From d55e4555042fe910fe32b7a78c6ef0d3a165aa6d Mon Sep 17 00:00:00 2001
From: Mats Klepsland <mats.klepsland@gmail.com>
Date: Thu, 28 Dec 2017 22:40:27 +0100
Subject: [PATCH] eve: add JA3 fields to TLS JSON logger

Add JA3 object to TLS JSON logger (extended log).
---
 src/output-json-tls.c | 44 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/src/output-json-tls.c b/src/output-json-tls.c
index 5c424c0d5..08049aa6d 100644
--- a/src/output-json-tls.c
+++ b/src/output-json-tls.c
@@ -46,6 +46,7 @@
 
 #include "util-logopenfile.h"
 #include "util-crypt.h"
+#include "util-ja3.h"
 
 #include "output-json.h"
 #include "output-json-tls.h"
@@ -77,6 +78,7 @@ SC_ATOMIC_DECLARE(unsigned int, cert_id);
 #define LOG_TLS_FIELD_CERTIFICATE       (1 << 8)
 #define LOG_TLS_FIELD_CHAIN             (1 << 9)
 #define LOG_TLS_FIELD_SESSION_RESUMED   (1 << 10)
+#define LOG_TLS_FIELD_JA3               (1 << 11)
 
 typedef struct {
     const char *name;
@@ -95,6 +97,7 @@ TlsFields tls_fields[] = {
     { "certificate",     LOG_TLS_FIELD_CERTIFICATE },
     { "chain",           LOG_TLS_FIELD_CHAIN },
     { "session_resumed", LOG_TLS_FIELD_SESSION_RESUMED },
+    { "ja3",             LOG_TLS_FIELD_JA3 },
     { NULL,              -1 }
 };
 
@@ -211,6 +214,34 @@ static void JsonTlsLogNotAfter(json_t *js, SSLState *ssl_state)
     }
 }
 
+static void JsonTlsLogJa3Hash(json_t *js, SSLState *ssl_state)
+{
+    if (ssl_state->ja3_hash != NULL) {
+        json_object_set_new(js, "hash", json_string(ssl_state->ja3_hash));
+    }
+}
+
+static void JsonTlsLogJa3String(json_t *js, SSLState *ssl_state)
+{
+    if ((ssl_state->ja3_str != NULL) &&
+            ssl_state->ja3_str->data != NULL) {
+        json_object_set_new(js, "string",
+                            json_string(ssl_state->ja3_str->data));
+    }
+}
+
+static void JsonTlsLogJa3(json_t *js, SSLState *ssl_state)
+{
+    json_t *tjs = json_object();
+    if (unlikely(tjs == NULL))
+        return;
+
+    JsonTlsLogJa3Hash(tjs, ssl_state);
+    JsonTlsLogJa3String(tjs, ssl_state);
+
+    json_object_set_new(js, "ja3", tjs);
+}
+
 static void JsonTlsLogCertificate(json_t *js, SSLState *ssl_state)
 {
     if ((ssl_state->server_connp.cert_input == NULL) ||
@@ -314,6 +345,10 @@ static void JsonTlsLogJSONCustom(OutputTlsCtx *tls_ctx, json_t *js,
     /* tls chain */
     if (tls_ctx->fields & LOG_TLS_FIELD_CHAIN)
         JsonTlsLogChain(js, ssl_state);
+
+    /* tls ja3_hash */
+    if (tls_ctx->fields & LOG_TLS_FIELD_JA3)
+        JsonTlsLogJa3(js, ssl_state);
 }
 
 void JsonTlsLogJSONExtended(json_t *tjs, SSLState * state)
@@ -337,6 +372,9 @@ void JsonTlsLogJSONExtended(json_t *tjs, SSLState * state)
 
     /* tls notafter */
     JsonTlsLogNotAfter(tjs, state);
+
+    /* tls ja3 */
+    JsonTlsLogJa3(tjs, state);
 }
 
 static int JsonTlsLogger(ThreadVars *tv, void *thread_data, const Packet *p,
@@ -497,6 +535,12 @@ static OutputTlsCtx *OutputTlsInitCtx(ConfNode *conf)
         tls_ctx->flags |= LOG_TLS_SESSION_RESUMPTION;
     }
 
+    if ((tls_ctx->fields & LOG_TLS_FIELD_JA3) &&
+            Ja3IsDisabled("fields")) {
+        /* JA3 is disabled, so don't log any JA3 fields */
+        tls_ctx->fields &= ~LOG_TLS_FIELD_JA3;
+    }
+
     if ((tls_ctx->fields & LOG_TLS_FIELD_CERTIFICATE) &&
             (tls_ctx->fields & LOG_TLS_FIELD_CHAIN)) {
         SCLogWarning(SC_WARN_DUPLICATE_OUTPUT,
-- 
2.47.3