PEM_READ_CMS(3)

NAME
DECLARE_PEM_rw, PEM_read_CMS, PEM_read_bio_CMS, PEM_write_CMS, PEM_write_bio_CMS, PEM_write_DHxparams, PEM_write_bio_DHxparams, PEM_read_ECPKParameters, PEM_read_bio_ECPKParameters, PEM_write_ECPKParameters, PEM_write_bio_ECPKParameters, PEM_read_ECPrivateKey, PEM_write_ECPrivateKey, PEM_write_bio_ECPrivateKey, PEM_read_EC_PUBKEY, PEM_read_bio_EC_PUBKEY, PEM_write_EC_PUBKEY, PEM_write_bio_EC_PUBKEY, PEM_read_NETSCAPE_CERT_SEQUENCE, PEM_read_bio_NETSCAPE_CERT_SEQUENCE, PEM_write_NETSCAPE_CERT_SEQUENCE, PEM_write_bio_NETSCAPE_CERT_SEQUENCE, PEM_read_PKCS8, PEM_read_bio_PKCS8, PEM_write_PKCS8, PEM_write_bio_PKCS8, PEM_write_PKCS8_PRIV_KEY_INFO, PEM_read_bio_PKCS8_PRIV_KEY_INFO, PEM_read_PKCS8_PRIV_KEY_INFO, PEM_write_bio_PKCS8_PRIV_KEY_INFO, PEM_read_SSL_SESSION, PEM_read_bio_SSL_SESSION, PEM_write_SSL_SESSION, PEM_write_bio_SSL_SESSION, PEM_read_X509_PUBKEY, PEM_read_bio_X509_PUBKEY, PEM_write_X509_PUBKEY, PEM_write_bio_X509_PUBKEY - PEM object encoding routines

SYNOPSIS
 #include <openssl/pem.h>

 DECLARE_PEM_rw(name, TYPE)

 TYPE *PEM_read_TYPE(FILE *fp, TYPE **a, pem_password_cb *cb, void *u);
 TYPE *PEM_read_bio_TYPE(BIO *bp, TYPE **a, pem_password_cb *cb, void *u);
 int PEM_write_TYPE(FILE *fp, const TYPE *a);
 int PEM_write_bio_TYPE(BIO *bp, const TYPE *a);

The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):

 #include <openssl/pem.h>

 int PEM_write_DHxparams(FILE *out, const DH *dh);
 int PEM_write_bio_DHxparams(BIO *out, const DH *dh);
 EC_GROUP *PEM_read_ECPKParameters(FILE *fp, EC_GROUP **x, pem_password_cb *cb, void *u);
 EC_GROUP *PEM_read_bio_ECPKParameters(BIO *bp, EC_GROUP **x, pem_password_cb *cb, void *u);
 int PEM_write_ECPKParameters(FILE *out, const EC_GROUP *x);
 int PEM_write_bio_ECPKParameters(BIO *out, const EC_GROUP *x),

 EC_KEY *PEM_read_EC_PUBKEY(FILE *fp, EC_KEY **x, pem_password_cb *cb, void *u);
 EC_KEY *PEM_read_bio_EC_PUBKEY(BIO *bp, EC_KEY **x, pem_password_cb *cb, void *u);
 int PEM_write_EC_PUBKEY(FILE *out, const EC_KEY *x);
 int PEM_write_bio_EC_PUBKEY(BIO *out, const EC_KEY *x);

 EC_KEY *PEM_read_ECPrivateKey(FILE *out, EC_KEY **x, pem_password_cb *cb, void *u);
 EC_KEY *PEM_read_bio_ECPrivateKey(BIO *out, EC_KEY **x, pem_password_cb *cb, void *u);
 int PEM_write_ECPrivateKey(FILE *out, const EC_KEY *x, const EVP_CIPHER *enc,
                            const unsigned char *kstr, int klen,
                            pem_password_cb *cb, void *u);
 int PEM_write_bio_ECPrivateKey(BIO *out, const EC_KEY *x, const EVP_CIPHER *enc,
                                const unsigned char *kstr, int klen,
                                pem_password_cb *cb, void *u);

DESCRIPTION
To replace the deprecated functions listed above, applications should use the EVP_PKEY type and OSSL_DECODER_from_bio() and OSSL_ENCODER_to_bio() to read and write PEM data containing key parameters or private and public keys.

In the description below, TYPE is used as a placeholder for any of the OpenSSL datatypes, such as X509. The macro DECLARE_PEM_rw expands to the set of declarations shown in the next four lines of the synopsis.

These routines convert between local instances of ASN1 datatypes and the PEM encoding. For more information on the templates, see ASN1_ITEM(3). For more information on the lower-level routines used by the functions here, see PEM_read(3).

PEM_read_TYPE() reads a PEM-encoded object of TYPE from the file fp and returns it. The cb and u parameters are as described in pem_password_cb(3).

PEM_read_bio_TYPE() is similar to PEM_read_TYPE() but reads from the BIO bp.

PEM_write_TYPE() writes the PEM encoding of the object a to the file fp.

PEM_write_bio_TYPE() similarly writes to the BIO bp.

NOTES
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
PEM_read_TYPE() and PEM_read_bio_TYPE() return a pointer to an allocated object, which should be released by calling TYPE_free(), or NULL on error.

PEM_write_TYPE() and PEM_write_bio_TYPE() return 1 for success or 0 for failure.

SEE ALSO
PEM_read(3), passphrase-encoding(7)

HISTORY
The functions PEM_write_DHxparams(), PEM_write_bio_DHxparams(), PEM_read_ECPKParameters(), PEM_read_bio_ECPKParameters(), PEM_write_ECPKParameters(), PEM_write_bio_ECPKParameters(), PEM_read_EC_PUBKEY(), PEM_read_bio_EC_PUBKEY(), PEM_write_EC_PUBKEY(), PEM_write_bio_EC_PUBKEY(), PEM_read_ECPrivateKey(), PEM_read_bio_ECPrivateKey(), PEM_write_ECPrivateKey() and PEM_write_bio_ECPrivateKey() were deprecated in OpenSSL 3.0.

COPYRIGHT
Copyright 1998-2025 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>.