EVP_PKEY_ADD1_ATTR(3)      Library Functions Manual      EVP_PKEY_ADD1_ATTR(3)

NAME
     EVP_PKEY_add1_attr, EVP_PKEY_add1_attr_by_OBJ, EVP_PKEY_add1_attr_by_NID,
     EVP_PKEY_add1_attr_by_txt, EVP_PKEY_delete_attr, EVP_PKEY_get_attr,
     EVP_PKEY_get_attr_count, EVP_PKEY_get_attr_by_OBJ,
     EVP_PKEY_get_attr_by_NID - X.501 Attributes of private keys

SYNOPSIS
     #include <openssl/x509.h>

     int
     EVP_PKEY_add1_attr(EVP_PKEY *key, X509_ATTRIBUTE *attr);

     int
     EVP_PKEY_add1_attr_by_OBJ(EVP_PKEY *key, const ASN1_OBJECT *obj,
         int type, const unsigned char *data, int len);

     int
     EVP_PKEY_add1_attr_by_NID(EVP_PKEY *key, int nid, int type,
         const unsigned char *data, int len);

     int
     EVP_PKEY_add1_attr_by_txt(EVP_PKEY *key, const char *name, int type,
         const unsigned char *data, int len);

     X509_ATTRIBUTE *
     EVP_PKEY_delete_attr(EVP_PKEY *key, int index);

     X509_ATTRIBUTE *
     EVP_PKEY_get_attr(const EVP_PKEY *key, int index);

     int
     EVP_PKEY_get_attr_count(const EVP_PKEY *key);

     int
     EVP_PKEY_get_attr_by_OBJ(const EVP_PKEY *key, const ASN1_OBJECT *obj,
         int start_after);

     int
     EVP_PKEY_get_attr_by_NID(const EVP_PKEY *key, int nid, int start_after);

DESCRIPTION
     These functions support associating an array of X.501 Attributes with a
     private key.  Such attributes can for example be included in PKCS#12
     structures.

     EVP_PKEY_add1_attr() appends a deep copy of the attr using
     X509at_add1_attr(3).

     EVP_PKEY_add1_attr_by_OBJ(), EVP_PKEY_add1_attr_by_NID(), and
     EVP_PKEY_add1_attr_by_txt() create a new X.501 Attribute object using
     X509_ATTRIBUTE_create_by_OBJ(3), X509_ATTRIBUTE_create_by_NID(3), or
     X509_ATTRIBUTE_create_by_txt(3), respectively, and append it using
     X509at_add1_attr(3).

     EVP_PKEY_delete_attr() deletes the attribute with the zero-based index
     using X509at_delete_attr(3).

     EVP_PKEY_get_attr() returns the attribute with the zero-based index using
     X509at_get_attr(3).

     EVP_PKEY_get_attr_count() returns the number of attributes currently
     associated with the key using X509at_get_attr_count(3).

     EVP_PKEY_get_attr_by_OBJ() and EVP_PKEY_get_attr_by_NID() search for an
     attribute of the type obj or nid using X509at_get_attr_by_OBJ(3) or
     X509at_get_attr_by_NID(3), respectively.

RETURN VALUES
     EVP_PKEY_add1_attr(), EVP_PKEY_add1_attr_by_OBJ(),
     EVP_PKEY_add1_attr_by_NID(), and EVP_PKEY_add1_attr_by_txt() return 1 for
     success or 0 for failure.

     EVP_PKEY_delete_attr() and EVP_PKEY_get_attr() return the deleted or
     requested attribute or NULL if the requested index is negative or greater
     than or equal to the current number of attributes associated with the
     key.

     EVP_PKEY_get_attr_count() returns the current number of attributes.

     EVP_PKEY_get_attr_by_OBJ() and EVP_PKEY_get_attr_by_NID() return the
     index of the first attribute that has an index greater than start_after
     and a type matching obj or nid, respectively, or -1 on failure.  In
     addition, EVP_PKEY_get_attr_by_NID() returns -2 if OBJ_nid2obj(3) fails
     on the requested nid.

SEE ALSO
     EVP_PKEY_new(3), OBJ_nid2obj(3), PKCS12_create(3),
     X509_ATTRIBUTE_create_by_OBJ(3), X509_ATTRIBUTE_new(3),
     X509at_add1_attr(3), X509at_get_attr(3)

HISTORY
     These functions first appeared in OpenSSL 0.9.8 and have been available
     since OpenBSD 4.5.

Linux 6.8.2-arch2-1            October 26, 2021            Linux 6.8.2-arch2-1