Add ability to filter/ignore specific vulnerabilities (#778)

Solves #662 

> By placing a `osv-scanner.toml` file in any parent directory of the
file being
> scanned will be used to configure scanning of that file. This can be
overridden
> by passing the `--config=/path/to/config` flag.
> 
> Currently, there is only 1 option to configure:
> ### Ignore vulnerabilities by ID
> Vulnerabilities can be marked as ignored by putting the vuln ID in an
array
> under the `IgnoreVulnIds` key. 
> ```
> IgnoredVulnIds = [
>     "GO-2022-0968",
>     "GO-2022-1059"
> ]
> ```

Co-authored-by: Andrew Pollock <andrewpollock@users.noreply.github.com>

docker/indexer/osv-scanner.toml

@@ -0,0 +1,19 @@
+[[IgnoredVulns]]
+id = "GO-2022-0968"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No ssh servers are connected to or hosted in Go lang"
+
+[[IgnoredVulns]]
+id = "GO-2022-1059"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No external http servers are written in Go lang."
+
+[[IgnoredVulns]]
+id = "GO-2022-0356"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No ssh servers"
+
+[[IgnoredVulns]]
+id = "GO-2022-0969"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No external http servers in Go lang."

osv-scanner.toml

@@ -0,0 +1,19 @@
+[[IgnoredVulns]]
+id = "GO-2022-0968"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No ssh servers are connected to or hosted in Go lang"
+
+[[IgnoredVulns]]
+id = "GO-2022-1059"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No external http servers are written in Go lang."
+
+[[IgnoredVulns]]
+id = "GO-2022-0356"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No ssh servers"
+
+[[IgnoredVulns]]
+id = "GO-2022-0969"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No external http servers in Go lang."

tools/osv-scanner/README.md

@@ -71,7 +71,7 @@ This tool will walk through a list of directories to find:
 
 and make requests to OSV to determine affected vulnerabilities.
 
-You can have it recursively walk through subdirectories with the `--recursive` flag.
+You can have it recursively walk through subdirectories with the `--recursive` / `-r` flag.
 
 Searching for git commit hash is intended to work with projects that use
 git submodules or a similar mechanism where dependencies are checked out
@@ -80,8 +80,32 @@ as real git repositories.
 ### Example
 
 ```bash
-$ go run ./cmd/osv-scanner /path/to/your/dir
+$ go run ./cmd/osv-scanner -r /path/to/your/dir
 ```
+
+## Configure `osv-scanner`
+
+By placing a `osv-scanner.toml` file in any parent directory of the file being
+scanned will be used to configure scanning of that file. This can be overridden
+by passing the `--config=/path/to/config` flag.
+
+Currently, there is only 1 option to configure:
+### Ignore vulnerabilities by ID
+Vulnerabilities can be marked as ignored by putting the ID an entry
+under the `IgnoreVulns` key, along with optional reason and expiry date.
+
+#### Example
+```
+[[IgnoredVulns]]
+id = "GO-2022-0968"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No ssh servers are connected to or hosted in Go lang"
+
+id = "GO-2022-1059"
+# ignoreUntil = 2022-11-09 # Optional exception expiry date
+reason = "No external http servers are written in Go lang."
+```
+
 ## JSON output
 By default osv-scanner outputs a human readable table. To have osv-scanner output JSON instead, pass the `--json` flag when calling osv-scanner. 
 

tools/osv-scanner/cmd/osv-scanner/config.go

@@ -0,0 +1,119 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/BurntSushi/toml"
+	"golang.org/x/exp/slices"
+)
+
+type ConfigManager struct {
+	// Override to replace all other configs
+	overrideConfig *Config
+	// Config to use if no config file is found alongside manifests
+	defaultConfig Config
+	// Cache to store loaded configs
+	configMap map[string]Config
+}
+
+type Config struct {
+	IgnoredVulns []IgnoreEntry
+	LoadPath     string
+}
+
+type IgnoreEntry struct {
+	ID          string    `toml:"id"`
+	IgnoreUntil time.Time `toml:"ignoreUntil"`
+	Reason      string    `toml:"reason"`
+}
+
+func (c *Config) ShouldIgnore(vulnID string) (bool, IgnoreEntry) {
+	index := slices.IndexFunc(c.IgnoredVulns, func(elem IgnoreEntry) bool { return elem.ID == vulnID })
+	if index == -1 {
+		return false, IgnoreEntry{}
+	}
+	ignoredLine := c.IgnoredVulns[index]
+	if ignoredLine.IgnoreUntil.IsZero() {
+		// If IgnoreUntil is not set, should ignore.
+		return true, ignoredLine
+	}
+	// Should ignore if IgnoreUntil is still after current time
+	// Takes timezone offsets into account if it is specified. otherwise it's using local time
+	return ignoredLine.IgnoreUntil.After(time.Now()), ignoredLine
+
+}
+
+// Sets the override config by reading the config file at configPath.
+// Will return an error if loading the config file fails
+func (c *ConfigManager) UseOverride(configPath string) error {
+	config := Config{}
+	_, err := toml.DecodeFile(configPath, &config)
+	if err != nil {
+		return err
+	}
+	config.LoadPath = configPath
+	c.overrideConfig = &config
+	return nil
+}
+
+// Attempts to get the config
+func (c *ConfigManager) Get(targetPath string) Config {
+	if c.overrideConfig != nil {
+		return *c.overrideConfig
+	}
+
+	configPath := normalizeConfigLoadPath(targetPath)
+	config, alreadyExists := c.configMap[configPath]
+	if alreadyExists {
+		return config
+	}
+
+	config, configErr := tryLoadConfig(configPath)
+	if configErr == nil {
+		log.Printf("Loaded filter from: %s", config.LoadPath)
+	} else {
+		// If config doesn't exist, use the default config
+		config = c.defaultConfig
+	}
+	c.configMap[configPath] = config
+
+	return config
+}
+
+// Finds the containing folder of `target`, then appends osvScannerConfigName
+func normalizeConfigLoadPath(target string) string {
+	stat, err := os.Stat(target)
+	if err != nil {
+		log.Fatalf("Failed to stat target: %s", err)
+	}
+
+	var containingFolder string
+	if !stat.IsDir() {
+		containingFolder = filepath.Dir(target)
+	} else {
+		containingFolder = target
+	}
+	configPath := filepath.Join(containingFolder, osvScannerConfigName)
+	return configPath
+}
+
+// tryLoadConfig tries to load config in `target` (or it's containing directory)
+// `target` will be the key for the entry in configMap
+func tryLoadConfig(configPath string) (Config, error) {
+	configFile, err := os.Open(configPath)
+	var config Config
+	if err == nil { // File exists, and we have permission to read
+		_, err := toml.NewDecoder(configFile).Decode(&config)
+		if err != nil {
+			log.Fatalf("Failed to read config file: %s\n", err)
+		}
+		config.LoadPath = configPath
+		return config, nil
+	}
+
+	return Config{}, fmt.Errorf("No config file found on this path: %s", configPath)
+}

tools/osv-scanner/cmd/osv-scanner/config_test.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type testStruct struct {
+	targetPath   string
+	config       Config
+	configHasErr bool
+}
+
+func TestTryLoadConfig(t *testing.T) {
+
+	expectedConfig := Config{
+		IgnoredVulns: []IgnoreEntry{
+			{
+				ID: "GO-2022-0968",
+			},
+			{
+				ID: "GO-2022-1059",
+			},
+		},
+	}
+	testPaths := []testStruct{
+		{
+			targetPath:   "../../testdata/testdatainner/innerFolder/test.yaml",
+			config:       expectedConfig,
+			configHasErr: true,
+		},
+		{
+			targetPath:   "../../testdata/testdatainner/innerFolder/",
+			config:       Config{},
+			configHasErr: true,
+		},
+		{ // Test no slash at the end
+			targetPath:   "../../testdata/testdatainner/innerFolder",
+			config:       Config{},
+			configHasErr: true,
+		},
+		{
+			targetPath:   "../../testdata/testdatainner/",
+			config:       expectedConfig,
+			configHasErr: false,
+		},
+		{
+			targetPath:   "../../testdata/testdatainner/some-manifest.yaml",
+			config:       expectedConfig,
+			configHasErr: false,
+		},
+	}
+
+	for _, testData := range testPaths {
+		absPath, err := filepath.Abs(testData.targetPath)
+		if err != nil {
+			t.Errorf("%s", err)
+		}
+		configPath := normalizeConfigLoadPath(absPath)
+		config, configErr := tryLoadConfig(configPath)
+		cmp.Equal(config, testData.config)
+		if testData.configHasErr {
+			cmp.Equal(configErr, nil)
+		}
+	}
+}