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EVP_PKEY_print_public, EVP_PKEY_print_private, EVP_PKEY_print_params, EVP_PKEY_print_public_fp, EVP_PKEY_print_private_fp, EVP_PKEY_print_params_fp - public key algorithm printing routines


 #include <openssl/evp.h>
 int EVP_PKEY_print_public(BIO *out, const EVP_PKEY *pkey,
                           int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_public_fp(FILE *fp, const EVP_PKEY *pkey,
                              int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_private(BIO *out, const EVP_PKEY *pkey,
                            int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_private_fp(FILE *fp, const EVP_PKEY *pkey,
                               int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_params(BIO *out, const EVP_PKEY *pkey,
                           int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_params_fp(FILE *fp, const EVP_PKEY *pkey,
                              int indent, ASN1_PCTX *pctx);


The functions EVP_PKEY_print_public(), EVP_PKEY_print_private() and EVP_PKEY_print_params() print out the public, private or parameter components of key pkey respectively. The key is sent to BIO out in human readable form. The parameter indent indicates how far the printout should be indented.

The pctx parameter allows the print output to be finely tuned by using ASN1 printing options. If pctx is set to NULL then default values will be used.

The functions EVP_PKEY_print_public_fp(), EVP_PKEY_print_private_fp() and EVP_PKEY_print_params_fp() do the same as the BIO based functions but use FILE fp instead.


Currently no public key algorithms include any options in the pctx parameter.

If the key does not include all the components indicated by the function then only those contained in the key will be printed. For example passing a public key to EVP_PKEY_print_private() will only print the public components.


These functions all return 1 for success and 0 or a negative value for failure. In particular a return value of -2 indicates the operation is not supported by the public key algorithm.


EVP_PKEY_CTX_new(3), EVP_PKEY_keygen(3)


The functions EVP_PKEY_print_public(), EVP_PKEY_print_private(), and EVP_PKEY_print_params() were added in OpenSSL 1.0.0.

The functions EVP_PKEY_print_public_fp(), EVP_PKEY_print_private_fp(), and EVP_PKEY_print_params_fp() were added in OpenSSL 3.0.


Copyright 2006-2021 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 <>.

2023-09-26 3.0.11