From b4cd538dfae05fc257f908298894ed4a7bd2ff67 Mon Sep 17 00:00:00 2001
From: mathewmarcus <mathewmarcus456@gmail.com>
Date: Fri, 22 Jun 2018 14:54:22 -0500
Subject: [PATCH] calculate session hash

---
 ssl/ssldecode.c | 108 ++++++++++++++++++++++++++++++++----------------
 1 file changed, 73 insertions(+), 35 deletions(-)

diff --git a/ssl/ssldecode.c b/ssl/ssldecode.c
index 08f96a6..fa8d8ef 100644
--- a/ssl/ssldecode.c
+++ b/ssl/ssldecode.c
@@ -92,6 +92,7 @@ struct ssl_decoder_ {
      Data *PMS;
      Data *MS;
      Data *handshake_messages;
+     Data *session_hash;
      ssl_rec_decoder *c_to_s;
      ssl_rec_decoder *s_to_c;     
      ssl_rec_decoder *c_to_s_n;
@@ -112,6 +113,8 @@ static int ssl3_generate_export_iv PROTO_LIST((ssl_obj *ssl,
   Data *rnd1,Data *rnd2,Data *out));
 static int ssl_generate_keying_material PROTO_LIST((ssl_obj *ssl,
   ssl_decoder *d));
+static int ssl_generate_session_hash PROTO_LIST((ssl_obj *ssl,
+						 ssl_decoder *d));
 #endif
 
 static int ssl_create_session_lookup_key PROTO_LIST((ssl_obj *ssl,
@@ -216,6 +219,7 @@ int ssl_decoder_destroy(dp)
     r_data_destroy(&d->PMS);
     r_data_destroy(&d->MS);
     r_data_destroy(&d->handshake_messages);
+    r_data_destroy(&d->session_hash);
     ssl_destroy_rec_decoder(&d->c_to_s);
     ssl_destroy_rec_decoder(&d->c_to_s_n);
     ssl_destroy_rec_decoder(&d->s_to_c);
@@ -384,6 +388,35 @@ int ssl_decode_record(ssl,dec,direction,ct,version,d)
 #endif    
   }
 
+int ssl_update_handshake_messages(ssl,data)
+  ssl_obj *ssl;
+  Data *data;
+  {
+    Data *hms;
+    UCHAR *d;
+    int l,r,_status;
+
+    hms = ssl->decoder->handshake_messages;
+    d = data->data-4;
+    l = data->len+4;
+
+    if(hms){
+      if(!(hms->data = realloc(hms->data,l+hms->len)))
+	ABORT(R_NO_MEMORY);
+
+      memcpy(hms->data+hms->len,d,l);
+      hms->len+=l;
+    }
+    else{
+      if(r=r_data_create(&hms,d,l))
+  	ABORT(r);
+      ssl->decoder->handshake_messages=hms;
+    }
+
+    _status=0;
+  abort:
+    return(_status);
+  }
 
 static int ssl_create_session_lookup_key(ssl,id,idlen,keyp,keyl)
   ssl_obj *ssl;
@@ -567,37 +600,6 @@ int ssl_process_client_key_exchange(ssl,d,msg,len)
   }
 
 
-
-int ssl_update_handshake_messages(ssl,data)
-  ssl_obj *ssl;
-  Data *data;
-  {
-    Data *hms;
-    UCHAR *d;
-    int l,r,_status;
-
-    hms = ssl->decoder->handshake_messages;
-    d = data->data-4;
-    l = data->len+4;
-
-    if(hms){
-      if(!(hms->data = realloc(hms->data,l+hms->len)))
-	ABORT(R_NO_MEMORY);
-
-      memcpy(hms->data+hms->len,d,l);
-      hms->len+=l;
-    }
-    else{
-      if(r=r_data_create(&hms,d,l))
-  	ABORT(r);
-      ssl->decoder->handshake_messages=hms;
-    }
-
-    _status=0;
-  abort:
-    return(_status);
-  }
-
 #ifdef OPENSSL
 static int tls_P_hash(ssl,secret,seed,md,out)
   ssl_obj *ssl;
@@ -854,10 +856,13 @@ static int ssl_generate_keying_material(ssl,d)
     if(!d->MS){
       if(r=r_data_alloc(&d->MS,48))
         ABORT(r);
-    
-      if(r=PRF(ssl,d->PMS,"master secret",d->client_random,d->server_random,
-        d->MS))
-        ABORT(r);
+
+      if (ssl->extensions->extended_master_secret)
+	ssl_generate_session_hash(ssl,d);
+      else
+	if(r=PRF(ssl,d->PMS,"master secret",d->client_random,d->server_random,
+	  d->MS))
+	  ABORT(r);
 
       CRDUMPD("MS",d->MS);
     }
@@ -992,4 +997,37 @@ static int ssl_generate_keying_material(ssl,d)
     return(_status);
   }
 
+static int ssl_generate_session_hash(ssl,d)
+  ssl_obj *ssl;
+  ssl_decoder *d;
+  /* Data **sh; */
+  {
+    UCHAR *out[32];
+    int dgi;
+    unsigned int len;
+    const EVP_MD *md;
+    EVP_MD_CTX dgictx;
+
+    switch(ssl->version){
+    case TLSV12_VERSION:
+      dgi = MAX(DIG_SHA256, ssl->cs->dig)-0x40;
+      if ((md=EVP_get_digestbyname(digests[dgi])) == NULL) {
+	DBG((0,"Cannot get EVP for digest %s, openssl library current?",
+	     digests[dgi]));
+	ERETURN(SSL_BAD_MAC);
+      }
+      break;
+      case SSLV3_VERSION:
+      case TLSV1_VERSION:
+      case TLSV11_VERSION:
+      default:
+	exit(1);
+	/* ABORT(SSL_CANT_DO_CIPHER);	 */
+    }
+
+    EVP_DigestInit(&dgictx, md);
+    EVP_DigestUpdate(&dgictx, d->handshake_messages->data, d->handshake_messages->len);
+    EVP_DigestFinal(&dgictx, out, &len);
+    exit(0);
+  }
 #endif