From e97b5856591958dfd39edbaa1a76970e46a84d8d Mon Sep 17 00:00:00 2001
From: sowle <crypto.sowle@gmail.com>
Date: Fri, 2 Aug 2024 12:00:35 +0200
Subject: [PATCH] crypto: eth_secret_key_to_public_key() implemented, other
 useful stuff for eth sig added

---
 src/crypto/crypto-sugar.h    | 10 +++++++++
 src/crypto/eth_signature.cpp | 41 ++++++++++++++++++++++++++++++++++--
 src/crypto/eth_signature.h   | 27 ++++++++++++++++++++++++
 3 files changed, 76 insertions(+), 2 deletions(-)

diff --git a/src/crypto/crypto-sugar.h b/src/crypto/crypto-sugar.h
index 846e4572..3738d118 100644
--- a/src/crypto/crypto-sugar.h
+++ b/src/crypto/crypto-sugar.h
@@ -8,6 +8,7 @@
 #include <string>
 #include <boost/multiprecision/cpp_int.hpp>
 #include "crypto.h"
+#include "eth_signature.h"
 
 namespace crypto
 {
@@ -1209,6 +1210,15 @@ namespace crypto
         m_elements.emplace_back(pk);
       }
 
+      void add_eth_pub_key(const crypto::eth_public_key& epk)
+      {
+        static_assert(sizeof epk.data == 33, "unexpected size of eth_public_key");
+        m_elements.emplace_back(c_scalar_0);
+        m_elements.emplace_back(c_scalar_0);
+        char* p = m_elements[m_elements.size() - 2].c; // pointer to the first of the two added items
+        memcpy_s(p, 2 * sizeof(item_t), &epk.data, sizeof epk.data);
+      }
+
       void add_key_image(const crypto::key_image& ki)
       {
         m_elements.emplace_back(ki);
diff --git a/src/crypto/eth_signature.cpp b/src/crypto/eth_signature.cpp
index 3aaec568..0e33c47f 100644
--- a/src/crypto/eth_signature.cpp
+++ b/src/crypto/eth_signature.cpp
@@ -6,6 +6,7 @@
 #include "bitcoin-secp256k1/include/secp256k1.h"
 #include "random.h"
 #include "misc_language.h"
+#include <string_tools.h>
 
 
 namespace crypto
@@ -50,6 +51,32 @@ namespace crypto
     }
   }
 
+  bool eth_secret_key_to_public_key(const eth_secret_key& sec_key, eth_public_key& pub_key) noexcept
+  {
+    try
+    {
+      // TODO: do we need this? consider using static context
+      secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
+      auto slh = epee::misc_utils::create_scope_leave_handler([&ctx](){
+        secp256k1_context_destroy(ctx);
+        ctx = nullptr;
+        });
+
+      secp256k1_pubkey uncompressed_pub_key{};
+      if (!secp256k1_ec_pubkey_create(ctx, &uncompressed_pub_key, sec_key.data))
+        return false;
+
+      size_t output_len = sizeof pub_key;
+      if (!secp256k1_ec_pubkey_serialize(ctx, pub_key.data, &output_len, &uncompressed_pub_key, SECP256K1_EC_COMPRESSED))
+        return false;
+
+      return true;
+    }
+    catch(...)
+    {
+      return false;
+    }
+  }
 
   // generates secp256k1 ECDSA signature
   bool generate_eth_signature(const hash& m, const eth_secret_key& sec_key, eth_signature& sig) noexcept
@@ -91,8 +118,8 @@ namespace crypto
 
       secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
       auto slh = epee::misc_utils::create_scope_leave_handler([&ctx](){
-        secp256k1_context_destroy(ctx);
-        ctx = nullptr;
+          secp256k1_context_destroy(ctx);
+          ctx = nullptr;
         });
 
       uint8_t randomness[32];
@@ -121,5 +148,15 @@ namespace crypto
     }
   }
 
+  std::ostream& operator<<(std::ostream& o, const eth_secret_key& v)
+  {
+    return o << epee::string_tools::pod_to_hex(v);
+  }
+
+  std::ostream& operator<<(std::ostream& o, const eth_public_key& v)
+  {
+    return o << epee::string_tools::pod_to_hex(v);
+  }
+
 
 } // namespace crypto
diff --git a/src/crypto/eth_signature.h b/src/crypto/eth_signature.h
index c0434525..b186114a 100644
--- a/src/crypto/eth_signature.h
+++ b/src/crypto/eth_signature.h
@@ -3,6 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #pragma once
 #include <cstdint>
+#include <iosfwd>
 #include "hash.h"
 
 namespace crypto
@@ -29,6 +30,9 @@ namespace crypto
   // generates secp256k1 keypair
   bool generate_eth_key_pair(eth_secret_key& sec_key, eth_public_key& pub_key) noexcept;
 
+  // converts eth_secret_key to eth_public_key
+  bool eth_secret_key_to_public_key(const eth_secret_key& sec_key, eth_public_key& pub_key) noexcept;
+
   // generates secp256k1 ECDSA signature
   bool generate_eth_signature(const hash& m, const eth_secret_key& sec_key, eth_signature& sig) noexcept;
 
@@ -36,4 +40,27 @@ namespace crypto
   bool verify_eth_signature(const hash& m, const eth_public_key& pub_key, const eth_signature& sig) noexcept;
 
 
+  inline bool operator==(const eth_public_key& lhs, const eth_public_key& rhs)
+  {
+    return memcmp(lhs.data, rhs.data, sizeof lhs.data) == 0;
+  }
+
+  inline bool operator!=(const eth_public_key& lhs, const eth_public_key& rhs)
+  {
+    return !(lhs == rhs);
+  }
+
+  inline bool operator==(const eth_secret_key& lhs, const eth_secret_key& rhs)
+  {
+    return memcmp(lhs.data, rhs.data, sizeof lhs.data) == 0;
+  }
+
+  inline bool operator!=(const eth_secret_key& lhs, const eth_secret_key& rhs)
+  {
+    return !(lhs == rhs);
+  }
+
+  std::ostream& operator<<(std::ostream& o, const eth_secret_key& v);
+  std::ostream& operator<<(std::ostream& o, const eth_public_key& v);
+
 } // namespace crypto