D2I_PKCS8PRIVATEKEY_BIO(3ossl) OpenSSL D2I_PKCS8PRIVATEKEY_BIO(3ossl)
NAME
d2i_PKCS8PrivateKey_bio, d2i_PKCS8PrivateKey_fp,
i2d_PKCS8PrivateKey_bio, i2d_PKCS8PrivateKey_fp,
i2d_PKCS8PrivateKey_nid_bio, i2d_PKCS8PrivateKey_nid_fp - PKCS#8 format
private key functions
SYNOPSIS
#include <openssl/pem.h>
EVP_PKEY *d2i_PKCS8PrivateKey_bio(BIO *bp, EVP_PKEY **x, pem_password_cb *cb, void *u);
EVP_PKEY *d2i_PKCS8PrivateKey_fp(FILE *fp, EVP_PKEY **x, pem_password_cb *cb, void *u);
int i2d_PKCS8PrivateKey_bio(BIO *bp, const EVP_PKEY *x, const EVP_CIPHER *enc,
char *kstr, int klen,
pem_password_cb *cb, void *u);
int i2d_PKCS8PrivateKey_fp(FILE *fp, const EVP_PKEY *x, const EVP_CIPHER *enc,
char *kstr, int klen,
pem_password_cb *cb, void *u);
int i2d_PKCS8PrivateKey_nid_bio(BIO *bp, const EVP_PKEY *x, int nid,
char *kstr, int klen,
pem_password_cb *cb, void *u);
int i2d_PKCS8PrivateKey_nid_fp(FILE *fp, const EVP_PKEY *x, int nid,
char *kstr, int klen,
pem_password_cb *cb, void *u);
DESCRIPTION
The PKCS#8 functions encode and decode private keys in PKCS#8 format
using both PKCS#5 v1.5 and PKCS#5 v2.0 password based encryption
algorithms.
Other than the use of DER as opposed to PEM these functions are
identical to the corresponding PEM function as described in
PEM_read_PrivateKey(3).
NOTES
These functions are currently the only way to store encrypted private
keys using DER format.
Currently all the functions use BIOs or FILE pointers, there are no
functions which support password-protection and work directly on
memory: this can be readily worked around by converting the buffers to
memory BIOs, see BIO_s_mem(3) for details. If password-protection is
not required, the i2d_PKCS8PrivateKey(3) function encodes a private key
to an unencrypted DER PKCS#8 form.
These functions make no assumption regarding the pass phrase received
from the password callback. It will simply be treated as a byte
sequence.
RETURN VALUES
d2i_PKCS8PrivateKey_bio(3) and d2i_PKCS8PrivateKey_fp() return a valid
EVP_PKEY structure or NULL if an error occurred.
i2d_PKCS8PrivateKey_bio(), i2d_PKCS8PrivateKey_fp(),
i2d_PKCS8PrivateKey_nid_bio() and i2d_PKCS8PrivateKey_nid_fp() return 1
on success or 0 on error.
SEE ALSO
i2d_PKCS8PrivateKey(3), PEM_read_PrivateKey(3), passphrase-encoding(7)
HISTORY
i2d_PKCS8PrivateKey(3) was added in OpenSSL 3.6.
COPYRIGHT
Copyright 2002-2025 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>.
3.6.0 2025-10-01 D2I_PKCS8PRIVATEKEY_BIO(3ossl)
openssl 3.6.0 - Generated Mon Jan 19 13:47:38 CST 2026