=head1 NAME
-EVP_MD_CTX_new, EVP_MD_CTX_reset, EVP_MD_CTX_free, EVP_MD_CTX_copy_ex,
-EVP_MD_CTX_ctrl, EVP_DigestInit_ex, EVP_DigestInit, EVP_DigestUpdate,
+EVP_MD_fetch, EVP_MD_up_ref, EVP_MD_free,
+EVP_MD_get_params, EVP_MD_gettable_params,
+EVP_MD_CTX_new, EVP_MD_CTX_reset, EVP_MD_CTX_free, EVP_MD_CTX_copy,
+EVP_MD_CTX_copy_ex, EVP_MD_CTX_ctrl,
+EVP_MD_CTX_set_params, EVP_MD_CTX_get_params,
+EVP_MD_settable_ctx_params, EVP_MD_gettable_ctx_params,
+EVP_MD_CTX_settable_params, EVP_MD_CTX_gettable_params,
+EVP_MD_CTX_set_flags, EVP_MD_CTX_clear_flags, EVP_MD_CTX_test_flags,
+EVP_Digest, EVP_DigestInit_ex, EVP_DigestInit, EVP_DigestUpdate,
EVP_DigestFinal_ex, EVP_DigestFinalXOF, EVP_DigestFinal,
-EVP_MD_CTX_copy, EVP_MD_type, EVP_MD_pkey_type, EVP_MD_size,
-EVP_MD_block_size, EVP_MD_CTX_md, EVP_MD_CTX_size,
-EVP_MD_CTX_block_size, EVP_MD_CTX_type, EVP_md_null,
-EVP_get_digestbyname, EVP_get_digestbynid,
-EVP_get_digestbyobj - EVP digest routines
+EVP_MD_name, EVP_MD_provider,
+EVP_MD_type, EVP_MD_pkey_type, EVP_MD_size, EVP_MD_block_size, EVP_MD_flags,
+EVP_MD_CTX_name,
+EVP_MD_CTX_md, EVP_MD_CTX_type, EVP_MD_CTX_size, EVP_MD_CTX_block_size,
+EVP_MD_CTX_md_data, EVP_MD_CTX_update_fn, EVP_MD_CTX_set_update_fn,
+EVP_md_null,
+EVP_get_digestbyname, EVP_get_digestbynid, EVP_get_digestbyobj,
+EVP_MD_CTX_pkey_ctx, EVP_MD_CTX_set_pkey_ctx,
+EVP_MD_do_all_ex
+- EVP digest routines
=head1 SYNOPSIS
#include <openssl/evp.h>
+ EVP_MD *EVP_MD_fetch(OPENSSL_CTX *ctx, const char *algorithm,
+ const char *properties);
+ int EVP_MD_up_ref(EVP_MD *md);
+ void EVP_MD_free(EVP_MD *md);
+ int EVP_MD_get_params(const EVP_MD *digest, OSSL_PARAM params[]);
+ const OSSL_PARAM *EVP_MD_gettable_params(const EVP_MD *digest);
EVP_MD_CTX *EVP_MD_CTX_new(void);
int EVP_MD_CTX_reset(EVP_MD_CTX *ctx);
void EVP_MD_CTX_free(EVP_MD_CTX *ctx);
void EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void* p2);
-
+ int EVP_MD_CTX_get_params(EVP_MD_CTX *ctx, OSSL_PARAM params[]);
+ int EVP_MD_CTX_set_params(EVP_MD_CTX *ctx, const OSSL_PARAM params[]);
+ const OSSL_PARAM *EVP_MD_settable_ctx_params(const EVP_MD *md);
+ const OSSL_PARAM *EVP_MD_gettable_ctx_params(const EVP_MD *md);
+ const OSSL_PARAM *EVP_MD_CTX_settable_params(EVP_MD_CTX *ctx);
+ const OSSL_PARAM *EVP_MD_CTX_gettable_params(EVP_MD_CTX *ctx);
+ void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, int flags);
+ void EVP_MD_CTX_clear_flags(EVP_MD_CTX *ctx, int flags);
+ int EVP_MD_CTX_test_flags(const EVP_MD_CTX *ctx, int flags);
+
+ int EVP_Digest(const void *data, size_t count, unsigned char *md,
+ unsigned int *size, const EVP_MD *type, ENGINE *impl);
int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl);
int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt);
int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s);
int EVP_MD_CTX_copy(EVP_MD_CTX *out, EVP_MD_CTX *in);
+ const char *EVP_MD_name(const EVP_MD *md);
+ const OSSL_PROVIDER *EVP_MD_provider(const EVP_MD *md);
int EVP_MD_type(const EVP_MD *md);
int EVP_MD_pkey_type(const EVP_MD *md);
int EVP_MD_size(const EVP_MD *md);
int EVP_MD_block_size(const EVP_MD *md);
+ unsigned long EVP_MD_flags(const EVP_MD *md);
const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx);
- int EVP_MD_CTX_size(const EVP_MD *ctx);
- int EVP_MD_CTX_block_size(const EVP_MD *ctx);
- int EVP_MD_CTX_type(const EVP_MD *ctx);
+ const char *EVP_MD_CTX_name(const EVP_MD_CTX *ctx);
+ int EVP_MD_CTX_size(const EVP_MD_CTX *ctx);
+ int EVP_MD_CTX_block_size(const EVP_MD_CTX *ctx);
+ int EVP_MD_CTX_type(const EVP_MD_CTX *ctx);
+ void *EVP_MD_CTX_md_data(const EVP_MD_CTX *ctx);
+ int (*EVP_MD_CTX_update_fn(EVP_MD_CTX *ctx))(EVP_MD_CTX *ctx,
+ const void *data, size_t count);
+ void EVP_MD_CTX_set_update_fn(EVP_MD_CTX *ctx,
+ int (*update)(EVP_MD_CTX *ctx,
+ const void *data, size_t count));
const EVP_MD *EVP_md_null(void);
const EVP_MD *EVP_get_digestbynid(int type);
const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *o);
+ EVP_PKEY_CTX *EVP_MD_CTX_pkey_ctx(const EVP_MD_CTX *ctx);
+ void EVP_MD_CTX_set_pkey_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pctx);
+
+ void EVP_MD_do_all_ex(OPENSSL_CTX *libctx,
+ void (*fn)(EVP_MD *mac, void *arg),
+ void *arg);
+
=head1 DESCRIPTION
The EVP digest routines are a high level interface to message digests,
-and should be used instead of the cipher-specific functions.
+and should be used instead of the digest-specific functions.
+
+The B<EVP_MD> type is a structure for digest method implementation.
=over 4
+=item EVP_MD_fetch()
+
+Fetches the digest implementation for the given B<algorithm> from any
+provider offering it, within the criteria given by the B<properties>.
+See L<provider(7)/Fetching algorithms> for further information.
+
+The returned value must eventually be freed with EVP_MD_free().
+
+Fetched B<EVP_MD> structures are reference counted.
+
+=item EVP_MD_up_ref()
+
+Increments the reference count for an B<EVP_MD> structure.
+
+=item EVP_MD_free()
+
+Decrements the reference count for the fetched B<EVP_MD> structure.
+If the reference count drops to 0 then the structure is freed.
+
=item EVP_MD_CTX_new()
-Allocates, initializes and returns a digest context.
+Allocates and returns a digest context.
=item EVP_MD_CTX_reset()
=item EVP_MD_CTX_ctrl()
-Performs digest-specific control actions on context B<ctx>.
+This is a legacy method. EVP_MD_CTX_set_params() and EVP_MD_CTX_get_params()
+is the mechanism that should be used to set and get parameters that are used by
+providers.
+Performs digest-specific control actions on context B<ctx>. The control command
+is indicated in B<cmd> and any additional arguments in B<p1> and B<p2>.
+EVP_MD_CTX_ctrl() must be called after EVP_DigestInit_ex(). Other restrictions
+may apply depending on the control type and digest implementation.
+See L</CONTROLS> below for more information.
+
+=item EVP_MD_get_params()
+
+Retrieves the requested list of B<params> from a MD B<md>.
+See L</PARAMETERS> below for more information.
+
+=item EVP_MD_CTX_get_params()
+
+Retrieves the requested list of B<params> from a MD context B<ctx>.
+See L</PARAMETERS> below for more information.
+
+=item EVP_MD_CTX_set_params()
+
+Sets the list of B<params> into a MD context B<ctx>.
+See L</PARAMETERS> below for more information.
+
+=item EVP_MD_gettable_params(), EVP_MD_gettable_ctx_params(),
+EVP_MD_settable_ctx_params(), EVP_MD_CTX_gettable_params(),
+EVP_MD_CTX_settable_params()
+
+Get a B<OSSL_PARAM> array that describes the retrievable and settable
+parameters. EVP_MD_gettable_params() returns parameters that can be used with
+EVP_MD_get_params(). EVP_MD_gettable_ctx_params() and
+EVP_MD_CTX_gettable_params() return parameters that can be used with
+EVP_MD_CTX_get_params(). EVP_MD_settable_ctx_params() and
+EVP_MD_CTX_settable_params() return parameters that can be used with
+EVP_MD_CTX_set_params().
+See L<OSSL_PARAM(3)> for the use of B<OSSL_PARAM> as parameter descriptor.
+
+=item EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags(), EVP_MD_CTX_test_flags()
+
+Sets, clears and tests B<ctx> flags. See L</FLAGS> below for more information.
+
+=item EVP_Digest()
+
+A wrapper around the Digest Init_ex, Update and Final_ex functions.
+Hashes B<count> bytes of data at B<data> using a digest B<type> from ENGINE
+B<impl>. The digest value is placed in B<md> and its length is written at B<size>
+if the pointer is not NULL. At most B<EVP_MAX_MD_SIZE> bytes will be written.
+If B<impl> is NULL the default implementation of digest B<type> is used.
=item EVP_DigestInit_ex()
-Sets up digest context B<ctx> to use a digest B<type> from ENGINE B<impl>.
-B<ctx> must be initialized before calling this function. B<type> will typically
-be supplied by a function such as EVP_sha1(). If B<impl> is NULL then the
-default implementation of digest B<type> is used.
+Sets up digest context B<ctx> to use a digest B<type>.
+B<type> is typically supplied by a function such as EVP_sha1(), or a
+value explicitly fetched with EVP_MD_fetch().
+
+If B<impl> is non-NULL, its implementation of the digest B<type> is used if
+there is one, and if not, the default implementation is used.
=item EVP_DigestUpdate()
Can be used to copy the message digest state from B<in> to B<out>. This is
useful if large amounts of data are to be hashed which only differ in the last
-few bytes. B<out> must be initialized before calling this function.
+few bytes.
=item EVP_DigestInit()
-Behaves in the same way as EVP_DigestInit_ex() except the passed context B<ctx>
-does not have to be initialized, and it always uses the default digest
-implementation.
+Behaves in the same way as EVP_DigestInit_ex() except it always uses the
+default digest implementation.
=item EVP_DigestFinal()
Similar to EVP_MD_CTX_copy_ex() except the destination B<out> does not have to
be initialized.
+=item EVP_MD_name(),
+EVP_MD_CTX_name()
+
+Return the name of the given message digest.
+
+=item EVP_MD_provider()
+
+Returns an B<OSSL_PROVIDER> pointer to the provider that implements the given
+B<EVP_MD>.
+
=item EVP_MD_size(),
EVP_MD_CTX_size()
when passed an B<EVP_MD> structure. For example, C<EVP_MD_type(EVP_sha1())>
returns B<NID_sha1>. This function is normally used when setting ASN1 OIDs.
+=item EVP_MD_CTX_md_data()
+
+Return the digest method private data for the passed B<EVP_MD_CTX>.
+The space is allocated by OpenSSL and has the size originally set with
+EVP_MD_meth_set_app_datasize().
+
=item EVP_MD_CTX_md()
-Returns the B<EVP_MD> structure corresponding to the passed B<EVP_MD_CTX>.
+Returns the B<EVP_MD> structure corresponding to the passed B<EVP_MD_CTX>. This
+will be the same B<EVP_MD> object originally passed to EVP_DigestInit_ex() (or
+other similar function) when the EVP_MD_CTX was first initialised. Note that
+where explicit fetch is in use (see L<EVP_MD_fetch(3)>) the value returned from
+this function will not have its reference count incremented and therefore it
+should not be used after the EVP_MD_CTX is freed.
+
+=item EVP_MD_CTX_set_update_fn()
+
+Sets the update function for B<ctx> to B<update>.
+This is the function that is called by EVP_DigestUpdate. If not set, the
+update function from the B<EVP_MD> type specified at initialization is used.
+
+=item EVP_MD_CTX_update_fn()
+
+Returns the update function for B<ctx>.
+
+=item EVP_MD_flags()
+
+Returns the B<md> flags. Note that these are different from the B<EVP_MD_CTX>
+ones. See L<EVP_MD_meth_set_flags(3)> for more information.
=item EVP_MD_pkey_type()
Returns an B<EVP_MD> structure when passed a digest name, a digest B<NID> or an
B<ASN1_OBJECT> structure respectively.
+=item EVP_MD_CTX_pkey_ctx()
+
+Returns the B<EVP_PKEY_CTX> assigned to B<ctx>. The returned pointer should not
+be freed by the caller.
+
+=item EVP_MD_CTX_set_pkey_ctx()
+
+Assigns an B<EVP_PKEY_CTX> to B<EVP_MD_CTX>. This is usually used to provide
+a customized B<EVP_PKEY_CTX> to L<EVP_DigestSignInit(3)> or
+L<EVP_DigestVerifyInit(3)>. The B<pctx> passed to this function should be freed
+by the caller. A NULL B<pctx> pointer is also allowed to clear the B<EVP_PKEY_CTX>
+assigned to B<ctx>. In such case, freeing the cleared B<EVP_PKEY_CTX> or not
+depends on how the B<EVP_PKEY_CTX> is created.
+
+=item EVP_MD_do_all_ex()
+
+Traverses all messages digests implemented by all activated providers
+in the given library context I<libctx>, and for each of the implementations,
+calls the given function I<fn> with the implementation method and the given
+I<arg> as argument.
+
+=back
+
+=head1 PARAMETERS
+
+See L<OSSL_PARAM(3)> for information about passing parameters.
+
+EVP_MD_CTX_set_params() can be used with the following OSSL_PARAM keys:
+
+=over 4
+
+=item OSSL_PARAM_DIGEST_KEY_XOFLEN <unsigned integer>
+
+Sets the digest length for extendable output functions.
+It is used by the SHAKE algorithm and should not exceed what can be given
+using a B<size_t>.
+
+=item OSSL_PARAM_DIGEST_KEY_PAD_TYPE <integer>
+
+Sets the pad type.
+It is used by the MDC2 algorithm.
+
+=back
+
+EVP_MD_CTX_get_params() can be used with the following OSSL_PARAM keys:
+
+=over 4
+
+=item OSSL_PARAM_DIGEST_KEY_MICALG <UTF8 string>.
+
+Gets the digest Message Integrity Check algorithm string. This is used when
+creating S/MIME multipart/signed messages, as specified in RFC 3851.
+It may be used by external engines or providers.
+
+=back
+
+=head1 CONTROLS
+
+EVP_MD_CTX_ctrl() can be used to send the following standard controls:
+
+=over 4
+
+=item EVP_MD_CTRL_MICALG
+
+Gets the digest Message Integrity Check algorithm string. This is used when
+creating S/MIME multipart/signed messages, as specified in RFC 3851.
+The string value is written to B<p2>.
+
+=item EVP_MD_CTRL_XOF_LEN
+
+This control sets the digest length for extendable output functions to B<p1>.
+Sending this control directly should not be necessary, the use of
+C<EVP_DigestFinalXOF()> is preferred.
+Currently used by SHAKE.
+
+=back
+
+=head1 FLAGS
+
+EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags() and EVP_MD_CTX_test_flags()
+can be used the manipulate and test these B<EVP_MD_CTX> flags:
+
+=over 4
+
+=item EVP_MD_CTX_FLAG_ONESHOT
+
+This flag instructs the digest to optimize for one update only, if possible.
+
+=for comment EVP_MD_CTX_FLAG_CLEANED is internal, don't mention it
+
+=for comment EVP_MD_CTX_FLAG_REUSE is internal, don't mention it
+
+=for comment We currently avoid documenting flags that are only bit holder:
+EVP_MD_CTX_FLAG_NON_FIPS_ALLOW, EVP_MD_CTX_FLAGS_PAD_*
+
+=item EVP_MD_CTX_FLAG_NO_INIT
+
+This flag instructs EVP_DigestInit() and similar not to initialise the
+implementation specific data.
+
+=item EVP_MD_CTX_FLAG_FINALISE
+
+Some functions such as EVP_DigestSign only finalise copies of internal
+contexts so additional data can be included after the finalisation call.
+This is inefficient if this functionality is not required, and can be
+disabled with this flag.
+
=back
=head1 RETURN VALUES
=over 4
+=item EVP_MD_fetch()
+
+Returns a pointer to a B<EVP_MD> for success or NULL for failure.
+
+=item EVP_MD_up_ref()
+
+Returns 1 for success or 0 for failure.
+
=item EVP_DigestInit_ex(),
EVP_DigestUpdate(),
EVP_DigestFinal_ex()
Returns 1 if successful or 0 for failure.
+=item EVP_MD_CTX_set_params(),
+EVP_MD_CTX_get_params()
+
+Returns 1 if successful or 0 for failure.
+
+=item EVP_MD_CTX_settable_params(),
+EVP_MD_CTX_gettable_params()
+
+Return an array of constant B<OSSL_PARAM>s, or NULL if there is none
+to get.
+
=item EVP_MD_CTX_copy_ex()
Returns 1 if successful or 0 for failure.
=item EVP_MD_type(),
-EVP_MD_pkey_type(),
-EVP_MD_type()
+EVP_MD_pkey_type()
Returns the NID of the corresponding OBJECT IDENTIFIER or NID_undef if none
exists.
Returns either an B<EVP_MD> structure or NULL if an error occurs.
+=item EVP_MD_CTX_set_pkey_ctx()
+
+This function has no return value.
+
=back
=head1 NOTES
transparent to the digest used and much more flexible.
New applications should use the SHA-2 (such as L<EVP_sha256(3)>) or the SHA-3
-digest algorithms (such as L<EVP_sha3_512>). The other digest algorithms are
-still in common use.
+digest algorithms (such as L<EVP_sha3_512(3)>). The other digest algorithms
+are still in common use.
For most applications the B<impl> parameter to EVP_DigestInit_ex() will be
set to NULL to use the default digest implementation.
instead of initializing and cleaning it up on each call and allow non default
implementations of digests to be specified.
-If digest contexts are not cleaned up after use
+If digest contexts are not cleaned up after use,
memory leaks will occur.
-EVP_MD_CTX_size(), EVP_MD_CTX_block_size(), EVP_MD_CTX_type(),
-EVP_get_digestbynid() and EVP_get_digestbyobj() are defined as
-macros.
+EVP_MD_CTX_name(), EVP_MD_CTX_size(), EVP_MD_CTX_block_size(),
+EVP_MD_CTX_type(), EVP_get_digestbynid() and EVP_get_digestbyobj() are defined
+as macros.
EVP_MD_CTX_ctrl() sends commands to message digests for additional configuration
or control.
-=head1 EXAMPLE
+=head1 EXAMPLES
This example digests the data "Test Message\n" and "Hello World\n", using the
digest name passed on the command line.
#include <stdio.h>
+ #include <string.h>
#include <openssl/evp.h>
- main(int argc, char *argv[])
+ int main(int argc, char *argv[])
{
EVP_MD_CTX *mdctx;
const EVP_MD *md;
char mess1[] = "Test Message\n";
char mess2[] = "Hello World\n";
unsigned char md_value[EVP_MAX_MD_SIZE];
- int md_len, i;
+ unsigned int md_len, i;
if (argv[1] == NULL) {
printf("Usage: mdtest digestname\n");
=head1 SEE ALSO
+L<EVP_MD_meth_new(3)>,
L<dgst(1)>,
-L<evp(7)>
+L<evp(7)>,
+L<OSSL_PROVIDER(3)>,
+L<OSSL_PARAM(3)>
The full list of digest algorithms are provided below.
L<EVP_sha3_224(3)>,
L<EVP_sm3(3)>,
L<EVP_whirlpool(3)>
+L<provider(7)/Fetching algorithms>
=head1 HISTORY
-EVP_MD_CTX_create() and EVP_MD_CTX_destroy() were renamed to
-EVP_MD_CTX_new() and EVP_MD_CTX_free() in OpenSSL 1.1.0.
+The EVP_MD_CTX_create() and EVP_MD_CTX_destroy() functions were renamed to
+EVP_MD_CTX_new() and EVP_MD_CTX_free() in OpenSSL 1.1.0, respectively.
The link between digests and signing algorithms was fixed in OpenSSL 1.0 and
later, so now EVP_sha1() can be used with RSA and DSA.
-EVP_dss1() was removed in OpenSSL 1.1.0.
+The EVP_dss1() function was removed in OpenSSL 1.1.0.
+
+The EVP_MD_CTX_set_pkey_ctx() function was added in 1.1.1.
+
+The EVP_MD_fetch(), EVP_MD_free(), EVP_MD_up_ref(), EVP_MD_CTX_set_params()
+and EVP_MD_CTX_get_params() functions were added in 3.0.
=head1 COPYRIGHT
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
-Licensed under the OpenSSL license (the "License"). You may not use
+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
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.