=head1 NAME
-EVP_MD_CTX_new, EVP_MD_CTX_reset, EVP_MD_CTX_free, EVP_MD_CTX_copy_ex,
-EVP_MD_CTX_ctrl, EVP_MD_CTX_set_flags, EVP_MD_CTX_clear_flags,
-EVP_MD_CTX_test_flags, 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_CTX_md_data,
+EVP_MD_is_a, EVP_MD_name, EVP_MD_number, EVP_MD_names_do_all, 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_set_pkey_ctx - EVP digest routines
+EVP_get_digestbyname, EVP_get_digestbynid, EVP_get_digestbyobj,
+EVP_MD_CTX_pkey_ctx, EVP_MD_CTX_set_pkey_ctx,
+EVP_MD_do_all_provided
+- 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);
+ int EVP_MD_number(const EVP_MD *md);
+ int EVP_MD_is_a(const EVP_MD *md, const char *name);
+ void EVP_MD_names_do_all(const EVP_MD *md,
+ void (*fn)(const char *name, void *data),
+ void *data);
+ 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_provided(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 I<algorithm> from any
+provider offering it, within the criteria given by the I<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 and returns a digest context.
=item EVP_MD_CTX_reset()
-Resets the digest context B<ctx>. This can be used to reuse an already
+Resets the digest context I<ctx>. This can be used to reuse an already
existing context.
=item EVP_MD_CTX_free()
-Cleans up digest context B<ctx> and frees up the space allocated to it.
+Cleans up digest context I<ctx> and frees up the space allocated to it.
=item EVP_MD_CTX_ctrl()
-Performs digest-specific control actions on context B<ctx>.
+I<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 I<ctx>. The control command
+is indicated in I<cmd> and any additional arguments in I<p1> and I<p2>.
+EVP_MD_CTX_ctrl() must be called after EVP_DigestInit_ex(). Other restrictions
+may apply depending on the control type and digest implementation.
+
+If this function happens to be used with a fetched B<EVP_MD>, it will
+translate the controls that are known to OpenSSL into L<OSSL_PARAM(3)>
+parameters with keys defined by OpenSSL and call EVP_MD_CTX_get_params() or
+EVP_MD_CTX_set_params() as is appropriate for each control command.
+
+See L</CONTROLS> below for more information, including what translations are
+being done.
+
+=item EVP_MD_get_params()
+
+Retrieves the requested list of I<params> from a MD I<md>.
+See L</PARAMETERS> below for more information.
+
+=item EVP_MD_CTX_get_params()
+
+Retrieves the requested list of I<params> from a MD context I<ctx>.
+See L</PARAMETERS> below for more information.
+
+=item EVP_MD_CTX_set_params()
+
+Sets the list of I<params> into a MD context I<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.
+Sets, clears and tests I<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 I<count> bytes of data at I<data> using a digest I<type> from ENGINE
+I<impl>. The digest value is placed in I<md> and its length is written at I<size>
+if the pointer is not NULL. At most B<EVP_MAX_MD_SIZE> bytes will be written.
+If I<impl> is NULL the default implementation of digest I<type> is used.
=item EVP_DigestInit_ex()
-Sets up digest context B<ctx> to use a digest B<type> from ENGINE B<impl>.
-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 I<ctx> to use a digest I<type>.
+I<type> is typically supplied by a function such as EVP_sha1(), or a
+value explicitly fetched with EVP_MD_fetch().
+
+If I<impl> is non-NULL, its implementation of the digest I<type> is used if
+there is one, and if not, the default implementation is used.
=item EVP_DigestUpdate()
-Hashes B<cnt> bytes of data at B<d> into the digest context B<ctx>. This
-function can be called several times on the same B<ctx> to hash additional
+Hashes I<cnt> bytes of data at I<d> into the digest context I<ctx>. This
+function can be called several times on the same I<ctx> to hash additional
data.
=item EVP_DigestFinal_ex()
-Retrieves the digest value from B<ctx> and places it in B<md>. If the B<s>
+Retrieves the digest value from I<ctx> and places it in I<md>. If the I<s>
parameter is not NULL then the number of bytes of data written (i.e. the
-length of the digest) will be written to the integer at B<s>, at most
+length of the digest) will be written to the integer at I<s>, at most
B<EVP_MAX_MD_SIZE> bytes will be written. After calling EVP_DigestFinal_ex()
no additional calls to EVP_DigestUpdate() can be made, but
EVP_DigestInit_ex() can be called to initialize a new digest operation.
=item EVP_DigestFinalXOF()
Interfaces to extendable-output functions, XOFs, such as SHAKE128 and SHAKE256.
-It retrieves the digest value from B<ctx> and places it in B<len>-sized <B>md.
+It retrieves the digest value from I<ctx> and places it in I<len>-sized I<md>.
After calling this function no additional calls to EVP_DigestUpdate() can be
made, but EVP_DigestInit_ex() can be called to initialize a new operation.
=item EVP_MD_CTX_copy_ex()
-Can be used to copy the message digest state from B<in> to B<out>. This is
+Can be used to copy the message digest state from I<in> to I<out>. This is
useful if large amounts of data are to be hashed which only differ in the last
few bytes.
=item EVP_DigestInit()
Behaves in the same way as EVP_DigestInit_ex() except it always uses the
-default digest implementation.
+default digest implementation and calls EVP_MD_CTX_reset().
=item EVP_DigestFinal()
-Similar to EVP_DigestFinal_ex() except the digest context B<ctx> is
+Similar to EVP_DigestFinal_ex() except the digest context I<ctx> is
automatically cleaned up.
=item EVP_MD_CTX_copy()
-Similar to EVP_MD_CTX_copy_ex() except the destination B<out> does not have to
+Similar to EVP_MD_CTX_copy_ex() except the destination I<out> does not have to
be initialized.
+=item EVP_MD_is_a()
+
+Returns 1 if I<md> is an implementation of an algorithm that's
+identifiable with I<name>, otherwise 0.
+
+If I<md> is a legacy digest (it's the return value from the likes of
+EVP_sha256() rather than the result of an EVP_MD_fetch()), only cipher
+names registered with the default library context (see
+L<OPENSSL_CTX(3)>) will be considered.
+
+=item EVP_MD_number()
+
+Returns the internal dynamic number assigned to the I<md>. This is
+only useful with fetched B<EVP_MD>s.
+
+=item EVP_MD_name(),
+EVP_MD_CTX_name()
+
+Return the name of the given message digest. For fetched message
+digests with multiple names, only one of them is returned; it's
+recommended to use EVP_MD_names_do_all() instead.
+
+=item EVP_MD_names_do_all()
+
+Traverses all names for the I<md>, and calls I<fn> with each name and
+I<data>. This is only useful with fetched B<EVP_MD>s.
+
+=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()
=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 I<ctx> to I<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 I<ctx>.
+
+=item EVP_MD_flags()
+
+Returns the I<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 I<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 customzied 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
+a customized B<EVP_PKEY_CTX> to L<EVP_DigestSignInit(3)> or
+L<EVP_DigestVerifyInit(3)>. The
I<pctx> passed to this function should be freed
+by the caller. A NULL
I<pctx> pointer is also allowed to clear the B<EVP_PKEY_CTX>
+assigned to I<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_provided()
+
+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 "xoflen" (B<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 "pad_type" (B<OSSL_PARAM_DIGEST_KEY_PAD_TYPE>) <integer>
+
+Sets the padding 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 "micalg" (B<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 I<p2>.
+
+When used with a fetched B<EVP_MD>, EVP_MD_CTX_get_params() gets called with
+an L<OSSL_PARAM(3)> item with the key "micalg" (B<OSSL_DIGEST_PARAM_MICALG>).
+
+=item EVP_MD_CTRL_XOF_LEN
+
+This control sets the digest length for extendable output functions to I<p1>.
+Sending this control directly should not be necessary, the use of
+EVP_DigestFinalXOF() is preferred.
+Currently used by SHAKE.
+
+When used with a fetched B<EVP_MD>, EVP_MD_CTX_get_params() gets called with
+an L<OSSL_PARAM(3)> item with the key "xoflen" (B<OSSL_DIGEST_PARAM_XOFLEN>).
+
=back
=head1 FLAGS
=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.
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
+For most applications the I<impl> parameter to EVP_DigestInit_ex() will be
set to NULL to use the default digest implementation.
The functions EVP_DigestInit(), EVP_DigestFinal() and EVP_MD_CTX_copy() are
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.
=head1 SEE ALSO
-L<dgst(1)>,
-L<evp(7)>
+L<EVP_MD_meth_new(3)>,
+L<openssl-dgst(1)>,
+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.
-EVP_MD_CTX_set_pkey_ctx() 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 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 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>.
projects / openssl.git / blobdiff