=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_DigestUpdate, EVP_DigestFinal_ex,
-EVP_DigestInit, 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_md2, EVP_md5, EVP_sha1,
-EVP_sha224, EVP_sha256, EVP_sha384, EVP_sha512, EVP_mdc2,
-EVP_ripemd160, EVP_blake2b512, EVP_blake2s256, EVP_get_digestbyname,
-EVP_get_digestbynid, EVP_get_digestbyobj - EVP digest routines
+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_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_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(OSSL_LIB_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_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s);
+ int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t len);
int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in);
int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type);
- int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md,
- unsigned int *s);
+ int EVP_DigestFinal(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_md2(void);
- const EVP_MD *EVP_md5(void);
- const EVP_MD *EVP_sha1(void);
- const EVP_MD *EVP_mdc2(void);
- const EVP_MD *EVP_ripemd160(void);
- const EVP_MD *EVP_blake2b512(void);
- const EVP_MD *EVP_blake2s256(void);
-
- const EVP_MD *EVP_sha224(void);
- const EVP_MD *EVP_sha256(void);
- const EVP_MD *EVP_sha384(void);
- const EVP_MD *EVP_sha512(void);
const EVP_MD *EVP_get_digestbyname(const char *name);
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(OSSL_LIB_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.
+The EVP digest routines are a high-level interface to message digests,
+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 I<ctx>. This can be used to reuse an already
+existing context.
+
+=item EVP_MD_CTX_free()
+
+Cleans up digest context I<ctx> and frees up the space allocated to it.
+
+=item EVP_MD_CTX_ctrl()
+
+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 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 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.
+
+The I<type> parameter can be NULL if I<ctx> has been already initialized
+with another EVP_DigestInit_ex() call and has not been reset with
+EVP_MD_CTX_reset().
+
+=item EVP_DigestUpdate()
+
+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 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 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 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 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 and calls EVP_MD_CTX_reset() so it cannot
+be used with an I<type> of NULL.
+
+=item EVP_DigestFinal()
+
+Similar to EVP_DigestFinal_ex() except after computing the digest
+the digest context I<ctx> is automatically cleaned up with EVP_MD_CTX_reset().
+
+=item EVP_MD_CTX_copy()
+
+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<OSSL_LIB_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()
+
+Return the size of the message digest when passed an B<EVP_MD> or an
+B<EVP_MD_CTX> structure, i.e. the size of the hash.
+
+=item EVP_MD_block_size(),
+EVP_MD_CTX_block_size()
+
+Return the block size of the message digest when passed an B<EVP_MD> or an
+B<EVP_MD_CTX> structure.
+
+=item EVP_MD_type(),
+EVP_MD_CTX_type()
+
+Return the NID of the OBJECT IDENTIFIER representing the given message digest
+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.
-EVP_MD_CTX_new() allocates, initializes and returns a digest context.
+=item EVP_MD_CTX_md_data()
-EVP_MD_CTX_reset() resets the digest context B<ctx>. This can be used
-to reuse an already existing context.
+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().
-EVP_MD_CTX_free() cleans up digest context B<ctx> and frees up the
-space allocated to it.
+=item EVP_MD_CTX_md()
-EVP_MD_CTX_ctrl() performs digest-specific control actions on context B<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.
-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.
+=item EVP_MD_CTX_set_update_fn()
-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 data.
+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.
-EVP_DigestFinal_ex() retrieves the digest value from B<ctx> and places
-it in B<md>. If the B<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 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_MD_CTX_update_fn()
-EVP_MD_CTX_copy_ex() 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.
+Returns the update function for I<ctx>.
-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.
+=item EVP_MD_flags()
-EVP_DigestFinal() is similar to EVP_DigestFinal_ex() except the digest
-context B<ctx> is automatically cleaned up.
+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.
-EVP_MD_CTX_copy() is similar to EVP_MD_CTX_copy_ex() except the destination
-B<out> does not have to be initialized.
+=item EVP_MD_pkey_type()
-EVP_MD_size() and EVP_MD_CTX_size() return the size of the message digest
-when passed an B<EVP_MD> or an B<EVP_MD_CTX> structure, i.e. the size of the
-hash.
+Returns the NID of the public key signing algorithm associated with this
+digest. For example EVP_sha1() is associated with RSA so this will return
+B<NID_sha1WithRSAEncryption>. Since digests and signature algorithms are no
+longer linked this function is only retained for compatibility reasons.
-EVP_MD_block_size() and EVP_MD_CTX_block_size() return the block size of the
-message digest when passed an B<EVP_MD> or an B<EVP_MD_CTX> structure.
+=item EVP_md_null()
-EVP_MD_type() and EVP_MD_CTX_type() return the NID of the OBJECT IDENTIFIER
-representing the given message digest when passed an B<EVP_MD> structure.
-For example EVP_MD_type(EVP_sha1()) returns B<NID_sha1>. This function is
-normally used when setting ASN1 OIDs.
+A "null" message digest that does nothing: i.e. the hash it returns is of zero
+length.
-EVP_MD_CTX_md() returns the B<EVP_MD> structure corresponding to the passed
-B<EVP_MD_CTX>.
+=item EVP_get_digestbyname(),
+EVP_get_digestbynid(),
+EVP_get_digestbyobj()
-EVP_MD_pkey_type() returns the NID of the public key signing algorithm associated
-with this digest. For example EVP_sha1() is associated with RSA so this will
-return B<NID_sha1WithRSAEncryption>. Since digests and signature algorithms
-are no longer linked this function is only retained for compatibility
-reasons.
+Returns an B<EVP_MD> structure when passed a digest name, a digest B<NID> or an
+B<ASN1_OBJECT> structure respectively.
-EVP_md2(), EVP_md5(), EVP_sha1(), EVP_sha224(), EVP_sha256(),
-EVP_sha384(), EVP_sha512(), EVP_mdc2(), EVP_ripemd160(), EVP_blake2b512(), and
-EVP_blake2s256() return B<EVP_MD> structures for the MD2, MD5, SHA1, SHA224,
-SHA256, SHA384, SHA512, MDC2, RIPEMD160, BLAKE2b-512, and BLAKE2s-256 digest
-algorithms respectively.
+=item EVP_MD_CTX_pkey_ctx()
-EVP_md_null() is a "null" message digest that does nothing: i.e. the hash it
-returns is of zero length.
+Returns the B<EVP_PKEY_CTX> assigned to I<ctx>. The returned pointer should not
+be freed by the caller.
-EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj()
-return an B<EVP_MD> structure when passed a digest name, a digest NID or
-an ASN1_OBJECT structure respectively.
+=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 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
+
+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
-EVP_DigestInit_ex(), EVP_DigestUpdate() and EVP_DigestFinal_ex() return 1 for
+=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 for
success and 0 for failure.
-EVP_MD_CTX_ctrl() returns 1 if successful or 0 for failure.
+=item EVP_MD_CTX_ctrl()
+
+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()
-EVP_MD_CTX_copy_ex() returns 1 if successful or 0 for failure.
+Returns 1 if successful or 0 for failure.
-EVP_MD_type(), EVP_MD_pkey_type() and EVP_MD_type() return the NID of the
-corresponding OBJECT IDENTIFIER or NID_undef if none exists.
+=item EVP_MD_type(),
+EVP_MD_pkey_type()
-EVP_MD_size(), EVP_MD_block_size(), EVP_MD_CTX_size() and
-EVP_MD_CTX_block_size() return the digest or block size in bytes.
+Returns the NID of the corresponding OBJECT IDENTIFIER or NID_undef if none
+exists.
-EVP_md_null(), EVP_md2(), EVP_md5(), EVP_sha1(),
-EVP_mdc2(), EVP_ripemd160(), EVP_blake2b512(), and EVP_blake2s256() return
-pointers to the corresponding EVP_MD structures.
+=item EVP_MD_size(),
+EVP_MD_block_size(),
+EVP_MD_CTX_size(),
+EVP_MD_CTX_block_size()
-EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj()
-return either an B<EVP_MD> structure or NULL if an error occurs.
+Returns the digest or block size in bytes.
+
+=item EVP_md_null()
+
+Returns a pointer to the B<EVP_MD> structure of the "null" message digest.
+
+=item EVP_get_digestbyname(),
+EVP_get_digestbynid(),
+EVP_get_digestbyobj()
+
+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
The B<EVP> interface to message digests should almost always be used in
-preference to the low level interfaces. This is because the code then becomes
+preference to the low-level interfaces. This is because the code then becomes
transparent to the digest used and much more flexible.
-New applications should use the SHA2 digest algorithms such as SHA256.
-The other digest algorithms are still in common use.
+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(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
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;
-
- if (!argv[1]) {
- printf("Usage: mdtest digestname\n");
- exit(1);
- }
-
- md = EVP_get_digestbyname(argv[1]);
- if (md == NULL) {
- printf("Unknown message digest %s\n", argv[1]);
- exit(1);
- }
-
- mdctx = EVP_MD_CTX_new();
- EVP_DigestInit_ex(mdctx, md, NULL);
- EVP_DigestUpdate(mdctx, mess1, strlen(mess1));
- EVP_DigestUpdate(mdctx, mess2, strlen(mess2));
- EVP_DigestFinal_ex(mdctx, md_value, &md_len);
- EVP_MD_CTX_free(mdctx);
-
- printf("Digest is: ");
- for (i = 0; i < md_len; i++)
- printf("%02x", md_value[i]);
- printf("\n");
-
- exit(0);
+ 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];
+ unsigned int md_len, i;
+
+ if (argv[1] == NULL) {
+ printf("Usage: mdtest digestname\n");
+ exit(1);
+ }
+
+ md = EVP_get_digestbyname(argv[1]);
+ if (md == NULL) {
+ printf("Unknown message digest %s\n", argv[1]);
+ exit(1);
+ }
+
+ mdctx = EVP_MD_CTX_new();
+ EVP_DigestInit_ex(mdctx, md, NULL);
+ EVP_DigestUpdate(mdctx, mess1, strlen(mess1));
+ EVP_DigestUpdate(mdctx, mess2, strlen(mess2));
+ EVP_DigestFinal_ex(mdctx, md_value, &md_len);
+ EVP_MD_CTX_free(mdctx);
+
+ printf("Digest is: ");
+ for (i = 0; i < md_len; i++)
+ printf("%02x", md_value[i]);
+ printf("\n");
+
+ exit(0);
}
=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_blake2b512(3)>,
+L<EVP_md2(3)>,
+L<EVP_md4(3)>,
+L<EVP_md5(3)>,
+L<EVP_mdc2(3)>,
+L<EVP_ripemd160(3)>,
+L<EVP_sha1(3)>,
+L<EVP_sha224(3)>,
+L<EVP_sha3_224(3)>,
+L<EVP_sm3(3)>,
+L<EVP_whirlpool(3)>
+L<provider(7)/Fetching algorithms>
=head1 HISTORY
-B<EVP_MD_CTX> became opaque in OpenSSL 1.1. Consequently, stack
-allocated B<EVP_MD_CTX>s are no longer supported.
-
-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.
+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. The legacy EVP_dss1()
-was removed in OpenSSL 1.1.0
+later, so now EVP_sha1() can be used with RSA and DSA.
+
+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 2000-2020 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