gosec - Golang Security Checker

Inspects source code for security problems by scanning the Go AST.


Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance with the License. You may obtain a copy of the License here.

Project status

CII Best Practices Build Status Coverage Status GoReport GoDoc Docs Downloads Docker Pulls Slack


CI Installation
# binary will be $GOPATH/bin/gosec
curl -sfL | sh -s -- -b $GOPATH/bin vX.Y.Z

# or install it into ./bin/
curl -sfL | sh -s vX.Y.Z

# In alpine linux (as it does not come with curl by default)
wget -O - -q | sh -s vX.Y.Z

# If you want to use the checksums provided on the "Releases" page
# then you will have to download a tar.gz file for your operating system instead of a binary file

# The file will be in the current folder where you run the command 
# and you can check the checksum like this
echo "<check sum from the check sum file>  gosec_vX.Y.Z_OS.tar.gz" | sha256sum -c -

gosec --help
Local Installation
go get


Gosec can be configured to only run a subset of rules, to exclude certain file paths, and produce reports in different formats. By default all rules will be run against the supplied input files. To recursively scan from the current directory you can supply ./... as the input argument.

Available rules
  • G101: Look for hard coded credentials
  • G102: Bind to all interfaces
  • G103: Audit the use of unsafe block
  • G104: Audit errors not checked
  • G106: Audit the use of ssh.InsecureIgnoreHostKey
  • G107: Url provided to HTTP request as taint input
  • G108: Profiling endpoint automatically exposed on /debug/pprof
  • G109: Potential Integer overflow made by strconv.Atoi result conversion to int16/32
  • G110: Potential DoS vulnerability via decompression bomb
  • G201: SQL query construction using format string
  • G202: SQL query construction using string concatenation
  • G203: Use of unescaped data in HTML templates
  • G204: Audit use of command execution
  • G301: Poor file permissions used when creating a directory
  • G302: Poor file permissions used with chmod
  • G303: Creating tempfile using a predictable path
  • G304: File path provided as taint input
  • G305: File traversal when extracting zip archive
  • G306: Poor file permissions used when writing to a new file
  • G307: Deferring a method which returns an error
  • G401: Detect the usage of DES, RC4, MD5 or SHA1
  • G402: Look for bad TLS connection settings
  • G403: Ensure minimum RSA key length of 2048 bits
  • G404: Insecure random number source (rand)
  • G501: Import blacklist: crypto/md5
  • G502: Import blacklist: crypto/des
  • G503: Import blacklist: crypto/rc4
  • G504: Import blacklist: net/http/cgi
  • G505: Import blacklist: crypto/sha1
Retired rules
Selecting rules

By default, gosec will run all rules against the supplied file paths. It is however possible to select a subset of rules to run via the -include= flag, or to specify a set of rules to explicitly exclude using the -exclude= flag.

# Run a specific set of rules
$ gosec -include=G101,G203,G401 ./...

# Run everything except for rule G303
$ gosec -exclude=G303 ./...
CWE Mapping

Every issue detected by gosec is mapped to a CWE (Common Weakness Enumeration) which describes in more generic terms the vulnerability. The exact mapping can be found here.


A number of global settings can be provided in a configuration file as follows:

    "global": {
        "nosec": "enabled",
        "audit": "enabled"
  • nosec: this setting will overwrite all #nosec directives defined throughout the code base
  • audit: runs in audit mode which enables addition checks that for normal code analysis might be too nosy
# Run with a global configuration file
$ gosec -conf config.json .

Also some rules accept configuration. For instance on rule G104, it is possible to define packages along with a list of functions which will be skipped when auditing the not checked errors:

    "G104": {
        "io/ioutil": ["WriteFile"]

gosec will fetch automatically the dependencies of the code which is being analyzed when go module is turned on (e.g. GO111MODULE=on). If this is not the case, the dependencies need to be explicitly downloaded by running the go get -d command before the scan.

Excluding test files and folders

gosec will ignore test files across all packages and any dependencies in your vendor directory.

The scanning of test files can be enabled with the following flag:

gosec -tests ./...

Also additional folders can be excluded as follows:

 gosec -exclude-dir=rules -exclude-dir=cmd ./...
Annotating code

As with all automated detection tools, there will be cases of false positives. In cases where gosec reports a failure that has been manually verified as being safe, it is possible to annotate the code with a #nosec comment.

The annotation causes gosec to stop processing any further nodes within the AST so can apply to a whole block or more granularly to a single expression.

import "md5" // #nosec

func main(){

    /* #nosec */
    if x > y {
        h := md5.New() // this will also be ignored


When a specific false positive has been identified and verified as safe, you may wish to suppress only that single rule (or a specific set of rules) within a section of code, while continuing to scan for other problems. To do this, you can list the rule(s) to be suppressed within the #nosec annotation, e.g: /* #nosec G401 */ or // #nosec G201 G202 G203

In some cases you may also want to revisit places where #nosec annotations have been used. To run the scanner and ignore any #nosec annotations you can do the following:

gosec -nosec=true ./...
Build tags

gosec is able to pass your Go build tags to the analyzer. They can be provided as a comma separated list as follows:

gosec -tag debug,ignore ./...
Output formats

gosec currently supports text, json, yaml, csv, sonarqube, JUnit XML and golint output formats. By default results will be reported to stdout, but can also be written to an output file. The output format is controlled by the '-fmt' flag, and the output file is controlled by the '-out' flag as follows:

# Write output in json format to results.json
$ gosec -fmt=json -out=results.json *.go


make test
Release Build

Make sure you have installed the goreleaser tool and then you can release gosec as follows:

git tag v1.0.0
make release

The released version of the tool is available in the dist folder. The build information should be displayed in the usage text.

./dist/darwin_amd64/gosec -h
gosec  - Golang security checker

gosec analyzes Go source code to look for common programming mistakes that

VERSION: 1.0.0
GIT TAG: v1.0.0
BUILD DATE: 2018-04-27T12:41:38Z

Note that all released archives are also uploaded to GitHub.

Docker image

You can build the docker image as follows:

make image

You can run the gosec tool in a container against your local Go project. You just have to mount the project into a volume as follows:

docker run -it -v <YOUR PROJECT PATH>/<PROJECT>:/<PROJECT> securego/gosec /<PROJECT>/...
Generate TLS rule

The configuration of TLS rule can be generated from Mozilla's TLS ciphers recommendation.

First you need to install the generator tool:

go get

You can invoke now the go generate in the root of the project:

go generate ./...

This will generate the rules/tls_config.go file which will contain the current ciphers recommendation from Mozilla.



    Package gosec holds the central scanning logic used by gosec security scanner



    View Source
    const (
    	// Globals are applicable to all rules and used for general
    	// configuration settings for gosec.
    	Globals = "global"

      LoadMode controls the amount of details to return when loading the packages


      View Source
      var IssueToCWE = map[string]Cwe{
      	"G101": GetCwe("798"),
      	"G102": GetCwe("200"),
      	"G103": GetCwe("242"),
      	"G104": GetCwe("703"),
      	"G106": GetCwe("322"),
      	"G107": GetCwe("88"),
      	"G109": GetCwe("190"),
      	"G110": GetCwe("409"),
      	"G201": GetCwe("89"),
      	"G202": GetCwe("89"),
      	"G203": GetCwe("79"),
      	"G204": GetCwe("78"),
      	"G301": GetCwe("276"),
      	"G302": GetCwe("276"),
      	"G303": GetCwe("377"),
      	"G304": GetCwe("22"),
      	"G305": GetCwe("22"),
      	"G401": GetCwe("326"),
      	"G402": GetCwe("295"),
      	"G403": GetCwe("310"),
      	"G404": GetCwe("338"),
      	"G501": GetCwe("327"),
      	"G502": GetCwe("327"),
      	"G503": GetCwe("327"),
      	"G504": GetCwe("327"),
      	"G505": GetCwe("327"),

        IssueToCWE maps gosec rules to CWEs


        func ConcatString

        func ConcatString(n *ast.BinaryExpr) (string, bool)

          ConcatString recursively concatenates strings from a binary expression

          func ExcludedDirsRegExp

          func ExcludedDirsRegExp(excludedDirs []string) []*regexp.Regexp

            ExcludedDirsRegExp builds the regexps for a list of excluded dirs provided as strings

            func FindVarIdentities

            func FindVarIdentities(n *ast.BinaryExpr, c *Context) ([]*ast.Ident, bool)

              FindVarIdentities returns array of all variable identities in a given binary expression

              func GetCallInfo

              func GetCallInfo(n ast.Node, ctx *Context) (string, string, error)

                GetCallInfo returns the package or type and name associated with a call expression.

                func GetCallObject

                func GetCallObject(n ast.Node, ctx *Context) (*ast.CallExpr, types.Object)

                  GetCallObject returns the object and call expression and associated object for a given AST node. nil, nil will be returned if the object cannot be resolved.

                  func GetCallStringArgsValues

                  func GetCallStringArgsValues(n ast.Node, ctx *Context) []string

                    GetCallStringArgsValues returns the values of strings arguments if they can be resolved

                    func GetChar

                    func GetChar(n ast.Node) (byte, error)

                      GetChar will read and return a char value from an ast.BasicLit

                      func GetFloat

                      func GetFloat(n ast.Node) (float64, error)

                        GetFloat will read and return a float value from an ast.BasicLit

                        func GetIdentStringValues

                        func GetIdentStringValues(ident *ast.Ident) []string

                          GetIdentStringValues return the string values of an Ident if they can be resolved

                          func GetImportPath

                          func GetImportPath(name string, ctx *Context) (string, bool)

                            GetImportPath resolves the full import path of an identifier based on the imports in the current context.

                            func GetImportedName

                            func GetImportedName(path string, ctx *Context) (string, bool)

                              GetImportedName returns the name used for the package within the code. It will resolve aliases and ignores initialization only imports.

                              func GetInt

                              func GetInt(n ast.Node) (int64, error)

                                GetInt will read and return an integer value from an ast.BasicLit

                                func GetLocation

                                func GetLocation(n ast.Node, ctx *Context) (string, int)

                                  GetLocation returns the filename and line number of an ast.Node

                                  func GetPkgAbsPath

                                  func GetPkgAbsPath(pkgPath string) (string, error)

                                    GetPkgAbsPath returns the Go package absolute path derived from the given path

                                    func GetPkgRelativePath

                                    func GetPkgRelativePath(path string) (string, error)

                                      GetPkgRelativePath returns the Go relative relative path derived form the given path

                                      func GetString

                                      func GetString(n ast.Node) (string, error)

                                        GetString will read and return a string value from an ast.BasicLit

                                        func Getenv

                                        func Getenv(key, userDefault string) string

                                          Getenv returns the values of the environment variable, otherwise returns the default if variable is not set

                                          func Gopath

                                          func Gopath() []string

                                            Gopath returns all GOPATHs

                                            func MatchCallByPackage

                                            func MatchCallByPackage(n ast.Node, c *Context, pkg string, names ...string) (*ast.CallExpr, bool)

                                              MatchCallByPackage ensures that the specified package is imported, adjusts the name for any aliases and ignores cases that are initialization only imports.


                                              node, matched := MatchCallByPackage(n, ctx, "math/rand", "Read")

                                              func MatchCompLit

                                              func MatchCompLit(n ast.Node, ctx *Context, required string) *ast.CompositeLit

                                                MatchCompLit will match an ast.CompositeLit based on the supplied type

                                                func PackagePaths

                                                func PackagePaths(root string, excludes []*regexp.Regexp) ([]string, error)

                                                  PackagePaths returns a slice with all packages path at given root directory

                                                  func RootPath

                                                  func RootPath(root string) (string, error)

                                                    RootPath returns the absolute root path of a scan

                                                    func TryResolve

                                                    func TryResolve(n ast.Node, c *Context) bool

                                                      TryResolve will attempt, given a subtree starting at some AST node, to resolve all values contained within to a known constant. It is used to check for any unknown values in compound expressions.


                                                      type Analyzer

                                                      type Analyzer struct {
                                                      	// contains filtered or unexported fields

                                                        Analyzer object is the main object of gosec. It has methods traverse an AST and invoke the correct checking rules as on each node as required.

                                                        func NewAnalyzer

                                                        func NewAnalyzer(conf Config, tests bool, logger *log.Logger) *Analyzer

                                                          NewAnalyzer builds a new analyzer.

                                                          func (*Analyzer) AppendError

                                                          func (gosec *Analyzer) AppendError(file string, err error)

                                                            AppendError appends an error to the file errors

                                                            func (*Analyzer) Check

                                                            func (gosec *Analyzer) Check(pkg *packages.Package)

                                                              Check runs analysis on the given package

                                                              func (*Analyzer) Config

                                                              func (gosec *Analyzer) Config() Config

                                                                Config returns the current configuration

                                                                func (*Analyzer) LoadRules

                                                                func (gosec *Analyzer) LoadRules(ruleDefinitions map[string]RuleBuilder)

                                                                  LoadRules instantiates all the rules to be used when analyzing source packages

                                                                  func (*Analyzer) ParseErrors

                                                                  func (gosec *Analyzer) ParseErrors(pkg *packages.Package) error

                                                                    ParseErrors parses the errors from given package

                                                                    func (*Analyzer) Process

                                                                    func (gosec *Analyzer) Process(buildTags []string, packagePaths ...string) error

                                                                      Process kicks off the analysis process for a given package

                                                                      func (*Analyzer) Report

                                                                      func (gosec *Analyzer) Report() ([]*Issue, *Metrics, map[string][]Error)

                                                                        Report returns the current issues discovered and the metrics about the scan

                                                                        func (*Analyzer) Reset

                                                                        func (gosec *Analyzer) Reset()

                                                                          Reset clears state such as context, issues and metrics from the configured analyzer

                                                                          func (*Analyzer) SetConfig

                                                                          func (gosec *Analyzer) SetConfig(conf Config)

                                                                            SetConfig upates the analyzer configuration

                                                                            func (*Analyzer) Visit

                                                                            func (gosec *Analyzer) Visit(n ast.Node) ast.Visitor

                                                                              Visit runs the gosec visitor logic over an AST created by parsing go code. Rule methods added with AddRule will be invoked as necessary.

                                                                              type CallList

                                                                              type CallList map[string]set

                                                                                CallList is used to check for usage of specific packages and functions.

                                                                                func NewCallList

                                                                                func NewCallList() CallList

                                                                                  NewCallList creates a new empty CallList

                                                                                  func (CallList) Add

                                                                                  func (c CallList) Add(selector, ident string)

                                                                                    Add a selector and call to the call list

                                                                                    func (CallList) AddAll

                                                                                    func (c CallList) AddAll(selector string, idents ...string)

                                                                                      AddAll will add several calls to the call list at once

                                                                                      func (CallList) Contains

                                                                                      func (c CallList) Contains(selector, ident string) bool

                                                                                        Contains returns true if the package and function are / members of this call list.

                                                                                        func (CallList) ContainsCallExpr

                                                                                        func (c CallList) ContainsCallExpr(n ast.Node, ctx *Context) *ast.CallExpr

                                                                                          ContainsCallExpr resolves the call expression name and type, and then determines if the call exists with the call list

                                                                                          func (CallList) ContainsPkgCallExpr

                                                                                          func (c CallList) ContainsPkgCallExpr(n ast.Node, ctx *Context, stripVendor bool) *ast.CallExpr

                                                                                            ContainsPkgCallExpr resolves the call expression name and type, and then further looks

                                                                                            up the package path for that type. Finally, it determines if the call exists within the call list

                                                                                            func (CallList) ContainsPointer

                                                                                            func (c CallList) ContainsPointer(selector, indent string) bool

                                                                                              ContainsPointer returns true if a pointer to the selector type or the type itself is a members of this call list.

                                                                                              type Config

                                                                                              type Config map[string]interface{}

                                                                                                Config is used to provide configuration and customization to each of the rules.

                                                                                                func NewConfig

                                                                                                func NewConfig() Config

                                                                                                  NewConfig initializes a new configuration instance. The configuration data then needs to be loaded via c.ReadFrom(strings.NewReader("config data")) or from a *os.File.

                                                                                                  func (Config) Get

                                                                                                  func (c Config) Get(section string) (interface{}, error)

                                                                                                    Get returns the configuration section for the supplied key

                                                                                                    func (Config) GetGlobal

                                                                                                    func (c Config) GetGlobal(option GlobalOption) (string, error)

                                                                                                      GetGlobal returns value associated with global configuration option

                                                                                                      func (Config) IsGlobalEnabled

                                                                                                      func (c Config) IsGlobalEnabled(option GlobalOption) (bool, error)

                                                                                                        IsGlobalEnabled checks if a global option is enabled

                                                                                                        func (Config) ReadFrom

                                                                                                        func (c Config) ReadFrom(r io.Reader) (int64, error)

                                                                                                          ReadFrom implements the io.ReaderFrom interface. This should be used with io.Reader to load configuration from file or from string etc.

                                                                                                          func (Config) Set

                                                                                                          func (c Config) Set(section string, value interface{})

                                                                                                            Set section in the configuration to specified value

                                                                                                            func (Config) SetGlobal

                                                                                                            func (c Config) SetGlobal(option GlobalOption, value string)

                                                                                                              SetGlobal associates a value with a global configuration option

                                                                                                              func (Config) WriteTo

                                                                                                              func (c Config) WriteTo(w io.Writer) (int64, error)

                                                                                                                WriteTo implements the io.WriteTo interface. This should be used to save or print out the configuration information.

                                                                                                                type Context

                                                                                                                type Context struct {
                                                                                                                	FileSet      *token.FileSet
                                                                                                                	Comments     ast.CommentMap
                                                                                                                	Info         *types.Info
                                                                                                                	Pkg          *types.Package
                                                                                                                	PkgFiles     []*ast.File
                                                                                                                	Root         *ast.File
                                                                                                                	Config       Config
                                                                                                                	Imports      *ImportTracker
                                                                                                                	Ignores      []map[string]bool
                                                                                                                	PassedValues map[string]interface{}

                                                                                                                  The Context is populated with data parsed from the source code as it is scanned. It is passed through to all rule functions as they are called. Rules may use this data in conjunction withe the encountered AST node.

                                                                                                                  type Cwe

                                                                                                                  type Cwe struct {
                                                                                                                  	ID  string
                                                                                                                  	URL string

                                                                                                                    Cwe id and url

                                                                                                                    func GetCwe

                                                                                                                    func GetCwe(id string) Cwe

                                                                                                                      GetCwe creates a cwe object for a given RuleID

                                                                                                                      type Error

                                                                                                                      type Error struct {
                                                                                                                      	Line   int    `json:"line"`
                                                                                                                      	Column int    `json:"column"`
                                                                                                                      	Err    string `json:"error"`

                                                                                                                        Error is used when there are golang errors while parsing the AST

                                                                                                                        func NewError

                                                                                                                        func NewError(line, column int, err string) *Error

                                                                                                                          NewError creates Error object

                                                                                                                          type GlobalOption

                                                                                                                          type GlobalOption string

                                                                                                                            GlobalOption defines the name of the global options

                                                                                                                            const (
                                                                                                                            	// Nosec global option for #nosec directive
                                                                                                                            	Nosec GlobalOption = "nosec"
                                                                                                                            	// Audit global option which indicates that gosec runs in audit mode
                                                                                                                            	Audit GlobalOption = "audit"
                                                                                                                            	// NoSecAlternative global option alternative for #nosec directive
                                                                                                                            	NoSecAlternative GlobalOption = "#nosec"

                                                                                                                            type ImportTracker

                                                                                                                            type ImportTracker struct {
                                                                                                                            	Imported map[string]string
                                                                                                                            	Aliased  map[string]string
                                                                                                                            	InitOnly map[string]bool

                                                                                                                              ImportTracker is used to normalize the packages that have been imported by a source file. It is able to differentiate between plain imports, aliased imports and init only imports.

                                                                                                                              func NewImportTracker

                                                                                                                              func NewImportTracker() *ImportTracker

                                                                                                                                NewImportTracker creates an empty Import tracker instance

                                                                                                                                func (*ImportTracker) TrackFile

                                                                                                                                func (t *ImportTracker) TrackFile(file *ast.File)

                                                                                                                                  TrackFile track all the imports used by the supplied file

                                                                                                                                  func (*ImportTracker) TrackImport

                                                                                                                                  func (t *ImportTracker) TrackImport(n ast.Node)

                                                                                                                                    TrackImport tracks imports and handles the 'unsafe' import

                                                                                                                                    func (*ImportTracker) TrackPackages

                                                                                                                                    func (t *ImportTracker) TrackPackages(pkgs ...*types.Package)

                                                                                                                                      TrackPackages tracks all the imports used by the supplied packages

                                                                                                                                      type Issue

                                                                                                                                      type Issue struct {
                                                                                                                                      	Severity   Score  `json:"severity"`   // issue severity (how problematic it is)
                                                                                                                                      	Confidence Score  `json:"confidence"` // issue confidence (how sure we are we found it)
                                                                                                                                      	Cwe        Cwe    `json:"cwe"`        // Cwe associated with RuleID
                                                                                                                                      	RuleID     string `json:"rule_id"`    // Human readable explanation
                                                                                                                                      	What       string `json:"details"`    // Human readable explanation
                                                                                                                                      	File       string `json:"file"`       // File name we found it in
                                                                                                                                      	Code       string `json:"code"`       // Impacted code line
                                                                                                                                      	Line       string `json:"line"`       // Line number in file
                                                                                                                                      	Col        string `json:"column"`     // Column number in line

                                                                                                                                        Issue is returned by a gosec rule if it discovers an issue with the scanned code.

                                                                                                                                        func NewIssue

                                                                                                                                        func NewIssue(ctx *Context, node ast.Node, ruleID, desc string, severity Score, confidence Score) *Issue

                                                                                                                                          NewIssue creates a new Issue

                                                                                                                                          type MetaData

                                                                                                                                          type MetaData struct {
                                                                                                                                          	ID         string
                                                                                                                                          	Severity   Score
                                                                                                                                          	Confidence Score
                                                                                                                                          	What       string

                                                                                                                                            MetaData is embedded in all gosec rules. The Severity, Confidence and What message will be passed through to reported issues.

                                                                                                                                            type Metrics

                                                                                                                                            type Metrics struct {
                                                                                                                                            	NumFiles int `json:"files"`
                                                                                                                                            	NumLines int `json:"lines"`
                                                                                                                                            	NumNosec int `json:"nosec"`
                                                                                                                                            	NumFound int `json:"found"`

                                                                                                                                              Metrics used when reporting information about a scanning run.

                                                                                                                                              type Rule

                                                                                                                                              type Rule interface {
                                                                                                                                              	ID() string
                                                                                                                                              	Match(ast.Node, *Context) (*Issue, error)

                                                                                                                                                The Rule interface used by all rules supported by gosec.

                                                                                                                                                type RuleBuilder

                                                                                                                                                type RuleBuilder func(id string, c Config) (Rule, []ast.Node)

                                                                                                                                                  RuleBuilder is used to register a rule definition with the analyzer

                                                                                                                                                  type RuleSet

                                                                                                                                                  type RuleSet map[reflect.Type][]Rule

                                                                                                                                                    A RuleSet maps lists of rules to the type of AST node they should be run on. The analyzer will only invoke rules contained in the list associated with the type of AST node it is currently visiting.

                                                                                                                                                    func NewRuleSet

                                                                                                                                                    func NewRuleSet() RuleSet

                                                                                                                                                      NewRuleSet constructs a new RuleSet

                                                                                                                                                      func (RuleSet) Register

                                                                                                                                                      func (r RuleSet) Register(rule Rule, nodes ...ast.Node)

                                                                                                                                                        Register adds a trigger for the supplied rule for the the specified ast nodes.

                                                                                                                                                        func (RuleSet) RegisteredFor

                                                                                                                                                        func (r RuleSet) RegisteredFor(n ast.Node) []Rule

                                                                                                                                                          RegisteredFor will return all rules that are registered for a specified ast node.

                                                                                                                                                          type Score

                                                                                                                                                          type Score int

                                                                                                                                                            Score type used by severity and confidence values

                                                                                                                                                            const (
                                                                                                                                                            	// Low severity or confidence
                                                                                                                                                            	Low Score = iota
                                                                                                                                                            	// Medium severity or confidence
                                                                                                                                                            	// High severity or confidence

                                                                                                                                                            func (Score) MarshalJSON

                                                                                                                                                            func (c Score) MarshalJSON() ([]byte, error)

                                                                                                                                                              MarshalJSON is used convert a Score object into a JSON representation

                                                                                                                                                              func (Score) String

                                                                                                                                                              func (c Score) String() string

                                                                                                                                                                String converts a Score into a string


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