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. 77 78EVP_MD_meth_set_input_blocksize() sets the internal input block size 79for the method B<md> to B<blocksize> bytes. 80 81EVP_MD_meth_set_result_size() sets the size of the result that the 82digest method in B<md> is expected to produce to B<resultsize> bytes. 83 84The digest method may have its own private data, which OpenSSL will 85allocate for it. EVP_MD_meth_set_app_datasize() should be used to 86set the size for it to B<datasize>. 87 88EVP_MD_meth_set_flags() sets the flags to describe optional 89behaviours in the particular B<md>. Several flags can be or'd 90together. The available flags are: 91 92=over 4 93 94=item EVP_MD_FLAG_ONESHOT 95 96This digest method can only handle one block of input. 97 98=item EVP_MD_FLAG_XOF 99 100This digest method is an extensible-output function (XOF) and supports 101the B<EVP_MD_CTRL_XOF_LEN> control. 102 103=item EVP_MD_FLAG_DIGALGID_NULL 104 105When setting up a DigestAlgorithmIdentifier, this flag will have the 106parameter set to NULL by default. Use this for PKCS#1. I<Note: if 107combined with EVP_MD_FLAG_DIGALGID_ABSENT, the latter will override.> 108 109=item EVP_MD_FLAG_DIGALGID_ABSENT 110 111When setting up a DigestAlgorithmIdentifier, this flag will have the 112parameter be left absent by default. I<Note: if combined with 113EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.> 114 115=item EVP_MD_FLAG_DIGALGID_CUSTOM 116 117Custom DigestAlgorithmIdentifier handling via ctrl, with 118B<EVP_MD_FLAG_DIGALGID_ABSENT> as default. I<Note: if combined with 119EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.> 120Currently unused. 121 122=item EVP_MD_FLAG_FIPS 123 124This digest method is suitable for use in FIPS mode. 125Currently unused. 126 127=back 128 129EVP_MD_meth_set_init() sets the digest init function for B<md>. 130The digest init function is called by EVP_Digest(), EVP_DigestInit(), 131EVP_DigestInit_ex(), EVP_SignInit, EVP_SignInit_ex(), EVP_VerifyInit() 132and EVP_VerifyInit_ex(). 133 134EVP_MD_meth_set_update() sets the digest update function for B<md>. 135The digest update function is called by EVP_Digest(), EVP_DigestUpdate() and 136EVP_SignUpdate(). 137 138EVP_MD_meth_set_final() sets the digest final function for B<md>. 139The digest final function is called by EVP_Digest(), EVP_DigestFinal(), 140EVP_DigestFinal_ex(), EVP_SignFinal() and EVP_VerifyFinal(). 141 142EVP_MD_meth_set_copy() sets the function for B<md> to do extra 143computations after the method's private data structure has been copied 144from one B<EVP_MD_CTX> to another. If all that's needed is to copy 145the data, there is no need for this copy function. 146Note that the copy function is passed two B<EVP_MD_CTX *>, the private 147data structure is then available with EVP_MD_CTX_get0_md_data(). 148This copy function is called by EVP_MD_CTX_copy() and 149EVP_MD_CTX_copy_ex(). 150 151EVP_MD_meth_set_cleanup() sets the function for B<md> to do extra 152cleanup before the method's private data structure is cleaned out and 153freed. 154Note that the cleanup function is passed a B<EVP_MD_CTX *>, the 155private data structure is then available with EVP_MD_CTX_get0_md_data(). 156This cleanup function is called by EVP_MD_CTX_reset() and 157EVP_MD_CTX_free(). 158 159EVP_MD_meth_set_ctrl() sets the control function for B<md>. 160See L<EVP_MD_CTX_ctrl(3)> for the available controls. 161 162EVP_MD_meth_get_input_blocksize(), EVP_MD_meth_get_result_size(), 163EVP_MD_meth_get_app_datasize(), EVP_MD_meth_get_flags(), 164EVP_MD_meth_get_init(), EVP_MD_meth_get_update(), 165EVP_MD_meth_get_final(), EVP_MD_meth_get_copy(), 166EVP_MD_meth_get_cleanup() and EVP_MD_meth_get_ctrl() are all used 167to retrieve the method data given with the EVP_MD_meth_set_*() 168functions above. 169 170=head1 RETURN VALUES 171 172EVP_MD_meth_new() and EVP_MD_meth_dup() return a pointer to a newly 173created B<EVP_MD>, or NULL on failure. 174All EVP_MD_meth_set_*() functions return 1. 175EVP_MD_get_input_blocksize(), EVP_MD_meth_get_result_size(), 176EVP_MD_meth_get_app_datasize() and EVP_MD_meth_get_flags() return the 177indicated sizes or flags. 178All other EVP_CIPHER_meth_get_*() functions return pointers to their 179respective B<md> function. 180 181=head1 SEE ALSO 182 183L<EVP_DigestInit(3)>, L<EVP_SignInit(3)>, L<EVP_VerifyInit(3)> 184 185=head1 HISTORY 186 187All of these functions were deprecated in OpenSSL 3.0. 188 189The B<EVP_MD> structure was openly available in OpenSSL before version 1901.1. 191The functions described here were added in OpenSSL 1.1. 192The B<EVP_MD> structure created with these functions became reference 193counted in OpenSSL 3.0. 194 195=head1 COPYRIGHT 196 197Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved. 198 199Licensed under the Apache License 2.0 (the "License"). You may not use 200this file except in compliance with the License. You can obtain a copy 201in the file LICENSE in the source distribution or at 202L<https://www.openssl.org/source/license.html>. 203 204=cut 205