DOC: Extend the description of EVP_PKEY_CTX_new_from_name()

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

diff --git a/doc/man3/EVP_PKEY_CTX_new.pod b/doc/man3/EVP_PKEY_CTX_new.pod
index 90486ae0dcbcf83a2261a3ba70c4107c549b67cb..327d09f348e45044c78846766730eef40ba50711 100644 (file)
--- a/doc/man3/EVP_PKEY_CTX_new.pod
+++ b/doc/man3/EVP_PKEY_CTX_new.pod
@@ -2,8 +2,8 @@
 
 =head1 NAME
 
-EVP_PKEY_CTX_new, EVP_PKEY_CTX_new_id, EVP_PKEY_CTX_new_provided,
-EVP_PKEY_CTX_dup, EVP_PKEY_CTX_free
+EVP_PKEY_CTX_new, EVP_PKEY_CTX_new_id, EVP_PKEY_CTX_new_from_name,
+EVP_PKEY_CTX_new_from_pkey, EVP_PKEY_CTX_dup, EVP_PKEY_CTX_free
 - public key algorithm context functions
 
 =head1 SYNOPSIS
@@ -12,9 +12,11 @@ EVP_PKEY_CTX_dup, EVP_PKEY_CTX_free
 
  EVP_PKEY_CTX *EVP_PKEY_CTX_new(EVP_PKEY *pkey, ENGINE *e);
  EVP_PKEY_CTX *EVP_PKEY_CTX_new_id(int id, ENGINE *e);
- EVP_PKEY_CTX *EVP_PKEY_CTX_new_provided(OPENSSL_CTX *libctx,
-                                         const char *name,
-                                         const char *propquery);
+ EVP_PKEY_CTX *EVP_PKEY_CTX_new_from_name(OPENSSL_CTX *libctx,
+                                          const char *name,
+                                          const char *propquery);
+ EVP_PKEY_CTX *EVP_PKEY_CTX_new_from_pkey(OPENSSL_CTX *libctx,
+                                          EVP_PKEY *pkey);
  EVP_PKEY_CTX *EVP_PKEY_CTX_dup(const EVP_PKEY_CTX *ctx);
  void EVP_PKEY_CTX_free(EVP_PKEY_CTX *ctx);
 
@@ -26,13 +28,20 @@ the I<pkey> key type and ENGINE I<e>.
 The EVP_PKEY_CTX_new_id() function allocates public key algorithm context
 using the key type specified by I<id> and ENGINE I<e>.
 
-The EVP_PKEY_CTX_new_provided() function allocates a public key algorithm
+The EVP_PKEY_CTX_new_from_name() function allocates a public key algorithm
 context using the library context I<libctx> (see L<OPENSSL_CTX(3)>), the
 key type specified by I<name> and the property query I<propquery>.  None
 of the arguments are duplicated, so they  must remain unchanged for the
-lifetime of the returned B<EVP_PKEY_CTX> or of any of its duplicates.
+lifetime of the returned B<EVP_PKEY_CTX> or of any of its duplicates.  Read
+further about the possible names in L</NOTES> below.
 
-EVP_PKEY_CTX_new_id() and EVP_PKEY_CTX_new_provided() are normally
+The EVP_PKEY_CTX_new_from_pkey() function allocates a public key algorithm
+context using the library context I<libctx> (see L<OPENSSL_CTX(3)>) and the
+algorithm specified by I<pkey> and the property query I<propquery>. None of the
+arguments are duplicated, so they must remain unchanged for the lifetime of the
+returned B<EVP_PKEY_CTX> or any of its duplicates.
+
+EVP_PKEY_CTX_new_id() and EVP_PKEY_CTX_new_from_name() are normally
 used when no B<EVP_PKEY> structure is associated with the operations,
 for example during parameter generation or key generation for some
 algorithms.
@@ -44,16 +53,14 @@ If I<ctx> is NULL, nothing is done.
 
 =head1 NOTES
 
-=over 4
-
-=item 1.
+=head2 On B<EVP_PKEY_CTX>
 
 The B<EVP_PKEY_CTX> structure is an opaque public key algorithm context used
 by the OpenSSL high level public key API. Contexts B<MUST NOT> be shared between
 threads: that is it is not permissible to use the same context simultaneously
 in two threads.
 
-=item 2.
+=head2 On Key Types
 
 We mention "key type" in this manual, which is the same
 as "algorithm" in most cases, allowing either term to be used
@@ -61,6 +68,29 @@ interchangeably.  There are algorithms where the I<key type> and the
 I<algorithm> of the operations that use the keys are not the same,
 such as EC keys being used for ECDSA and ECDH operations.
 
+Key types are given in two different manners:
+
+=over 4
+
+=item Legacy NID or EVP_PKEY type
+
+This is the I<id> used with EVP_PKEY_CTX_new_id().
+
+These are B<EVP_PKEY_RSA>, B<EVP_PKEY_RSA_PSS>, B<EVP_PKEY_DSA>,
+B<EVP_PKEY_DH>, B<EVP_PKEY_EC>, B<EVP_PKEY_SM2>, B<EVP_PKEY_X25519>,
+B<EVP_PKEY_X448>, and are used by legacy methods.
+
+=item Name strings
+
+This is the I<name> used with EVP_PKEY_CTX_new_from_name().
+
+These are names like "RSA", "DSA", and what's available depends on what
+providers are currently accessible.
+
+The OpenSSL providers offer a set of key types available this way, please
+see L<OSSL_PROVIDER-FIPS(7)> and L<OSSL_PROVIDER-default(7)> and related
+documentation for more information.
+
 =back
 
 =head1 RETURN VALUES
@@ -76,7 +106,11 @@ L<EVP_PKEY_new(3)>
 
 =head1 HISTORY
 
-These functions were added in OpenSSL 1.0.0.
+The EVP_PKEY_CTX_new(), EVP_PKEY_CTX_new_id(), EVP_PKEY_CTX_dup() and
+EVP_PKEY_CTX_free() functions were added in OpenSSL 1.0.0.
+
+The EVP_PKEY_CTX_new_from_name() and EVP_PKEY_CTX_new_from_pkey() functions were
+added in OpenSSL 3.0.
 
 =head1 COPYRIGHT