add basic discord support

DPP/mlspp/lib/hpke/src/rsa.h

@@ -0,0 +1,97 @@
+#pragma once
+
+#include <hpke/digest.h>
+#include <hpke/hpke.h>
+#include <hpke/signature.h>
+
+#include "openssl_common.h"
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+
+namespace mlspp::hpke {
+
+// XXX(RLB): There is a lot of code in RSASignature that is duplicated in
+// EVPGroup.  I have allowed this duplication rather than factoring it out
+// because I would like to be able to cleanly remove RSA later.
+struct RSASignature : public Signature
+{
+  struct PublicKey : public Signature::PublicKey
+  {
+    explicit PublicKey(EVP_PKEY* pkey_in)
+      : pkey(pkey_in, typed_delete<EVP_PKEY>)
+    {
+    }
+
+    ~PublicKey() override = default;
+
+    typed_unique_ptr<EVP_PKEY> pkey;
+  };
+
+  struct PrivateKey : public Signature::PrivateKey
+  {
+    explicit PrivateKey(EVP_PKEY* pkey_in)
+      : pkey(pkey_in, typed_delete<EVP_PKEY>)
+    {
+    }
+
+    ~PrivateKey() override = default;
+
+    std::unique_ptr<Signature::PublicKey> public_key() const override
+    {
+      if (1 != EVP_PKEY_up_ref(pkey.get())) {
+        throw openssl_error();
+      }
+      return std::make_unique<PublicKey>(pkey.get());
+    }
+
+    typed_unique_ptr<EVP_PKEY> pkey;
+  };
+
+  explicit RSASignature(Digest::ID digest)
+    : Signature(digest_to_sig(digest))
+    , md(digest_to_md(digest))
+  {
+  }
+
+  std::unique_ptr<Signature::PrivateKey> generate_key_pair() const override;
+
+  std::unique_ptr<Signature::PrivateKey> derive_key_pair(
+    const bytes& /*ikm*/) const override;
+
+  static std::unique_ptr<Signature::PrivateKey> generate_key_pair(size_t bits);
+
+  // TODO(rlb): Implement derive() with sizes
+
+  bytes serialize(const Signature::PublicKey& pk) const override;
+
+  std::unique_ptr<Signature::PublicKey> deserialize(
+    const bytes& enc) const override;
+
+  bytes serialize_private(const Signature::PrivateKey& sk) const override;
+
+  std::unique_ptr<Signature::PrivateKey> deserialize_private(
+    const bytes& skm) const override;
+
+  bytes sign(const bytes& data, const Signature::PrivateKey& sk) const override;
+
+  bool verify(const bytes& data,
+              const bytes& sig,
+              const Signature::PublicKey& pk) const override;
+
+  std::unique_ptr<Signature::PrivateKey> import_jwk_private(
+    const std::string& json_str) const override;
+  std::unique_ptr<Signature::PublicKey> import_jwk(
+    const std::string& json_str) const override;
+  std::string export_jwk_private(
+    const Signature::PrivateKey& sk) const override;
+  std::string export_jwk(const Signature::PublicKey& pk) const override;
+
+private:
+  const EVP_MD* md;
+
+  static const EVP_MD* digest_to_md(Digest::ID digest);
+
+  static Signature::ID digest_to_sig(Digest::ID digest);
+};
+
+} // namespace mlspp::hpke