET STRING object containing a copy of the .Fa len bytes pointed to by .Fa data . .Pp .Fn ASN1_TYPE_get_int_octetstring copies the integer value from the first element of the ASN.1 sequence .Fa a to .Pf * Fa num unless .Fa num is a .Dv NULL pointer and copies the octet string value from the second element, but not more than .Fa buflen bytes, into the .Fa buffer provided by the caller unless .Fa buffer is a .Dv NULL pointer. .Pp .Fn ASN1_TYPE_cmp checks that .Fa a and .Fa b hold the same type, the same value, and are encoded in the same way. .Pp If the types agree and the values have the same meaning but are encoded differently, they are considered different. For example, a boolean value is represented using a single content octet. Under BER, any non-zero octet represents the TRUE value, but .Fn ASN1_TYPE_cmp will only report a match if the content octet is the same. .Pp If either or both of the arguments passed to .Fn ASN1_TYPE_cmp is .Dv NULL , the result is a mismatch. Technically, if both arguments are .Dv NULL , the two types could be absent OPTIONAL fields and so should match, however passing .Dv NULL values could also indicate a programming error (for example an unparsable type which returns .Dv NULL ) for types which do .Sy not match. So applications should handle the case of two absent values separately. .Sh RETURN VALUES .Fn ASN1_TYPE_new returns the new .Vt ASN1_TYPE object or .Dv NULL if an error occurs. .Pp .Fn ASN1_TYPE_get returns the type currently held by .Fa a or 0 if an error occurs. The latter can happen if .Fa a does not contain a value even though its type is not .Dv V_ASN1_NULL . For example, it will always happen for empty objects newly constructed with .Fn ASN1_TYPE_new . .Pp .Fn ASN1_TYPE_set1 , .Fn ASN1_TYPE_set_octetstring , and .Fn ASN1_TYPE_set_int_octetstring return 1 on success or 0 on failure. .Pp .Fn ASN1_TYPE_get_octetstring returns the number of data bytes contained in the .Vt ASN1_OCTET_STRING object contained in .Fa a or \-1 if .Fa a is not of the type .Dv V_ASN1_OCTET_STRING or does not contain any object. If the return value is greater than the .Fa buflen argument, the content was truncated when copied to the .Fa buffer . .Pp .Fn ASN1_TYPE_get_int_octetstring returns the number of data bytes contained in the .Vt ASN1_OCTET_STRING object that is the second element of the ASN.1 sequence .Fa a or \-1 if .Fa a is not of the type .Dv V_ASN1_SEQUENCE or if decoding fails. If the return value is greater than the .Fa buflen argument, the content was truncated when copied to the .Fa buffer . .Pp .Fn ASN1_TYPE_cmp returns 0 for a match or non-zero for a mismatch. .Sh SEE ALSO .Xr ASN1_generate_nconf 3 , .Xr ASN1_get_object 3 , .Xr ASN1_item_free 3 , .Xr ASN1_OBJECT_new 3 , .Xr ASN1_parse_dump 3 , .Xr ASN1_put_object 3 , .Xr ASN1_STRING_dup 3 , .Xr ASN1_STRING_new 3 , .Xr crypto 3 , .Xr d2i_ASN1_NULL 3 , .Xr d2i_ASN1_SEQUENCE_ANY 3 , .Xr d2i_ASN1_TYPE 3 , .Xr OBJ_dup 3 .Sh HISTORY .Fn ASN1_TYPE_new and .Fn ASN1_TYPE_free first appeared in SSLeay 0.5.1, .Fn ASN1_TYPE_get and .Fn ASN1_TYPE_set in SSLeay 0.8.0, and .Fn ASN1_TYPE_set_octetstring , .Fn ASN1_TYPE_get_octetstring , .Fn ASN1_TYPE_set_int_octetstring , and .Fn ASN1_TYPE_get_int_octetstring in SSLeay 0.9.0. These functions have been available since .Ox 2.4 . .Pp .Fn ASN1_TYPE_set1 first appeared in OpenSSL 0.9.8h and has been available since .Ox 4.5 . .Pp .Fn ASN1_TYPE_cmp first appeared in OpenSSL 0.9.8zd, 1.0.0p, and 1.0.1k and has been available since .Ox 4.9 .