pkey: implement {DH,DSA,RSA}#public_key in Ruby

The low-level API that is used to implement #public_key is deprecated
in OpenSSL 3.0. It is actually very simple to implement in another way,
using existing methods only, in much shorter code. Let's do it.

While we are at it, the documentation is updated to recommend against
using #public_key. Now that OpenSSL::PKey::PKey implements public_to_der
method, there is no real use case for #public_key in newly written Ruby
programs.

1 files changed, 1 insertions, 57 deletions

diff --git a/ext/openssl/ossl_pkey_rsa.c b/ext/openssl/ossl_pkey_rsa.c
index 7a7e66db..1c5476cd 100644
--- a/ext/openssl/ossl_pkey_rsa.c
+++ b/ext/openssl/ossl_pkey_rsa.c
@@ -390,7 +390,7 @@ ossl_rsa_private_decrypt(int argc, VALUE *argv, VALUE self)
  *   data = "Sign me!"
  *   pkey = OpenSSL::PKey::RSA.new(2048)
  *   signature = pkey.sign_pss("SHA256", data, salt_length: :max, mgf1_hash: "SHA256")
- *   pub_key = pkey.public_key
+ *   pub_key = OpenSSL::PKey.read(pkey.public_to_der)
  *   puts pub_key.verify_pss("SHA256", signature, data,
  *                           salt_length: :auto, mgf1_hash: "SHA256") # => true
  */
@@ -588,61 +588,6 @@ ossl_rsa_get_params(VALUE self)
 }
 
 /*
- * call-seq:
- *    rsa.public_key -> RSA
- *
- * Makes new RSA instance containing the public key from the private key.
- */
-static VALUE
-ossl_rsa_to_public_key(VALUE self)
-{
-    EVP_PKEY *pkey, *pkey_new;
-    RSA *rsa;
-    VALUE obj;
-
-    GetPKeyRSA(self, pkey);
-    obj = rb_obj_alloc(rb_obj_class(self));
-    GetPKey(obj, pkey_new);
-
-    rsa = RSAPublicKey_dup(EVP_PKEY_get0_RSA(pkey));
-    if (!rsa)
-        ossl_raise(eRSAError, "RSAPublicKey_dup");
-    if (!EVP_PKEY_assign_RSA(pkey_new, rsa)) {
-        RSA_free(rsa);
-        ossl_raise(eRSAError, "EVP_PKEY_assign_RSA");
-    }
-    return obj;
-}
-
-/*
- * TODO: Test me
-
-static VALUE
-ossl_rsa_blinding_on(VALUE self)
-{
-    RSA *rsa;
-
-    GetRSA(self, rsa);
-
-    if (RSA_blinding_on(rsa, ossl_bn_ctx) != 1) {
-	ossl_raise(eRSAError, NULL);
-    }
-    return self;
-}
-
-static VALUE
-ossl_rsa_blinding_off(VALUE self)
-{
-    RSA *rsa;
-
-    GetRSA(self, rsa);
-    RSA_blinding_off(rsa);
-
-    return self;
-}
- */
-
-/*
  * Document-method: OpenSSL::PKey::RSA#set_key
  * call-seq:
  *   rsa.set_key(n, e, d) -> self
@@ -712,7 +657,6 @@ 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_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);