From 7bfc3562af5befe514cd76693b6989aa8b40dcc4 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Fri, 19 Feb 2016 16:13:46 -0500
Subject: [PATCH] extract EcDSA key from family certificate

---
 Family.cpp | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 Family.h   |  3 +++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/Family.cpp b/Family.cpp
index 5470a92c..7e2d6e6c 100644
--- a/Family.cpp
+++ b/Family.cpp
@@ -1,7 +1,9 @@
+#include <string.h>
 #include "util.h"
 #include <openssl/evp.h>
 #include <openssl/ssl.h>
 #include "Log.h"
+#include "Crypto.h"
 #include "Family.h"
 
 namespace i2p
@@ -24,12 +26,14 @@ namespace data
 		{	
 			SSL * ssl = SSL_new (ctx);
 			X509 * cert = SSL_get_certificate (ssl);
-			// verify
 			if (cert)
 			{	
+				std::shared_ptr<i2p::crypto::Verifier> verifier;
 				// extract issuer name
 				char name[100];
 				X509_NAME_oneline (X509_get_issuer_name(cert), name, 100);
+				char * family = strstr (name, ".family");
+				if (family) family[0] = 0;
 				auto pkey = X509_get_pubkey (cert);
 				int keyType = EVP_PKEY_type(pkey->type);
 				switch (keyType)
@@ -39,13 +43,37 @@ namespace data
 					break;
 					case EVP_PKEY_EC:
 					{
-						//EC_KEY * ecKey = EVP_PKEY_get0_EC_KEY (pkey);
+						EC_KEY * ecKey = EVP_PKEY_get1_EC_KEY (pkey);
+						if (ecKey)
+						{
+							auto group = EC_KEY_get0_group (ecKey);
+							if (group)
+							{
+								int curve = EC_GROUP_get_curve_name (group);
+								if (curve == NID_X9_62_prime256v1)
+								{
+									uint8_t signingKey[64];
+									BIGNUM * x = BN_new(), * y = BN_new();
+									EC_POINT_get_affine_coordinates_GFp (group,
+										EC_KEY_get0_public_key (ecKey), x, y, NULL);
+									i2p::crypto::bn2buf (x, signingKey, 32);
+									i2p::crypto::bn2buf (y, signingKey + 32, 32);
+									BN_free (x); BN_free (y);
+									verifier = std::make_shared<i2p::crypto::ECDSAP256Verifier>(signingKey);
+								}	
+								else
+									LogPrint (eLogWarning, "Family: elliptic curve ", curve, " is not supported");
+							}
+							EC_KEY_free (ecKey);
+						}
 						break;
 					}
 					default:
 						LogPrint (eLogWarning, "Family: Certificate key type ", keyType, " is not supported");
 				}
 				EVP_PKEY_free (pkey);
+				if (verifier)
+					m_SigningKeys[name] = verifier;
 			}	
 			SSL_free (ssl);			
 		}	
@@ -72,6 +100,23 @@ namespace data
 		if (numCertificates > 0)
 			LogPrint (eLogInfo, "Family: ", numCertificates, " certificates loaded");
 	}
+
+	bool Families::VerifyFamily (const char * family, const IdentHash& ident, 
+		const char * signature, const char * key)
+	{
+		uint8_t buf[50], signatureBuf[64];
+		size_t len = strlen (family), signatureLen = strlen (signature);
+		memcpy (buf, family, len);
+		memcpy (buf + len, (const uint8_t *)ident, 32);
+		len += 32;	
+		Base64ToByteStream (signature, signatureLen, signatureBuf, 64);	
+		auto it = m_SigningKeys.find (family);
+		if (it != m_SigningKeys.end ())
+			return it->second->Verify (buf, len, signatureBuf);
+		// TODO: process key
+		return true;
+	}
+
 }
 }
 
diff --git a/Family.h b/Family.h
index ca8dac3f..78abd5b6 100644
--- a/Family.h
+++ b/Family.h
@@ -5,6 +5,7 @@
 #include <string>
 #include <memory>
 #include "Signature.h"
+#include "Identity.h"
 
 namespace i2p
 {
@@ -17,6 +18,8 @@ namespace data
 			Families ();
 			~Families ();
 			void LoadCertificates ();
+			bool VerifyFamily (const char * family, const IdentHash& ident, 
+				const char * signature, const char * key);
 
 		private: