ext/openssl: implement OpenSSL::PKey::{DSA,RSA,EC}#public_pkeytopic/openssl-pkey-ec

Add OpenSSL::PKey::{DSA,RSA,EC}#public_pkey. They return a new instance
of itself, which contains only parameters and public information.

The old methods, {DSA,RSA}#public_key, are now deprecated.

There are 3 types of PKey#public_key: 1) EC#public_key, which returns
the actual public key (EC::Point). 2) RSA/DSA#public_key, which returns
a new instance of PKey with no private information. 3) DH#public_key,
which returns a new instance of DH which contains only DH params. This
doesn't even contain 'private key'. This is very confusing. The new
methods are intend to replace the 2).

3 files changed, 44 insertions, 10 deletions

diff --git a/ext/openssl/ossl_pkey_dsa.c b/ext/openssl/ossl_pkey_dsa.c
index 04900cc649..592b03ae3d 100644
--- a/ext/openssl/ossl_pkey_dsa.c
+++ b/ext/openssl/ossl_pkey_dsa.c
@@ -261,7 +261,8 @@ ossl_dsa_initialize(int argc, VALUE *argv, VALUE self)
  *    dsa.public? -> true | false
  *
  * Indicates whether this DSA instance has a public key associated with it or
- * not. The public key may be retrieved with DSA#public_key.
+ * not. An DSA instance that contains only public key may be retrieved with
+ * DSA#public_pkey.
  */
 static VALUE
 ossl_dsa_is_public(VALUE self)
@@ -278,7 +279,7 @@ ossl_dsa_is_public(VALUE self)
  *    dsa.private? -> true | false
  *
  * Indicates whether this DSA instance has a private key associated with it or
- * not. The private key may be retrieved with DSA#private_key.
+ * not.
  */
 static VALUE
 ossl_dsa_is_private(VALUE self)
@@ -436,7 +437,7 @@ ossl_dsa_to_text(VALUE self)
 
 /*
  *  call-seq:
- *    dsa.public_key -> aDSA
+ *    dsa.public_pkey -> aDSA
  *
  * Returns a new DSA instance that carries just the public key information.
  * If the current instance has also private key information, this will no
@@ -446,13 +447,15 @@ ossl_dsa_to_text(VALUE self)
  *
  * === Example
  *  dsa = OpenSSL::PKey::DSA.new(2048) # has public and private information
- *  pub_key = dsa.public_key # has only the public part available
+ *  pub_key = dsa.public_pkey # has only the public part available
  *  pub_key_der = pub_key.to_der # it's safe to publish this
  *
- *
+ * === Note
+ *  This method was renamed from OpenSSL::PKey::DSA#public_key. It remains as
+ *  an alias.
  */
 static VALUE
-ossl_dsa_to_public_key(VALUE self)
+ossl_dsa_to_public_pkey(VALUE self)
 {
     EVP_PKEY *pkey;
     DSA *dsa;
@@ -603,7 +606,8 @@ Init_ossl_dsa(void)
     rb_define_alias(cDSA, "to_pem", "export");
     rb_define_alias(cDSA, "to_s", "export");
     rb_define_method(cDSA, "to_der", ossl_dsa_to_der, 0);
-    rb_define_method(cDSA, "public_key", ossl_dsa_to_public_key, 0);
+    rb_define_method(cDSA, "public_pkey", ossl_dsa_to_public_pkey, 0);
+    rb_define_alias(cDSA, "public_key", "public_pkey");
     rb_define_method(cDSA, "syssign", ossl_dsa_sign, 1);
     rb_define_method(cDSA, "sysverify", ossl_dsa_verify, 2);
 
diff --git a/ext/openssl/ossl_pkey_ec.c b/ext/openssl/ossl_pkey_ec.c
index bbdd8a7a5d..80c241aca1 100644
--- a/ext/openssl/ossl_pkey_ec.c
+++ b/ext/openssl/ossl_pkey_ec.c
@@ -632,6 +632,30 @@ static VALUE ossl_ec_key_check_key(VALUE self)
 
 /*
  *  call-seq:
+ *     key.public_pkey   => OpenSSL::PKey::EC
+ *
+ *  Returns a new EC instance that has only public information.
+ */
+static VALUE ossl_ec_key_public_pkey(VALUE self)
+{
+    EC_KEY *ec, *ec_new;
+
+    Require_EC_KEY(self, ec);
+
+    if (!EC_KEY_get0_public_key(ec))
+	ossl_raise(eECError, "public key is not set");
+
+    ec_new = EC_KEY_dup(ec);
+    if (!ec_new)
+	ossl_raise(eECError, "EC_KEY_dup");
+
+    EC_KEY_set_private_key(ec_new, NULL);
+
+    return ec_instance(cEC, ec_new);
+}
+
+/*
+ *  call-seq:
  *     key.dh_compute_key(pubkey)   => String
  *
  *  See the OpenSSL documentation for ECDH_compute_key()
@@ -1634,6 +1658,7 @@ void Init_ossl_ec(void)
 */
     rb_define_method(cEC, "generate_key", ossl_ec_key_generate_key, 0);
     rb_define_method(cEC, "check_key", ossl_ec_key_check_key, 0);
+    rb_define_method(cEC, "public_pkey", ossl_ec_key_public_pkey, 0);
 
     rb_define_method(cEC, "dh_compute_key", ossl_ec_key_dh_compute_key, 1);
     rb_define_method(cEC, "dsa_sign_asn1", ossl_ec_key_dsa_sign_asn1, 1);
diff --git a/ext/openssl/ossl_pkey_rsa.c b/ext/openssl/ossl_pkey_rsa.c
index 20b993abb8..bb51453442 100644
--- a/ext/openssl/ossl_pkey_rsa.c
+++ b/ext/openssl/ossl_pkey_rsa.c
@@ -562,12 +562,16 @@ ossl_rsa_to_text(VALUE self)
 
 /*
  * call-seq:
- *    rsa.public_key -> RSA
+ *    rsa.public_pkey -> RSA
  *
  * Makes new RSA instance containing the public key from the private key.
+ *
+ * === Note
+ *  This method was renamed from OpenSSL::PKey::RSA#public_key. It remains as
+ *  an alias.
  */
 static VALUE
-ossl_rsa_to_public_key(VALUE self)
+ossl_rsa_to_public_pkey(VALUE self)
 {
     EVP_PKEY *pkey;
     RSA *rsa;
@@ -664,7 +668,8 @@ Init_ossl_rsa(void)
     rb_define_alias(cRSA, "to_pem", "export");
     rb_define_alias(cRSA, "to_s", "export");
     rb_define_method(cRSA, "to_der", ossl_rsa_to_der, 0);
-    rb_define_method(cRSA, "public_key", ossl_rsa_to_public_key, 0);
+    rb_define_method(cRSA, "public_pkey", ossl_rsa_to_public_pkey, 0);
+    rb_define_alias(cRSA, "public_key", "public_pkey");
     rb_define_method(cRSA, "public_encrypt", ossl_rsa_public_encrypt, -1);
     rb_define_method(cRSA, "public_decrypt", ossl_rsa_public_decrypt, -1);
     rb_define_method(cRSA, "private_encrypt", ossl_rsa_private_encrypt, -1);