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Diffstat (limited to 'openssl-1.1.0h/doc/crypto/EVP_MD_meth_new.pod')
| -rw-r--r-- | openssl-1.1.0h/doc/crypto/EVP_MD_meth_new.pod | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/openssl-1.1.0h/doc/crypto/EVP_MD_meth_new.pod b/openssl-1.1.0h/doc/crypto/EVP_MD_meth_new.pod new file mode 100644 index 0000000..4dac672 --- /dev/null +++ b/openssl-1.1.0h/doc/crypto/EVP_MD_meth_new.pod @@ -0,0 +1,179 @@ +=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 handles one block of input. + +=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. + +=back + +EVP_MD_meth_set_init() sets the digest init function for B<md>. +The digest init function is called by 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_DigestUpdate(), +EVP_SignUpdate(). + +EVP_MD_meth_set_final() sets the digest final function for B<md>. +The digest final function is called by 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>. + +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 +1.1.0. The functions described here were added in OpenSSL 1.1.0. + +=head1 COPYRIGHT + +Copyright 2015-2017 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 |