NAME

       X509_REQ_get_attr_count, X509_REQ_get_attr_by_NID, X509_REQ_get_attr_by_OBJ,
       X509_REQ_get_attr, X509_REQ_delete_attr, X509_REQ_add1_attr, X509_REQ_add1_attr_by_OBJ,
       X509_REQ_add1_attr_by_NID, X509_REQ_add1_attr_by_txt - X509_ATTRIBUTE support for signed
       certificate requests

SYNOPSIS

        #include <openssl/x509.h>

        int X509_REQ_get_attr_count(const X509_REQ *req);
        int X509_REQ_get_attr_by_NID(const X509_REQ *req, int nid, int lastpos);
        int X509_REQ_get_attr_by_OBJ(const X509_REQ *req, const ASN1_OBJECT *obj,
                                     int lastpos);
        X509_ATTRIBUTE *X509_REQ_get_attr(const X509_REQ *req, int loc);
        X509_ATTRIBUTE *X509_REQ_delete_attr(X509_REQ *req, int loc);
        int X509_REQ_add1_attr(X509_REQ *req, X509_ATTRIBUTE *attr);
        int X509_REQ_add1_attr_by_OBJ(X509_REQ *req,
                                      const ASN1_OBJECT *obj, int type,
                                      const unsigned char *bytes, int len);
        int X509_REQ_add1_attr_by_NID(X509_REQ *req,
                                      int nid, int type,
                                      const unsigned char *bytes, int len);
        int X509_REQ_add1_attr_by_txt(X509_REQ *req,
                                      const char *attrname, int type,
                                      const unsigned char *bytes, int len);

DESCRIPTION

       X509_REQ_get_attr_by_OBJ() finds the location of the first matching object obj in the req
       attribute list. The search starts at the position after lastpos.  If the returned value is
       positive then it can be used on the next call to X509_REQ_get_attr_by_OBJ() as the value
       of lastpos in order to iterate through the remaining attributes. lastpos can be set to any
       negative value on the first call, in order to start searching from the start of the
       attribute list.

       X509_REQ_get_attr_by_NID() is similar to X509_REQ_get_attr_by_OBJ() except that it passes
       the numerical identifier (NID) nid associated with the object.  See <openssl/obj_mac.h>
       for a list of NID_*.

       X509_REQ_get_attr() returns the X509_ATTRIBUTE object at index loc in the req attribute
       list. loc should be in the range from 0 to X509_REQ_get_attr_count() - 1.

       X509_REQ_delete_attr() removes the X509_ATTRIBUTE object at index loc in the req objects
       list of attributes. An error occurs if req is NULL.

       X509_REQ_add1_attr() pushes a copy of the passed in X509_ATTRIBUTE attr> to the req
       object's attribute list. An error will occur if either the attribute list is NULL or the
       attribute already exists.

       X509_REQ_add1_attr_by_OBJ() creates a new X509_ATTRIBUTE using
       X509_ATTRIBUTE_set1_object() and X509_ATTRIBUTE_set1_data() to assign a new obj with type
       type and data bytes of length len and then pushes it to the req object's attribute list.
       req must be non NULL or an error will occur. If obj already exists in the attribute list
       then an error occurs.

       X509_REQ_add1_attr_by_NID() is similar to X509_REQ_add1_attr_by_OBJ() except that it
       passes the numerical identifier (NID) nid associated with the object.  See
       <openssl/obj_mac.h> for a list of NID_*.

       X509_REQ_add1_attr_by_txt() is similar to X509_REQ_add1_attr_by_OBJ() except that it
       passes a name attrname associated with the object.  See <openssl/obj_mac.h> for a list of
       SN_* names.

       Refer to X509_ATTRIBUTE(3) for information related to attributes.

RETURN VALUES

       X509_REQ_get_attr_count() returns the number of attributes in the req object attribute
       list or -1 if the attribute list is NULL.

       X509_REQ_get_attr_by_OBJ() returns -1 if either the req object's attribute list is empty
       OR obj is not found, otherwise it returns the location of the obj in the attribute list.

       X509_REQ_get_attr_by_NID() is similar to X509_REQ_get_attr_by_OBJ(), except that it
       returns -2 if the nid is not known by OpenSSL.

       X509_REQ_get_attr() returns either an X509_ATTRIBUTE or NULL on error.

       X509_REQ_delete_attr() returns either the removed X509_ATTRIBUTE or NULL if there is a
       error.

       X509_REQ_add1_attr(), X509_REQ_add1_attr_by_OBJ(), X509_REQ_add1_attr_by_NID() and
       X509_REQ_add1_attr_by_txt() return 1 on success or 0 on error.

NOTES

       Any functions that modify the attributes (add or delete) internally set a flag to indicate
       the ASN.1 encoding has been modified.

SEE ALSO

       X509_ATTRIBUTE(3)

COPYRIGHT

       Copyright 2023-2024 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>.