=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
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 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
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
projects / openssl.git / blobdiff