| =pod |
| |
| =head1 NAME |
| |
| EVP_MD_meth_dup, |
| EVP_MD_meth_new, EVP_MD_meth_free, EVP_MD_meth_set_input_blocksize, |
| EVP_MD_meth_set_result_size, EVP_MD_meth_set_app_datasize, |
| EVP_MD_meth_set_flags, EVP_MD_meth_set_init, EVP_MD_meth_set_update, |
| EVP_MD_meth_set_final, EVP_MD_meth_set_copy, EVP_MD_meth_set_cleanup, |
| EVP_MD_meth_set_ctrl, EVP_MD_meth_get_input_blocksize, |
| EVP_MD_meth_get_result_size, EVP_MD_meth_get_app_datasize, |
| EVP_MD_meth_get_flags, EVP_MD_meth_get_init, EVP_MD_meth_get_update, |
| EVP_MD_meth_get_final, EVP_MD_meth_get_copy, EVP_MD_meth_get_cleanup, |
| EVP_MD_meth_get_ctrl |
| - Routines to build up EVP_MD methods |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/evp.h> |
| |
| EVP_MD *EVP_MD_meth_new(int md_type, int pkey_type); |
| void EVP_MD_meth_free(EVP_MD *md); |
| EVP_MD *EVP_MD_meth_dup(const EVP_MD *md); |
| |
| int EVP_MD_meth_set_input_blocksize(EVP_MD *md, int blocksize); |
| int EVP_MD_meth_set_result_size(EVP_MD *md, int resultsize); |
| int EVP_MD_meth_set_app_datasize(EVP_MD *md, int datasize); |
| int EVP_MD_meth_set_flags(EVP_MD *md, unsigned long flags); |
| int EVP_MD_meth_set_init(EVP_MD *md, int (*init)(EVP_MD_CTX *ctx)); |
| int EVP_MD_meth_set_update(EVP_MD *md, int (*update)(EVP_MD_CTX *ctx, |
| const void *data, |
| size_t count)); |
| int EVP_MD_meth_set_final(EVP_MD *md, int (*final)(EVP_MD_CTX *ctx, |
| unsigned char *md)); |
| int EVP_MD_meth_set_copy(EVP_MD *md, int (*copy)(EVP_MD_CTX *to, |
| const EVP_MD_CTX *from)); |
| int EVP_MD_meth_set_cleanup(EVP_MD *md, int (*cleanup)(EVP_MD_CTX *ctx)); |
| int EVP_MD_meth_set_ctrl(EVP_MD *md, int (*ctrl)(EVP_MD_CTX *ctx, int cmd, |
| int p1, void *p2)); |
| |
| int EVP_MD_meth_get_input_blocksize(const EVP_MD *md); |
| int EVP_MD_meth_get_result_size(const EVP_MD *md); |
| int EVP_MD_meth_get_app_datasize(const EVP_MD *md); |
| unsigned long EVP_MD_meth_get_flags(const EVP_MD *md); |
| int (*EVP_MD_meth_get_init(const EVP_MD *md))(EVP_MD_CTX *ctx); |
| int (*EVP_MD_meth_get_update(const EVP_MD *md))(EVP_MD_CTX *ctx, |
| const void *data, |
| size_t count); |
| int (*EVP_MD_meth_get_final(const EVP_MD *md))(EVP_MD_CTX *ctx, |
| unsigned char *md); |
| int (*EVP_MD_meth_get_copy(const EVP_MD *md))(EVP_MD_CTX *to, |
| const EVP_MD_CTX *from); |
| int (*EVP_MD_meth_get_cleanup(const EVP_MD *md))(EVP_MD_CTX *ctx); |
| int (*EVP_MD_meth_get_ctrl(const EVP_MD *md))(EVP_MD_CTX *ctx, int cmd, |
| int p1, void *p2); |
| |
| =head1 DESCRIPTION |
| |
| The B<EVP_MD> type is a structure for digest method implementation. |
| It can also have associated public/private key signing and verifying |
| routines. |
| |
| EVP_MD_meth_new() creates a new B<EVP_MD> structure. |
| |
| EVP_MD_meth_dup() creates a copy of B<md>. |
| |
| EVP_MD_meth_free() destroys a B<EVP_MD> structure. |
| |
| EVP_MD_meth_set_input_blocksize() sets the internal input block size |
| for the method B<md> to B<blocksize> bytes. |
| |
| EVP_MD_meth_set_result_size() sets the size of the result that the |
| digest method in B<md> is expected to produce to B<resultsize> bytes. |
| |
| The digest method may have its own private data, which OpenSSL will |
| allocate for it. EVP_MD_meth_set_app_datasize() should be used to |
| set the size for it to B<datasize>. |
| |
| EVP_MD_meth_set_flags() sets the flags to describe optional |
| behaviours in the particular B<md>. Several flags can be or'd |
| together. The available flags are: |
| |
| =over 4 |
| |
| =item EVP_MD_FLAG_ONESHOT |
| |
| This digest method can only handle one block of input. |
| |
| =item EVP_MD_FLAG_XOF |
| |
| This digest method is an extensible-output function (XOF) and supports |
| the B<EVP_MD_CTRL_XOF_LEN> control. |
| |
| =item EVP_MD_FLAG_DIGALGID_NULL |
| |
| When setting up a DigestAlgorithmIdentifier, this flag will have the |
| parameter set to NULL by default. Use this for PKCS#1. I<Note: if |
| combined with EVP_MD_FLAG_DIGALGID_ABSENT, the latter will override.> |
| |
| =item EVP_MD_FLAG_DIGALGID_ABSENT |
| |
| When setting up a DigestAlgorithmIdentifier, this flag will have the |
| parameter be left absent by default. I<Note: if combined with |
| EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.> |
| |
| =item EVP_MD_FLAG_DIGALGID_CUSTOM |
| |
| Custom DigestAlgorithmIdentifier handling via ctrl, with |
| B<EVP_MD_FLAG_DIGALGID_ABSENT> as default. I<Note: if combined with |
| EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.> |
| Currently unused. |
| |
| =item EVP_MD_FLAG_FIPS |
| |
| This digest method is suitable for use in FIPS mode. |
| Currently unused. |
| |
| =back |
| |
| EVP_MD_meth_set_init() sets the digest init function for B<md>. |
| The digest init function is called by EVP_Digest(), EVP_DigestInit(), |
| EVP_DigestInit_ex(), EVP_SignInit, EVP_SignInit_ex(), EVP_VerifyInit() |
| and EVP_VerifyInit_ex(). |
| |
| EVP_MD_meth_set_update() sets the digest update function for B<md>. |
| The digest update function is called by EVP_Digest(), EVP_DigestUpdate() and |
| EVP_SignUpdate(). |
| |
| EVP_MD_meth_set_final() sets the digest final function for B<md>. |
| The digest final function is called by EVP_Digest(), EVP_DigestFinal(), |
| EVP_DigestFinal_ex(), EVP_SignFinal() and EVP_VerifyFinal(). |
| |
| EVP_MD_meth_set_copy() sets the function for B<md> to do extra |
| computations after the method's private data structure has been copied |
| from one B<EVP_MD_CTX> to another. If all that's needed is to copy |
| the data, there is no need for this copy function. |
| Note that the copy function is passed two B<EVP_MD_CTX *>, the private |
| data structure is then available with EVP_MD_CTX_md_data(). |
| This copy function is called by EVP_MD_CTX_copy() and |
| EVP_MD_CTX_copy_ex(). |
| |
| EVP_MD_meth_set_cleanup() sets the function for B<md> to do extra |
| cleanup before the method's private data structure is cleaned out and |
| freed. |
| Note that the cleanup function is passed a B<EVP_MD_CTX *>, the |
| private data structure is then available with EVP_MD_CTX_md_data(). |
| This cleanup function is called by EVP_MD_CTX_reset() and |
| EVP_MD_CTX_free(). |
| |
| EVP_MD_meth_set_ctrl() sets the control function for B<md>. |
| See L<EVP_MD_CTX_ctrl(3)> for the available controls. |
| |
| EVP_MD_meth_get_input_blocksize(), EVP_MD_meth_get_result_size(), |
| EVP_MD_meth_get_app_datasize(), EVP_MD_meth_get_flags(), |
| EVP_MD_meth_get_init(), EVP_MD_meth_get_update(), |
| EVP_MD_meth_get_final(), EVP_MD_meth_get_copy(), |
| EVP_MD_meth_get_cleanup() and EVP_MD_meth_get_ctrl() are all used |
| to retrieve the method data given with the EVP_MD_meth_set_*() |
| functions above. |
| |
| =head1 RETURN VALUES |
| |
| EVP_MD_meth_new() and EVP_MD_meth_dup() return a pointer to a newly |
| created B<EVP_MD>, or NULL on failure. |
| All EVP_MD_meth_set_*() functions return 1. |
| EVP_MD_get_input_blocksize(), EVP_MD_meth_get_result_size(), |
| EVP_MD_meth_get_app_datasize() and EVP_MD_meth_get_flags() return the |
| indicated sizes or flags. |
| All other EVP_CIPHER_meth_get_*() functions return pointers to their |
| respective B<md> function. |
| |
| =head1 SEE ALSO |
| |
| L<EVP_DigestInit(3)>, L<EVP_SignInit(3)>, L<EVP_VerifyInit(3)> |
| |
| =head1 HISTORY |
| |
| The B<EVP_MD> structure was openly available in OpenSSL before version |
| 1.1. The functions described here were added in OpenSSL 1.1. |
| |
| =head1 COPYRIGHT |
| |
| Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved. |
| |
| Licensed under the OpenSSL license (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 |
| L<https://www.openssl.org/source/license.html>. |
| |
| =cut |
