1=pod 2 3=head1 NAME 4 5EVP_MD_meth_new, EVP_MD_meth_dup, EVP_MD_meth_free, 6EVP_MD_meth_set_input_blocksize, 7EVP_MD_meth_set_result_size, EVP_MD_meth_set_app_datasize, 8EVP_MD_meth_set_flags, EVP_MD_meth_set_init, EVP_MD_meth_set_update, 9EVP_MD_meth_set_final, EVP_MD_meth_set_copy, EVP_MD_meth_set_cleanup, 10EVP_MD_meth_set_ctrl, EVP_MD_meth_get_input_blocksize, 11EVP_MD_meth_get_result_size, EVP_MD_meth_get_app_datasize, 12EVP_MD_meth_get_flags, EVP_MD_meth_get_init, EVP_MD_meth_get_update, 13EVP_MD_meth_get_final, EVP_MD_meth_get_copy, EVP_MD_meth_get_cleanup, 14EVP_MD_meth_get_ctrl 15- Routines to build up legacy EVP_MD methods 16 17=head1 SYNOPSIS 18 19 #include <openssl/evp.h> 20 21The following functions have been deprecated since OpenSSL 3.0, and can be 22hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 23see L<openssl_user_macros(7)>: 24 25 EVP_MD *EVP_MD_meth_new(int md_type, int pkey_type); 26 void EVP_MD_meth_free(EVP_MD *md); 27 EVP_MD *EVP_MD_meth_dup(const EVP_MD *md); 28 29 int EVP_MD_meth_set_input_blocksize(EVP_MD *md, int blocksize); 30 int EVP_MD_meth_set_result_size(EVP_MD *md, int resultsize); 31 int EVP_MD_meth_set_app_datasize(EVP_MD *md, int datasize); 32 int EVP_MD_meth_set_flags(EVP_MD *md, unsigned long flags); 33 int EVP_MD_meth_set_init(EVP_MD *md, int (*init)(EVP_MD_CTX *ctx)); 34 int EVP_MD_meth_set_update(EVP_MD *md, int (*update)(EVP_MD_CTX *ctx, 35 const void *data, 36 size_t count)); 37 int EVP_MD_meth_set_final(EVP_MD *md, int (*final)(EVP_MD_CTX *ctx, 38 unsigned char *md)); 39 int EVP_MD_meth_set_copy(EVP_MD *md, int (*copy)(EVP_MD_CTX *to, 40 const EVP_MD_CTX *from)); 41 int EVP_MD_meth_set_cleanup(EVP_MD *md, int (*cleanup)(EVP_MD_CTX *ctx)); 42 int EVP_MD_meth_set_ctrl(EVP_MD *md, int (*ctrl)(EVP_MD_CTX *ctx, int cmd, 43 int p1, void *p2)); 44 45 int EVP_MD_meth_get_input_blocksize(const EVP_MD *md); 46 int EVP_MD_meth_get_result_size(const EVP_MD *md); 47 int EVP_MD_meth_get_app_datasize(const EVP_MD *md); 48 unsigned long EVP_MD_meth_get_flags(const EVP_MD *md); 49 int (*EVP_MD_meth_get_init(const EVP_MD *md))(EVP_MD_CTX *ctx); 50 int (*EVP_MD_meth_get_update(const EVP_MD *md))(EVP_MD_CTX *ctx, 51 const void *data, 52 size_t count); 53 int (*EVP_MD_meth_get_final(const EVP_MD *md))(EVP_MD_CTX *ctx, 54 unsigned char *md); 55 int (*EVP_MD_meth_get_copy(const EVP_MD *md))(EVP_MD_CTX *to, 56 const EVP_MD_CTX *from); 57 int (*EVP_MD_meth_get_cleanup(const EVP_MD *md))(EVP_MD_CTX *ctx); 58 int (*EVP_MD_meth_get_ctrl(const EVP_MD *md))(EVP_MD_CTX *ctx, int cmd, 59 int p1, void *p2); 60 61=head1 DESCRIPTION 62 63All of the functions described on this page are deprecated. 64Applications should instead use the OSSL_PROVIDER APIs. 65 66The B<EVP_MD> type is a structure for digest method implementation. 67It can also have associated public/private key signing and verifying 68routines. 69 70EVP_MD_meth_new() creates a new B<EVP_MD> structure. 71These B<EVP_MD> structures are reference counted. 72 73EVP_MD_meth_dup() creates a copy of B<md>. 74 75EVP_MD_meth_free() decrements the reference count for the B<EVP_MD> structure. 76If the reference count drops to 0 then the structure is freed. 77If the argument is NULL, nothing is done. 78 79EVP_MD_meth_set_input_blocksize() sets the internal input block size 80for the method B<md> to B<blocksize> bytes. 81 82EVP_MD_meth_set_result_size() sets the size of the result that the 83digest method in B<md> is expected to produce to B<resultsize> bytes. 84 85The digest method may have its own private data, which OpenSSL will 86allocate for it. EVP_MD_meth_set_app_datasize() should be used to 87set the size for it to B<datasize>. 88 89EVP_MD_meth_set_flags() sets the flags to describe optional 90behaviours in the particular B<md>. Several flags can be or'd 91together. The available flags are: 92 93=over 4 94 95=item EVP_MD_FLAG_ONESHOT 96 97This digest method can only handle one block of input. 98 99=item EVP_MD_FLAG_XOF 100 101This digest method is an extensible-output function (XOF) and supports 102the B<EVP_MD_CTRL_XOF_LEN> control. 103 104=item EVP_MD_FLAG_DIGALGID_NULL 105 106When setting up a DigestAlgorithmIdentifier, this flag will have the 107parameter set to NULL by default. Use this for PKCS#1. I<Note: if 108combined with EVP_MD_FLAG_DIGALGID_ABSENT, the latter will override.> 109 110=item EVP_MD_FLAG_DIGALGID_ABSENT 111 112When setting up a DigestAlgorithmIdentifier, this flag will have the 113parameter be left absent by default. I<Note: if combined with 114EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.> 115 116=item EVP_MD_FLAG_DIGALGID_CUSTOM 117 118Custom DigestAlgorithmIdentifier handling via ctrl, with 119B<EVP_MD_FLAG_DIGALGID_ABSENT> as default. I<Note: if combined with 120EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.> 121Currently unused. 122 123=item EVP_MD_FLAG_FIPS 124 125This digest method is suitable for use in FIPS mode. 126Currently unused. 127 128=back 129 130EVP_MD_meth_set_init() sets the digest init function for B<md>. 131The digest init function is called by EVP_Digest(), EVP_DigestInit(), 132EVP_DigestInit_ex(), EVP_SignInit, EVP_SignInit_ex(), EVP_VerifyInit() 133and EVP_VerifyInit_ex(). 134 135EVP_MD_meth_set_update() sets the digest update function for B<md>. 136The digest update function is called by EVP_Digest(), EVP_DigestUpdate() and 137EVP_SignUpdate(). 138 139EVP_MD_meth_set_final() sets the digest final function for B<md>. 140The digest final function is called by EVP_Digest(), EVP_DigestFinal(), 141EVP_DigestFinal_ex(), EVP_SignFinal() and EVP_VerifyFinal(). 142 143EVP_MD_meth_set_copy() sets the function for B<md> to do extra 144computations after the method's private data structure has been copied 145from one B<EVP_MD_CTX> to another. If all that's needed is to copy 146the data, there is no need for this copy function. 147Note that the copy function is passed two B<EVP_MD_CTX *>, the private 148data structure is then available with EVP_MD_CTX_get0_md_data(). 149This copy function is called by EVP_MD_CTX_copy() and 150EVP_MD_CTX_copy_ex(). 151 152EVP_MD_meth_set_cleanup() sets the function for B<md> to do extra 153cleanup before the method's private data structure is cleaned out and 154freed. 155Note that the cleanup function is passed a B<EVP_MD_CTX *>, the 156private data structure is then available with EVP_MD_CTX_get0_md_data(). 157This cleanup function is called by EVP_MD_CTX_reset() and 158EVP_MD_CTX_free(). 159 160EVP_MD_meth_set_ctrl() sets the control function for B<md>. 161See L<EVP_MD_CTX_ctrl(3)> for the available controls. 162 163EVP_MD_meth_get_input_blocksize(), EVP_MD_meth_get_result_size(), 164EVP_MD_meth_get_app_datasize(), EVP_MD_meth_get_flags(), 165EVP_MD_meth_get_init(), EVP_MD_meth_get_update(), 166EVP_MD_meth_get_final(), EVP_MD_meth_get_copy(), 167EVP_MD_meth_get_cleanup() and EVP_MD_meth_get_ctrl() are all used 168to retrieve the method data given with the EVP_MD_meth_set_*() 169functions above. 170 171=head1 RETURN VALUES 172 173EVP_MD_meth_new() and EVP_MD_meth_dup() return a pointer to a newly 174created B<EVP_MD>, or NULL on failure. 175All EVP_MD_meth_set_*() functions return 1. 176EVP_MD_get_input_blocksize(), EVP_MD_meth_get_result_size(), 177EVP_MD_meth_get_app_datasize() and EVP_MD_meth_get_flags() return the 178indicated sizes or flags. 179All other EVP_CIPHER_meth_get_*() functions return pointers to their 180respective B<md> function. 181 182=head1 SEE ALSO 183 184L<EVP_DigestInit(3)>, L<EVP_SignInit(3)>, L<EVP_VerifyInit(3)> 185 186=head1 HISTORY 187 188All of these functions were deprecated in OpenSSL 3.0. 189 190The B<EVP_MD> structure was openly available in OpenSSL before version 1911.1. 192The functions described here were added in OpenSSL 1.1. 193The B<EVP_MD> structure created with these functions became reference 194counted in OpenSSL 3.0. 195 196=head1 COPYRIGHT 197 198Copyright 2015-2024 The OpenSSL Project Authors. All Rights Reserved. 199 200Licensed under the Apache License 2.0 (the "License"). You may not use 201this file except in compliance with the License. You can obtain a copy 202in the file LICENSE in the source distribution or at 203L<https://www.openssl.org/source/license.html>. 204 205=cut 206