added code to verify FIN

server/flow.c

@@ -100,7 +100,7 @@ int update_flow(flow *f) {
 		int i;
 		for(i=0; (i<current->data_len) && (i+data_len < record_len); i++){
 
-			record[data_len] = p[i];
+			record[data_len+i] = p[i];
 		}
 		//printf("Filled %d\n", i);
 		data_len += current->data_len;
@@ -121,28 +121,31 @@ int update_flow(flow *f) {
 			handshake_hdr = (struct handshake_header*) p;
 			f->state = handshake_hdr->type;
 
+			printf("record length: %d, hanshake length: %d\n", record_len, HANDSHAKE_MESSAGE_LEN(handshake_hdr));
+
 			/* Now see if there's anything extra to do */
 			switch(f->state){
 			/* Checks to see if this is a possibly tagged hello msg */
 				case TLS_CLNT_HELLO: 
 					/* Expecting server hello msg */
 					printf("Received client hello!\n");
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					break;
 				case TLS_SERV_HELLO:
 					extract_server_random(f, p);
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received server hello!\n");
 					break;
 				case TLS_NEW_SESS:
+					update_finish_hash(f, p);
 					printf("Received new session ticket!\n");
 					break;
 				case TLS_CERT:
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received certificate!\n");
 					break;
 				case TLS_SRVR_KEYEX:
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received server key exchange!\n");
 					/* Need to extract server params */
 					if(extract_parameters(f, p)){
@@ -153,22 +156,24 @@ int update_flow(flow *f) {
 					}
 					break;
 				case TLS_CERT_REQ:
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received certificate request!\n");
 					break;
 				case TLS_SRVR_HELLO_DONE:
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received server hello done!\n");
 					break;
 				case TLS_CERT_VERIFY:
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received certificate verify!\n");
 					break;
 				case TLS_CLNT_KEYEX:
-					//update_finish_hash(f, p);
+					update_finish_hash(f, p);
 					printf("Received client key exchange!\n");
 					break;
 				case TLS_FINISHED:
+					verify_finish_hash(f,p, incoming);
+					update_finish_hash(f, p);
 					printf("Received finished message!\n");
 					break;
 				default:
@@ -356,16 +361,13 @@ int add_packet(flow *f, uint8_t *p){
 /** UTILITY **/
 
 int update_finish_hash(flow *f, uint8_t *hs){
-	EVP_MD_CTX *ctx = f->finish_md_ctx;
 	//find handshake length
 	const struct handshake_header *hs_hdr;
 	uint8_t *p = hs;
 	hs_hdr = (struct handshake_header*) p;
 	uint32_t hs_len = HANDSHAKE_MESSAGE_LEN(hs_hdr);
 	
-	/* Now compute SHA384(secret, A+seed)
-	 * can't sign update, don't have master secret yet*/
-	EVP_DigestUpdate(&ctx, hs, hs_len);
+	EVP_DigestUpdate(f->finish_md_ctx, hs, hs_len+4);
 
 	return 1;
 	
@@ -463,41 +465,48 @@ int decrypt_fin(flow *f, uint8_t *hs, int32_t len, int32_t incoming){
 			13, buf);
 	printf("pad: %d\n", pad);
 
-	printf("Decrypting (%d bytes):\n", len);
-	for(int i=0; i<len; i++){
-		printf("%02x ", p[i]);
-	}
-	printf("\n");
 
 	int32_t n = EVP_Cipher(ds, p, p, len); //decrypt in place
 
 	p += EVP_GCM_TLS_EXPLICIT_IV_LEN;
 	len -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
 	//print out decrypted record
-	printf("Record (decrypted %d/%d bytes): \n", n, len);
-	for(int i=0; i<n; i++){
-		printf("%02x ", p[i]);
-	}
-	printf("\n");
 
-	/*get context
+	return 1;
+}
+
+int verify_finish_hash(flow *f, uint8_t *p, int32_t incoming){
+	EVP_MD_CTX ctx;
+	uint8_t hash[EVP_MAX_MD_SIZE];
+	int32_t hash_len;
+
+	EVP_MD_CTX_init(&ctx);
 	
 	//get header length
+	struct handshake_header *hs_hdr;
 	hs_hdr = (struct handshake_header*) p;
 	uint32_t fin_length = HANDSHAKE_MESSAGE_LEN(hs_hdr);
 	p += HANDSHAKE_HEADER_LEN;
 
 	//finalize hash of handshake msgs
 	EVP_MD_CTX_copy_ex(&ctx, f->finish_md_ctx);
-	EVP_DigestFinal(&ctx, hash, &hash_len);
+	EVP_DigestFinal_ex(&ctx, hash, &hash_len);
 
 	//now use pseudorandom function
 	uint8_t *output = calloc(1, fin_length);
-	PRF(f->master_secret, SSL3_MASTER_SECRET_SIZE, finished_label, finished_label_len, hash, hash_len, NULL, 0, NULL, 0, output, fin_length);
+	if(incoming){
+		PRF(f->master_secret, SSL3_MASTER_SECRET_SIZE, TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE , hash, hash_len, NULL, 0, NULL, 0, output, fin_length);
+	} else {
+		PRF(f->master_secret, SSL3_MASTER_SECRET_SIZE, TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE , hash, hash_len, NULL, 0, NULL, 0, output, fin_length);
+	}
 
 	//now compare
-	
-*/
+	if(CRYPTO_memcmp(p, output, fin_length) != 0){
+		printf("VERIFY FAILED\n");
+		return 0;
+	} else {
+		printf("VERIFY PASSED\n");
+	}
 
 	return 1;
 }
@@ -708,7 +717,7 @@ int init_ciphers(flow *f){
 	EVP_CIPHER_CTX_init(r_ctx);
 	EVP_CIPHER_CTX_init(w_ctx);
 
-//#ifdef KSSL_DEBUG
+/*#ifdef KSSL_DEBUG
     {
         int i;
         fprintf(stderr, "EVP_CipherInit_ex(r_ctx,c,key=,iv=,which)\n");
@@ -721,7 +730,7 @@ int init_ciphers(flow *f){
             fprintf(stderr, "%02x", read_iv[i]);
         fprintf(stderr, "\n");
     }
-//#endif                          /* KSSL_DEBUG_*/
+//#endif                           KSSL_DEBUG_
     {
         int i;
         fprintf(stderr, "EVP_CipherInit_ex(w_ctx,c,key=,iv=,which)\n");
@@ -734,21 +743,14 @@ int init_ciphers(flow *f){
             fprintf(stderr, "%02x", write_iv[i]);
         fprintf(stderr, "\n");
     }
-//#endif                          /* KSSL_DEBUG */
+//#endif                           KSSL_DEBUG */
 
 
 	EVP_CipherInit_ex(r_ctx, c, NULL, read_key, NULL, 0);
 	EVP_CipherInit_ex(w_ctx, c, NULL, write_key, NULL, 0);
 	EVP_CIPHER_CTX_ctrl(r_ctx, EVP_CTRL_GCM_SET_IV_FIXED, EVP_GCM_TLS_FIXED_IV_LEN, read_iv);
 	EVP_CIPHER_CTX_ctrl(w_ctx, EVP_CTRL_GCM_SET_IV_FIXED, EVP_GCM_TLS_FIXED_IV_LEN, write_iv);
-	fprintf(stderr, "\t\tIV: ");
-	for (int i = 0; i < r_ctx->cipher->iv_len; i++) 
-		fprintf(stderr, "%02X", r_ctx->iv[i]);
-	fprintf(stderr, "\n");
-		fprintf(stderr, "\t\tIV: ");
-		for (int i = 0; i < w_ctx->cipher->iv_len; i++) 
-			fprintf(stderr, "%02X", w_ctx->iv[i]);
-		fprintf(stderr, "\n");
+
 	f->read_ctx = r_ctx;
 	f->write_ctx = w_ctx;
 }