X509_ALGOR_dup(3) | OpenSSL | X509_ALGOR_dup(3)

# NAME

X509_ALGOR_dup, X509_ALGOR_set0, X509_ALGOR_get0, X509_ALGOR_set_md, X509_ALGOR_cmp, X509_ALGOR_copy - AlgorithmIdentifier functions

# SYNOPSIS

     #include <openssl/x509.h>
     X509_ALGOR *X509_ALGOR_dup(X509_ALGOR *alg);
     int X509_ALGOR_set0(X509_ALGOR *alg, ASN1_OBJECT *aobj, int ptype, void *pval);
     void X509_ALGOR_get0(const ASN1_OBJECT **paobj, int *pptype,
                          const void **ppval, const X509_ALGOR *alg);
     void X509_ALGOR_set_md(X509_ALGOR *alg, const EVP_MD *md);
     int X509_ALGOR_cmp(const X509_ALGOR *a, const X509_ALGOR *b);
     int X509_ALGOR_copy(X509_ALGOR *dest, const X509_ALGOR *src);

# DESCRIPTION

X509_ALGOR_dup() returns a copy of alg.

X509_ALGOR_set0() sets the algorithm OID of alg to aobj and the associated parameter type to ptype with value pval. If ptype is V_ASN1_UNDEF the parameter is omitted, otherwise ptype and pval have the same meaning as the type and value parameters to ASN1_TYPE_set(). All the supplied parameters are used internally so must NOT be freed after this call succeeded; otherwise ownership remains with the caller and alg remains untouched.

X509_ALGOR_get0() is the inverse of X509_ALGOR_set0(): it returns the algorithm OID in *paobj and the associated parameter in *pptype and *ppval from the AlgorithmIdentifier alg.

X509_ALGOR_set_md() sets the AlgorithmIdentifier alg to appropriate values for the message digest md.

X509_ALGOR_cmp() compares a and b and returns 0 if they have identical encodings and nonzero otherwise.

X509_ALGOR_copy() copies the source values into the dest structs; making a duplicate of each (and free any thing pointed to from within *dest).

# RETURN VALUES

X509_ALGOR_dup() returns a valid X509_ALGOR structure or NULL if an error occurred.

X509_ALGOR_set0() and X509_ALGOR_copy() return 1 on success or 0 on error.

X509_ALGOR_get0() and X509_ALGOR_set_md() return no values.

X509_ALGOR_cmp() returns 0 if the two parameters have identical encodings and nonzero otherwise.

# HISTORY

The X509_ALGOR_copy() was added in 1.1.1e.

# COPYRIGHT

Copyright 2002-2022 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>.

2026-06-09 | 3.5.7