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OSSL_DECODER_CTX_new_for_pkey(3) OpenSSL OSSL_DECODER_CTX_new_for_pkey(3)
NAME
OSSL_DECODER_CTX_new_for_pkey, OSSL_DECODER_CTX_set_passphrase,
OSSL_DECODER_CTX_set_pem_password_cb,
OSSL_DECODER_CTX_set_passphrase_ui, OSSL_DECODER_CTX_set_passphrase_cb
- Decoder routines to decode EVP_PKEYs
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
#include <openssl/decoder.h>
OSSL_DECODER_CTX *
OSSL_DECODER_CTX_new_for_pkey(EVP_PKEY **pkey,
const char *input_type,
const char *input_struct,
const char *keytype, int selection,
OSSL_LIB_CTX *libctx, const char *propquery);
int OSSL_DECODER_CTX_set_passphrase(OSSL_DECODER_CTX *ctx,
const unsigned char *kstr,
size_t klen);
int OSSL_DECODER_CTX_set_pem_password_cb(OSSL_DECODER_CTX *ctx,
pem_password_cb *cb,
void *cbarg);
int OSSL_DECODER_CTX_set_passphrase_ui(OSSL_DECODER_CTX *ctx,
const UI_METHOD *ui_method,
void *ui_data);
int OSSL_DECODER_CTX_set_passphrase_cb(OSSL_DECODER_CTX *ctx,
OSSL_PASSPHRASE_CALLBACK *cb,
void *cbarg);
DESCRIPTION
OSSL_DECODER_CTX_new_for_pkey() is a utility function that creates a
OSSL_DECODER_CTX, finds all applicable decoder implementations and sets
them up, so all the caller has to do next is call functions like
OSSL_DECODER_from_bio(3). The caller may use the optional input_type,
input_struct, keytype and selection to specify what the input is
expected to contain. The pkey must reference an EVP_PKEY * variable
that will be set to the newly created EVP_PKEY on successful decoding.
The referenced variable must be initialized to NULL before calling the
function.
Internally OSSL_DECODER_CTX_new_for_pkey() searches for all available
EVP_KEYMGMT(3) implementations, and then builds a list of all potential
decoder implementations that may be able to process the encoded input
into data suitable for EVP_PKEYs. All these implementations are
implicitly fetched using libctx and propquery.
The search of decoder implementations can be limited with input_type
and input_struct which specifies a starting input type and input
structure. NULL is valid for both of them and signifies that the
decoder implementations will find out the input type on their own.
They are set with OSSL_DECODER_CTX_set_input_type(3) and
OSSL_DECODER_CTX_set_input_structure(3). See "Input Types" and "Input
Structures" below for further information.
The search of decoder implementations can also be limited with keytype
and selection, which specifies the expected resulting keytype and
contents. NULL and zero are valid and signify that the decoder
implementations will find out the keytype and key contents on their own
from the input they get.
If no suitable decoder implementation is found,
OSSL_DECODER_CTX_new_for_pkey() still creates a OSSL_DECODER_CTX, but
with no associated decoder (OSSL_DECODER_CTX_get_num_decoders(3)
returns zero). This helps the caller to distinguish between an error
when creating the OSSL_ENCODER_CTX and missing encoder implementation,
and allows it to act accordingly.
OSSL_DECODER_CTX_set_passphrase() gives the implementation a pass
phrase to use when decrypting the encoded private key. Alternatively, a
pass phrase callback may be specified with the following functions.
OSSL_DECODER_CTX_set_pem_password_cb(),
OSSL_DECODER_CTX_set_passphrase_ui() and
OSSL_DECODER_CTX_set_passphrase_cb() set up a callback method that the
implementation can use to prompt for a pass phrase, giving the caller
the choice of preferred pass phrase callback form. These are called
indirectly, through an internal OSSL_PASSPHRASE_CALLBACK(3) function.
The internal OSSL_PASSPHRASE_CALLBACK(3) function caches the pass
phrase, to be re-used in all decodings that are performed in the same
decoding run (for example, within one OSSL_DECODER_from_bio(3) call).
Input Types
Available input types depend on the implementations that available
providers offer, and provider documentation should have the details.
Among the known input types that OpenSSL decoder implementations offer
for EVP_PKEYs are "DER", "PEM", "MSBLOB" and "PVK". See
openssl-glossary(7) for further information on what these input types
mean.
Input Structures
Available input structures depend on the implementations that available
providers offer, and provider documentation should have the details.
Among the known input structures that OpenSSL decoder implementations
offer for EVP_PKEYs are "pkcs8" and "SubjectPublicKeyInfo".
OpenSSL decoder implementations also support the input structure
"type-specific". This is the structure used for keys encoded according
to key type specific specifications. For example, RSA keys encoded
according to PKCS#1.
Selections
selection can be any one of the values described in "Selections" in
EVP_PKEY_fromdata(3). Additionally selection can also be set to 0 to
indicate that the code will auto detect the selection.
RETURN VALUES
OSSL_DECODER_CTX_new_for_pkey() returns a pointer to a
OSSL_DECODER_CTX, or NULL if it couldn't be created.
OSSL_DECODER_CTX_set_passphrase(),
OSSL_DECODER_CTX_set_pem_password_cb(),
OSSL_DECODER_CTX_set_passphrase_ui() and
OSSL_DECODER_CTX_set_passphrase_cb() all return 1 on success, or 0 on
failure.
SEE ALSO
provider(7), OSSL_DECODER(3), OSSL_DECODER_CTX(3)
HISTORY
The functions described here were added in OpenSSL 3.0.
COPYRIGHT
Copyright 2020-2023 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>.
3.0.12 2023-10-25 OSSL_DECODER_CTX_new_for_pkey(3)