pkey: implement #to_text using EVP API

Use EVP_PKEY_print_private() instead of the low-level API *_print()
functions, such as RSA_print().

EVP_PKEY_print_*() family was added in OpenSSL 1.0.0.

Note that it falls back to EVP_PKEY_print_public() and
EVP_PKEY_print_params() as necessary. This is required for EVP_PKEY_DH
type for which _private() fails if the private component is not set in
the pkey object.

Since the new API works in the same way for all key types, we now
implement #to_text in the base class OpenSSL::PKey::PKey rather than in
each subclass.

ext/openssl/ossl_pkey.c

@@ -539,6 +539,43 @@ ossl_pkey_inspect(VALUE self)
                       OBJ_nid2sn(nid));
 }
 
+/*
+ * call-seq:
+ *    pkey.to_text -> string
+ *
+ * Dumps key parameters, public key, and private key components contained in
+ * the key into a human-readable text.
+ *
+ * This is intended for debugging purpose.
+ *
+ * See also the man page EVP_PKEY_print_private(3).
+ */
+static VALUE
+ossl_pkey_to_text(VALUE self)
+{
+    EVP_PKEY *pkey;
+    BIO *bio;
+
+    GetPKey(self, pkey);
+    if (!(bio = BIO_new(BIO_s_mem())))
+        ossl_raise(ePKeyError, "BIO_new");
+
+    if (EVP_PKEY_print_private(bio, pkey, 0, NULL) == 1)
+        goto out;
+    OSSL_BIO_reset(bio);
+    if (EVP_PKEY_print_public(bio, pkey, 0, NULL) == 1)
+        goto out;
+    OSSL_BIO_reset(bio);
+    if (EVP_PKEY_print_params(bio, pkey, 0, NULL) == 1)
+        goto out;
+
+    BIO_free(bio);
+    ossl_raise(ePKeyError, "EVP_PKEY_print_params");
+
+  out:
+    return ossl_membio2str(bio);
+}
+
 VALUE
 ossl_pkey_export_traditional(int argc, VALUE *argv, VALUE self, int to_der)
 {
@@ -1077,6 +1114,7 @@ Init_ossl_pkey(void)
     rb_define_method(cPKey, "initialize", ossl_pkey_initialize, 0);
     rb_define_method(cPKey, "oid", ossl_pkey_oid, 0);
     rb_define_method(cPKey, "inspect", ossl_pkey_inspect, 0);
+    rb_define_method(cPKey, "to_text", ossl_pkey_to_text, 0);
     rb_define_method(cPKey, "private_to_der", ossl_pkey_private_to_der, -1);
     rb_define_method(cPKey, "private_to_pem", ossl_pkey_private_to_pem, -1);
     rb_define_method(cPKey, "public_to_der", ossl_pkey_public_to_der, 0);

ext/openssl/ossl_pkey_dh.c

@@ -266,34 +266,6 @@ ossl_dh_get_params(VALUE self)
     return hash;
 }
 
-/*
- *  call-seq:
- *     dh.to_text -> aString
- *
- * Prints all parameters of key to buffer
- * INSECURE: PRIVATE INFORMATIONS CAN LEAK OUT!!!
- * Don't use :-)) (I's up to you)
- */
-static VALUE
-ossl_dh_to_text(VALUE self)
-{
-    DH *dh;
-    BIO *out;
-    VALUE str;
-
-    GetDH(self, dh);
-    if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eDHError, NULL);
-    }
-    if (!DHparams_print(out, dh)) {
-	BIO_free(out);
-	ossl_raise(eDHError, NULL);
-    }
-    str = ossl_membio2str(out);
-
-    return str;
-}
-
 /*
  *  call-seq:
  *     dh.public_key -> aDH
@@ -426,7 +398,6 @@ Init_ossl_dh(void)
     rb_define_method(cDH, "initialize_copy", ossl_dh_initialize_copy, 1);
     rb_define_method(cDH, "public?", ossl_dh_is_public, 0);
     rb_define_method(cDH, "private?", ossl_dh_is_private, 0);
-    rb_define_method(cDH, "to_text", ossl_dh_to_text, 0);
     rb_define_method(cDH, "export", ossl_dh_export, 0);
     rb_define_alias(cDH, "to_pem", "export");
     rb_define_alias(cDH, "to_s", "export");

ext/openssl/ossl_pkey_dsa.c

@@ -264,34 +264,6 @@ ossl_dsa_get_params(VALUE self)
     return hash;
 }
 
-/*
- *  call-seq:
- *    dsa.to_text -> aString
- *
- * Prints all parameters of key to buffer
- * INSECURE: PRIVATE INFORMATIONS CAN LEAK OUT!!!
- * Don't use :-)) (I's up to you)
- */
-static VALUE
-ossl_dsa_to_text(VALUE self)
-{
-    DSA *dsa;
-    BIO *out;
-    VALUE str;
-
-    GetDSA(self, dsa);
-    if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eDSAError, NULL);
-    }
-    if (!DSA_print(out, dsa, 0)) { /* offset = 0 */
-	BIO_free(out);
-	ossl_raise(eDSAError, NULL);
-    }
-    str = ossl_membio2str(out);
-
-    return str;
-}
-
 /*
  *  call-seq:
  *    dsa.public_key -> aDSA
@@ -469,7 +441,6 @@ Init_ossl_dsa(void)
 
     rb_define_method(cDSA, "public?", ossl_dsa_is_public, 0);
     rb_define_method(cDSA, "private?", ossl_dsa_is_private, 0);
-    rb_define_method(cDSA, "to_text", ossl_dsa_to_text, 0);
     rb_define_method(cDSA, "export", ossl_dsa_export, -1);
     rb_define_alias(cDSA, "to_pem", "export");
     rb_define_alias(cDSA, "to_s", "export");

ext/openssl/ossl_pkey_ec.c

@@ -412,32 +412,6 @@ ossl_ec_key_to_der(VALUE self)
     else
         return ossl_pkey_export_spki(self, 1);
 }
-
-/*
- *  call-seq:
- *     key.to_text   => String
- *
- *  See the OpenSSL documentation for EC_KEY_print()
- */
-static VALUE ossl_ec_key_to_text(VALUE self)
-{
-    EC_KEY *ec;
-    BIO *out;
-    VALUE str;
-
-    GetEC(self, ec);
-    if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eECError, "BIO_new(BIO_s_mem())");
-    }
-    if (!EC_KEY_print(out, ec, 0)) {
-	BIO_free(out);
-	ossl_raise(eECError, "EC_KEY_print");
-    }
-    str = ossl_membio2str(out);
-
-    return str;
-}
-
 /*
  *  call-seq:
  *     key.generate_key!   => self
@@ -1601,7 +1575,6 @@ void Init_ossl_ec(void)
     rb_define_method(cEC, "export", ossl_ec_key_export, -1);
     rb_define_alias(cEC, "to_pem", "export");
     rb_define_method(cEC, "to_der", ossl_ec_key_to_der, 0);
-    rb_define_method(cEC, "to_text", ossl_ec_key_to_text, 0);
 
 
     rb_define_alloc_func(cEC_GROUP, ossl_ec_group_alloc);

ext/openssl/ossl_pkey_rsa.c

@@ -587,36 +587,6 @@ ossl_rsa_get_params(VALUE self)
     return hash;
 }
 
-/*
- * call-seq:
- *   rsa.to_text => String
- *
- * THIS METHOD IS INSECURE, PRIVATE INFORMATION CAN LEAK OUT!!!
- *
- * Dumps all parameters of a keypair to a String
- *
- * Don't use :-)) (It's up to you)
- */
-static VALUE
-ossl_rsa_to_text(VALUE self)
-{
-    RSA *rsa;
-    BIO *out;
-    VALUE str;
-
-    GetRSA(self, rsa);
-    if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eRSAError, NULL);
-    }
-    if (!RSA_print(out, rsa, 0)) { /* offset = 0 */
-	BIO_free(out);
-	ossl_raise(eRSAError, NULL);
-    }
-    str = ossl_membio2str(out);
-
-    return str;
-}
-
 /*
  * call-seq:
  *    rsa.public_key -> RSA
@@ -738,7 +708,6 @@ Init_ossl_rsa(void)
 
     rb_define_method(cRSA, "public?", ossl_rsa_is_public, 0);
     rb_define_method(cRSA, "private?", ossl_rsa_is_private, 0);
-    rb_define_method(cRSA, "to_text", ossl_rsa_to_text, 0);
     rb_define_method(cRSA, "export", ossl_rsa_export, -1);
     rb_define_alias(cRSA, "to_pem", "export");
     rb_define_alias(cRSA, "to_s", "export");

test/openssl/test_pkey.rb

@@ -169,4 +169,9 @@ def test_compare?
       key1.compare?(key4)
     end
   end
+
+  def test_to_text
+    rsa = Fixtures.pkey("rsa1024")
+    assert_include rsa.to_text, "publicExponent"
+  end
 end