Fix signature algorithm for certificates signed by EdDSA keys

lib/x509/signature_algorithm.ex

@@ -5,6 +5,8 @@ defmodule X509.SignatureAlgorithm do
 
   alias X509.Util
 
+  @edwards_curves [oid(:"id-Ed25519"), oid(:"id-Ed448")]
+
   # Returns a signature algorithm record for the given public key type and hash
   # algorithm; this is essentially the reverse of
   # `:public_key.pkix_sign_types/1`
@@ -15,6 +17,11 @@ defmodule X509.SignatureAlgorithm do
     new(hash, algorithm, type)
   end
 
+  def new(hash, ec_private_key(parameters: {:namedCurve, curve}), type)
+      when curve in @edwards_curves do
+    new(hash, {:eddsa, curve}, type)
+  end
+
   def new(hash, rsa_private_key(), type) do
     new(hash, :rsa, type)
   end
@@ -81,6 +88,7 @@ defmodule X509.SignatureAlgorithm do
   defp algorithm(:sha384, :ecdsa), do: {oid(:"ecdsa-with-SHA384"), :asn1_NOVALUE}
   defp algorithm(:sha512, :rsa), do: {oid(:sha512WithRSAEncryption), null()}
   defp algorithm(:sha512, :ecdsa), do: {oid(:"ecdsa-with-SHA512"), :asn1_NOVALUE}
+  defp algorithm(_, {:eddsa, curve}), do: {curve, :asn1_NOVALUE}
 
   defp algorithm(hash, :rsa) do
     raise ArgumentError, "Unsupported hashing algorithm for RSA signing: #{inspect(hash)}"

test/data/README.md

@@ -75,4 +75,5 @@ Generating PEM output:
 ```bash
 openssl req -new -key rsa.pem -days 365 -x509 -subj "/C=US/ST=NT/L=Springfield/O=ACME Inc." -out selfsigned_rsa.pem
 openssl req -new -key prime256v1.pem -days 365 -x509 -subj "/C=US/ST=NT/L=Springfield/O=ACME Inc." -out selfsigned_prime256v1.pem
+openssl req -new -key ed25519.pem -days 365 -x509 -subj "/C=US/ST=NT/L=Springfield/O=ACME Inc." -out selfsigned_ed25519.pem
 ```

test/data/selfsigned_ed25519.pem

@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

test/integration/openssl_test.exs

@@ -141,6 +141,26 @@ defmodule X509.OpenSSLTest do
       assert openssl_out =~ "DNS:acme.com, DNS:www.acme.com"
     end
 
+    test "OpenSSL can read certificates (EdDSA)" do
+      file =
+        X509.PrivateKey.new_ec(:ed25519)
+        |> X509.Certificate.self_signed(
+          "/C=US/ST=NT/L=Springfield/O=ACME Inc.",
+          extensions: [
+            subject_alt_name:
+              X509.Certificate.Extension.subject_alt_name(["acme.com", "www.acme.com"])
+          ]
+        )
+        |> X509.Certificate.to_pem()
+        |> write_tmp()
+
+      openssl_out = openssl(["x509", "-in", file, "-text", "-noout"])
+      assert openssl_out =~ ~r(Subject: C ?= ?US, ST ?= ?NT, L ?= ?Springfield, O ?= ?ACME Inc.)
+      assert openssl_out =~ "Public Key Algorithm: ED25519"
+      assert openssl_out =~ "Signature Algorithm: ED25519"
+      assert openssl_out =~ "DNS:acme.com, DNS:www.acme.com"
+    end
+
     test "OpenSSL can read CRLs (RSA)" do
       ca_key = X509.PrivateKey.new_rsa(512)
       ca = X509.Certificate.self_signed(ca_key, "/CN=My Root CA", template: :root_ca)
@@ -212,6 +232,42 @@ defmodule X509.OpenSSLTest do
       assert openssl_out =~ "Serial Number: FF"
       assert openssl_out =~ "Key Compromise"
     end
+
+    test "OpenSSL can read CRLs (EdDSA)" do
+      ca_key = X509.PrivateKey.new_ec(:ed25519)
+      ca = X509.Certificate.self_signed(ca_key, "/CN=My Root CA", template: :root_ca)
+
+      cert =
+        X509.PrivateKey.new_ec(:ed25519)
+        |> X509.PublicKey.derive()
+        |> X509.Certificate.new("/CN=Sample", ca, ca_key,
+          serial: 0xFF,
+          extensions: [
+            crl_distribution_points:
+              X509.Certificate.Extension.crl_distribution_points(["http://localhost/test.crl"])
+          ]
+        )
+
+      entry =
+        X509.CRL.Entry.new(cert, DateTime.utc_now(), [
+          X509.CRL.Extension.reason_code(:keyCompromise)
+        ])
+
+      file =
+        entry
+        |> List.wrap()
+        |> X509.CRL.new(ca, ca_key)
+        |> X509.CRL.to_pem()
+        |> write_tmp()
+
+      openssl_out = openssl(["crl", "-in", file, "-text", "-noout"])
+      assert openssl_out =~ "Certificate Revocation List (CRL)"
+      assert openssl_out =~ "Signature Algorithm: ED25519"
+      assert openssl_out =~ ~r(Issuer: /?CN ?= ?My Root CA)
+      assert openssl_out =~ "X509v3 Authority Key Identifier:"
+      assert openssl_out =~ "Serial Number: FF"
+      assert openssl_out =~ "Key Compromise"
+    end
   end
 
   describe "DER encode" do
@@ -333,6 +389,26 @@ defmodule X509.OpenSSLTest do
       assert openssl_out =~ "DNS:acme.com, DNS:www.acme.com"
     end
 
+    test "OpenSSL can read certificates (EdDSA)" do
+      file =
+        X509.PrivateKey.new_ec(:ed25519)
+        |> X509.Certificate.self_signed(
+          "/C=US/ST=NT/L=Springfield/O=ACME Inc.",
+          extensions: [
+            subject_alt_name:
+              X509.Certificate.Extension.subject_alt_name(["acme.com", "www.acme.com"])
+          ]
+        )
+        |> X509.Certificate.to_der()
+        |> write_tmp()
+
+      openssl_out = openssl(["x509", "-in", file, "-inform", "der", "-text", "-noout"])
+      assert openssl_out =~ ~r(Subject: C ?= ?US, ST ?= ?NT, L ?= ?Springfield, O ?= ?ACME Inc.)
+      assert openssl_out =~ "Public Key Algorithm: ED25519"
+      assert openssl_out =~ "Signature Algorithm: ED25519"
+      assert openssl_out =~ "DNS:acme.com, DNS:www.acme.com"
+    end
+
     test "OpenSSL can read CRLs (RSA)" do
       ca_key = X509.PrivateKey.new_rsa(512)
       ca = X509.Certificate.self_signed(ca_key, "/CN=My Root CA", template: :root_ca)
@@ -404,6 +480,42 @@ defmodule X509.OpenSSLTest do
       assert openssl_out =~ "Serial Number: FF"
       assert openssl_out =~ "Key Compromise"
     end
+
+    test "OpenSSL can read CRLs (EdDSA)" do
+      ca_key = X509.PrivateKey.new_ec(:ed25519)
+      ca = X509.Certificate.self_signed(ca_key, "/CN=My Root CA", template: :root_ca)
+
+      cert =
+        X509.PrivateKey.new_ec(:ed25519)
+        |> X509.PublicKey.derive()
+        |> X509.Certificate.new("/CN=Sample", ca, ca_key,
+          serial: 0xFF,
+          extensions: [
+            crl_distribution_points:
+              X509.Certificate.Extension.crl_distribution_points(["http://localhost/test.crl"])
+          ]
+        )
+
+      entry =
+        X509.CRL.Entry.new(cert, DateTime.utc_now(), [
+          X509.CRL.Extension.reason_code(:keyCompromise)
+        ])
+
+      file =
+        entry
+        |> List.wrap()
+        |> X509.CRL.new(ca, ca_key)
+        |> X509.CRL.to_der()
+        |> write_tmp()
+
+      openssl_out = openssl(["crl", "-in", file, "-inform", "der", "-text", "-noout"])
+      assert openssl_out =~ "Certificate Revocation List (CRL)"
+      assert openssl_out =~ "Signature Algorithm: ED25519"
+      assert openssl_out =~ ~r(Issuer: /?CN ?= ?My Root CA)
+      assert openssl_out =~ "X509v3 Authority Key Identifier:"
+      assert openssl_out =~ "Serial Number: FF"
+      assert openssl_out =~ "Key Compromise"
+    end
   end
 
   defp openssl(args) do

test/x509/certificate_test.exs

@@ -8,6 +8,7 @@ defmodule X509.CertificateTest do
     [
       rsa_key: X509.PrivateKey.new_rsa(512),
       ec_key: X509.PrivateKey.new_ec(:secp256r1),
+      eddsa_key: X509.PrivateKey.new_ec(:ed25519),
       selfsigned_rsa:
         "test/data/selfsigned_rsa.pem"
         |> File.read!()
@@ -23,6 +24,14 @@ defmodule X509.CertificateTest do
       selfsigned_ecdsa_key:
         "test/data/prime256v1.pem"
         |> File.read!()
+        |> X509.PrivateKey.from_pem!(),
+      selfsigned_eddsa:
+        "test/data/selfsigned_ed25519.pem"
+        |> File.read!()
+        |> X509.Certificate.from_pem!(),
+      selfsigned_eddsa_key:
+        "test/data/ed25519.pem"
+        |> File.read!()
         |> X509.PrivateKey.from_pem!()
     ]
   end
@@ -192,6 +201,75 @@ defmodule X509.CertificateTest do
     end
   end
 
+  describe "EdDSA" do
+    test :new, context do
+      cert =
+        context.eddsa_key
+        |> X509.PublicKey.derive()
+        |> X509.Certificate.new(
+          "/C=US/ST=NT/L=Springfield/O=ACME Inc./CN=Example",
+          context.selfsigned_eddsa,
+          context.selfsigned_eddsa_key
+        )
+
+      assert match?(otp_certificate(), cert)
+      refute :public_key.pkix_is_self_signed(cert)
+      assert :public_key.pkix_is_issuer(cert, context.selfsigned_eddsa)
+      assert {:ok, _} = :public_key.pkix_path_validation(context.selfsigned_eddsa, [cert], [])
+
+      assert cert
+             |> X509.Certificate.to_der()
+             |> :public_key.pkix_verify(X509.PublicKey.derive(context.selfsigned_eddsa_key))
+    end
+
+    test "intermediate", context do
+      root_key = X509.PrivateKey.new_ec(:ed25519)
+
+      root =
+        root_key
+        |> X509.Certificate.self_signed(
+          "/C=US/ST=NT/L=Springfield/O=ACME Inc./CN=Intermediate CA",
+          template: :root_ca
+        )
+
+      intermediate_key = X509.PrivateKey.new_ec(:ed25519)
+
+      intermediate =
+        intermediate_key
+        |> X509.PublicKey.derive()
+        |> X509.Certificate.new(
+          "/C=US/ST=NT/L=Springfield/O=ACME Inc./CN=Intermediate CA",
+          root,
+          root_key,
+          template: :ca
+        )
+
+      cert =
+        context.eddsa_key
+        |> X509.PublicKey.derive()
+        |> X509.Certificate.new(
+          "/C=US/ST=NT/L=Springfield/O=ACME Inc./CN=Example",
+          intermediate,
+          intermediate_key
+        )
+
+      assert {:ok, _} = :public_key.pkix_path_validation(root, [intermediate, cert], [])
+    end
+
+    test :self_signed, context do
+      cert =
+        context.eddsa_key
+        |> X509.Certificate.self_signed("/C=US/ST=NT/L=Springfield/O=ACME Inc.")
+
+      assert match?(otp_certificate(), cert)
+      assert :public_key.pkix_is_self_signed(cert)
+
+      assert cert
+             |> X509.Certificate.to_der()
+             |> :public_key.pkix_verify(X509.PublicKey.derive(context.eddsa_key))
+    end
+  end
+
   test :version, context do
     assert :v3 == X509.Certificate.version(context.selfsigned_rsa)
   end