=head1 NAME
-EVP_KDF_CTX, EVP_KDF_CTX_new_id, EVP_KDF_CTX_free, EVP_KDF_reset,
-EVP_KDF_ctrl, EVP_KDF_vctrl, EVP_KDF_ctrl_str, EVP_KDF_size,
-EVP_KDF_derive - EVP KDF routines
+EVP_KDF, EVP_KDF_CTX, EVP_KDF_CTX_new, EVP_KDF_CTX_new_id, EVP_KDF_CTX_free,
+EVP_KDF_CTX_kdf, EVP_KDF_reset, EVP_KDF_ctrl, EVP_KDF_vctrl, EVP_KDF_ctrl_str,
+EVP_KDF_size, EVP_KDF_derive, EVP_KDF_nid, EVP_KDF_name,
+EVP_get_kdfbyname, EVP_get_kdfbynid, EVP_get_kdfbyobj - EVP KDF routines
=head1 SYNOPSIS
#include <openssl/kdf.h>
+ typedef struct evp_kdf_st EVP_KDF;
typedef struct evp_kdf_ctx_st EVP_KDF_CTX;
- EVP_KDF_CTX *EVP_KDF_CTX_new_id(int id);
+ EVP_KDF_CTX *EVP_KDF_CTX_new(const EVP_KDF *kdf);
+ EVP_KDF_CTX *EVP_KDF_CTX_new_id(int nid);
+ const EVP_KDF *EVP_KDF_CTX_kdf(EVP_KDF_CTX *ctx);
void EVP_KDF_CTX_free(EVP_KDF_CTX *ctx);
void EVP_KDF_reset(EVP_KDF_CTX *ctx);
int EVP_KDF_ctrl(EVP_KDF_CTX *ctx, int cmd, ...);
int EVP_KDF_ctrl_str(EVP_KDF_CTX *ctx, const char *type, const char *value);
size_t EVP_KDF_size(EVP_KDF_CTX *ctx);
int EVP_KDF_derive(EVP_KDF_CTX *ctx, unsigned char *key, size_t keylen);
+ int EVP_KDF_nid(const EVP_KDF *kdf);
+ const char *EVP_KDF_name(const EVP_KDF *kdf);
+ const EVP_KDF *EVP_get_kdfbyname(const char *name);
+ const EVP_KDF *EVP_get_kdfbynid(int nid);
+ const EVP_KDF *EVP_get_kdfbyobj(const ASN1_OBJECT *o);
=head1 DESCRIPTION
The EVP KDF routines are a high level interface to Key Derivation Function
algorithms and should be used instead of algorithm-specific functions.
-After creating a C<EVP_KDF_CTX> for the required algorithm using
-EVP_KDF_CTX_new_id(), inputs to the algorithm are supplied using calls to
-EVP_KDF_ctrl(), EVP_KDF_vctrl() or EVP_KDF_ctrl_str() before calling
-EVP_KDF_derive() to derive the key.
+After creating a C<EVP_KDF_CTX> for the required algorithm using either
+EVP_KDF_CTX_new() or EVP_KDF_CTX_new_id(), inputs to the algorithm are supplied
+using calls to EVP_KDF_ctrl(), EVP_KDF_vctrl() or EVP_KDF_ctrl_str() before
+calling EVP_KDF_derive() to derive the key.
=head2 Types
+B<EVP_KDF> is a type that holds the implementation of a KDF.
+
B<EVP_KDF_CTX> is a context type that holds the algorithm inputs.
=head2 Context manipulation functions
-EVP_KDF_CTX_new_id() creates a KDF context for the algorithm identified by the
-specified NID.
+EVP_KDF_CTX_new() creates a new context for the KDF type C<kdf>.
+
+EVP_KDF_CTX_new_id() creates a new context for the numerical KDF identity C<nid>.
EVP_KDF_CTX_free() frees up the context C<ctx>. If C<ctx> is C<NULL>, nothing
is done.
+EVP_KDF_CTX_kdf() returns the B<EVP_KDF> associated with the context
+C<ctx>.
+
=head2 Computing functions
EVP_KDF_reset() resets the context to the default state as if the context
operation to a context C<ctx> in string form. This is intended to be used for
options specified on the command line or in text files.
+EVP_KDF_derive() derives C<keylen> bytes of key material and places it in the
+C<key> buffer. If the algorithm produces a fixed amount of output then an
+error will occur unless the C<keylen> parameter is equal to that output size,
+as returned by EVP_KDF_size().
+
+=head2 Information functions
+
EVP_KDF_size() returns the output size if the algorithm produces a fixed amount
of output and C<SIZE_MAX> otherwise. If an error occurs then 0 is returned.
For some algorithms an error may result if input parameters necessary to
calculate a fixed output size have not yet been supplied.
-EVP_KDF_derive() derives C<keylen> bytes of key material and places it in the
-C<key> buffer. If the algorithm produces a fixed amount of output then an
-error will occur unless the C<keylen> parameter is equal to that output size,
-as returned by EVP_KDF_size().
+EVP_KDF_nid() returns the numeric identity of the given KDF implementation.
+
+EVP_KDF_name() returns the name of the given KDF implementation.
+
+=head2 Object database functions
+
+EVP_get_kdfbyname() fetches a KDF implementation from the object
+database by name.
+
+EVP_get_kdfbynid() fetches a KDF implementation from the object
+database by numeric identity.
+
+EVP_get_kdfbyobj() fetches a KDF implementation from the object
+database by ASN.1 OBJECT (i.e. an encoded OID).
=head1 CONTROLS
The value string is expected to be a decimal number.
+=item B<EVP_KDF_CTRL_SET_MAC>
+
+This control expects one argument: C<EVP_MAC *mac>
+
+Some KDF implementations use a MAC as an underlying computation
+algorithm, this control sets what the MAC algorithm should be.
+
+EVP_KDF_ctrl_str() type string: "mac"
+
+The value string is expected to be the name of a MAC.
+
=item B<EVP_KDF_CTRL_SET_MD>
This control expects one argument: C<EVP_MD *md>
For MAC implementations that use a message digest as an underlying computation
-algorithm, this control set what the digest algorithm should be.
+algorithm, this control sets what the digest algorithm should be.
-EVP_KDF_ctrl_str() type string: "md"
+EVP_KDF_ctrl_str() type string: "digest"
The value string is expected to be the name of a digest.
=back
+=item B<EVP_KDF_CTRL_SET_MAC_SIZE>
+
+This control expects one argument: C<size_t size>
+
+Used by implementations that use a MAC with a variable output size (KMAC). For
+those KDF implementations that support it, this control sets the MAC output size.
+
+The default value, if any, is implementation dependent.
+
+EVP_KDF_ctrl_str() type string: "outlen"
+
+The value string is expected to be a decimal number.
+
=item B<EVP_KDF_CTRL_SET_MAXMEM_BYTES>
This control expects one argument: C<uint64_t maxmem_bytes>
=head1 RETURN VALUES
-EVP_KDF_CTX_new_id() returns either the newly allocated C<EVP_KDF_CTX>
-structure or C<NULL> if an error occurred.
+EVP_KDF_CTX_new() and EVP_KDF_CTX_new_id() return either the newly allocated
+C<EVP_KDF_CTX> structure or C<NULL> if an error occurred.
EVP_KDF_CTX_free() and EVP_KDF_reset() do not return a value.
EVP_KDF_size() returns the output size. C<SIZE_MAX> is returned to indicate
that the algorithm produces a variable amount of output; 0 to indicate failure.
+EVP_KDF_nid() returns the numeric identity for the given C<kdf>.
+
+EVP_KDF_name() returns the name for the given C<kdf>, if it has been
+added to the object database.
+
+EVP_add_kdf() returns 1 if the given C<kdf> was successfully added to
+the object database, otherwise 0.
+
+EVP_get_kdfbyname(), EVP_get_kdfbynid() and EVP_get_kdfbyobj() return
+the requested KDF implementation, if it exists in the object database,
+otherwise B<NULL>.
+
The remaining functions 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 KDF algorithm.
=head1 SEE ALSO
L<EVP_KDF_SCRYPT(7)>
+L<EVP_KDF_TLS1_PRF(7)>
+L<EVP_KDF_PBKDF2(7)>
+L<EVP_KDF_HKDF(7)>
+L<EVP_KDF_SS(7)>
+L<EVP_KDF_SSHKDF(7)>
+L<EVP_KDF_X963(7)>
+L<EVP_KDF_X942(7)>
+
+=head1 HISTORY
+
+This functionality was added to OpenSSL 3.0.
=head1 COPYRIGHT
-Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2019 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
projects / openssl.git / blobdiff