diff --git a/ext/openssl/ossl_ocsp.c b/ext/openssl/ossl_ocsp.c
index e82c2d8..ab8d3ee 100644
--- a/ext/openssl/ossl_ocsp.c
+++ b/ext/openssl/ossl_ocsp.c
@@ -693,6 +693,56 @@ ossl_ocspcid_get_serial(VALUE self)
     return asn1integer_to_num(id->serialNumber);
 }
 
+static VALUE
+ossl_ocspcid_get_issuer_name_hash(VALUE self)
+{
+    OCSP_CERTID *id;
+    BIO *out;
+    VALUE str;
+
+    GetOCSPCertId(self, id);
+    if (!(out = BIO_new(BIO_s_mem())))
+    ossl_raise(eOCSPError, NULL);
+    i2a_ASN1_STRING(out, id->issuerNameHash, V_ASN1_OCTET_STRING);
+    str = ossl_membio2str(out);
+
+    return str;
+}
+
+static VALUE
+ossl_ocspcid_get_issuer_key_hash(VALUE self)
+{
+    OCSP_CERTID *id;
+    BIO *out;
+    VALUE str;
+
+    GetOCSPCertId(self, id);
+    if (!(out = BIO_new(BIO_s_mem())))
+    ossl_raise(eOCSPError, NULL);
+    i2a_ASN1_STRING(out, id->issuerKeyHash, V_ASN1_OCTET_STRING);
+    str = ossl_membio2str(out);
+
+    return str;
+}
+
+static VALUE
+ossl_ocspcid_get_signature_algorithm(VALUE self)
+{
+    OCSP_CERTID *id;
+    BIO *out;
+    VALUE str;
+
+    GetOCSPCertId(self, id);
+    if (!(out = BIO_new(BIO_s_mem())))
+    ossl_raise(eOCSPError, NULL);
+
+    if (!i2a_ASN1_OBJECT(out, id->hashAlgorithm->algorithm)) {
+    BIO_free(out);
+    ossl_raise(eOCSPError, NULL);
+    }
+    str = ossl_membio2str(out);
+}
+
 void
 Init_ossl_ocsp()
 {
@@ -736,6 +786,9 @@ Init_ossl_ocsp()
     rb_define_method(cOCSPCertId, "cmp", ossl_ocspcid_cmp, 1);
     rb_define_method(cOCSPCertId, "cmp_issuer", ossl_ocspcid_cmp_issuer, 1);
     rb_define_method(cOCSPCertId, "serial", ossl_ocspcid_get_serial, 0);
+    rb_define_method(cOCSPCertId, "issuer_name_hash", ossl_ocspcid_get_issuer_name_hash, 0);
+    rb_define_method(cOCSPCertId, "issuer_key_hash", ossl_ocspcid_get_issuer_key_hash, 0);
+    rb_define_method(cOCSPCertId, "signature_algorithm", ossl_ocspcid_get_signature_algorithm, 0);
 
 #define DefOCSPConst(x) rb_define_const(mOCSP, #x, INT2NUM(OCSP_##x))
 
diff --git a/test/openssl/test_ocsp.rb b/test/openssl/test_ocsp.rb
index b42b57d..531df9a 100644
--- a/test/openssl/test_ocsp.rb
+++ b/test/openssl/test_ocsp.rb
@@ -27,12 +27,29 @@ class OpenSSL::TestOCSP < Test::Unit::TestCase
     assert_equal @cert.serial, cid.serial
   end
 
+  def test_certificate_id_issuer_name_hash
+    cid = OpenSSL::OCSP::CertificateId.new(@cert, @ca_cert)
+    assert_equal "D91F736AC4DC3242F0FB9B77A3149BD83C5C43D0", cid.issuer_name_hash
+  end
+
+  def test_certificate_id_issuer_key_hash
+    cid = OpenSSL::OCSP::CertificateId.new(@cert, @ca_cert)
+    assert_equal "D1FEF9FBF8AE1BC160CBFA03E2596DD873089213", cid.issuer_key_hash
+  end
+
   def test_new_certificate_id_with_digest
     cid = OpenSSL::OCSP::CertificateId.new(@cert, @ca_cert, OpenSSL::Digest::SHA256.new)
     assert_kind_of OpenSSL::OCSP::CertificateId, cid
     assert_equal @cert.serial, cid.serial
   end if defined?(OpenSSL::Digest::SHA256)
 
+  def test_certificate_id_signature_algorithm
+    cid_sha1 = OpenSSL::OCSP::CertificateId.new(@cert, @ca_cert, OpenSSL::Digest::SHA1.new)
+    cid_md5 = OpenSSL::OCSP::CertificateId.new(@cert, @ca_cert, OpenSSL::Digest::MD5.new)
+    assert_equal cid_sha1.signature_algorithm, "sha1"
+    assert_equal cid_md5.signature_algorithm, "md5"
+  end
+
   def test_new_ocsp_request
     request = OpenSSL::OCSP::Request.new
     cid = OpenSSL::OCSP::CertificateId.new(@cert, @ca_cert, OpenSSL::Digest::SHA1.new)