Adds support to SecResponseBodyLimit directive and OUTBOUND_DATA_ERROR var

headers/modsecurity/rules.h

@@ -48,6 +48,7 @@ class Rules {
     Rules()
         : m_referenceCount(0),
         requestBodyLimit(0),
+        responseBodyLimit(0),
         m_custom_debug_log(NULL) { }
 
     explicit Rules(DebugLog *custom_log)
@@ -126,6 +127,7 @@ class Rules {
     std::list<std::string> components;
 
     int requestBodyLimit;
+    int responseBodyLimit;
     AuditLog *audit_log;
 
  private:

src/assay.cc

@@ -718,6 +718,11 @@ int Assay::addResponseHeader(const unsigned char *key, size_t key_n,
  */
 int Assay::processResponseBody() {
     debug(4, "Starting phase RESPONSE_BODY. (SecRules 4)");
+
+    if (resolve_variable_first("OUTBOUND_DATA_ERROR") == NULL) {
+        store_variable("OUTBOUND_DATA_ERROR", "0");
+    }
+
     this->m_rules->evaluate(ModSecurity::ResponseBodyPhase, this);
     return 0;
 }
@@ -742,10 +747,16 @@ int Assay::processResponseBody() {
  *
  */
 int Assay::appendResponseBody(const unsigned char *buf, size_t len) {
-    /**
+    int current_size = this->m_responseBody.tellp();
-     * as part of the confiurations or rules it is expected to 
+
-     * set a higher value for this. Will not handle it for now.
+    debug(9, "Appending response body: " + std::to_string(len) + " bytes. " \
-     */
+        "Limit set to: " + std::to_string(this->m_rules->responseBodyLimit));
+
+    if (this->m_rules->responseBodyLimit > 0
+        && this->m_rules->responseBodyLimit < len + current_size) {
+        store_variable("OUTBOUND_DATA_ERROR", "1");
+    }
+
     this->m_responseBody.write(reinterpret_cast<const char*>(buf), len);
 
     return 0;

src/parser/driver.cc

@@ -21,6 +21,7 @@ Driver::Driver()
   : trace_scanning(false),
   trace_parsing(false),
   requestBodyLimit(0),
+  responseBodyLimit(0),
   audit_log(new ModSecurity::AuditLog()) {
 }
 

src/parser/driver.h

@@ -88,6 +88,7 @@ class Driver {
     bool sec_request_body_access;
     bool sec_response_body_access;
     int requestBodyLimit;
+    int responseBodyLimit;
 
     std::string debug_log_path;
     std::list<std::string> components;

src/parser/seclang-parser.yy

@@ -64,6 +64,7 @@ using ModSecurity::Utils::GeoLookup;
 %token <std::string> DIRECTIVE
 %token <std::string> CONFIG_DIRECTIVE
 %token <std::string> CONFIG_DIR_REQ_BODY_LIMIT
+%token <std::string> CONFIG_DIR_RES_BODY_LIMIT
 %token <std::string> CONFIG_DIR_RULE_ENG
 %token <std::string> CONFIG_DIR_REQ_BODY
 %token <std::string> CONFIG_DIR_RES_BODY
@@ -255,6 +256,10 @@ expression:
       {
         driver.requestBodyLimit = atoi($1.c_str());
       }
+    | CONFIG_DIR_RES_BODY_LIMIT
+      {
+        driver.responseBodyLimit = atoi($1.c_str());
+      }
 
 variables:
     variables PIPE VARIABLE

src/parser/seclang-scanner.ll

@@ -21,8 +21,9 @@ ACTION          (?i:accuracy|allow|append|auditlog|block|capture|chain|ctl|deny|
 ACTION_SEVERITY (?i:severity:[0-9]+|severity:'[0-9]+'|severity:(EMERGENCY|ALERT|CRITICAL|ERROR|WARNING|NOTICE|INFO|DEBUG)|severity:'(EMERGENCY|ALERT|CRITICAL|ERROR|WARNING|NOTICE|INFO|DEBUG)')
 DIRECTIVE       SecRule
 
-CONFIG_DIRECTIVE SecRequestBodyLimitAction|SecRequestBodyNoFilesLimit|SecRequestBodyInMemoryLimit|SecPcreMatchLimitRecursion|SecPcreMatchLimit|SecResponseBodyMimeType|SecResponseBodyLimitAction|SecResponseBodyLimit|SecTmpDir|SecDataDir|SecArgumentSeparator|SecCookieFormat|SecStatusEngine
+CONFIG_DIRECTIVE SecRequestBodyLimitAction|SecRequestBodyNoFilesLimit|SecRequestBodyInMemoryLimit|SecPcreMatchLimitRecursion|SecPcreMatchLimit|SecResponseBodyMimeType|SecResponseBodyLimitAction|SecTmpDir|SecDataDir|SecArgumentSeparator|SecCookieFormat|SecStatusEngine
 CONFIG_DIR_REQ_BODY_LIMIT (?i:SecRequestBodyLimit)
+CONFIG_DIR_RES_BODY_LIMIT (?i:SecResponseBodyLimit)
 
 
 CONFIG_DIR_GEO_DB (?i:SecGeoLookupDb)
@@ -59,7 +60,7 @@ OPERATORNOARG	(?i:@detectSQLi|@detectXSS|@geoLookup|@validateUrlEncoding|@valida
 
 TRANSFORMATION  t:(lowercase|urlDecodeUni|urlDecode|none|compressWhitespace|removeWhitespace|replaceNulls|removeNulls|htmlEntityDecode|jsDecode|cssDecode|trim)
 
-VARIABLE          (?i:MULTIPART_STRICT_ERROR|MULTIPART_NAME|MULTIPART_FILENAME|MULTIPART_CRLF_LF_LINES|MATCHED_VAR_NAME|MATCHED_VARS_NAMES|MATCHED_VAR|MATCHED_VARS|INBOUND_DATA_ERROR|FULL_REQUEST|FILES|AUTH_TYPE|ARGS_NAMES|ARGS|QUERY_STRING|REMOTE_ADDR|REQUEST_BASENAME|REQUEST_BODY|REQUEST_COOKIES_NAMES|REQUEST_COOKIES|REQUEST_FILENAME|REQUEST_HEADERS_NAMES|REQUEST_HEADERS|REQUEST_METHOD|REQUEST_PROTOCOL|REQUEST_URI|RESPONSE_BODY|RESPONSE_CONTENT_LENGTH|RESPONSE_CONTENT_TYPE|RESPONSE_HEADERS_NAMES|RESPONSE_HEADERS|RESPONSE_PROTOCOL|RESPONSE_STATUS|TX|GEO)
+VARIABLE          (?i:MULTIPART_STRICT_ERROR|MULTIPART_NAME|MULTIPART_FILENAME|MULTIPART_CRLF_LF_LINES|MATCHED_VAR_NAME|MATCHED_VARS_NAMES|MATCHED_VAR|MATCHED_VARS|INBOUND_DATA_ERROR|OUTBOUND_DATA_ERROR|FULL_REQUEST|FILES|AUTH_TYPE|ARGS_NAMES|ARGS|QUERY_STRING|REMOTE_ADDR|REQUEST_BASENAME|REQUEST_BODY|REQUEST_COOKIES_NAMES|REQUEST_COOKIES|REQUEST_FILENAME|REQUEST_HEADERS_NAMES|REQUEST_HEADERS|REQUEST_METHOD|REQUEST_PROTOCOL|REQUEST_URI|RESPONSE_BODY|RESPONSE_CONTENT_LENGTH|RESPONSE_CONTENT_TYPE|RESPONSE_HEADERS_NAMES|RESPONSE_HEADERS|RESPONSE_PROTOCOL|RESPONSE_STATUS|TX|GEO)
 RUN_TIME_VAR_DUR  (?i:DURATION)
 RUN_TIME_VAR_ENV  (?i:ENV)
 RUN_TIME_VAR_BLD  (?i:MODSEC_BUILD)
@@ -126,6 +127,8 @@ FREE_TEXT_NEW_LINE       [^\"|\n]+
 
 %{ /* Request body limit */ %}
 {CONFIG_DIR_REQ_BODY_LIMIT}[ ]{CONFIG_VALUE_NUMBER}  { return yy::seclang_parser::make_CONFIG_DIR_REQ_BODY_LIMIT(strchr(yytext, ' ') + 1, loc); }
+%{ /* Reponse body limit */ %}
+{CONFIG_DIR_RES_BODY_LIMIT}[ ]{CONFIG_VALUE_NUMBER}  { return yy::seclang_parser::make_CONFIG_DIR_RES_BODY_LIMIT(strchr(yytext, ' ') + 1, loc); }
 
 {CONFIG_COMPONENT_SIG}[ ]["]{FREE_TEXT}["] { return yy::seclang_parser::make_CONFIG_COMPONENT_SIG(strchr(yytext, ' ') + 2, loc); }
 

src/rules.cc

@@ -168,6 +168,7 @@ int Rules::merge(Driver *from) {
     this->debug_level = from->debug_level;
     this->components = from->components;
     this->requestBodyLimit = from->requestBodyLimit;
+    this->responseBodyLimit = from->responseBodyLimit;
 
     if (m_custom_debug_log) {
         this->debug_log = m_custom_debug_log->new_instance();
@@ -203,6 +204,7 @@ int Rules::merge(Rules *from) {
     this->sec_response_body_access = from->sec_response_body_access;
     this->components = from->components;
     this->requestBodyLimit = from->requestBodyLimit;
+    this->responseBodyLimit = from->responseBodyLimit;
 
     this->debug_log = from->debug_log;
 

test/test-cases/regression/variable-OUTBOUND_DATA_ERROR.json

@@ -0,0 +1,120 @@
+[  
+  {  
+    "enabled":1,
+    "version_min":300000,
+    "title":"Testing Variables :: OUTBOUND_DATA_ERROR (1/2)",
+    "client":{  
+      "ip":"200.249.12.31",
+      "port":123
+    },
+    "server":{  
+      "ip":"200.249.12.31",
+      "port":80
+    },
+    "request":{  
+      "headers":{  
+        "Host":"localhost",
+        "User-Agent":"curl/7.38.0",
+        "Accept":"*/*"
+      },
+      "uri":"/?key=value&key=other_value",
+      "protocol":"GET"
+    },
+    "response":{  
+      "headers":{  
+        "Date":"Mon, 13 Jul 2015 20:02:41 GMT",
+        "Last-Modified":"Sun, 26 Oct 2014 22:33:37 GMT",
+        "Content-Type":"text/html"
+      },
+      "body":[  
+        "no need."
+      ]
+    },
+    "expected":{  
+      "debug_log":"Target value: \"0\" \\(Variable: OUTBOUND_DATA_ERROR\\)"
+    },
+    "rules":[  
+      "SecRuleEngine On",
+      "SecDebugLog \/tmp\/modsec_debug.log",
+      "SecDebugLogLevel 9",
+      "SecRule OUTBOUND_DATA_ERROR \"@eq 1\" \"phase:4,pass,t:trim\""
+    ]
+  },
+  {  
+    "enabled":1,
+    "version_min":300000,
+    "title":"Testing Variables :: OUTBOUND_DATA_ERROR (2/2)",
+    "client":{  
+      "ip":"200.249.12.31",
+      "port":123
+    },
+    "server":{  
+      "ip":"200.249.12.31",
+      "port":80
+    },
+    "request":{  
+      "headers":{  
+        "Host":"localhost",
+        "User-Agent":"curl/7.38.0",
+        "Accept":"*/*",
+        "Content-Length":"330",
+        "Content-Type":"multipart/form-data; boundary=--------------------------756b6d74fa1a8ee2",
+        "Expect":"100-continue"
+      },
+      "uri":"/",
+      "protocol":"POST",
+      "body":[  
+        "--------------------------756b6d74fa1a8ee2",
+        "Content-Disposition: form-data; name=\"name\"",
+        "",
+        "test",
+        "--------------------------756b6d74fa1a8ee2",
+        "Content-Disposition: form-data; name=\"filedata\"; filename=\"small_text_file.txt\"",
+        "Content-Type: text/plain",
+        "",
+        "This is a very small test file..",
+        "--------------------------756b6d74fa1a8ee2",
+        "Content-Disposition: form-data; name=\"filedata\"; filename=\"small_text_file.txt\"",
+        "Content-Type: text/plain",
+        "",
+        "This is another very small test file..",
+        "--------------------------756b6d74fa1a8ee2--"
+      ]
+    },
+    "response":{  
+      "headers":{  
+        "Date":"Mon, 13 Jul 2015 20:02:41 GMT",
+        "Last-Modified":"Sun, 26 Oct 2014 22:33:37 GMT",
+        "Content-Type":"text/html"
+      },
+      "body":[  
+        "--------------------------756b6d74fa1a8ee2",
+        "Content-Disposition: form-data; name=\"name\"",
+        "",
+        "test",
+        "--------------------------756b6d74fa1a8ee2",
+        "Content-Disposition: form-data; name=\"filedata\"; filename=\"small_text_file.txt\"",
+        "Content-Type: text/plain",
+        "",
+        "This is a very small test file..",
+        "--------------------------756b6d74fa1a8ee2",
+        "Content-Disposition: form-data; name=\"filedata\"; filename=\"small_text_file.txt\"",
+        "Content-Type: text/plain",
+        "",
+        "This is another very small test file..",
+        "--------------------------756b6d74fa1a8ee2--"
+      ]
+    },
+    "expected":{  
+      "debug_log":"Target value: \"1\" \\(Variable: OUTBOUND_DATA_ERROR\\)"
+    },
+    "rules":[  
+      "SecRuleEngine On",
+      "SecDebugLog \/tmp\/modsec_debug.log",
+      "SecResponseBodyLimit 2",
+      "SecDebugLogLevel 9",
+      "SecRule OUTBOUND_DATA_ERROR \"@eq 1\" \"phase:4,pass,t:trim\""
+    ]
+  }
+]
+