Update documentation

[openssl.git] / doc / man3 / EVP_DigestSignInit.pod

diff --git a/doc/man3/EVP_DigestSignInit.pod b/doc/man3/EVP_DigestSignInit.pod
index 0f9c95230369861827e60459e9e7c26d2adc9504..f730ba7b0301af2011a96522cd5bff5e2987a290 100644 (file)
--- a/doc/man3/EVP_DigestSignInit.pod
+++ b/doc/man3/EVP_DigestSignInit.pod
@@ -2,13 +2,16 @@
 
 =head1 NAME
 
 
 =head1 NAME
 

-EVP_DigestSignInit, EVP_DigestSignUpdate, EVP_DigestSignFinal,
-EVP_DigestSign - EVP signing functions
+EVP_DigestSignInit_ex, EVP_DigestSignInit, EVP_DigestSignUpdate,
+EVP_DigestSignFinal, EVP_DigestSign - EVP signing functions

 
 =head1 SYNOPSIS
 
  #include <openssl/evp.h>
 
 
 =head1 SYNOPSIS
 
  #include <openssl/evp.h>
 

+ int EVP_DigestSignInit_ex(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
+                           const char *mdname, const char *props,
+                           EVP_PKEY *pkey, EVP_SIGNATURE *signature);

  int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
                         const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey);
  int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt);
  int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
                         const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey);
  int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt);


@@ -21,22 +24,44 @@ EVP_DigestSign - EVP signing functions
 =head1 DESCRIPTION
 
 The EVP signature routines are a high level interface to digital signatures.
 =head1 DESCRIPTION
 
 The EVP signature routines are a high level interface to digital signatures.

-
-EVP_DigestSignInit() sets up signing context B<ctx> to use digest B<type> from
-ENGINE B<e> and private key B<pkey>. B<ctx> must be created with
-EVP_MD_CTX_new() before calling this function. If B<pctx> is not NULL, the
-EVP_PKEY_CTX of the signing operation will be written to B<*pctx>: this can
-be used to set alternative signing options. Note that any existing value in
-B<*pctx> is overwritten. The EVP_PKEY_CTX value returned must not be freed
-directly by the application if B<ctx> is not assigned an EVP_PKEY_CTX value before
-being passed to EVP_DigestSignInit() (which means the EVP_PKEY_CTX is created
-inside EVP_DigestSignInit() and it will be freed automatically when the
-EVP_MD_CTX is freed).
-
-The digest B<type> may be NULL if the signing algorithm supports it.
-
-No B<EVP_PKEY_CTX> will be created by EVP_DigestSignInit() if the passed B<ctx>
-has already been assigned one via L<EVP_MD_CTX_set_ctx(3)>. See also L<SM2(7)>.
+Input data is digested first before the signing takes place.
+
+EVP_DigestSignInit_ex() sets up signing context B<ctx> to use a digest with the
+name B<mdname> and private key B<pkey>. The signature algorithm B<signature>
+will be used for the actual signing which must be compatible with the private
+key. The name of the digest to be used is passed to the provider of the
+signature algorithm in use. How that provider interprets the digest name is
+provider specific. The provider may implement that digest directly itself or it
+may (optionally) choose to fetch it (which could result in a digest from a
+different provider being selected). If the provider supports fetching the digest
+then it may use the B<props> argument for the properties to be used during the
+fetch.
+
+The B<signature> parameter may be NULL in which case a suitable signature
+algorithm implementation will be implicitly fetched based on the type of key in
+use. See L<provider(7)> for further information about providers and fetching
+algorithms.
+
+The OpenSSL default and legacy providers support fetching digests and can fetch
+those digests from any available provider. The OpenSSL fips provider also
+supports fetching digests but will only fetch digests that are themselves
+implemented inside the fips provider.
+
+B<ctx> must be created with EVP_MD_CTX_new() before calling this function. If
+B<pctx> is not NULL, the EVP_PKEY_CTX of the signing operation will be written
+to B<*pctx>: this can be used to set alternative signing options. Note that any
+existing value in B<*pctx> is overwritten. The EVP_PKEY_CTX value returned must
+not be freed directly by the application if B<ctx> is not assigned an
+EVP_PKEY_CTX value before being passed to EVP_DigestSignInit_ex() (which means
+the EVP_PKEY_CTX is created inside EVP_DigestSignInit_ex() and it will be freed
+automatically when the EVP_MD_CTX is freed).
+
+The digest B<mdname> may be NULL if the signing algorithm supports it. The
+B<props> argument can always be NULL.
+
+No B<EVP_PKEY_CTX> will be created by EVP_DigestSignInit_ex() if the passed
+B<ctx> has already been assigned one via L<EVP_MD_CTX_set_ctx(3)>. See also
+L<SM2(7)>.

 
 Only EVP_PKEY types that support signing can be used with these functions. This
 includes MAC algorithms where the MAC generation is considered as a form of
 
 Only EVP_PKEY types that support signing can be used with these functions. This
 includes MAC algorithms where the MAC generation is considered as a form of


@@ -84,10 +109,14 @@ Will ignore any digest provided.
 
 If RSA-PSS is used and restrictions apply then the digest must match.
 
 
 If RSA-PSS is used and restrictions apply then the digest must match.
 

+EVP_DigestSignInit() works in the same way as EVP_DigestSignInit_ex() except
+that the B<mdname> parameter will be inferred from the supplied digest B<type>,
+and B<props> will be NULL. Where supplied the ENGINE B<e> will be used for the
+signing and digest algorithm implementations. B<e> may be NULL.
+

 EVP_DigestSignUpdate() hashes B<cnt> bytes of data at B<d> into the
 signature context B<ctx>. This function can be called several times on the
 EVP_DigestSignUpdate() hashes B<cnt> bytes of data at B<d> into the
 signature context B<ctx>. This function can be called several times on the

-same B<ctx> to include additional data. This function is currently implemented
-using a macro.
+same B<ctx> to include additional data.

 
 EVP_DigestSignFinal() signs the data in B<ctx> and places the signature in B<sig>.
 If B<sig> is B<NULL> then the maximum size of the output buffer is written to
 
 EVP_DigestSignFinal() signs the data in B<ctx> and places the signature in B<sig>.
 If B<sig> is B<NULL> then the maximum size of the output buffer is written to


@@ -156,6 +185,10 @@ L<RAND(7)>
 EVP_DigestSignInit(), EVP_DigestSignUpdate() and EVP_DigestSignFinal()
 were added in OpenSSL 1.0.0.
 
 EVP_DigestSignInit(), EVP_DigestSignUpdate() and EVP_DigestSignFinal()
 were added in OpenSSL 1.0.0.
 

+EVP_DigestSignInit_ex() was added in OpenSSL 3.0.
+
+EVP_DigestSignUpdate() was converted from a macro to a function in OpenSSL 3.0.
+

 =head1 COPYRIGHT
 
 Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
 =head1 COPYRIGHT
 
 Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.