=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_CTX_ctrl, 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
=head1 SYNOPSIS
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_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_MD_CTX_type(const EVP_MD *ctx);
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);
The EVP digest routines are a high level interface to message digests,
and should be used instead of the cipher-specific functions.
-EVP_MD_CTX_new() allocates, initializes and returns a digest context.
+=over 4
-EVP_MD_CTX_reset() resets the digest context B<ctx>. This can be used
-to reuse an already existing context.
+=item EVP_MD_CTX_new()
-EVP_MD_CTX_free() cleans up digest context B<ctx> and frees up the
-space allocated to it.
+Allocates, initializes and returns a digest context.
-EVP_MD_CTX_ctrl() performs digest-specific control actions on context B<ctx>.
+=item EVP_MD_CTX_reset()
-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.
+Resets the digest context B<ctx>. This can be used to reuse an already
+existing context.
-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.
+=item EVP_MD_CTX_free()
-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.
+Cleans up digest context B<ctx> and frees up the space allocated to it.
-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.
+=item EVP_MD_CTX_ctrl()
-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.
+Performs digest-specific control actions on context B<ctx>.
-EVP_DigestFinal() is similar to EVP_DigestFinal_ex() except the digest
-context B<ctx> is automatically cleaned up.
+=item EVP_DigestInit_ex()
-EVP_MD_CTX_copy() is similar to EVP_MD_CTX_copy_ex() except the destination
-B<out> does not have to be initialized.
+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.
-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.
+=item EVP_DigestUpdate()
-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.
+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.
-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.
+=item EVP_DigestFinal_ex()
-EVP_MD_CTX_md() returns the B<EVP_MD> structure corresponding to the passed
-B<EVP_MD_CTX>.
+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.
-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.
+=item EVP_DigestFinalXOF()
-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.
+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.
+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.
-EVP_md_null() is a "null" message digest that does nothing: i.e. the hash it
-returns is of zero length.
+=item EVP_MD_CTX_copy_ex()
-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.
+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.
+
+=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.
+
+=item EVP_DigestFinal()
+
+Similar to EVP_DigestFinal_ex() except the digest context B<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
+be initialized.
+
+=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.
+
+=item EVP_MD_CTX_md()
+
+Returns the B<EVP_MD> structure corresponding to the passed B<EVP_MD_CTX>.
+
+=item 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.
+
+=item EVP_md_null()
+
+A "null" message digest that does nothing: i.e. the hash it returns is of zero
+length.
+
+=item EVP_get_digestbyname(),
+EVP_get_digestbynid(),
+EVP_get_digestbyobj()
+
+Returns an B<EVP_MD> structure when passed a digest name, a digest B<NID> or an
+B<ASN1_OBJECT> structure respectively.
+
+=back
=head1 RETURN VALUES
-EVP_DigestInit_ex(), EVP_DigestUpdate() and EVP_DigestFinal_ex() return 1 for
+=over 4
+
+=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.
-EVP_MD_CTX_copy_ex() returns 1 if successful or 0 for failure.
+=item EVP_MD_CTX_copy_ex()
-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.
+Returns 1 if successful or 0 for failure.
-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.
+=item EVP_MD_type(),
+EVP_MD_pkey_type(),
+EVP_MD_type()
-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.
+Returns the NID of the corresponding OBJECT IDENTIFIER or NID_undef if none
+exists.
-EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj()
-return either an B<EVP_MD> structure or NULL if an error occurs.
+=item EVP_MD_size(),
+EVP_MD_block_size(),
+EVP_MD_CTX_size(),
+EVP_MD_CTX_block_size()
+
+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.
+
+=back
=head1 NOTES
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>). 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.
L<dgst(1)>,
L<evp(7)>
+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_whirlpool(3)>
+
=head1 HISTORY
EVP_MD_CTX_create() and EVP_MD_CTX_destroy() were renamed to
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
+EVP_dss1() was removed in OpenSSL 1.1.0.
=head1 COPYRIGHT
projects / openssl.git / blobdiff