Merge pull request #1207 from hashicorp/audit-hash-accessor

Audit backends optionally hashing token accessor

audit/hashstructure.go

@@ -29,8 +29,10 @@ func Hash(salter *salt.Salt, raw interface{}) error {
 			return nil
 		}
 		if s.ClientToken != "" {
-			token := fn(s.ClientToken)
-			s.ClientToken = token
+			s.ClientToken = fn(s.ClientToken)
+		}
+		if s.Accessor != "" {
+			s.Accessor = fn(s.Accessor)
 		}
 
 	case *logical.Request:
@@ -44,8 +46,7 @@ func Hash(salter *salt.Salt, raw interface{}) error {
 		}
 
 		if s.ClientToken != "" {
-			token := fn(s.ClientToken)
-			s.ClientToken = token
+			s.ClientToken = fn(s.ClientToken)
 		}
 
 		data, err := HashStructure(s.Data, fn)

builtin/audit/file/backend.go

@@ -15,7 +15,7 @@ import (
 
 func Factory(conf *audit.BackendConfig) (audit.Backend, error) {
 	if conf.Salt == nil {
-		return nil, fmt.Errorf("Nil salt passed in")
+		return nil, fmt.Errorf("nil salt")
 	}
 
 	path, ok := conf.Config["path"]
@@ -23,6 +23,16 @@ func Factory(conf *audit.BackendConfig) (audit.Backend, error) {
 		return nil, fmt.Errorf("path is required")
 	}
 
+	// Check if hashing of accessor is disabled
+	hashAccessor := true
+	if hashAccessorRaw, ok := conf.Config["hash_accessor"]; ok {
+		value, err := strconv.ParseBool(hashAccessorRaw)
+		if err != nil {
+			return nil, err
+		}
+		hashAccessor = value
+	}
+
 	// Check if raw logging is enabled
 	logRaw := false
 	if raw, ok := conf.Config["log_raw"]; ok {
@@ -34,9 +44,10 @@ func Factory(conf *audit.BackendConfig) (audit.Backend, error) {
 	}
 
 	b := &Backend{
-		path:   path,
-		logRaw: logRaw,
-		salt:   conf.Salt,
+		path:         path,
+		logRaw:       logRaw,
+		hashAccessor: hashAccessor,
+		salt:         conf.Salt,
 	}
 
 	// Ensure that the file can be successfully opened for writing;
@@ -55,9 +66,10 @@ func Factory(conf *audit.BackendConfig) (audit.Backend, error) {
 // It doesn't do anything more at the moment to assist with rotation
 // or reset the write cursor, this should be done in the future.
 type Backend struct {
-	path   string
-	logRaw bool
-	salt   *salt.Salt
+	path         string
+	logRaw       bool
+	hashAccessor bool
+	salt         *salt.Salt
 
 	once sync.Once
 	f    *os.File
@@ -103,6 +115,7 @@ func (b *Backend) LogRequest(auth *logical.Auth, req *logical.Request, outerErr
 		if err := audit.Hash(b.salt, req); err != nil {
 			return err
 		}
+
 	}
 
 	var format audit.FormatJSON
@@ -149,15 +162,34 @@ func (b *Backend) LogResponse(
 		resp = cp.(*logical.Response)
 
 		// Hash any sensitive information
+
+		// Cache and restore accessor in the auth
+		var accessor string
+		if !b.hashAccessor && auth != nil && auth.Accessor != "" {
+			accessor = auth.Accessor
+		}
 		if err := audit.Hash(b.salt, auth); err != nil {
 			return err
 		}
+		if accessor != "" {
+			auth.Accessor = accessor
+		}
+
 		if err := audit.Hash(b.salt, req); err != nil {
 			return err
 		}
+
+		// Cache and restore accessor in the response
+		accessor = ""
+		if !b.hashAccessor && resp != nil && resp.Auth != nil && resp.Auth.Accessor != "" {
+			accessor = resp.Auth.Accessor
+		}
 		if err := audit.Hash(b.salt, resp); err != nil {
 			return err
 		}
+		if accessor != "" {
+			resp.Auth.Accessor = accessor
+		}
 	}
 
 	var format audit.FormatJSON

builtin/audit/syslog/backend.go

@@ -29,6 +29,16 @@ func Factory(conf *audit.BackendConfig) (audit.Backend, error) {
 		tag = "vault"
 	}
 
+	// Check if hashing of accessor is disabled
+	hashAccessor := true
+	if hashAccessorRaw, ok := conf.Config["hash_accessor"]; ok {
+		value, err := strconv.ParseBool(hashAccessorRaw)
+		if err != nil {
+			return nil, err
+		}
+		hashAccessor = value
+	}
+
 	// Check if raw logging is enabled
 	logRaw := false
 	if raw, ok := conf.Config["log_raw"]; ok {
@@ -46,18 +56,20 @@ func Factory(conf *audit.BackendConfig) (audit.Backend, error) {
 	}
 
 	b := &Backend{
-		logger: logger,
-		logRaw: logRaw,
-		salt:   conf.Salt,
+		logger:       logger,
+		logRaw:       logRaw,
+		hashAccessor: hashAccessor,
+		salt:         conf.Salt,
 	}
 	return b, nil
 }
 
 // Backend is the audit backend for the syslog-based audit store.
 type Backend struct {
-	logger gsyslog.Syslogger
-	logRaw bool
-	salt   *salt.Salt
+	logger       gsyslog.Syslogger
+	logRaw       bool
+	hashAccessor bool
+	salt         *salt.Salt
 }
 
 func (b *Backend) GetHash(data string) string {
@@ -145,15 +157,34 @@ func (b *Backend) LogResponse(auth *logical.Auth, req *logical.Request,
 		resp = cp.(*logical.Response)
 
 		// Hash any sensitive information
+
+		// Cache and restore accessor in the auth
+		var accessor string
+		if !b.hashAccessor && auth != nil && auth.Accessor != "" {
+			accessor = auth.Accessor
+		}
 		if err := audit.Hash(b.salt, auth); err != nil {
 			return err
 		}
+		if accessor != "" {
+			auth.Accessor = accessor
+		}
+
 		if err := audit.Hash(b.salt, req); err != nil {
 			return err
 		}
+
+		// Cache and restore accessor in the response
+		accessor = ""
+		if !b.hashAccessor && resp != nil && resp.Auth != nil && resp.Auth.Accessor != "" {
+			accessor = resp.Auth.Accessor
+		}
 		if err := audit.Hash(b.salt, resp); err != nil {
 			return err
 		}
+		if accessor != "" {
+			resp.Auth.Accessor = accessor
+		}
 	}
 
 	// Encode the entry as JSON

website/source/docs/audit/file.html.md

@@ -8,29 +8,59 @@ description: |-
 
 # Audit Backend: File
 
-Name: `file`
-
-The "file" audit backend writes audit logs to a file.
-
-This is a very simple audit backend: it appends logs to a file. It does
-not currently assist with any log rotation.
-
-## Options
-
-When enabling this backend, the following options are accepted:
-
-  * `path` (required) - The path to where the file will be written. If
-      this path exists, the audit backend will append to it.
-  * `log_raw` (optional) Should security sensitive information be logged raw. Defaults to "false".
+The `file` audit backend writes audit logs to a file. This is a very simple audit
+backend: it appends logs to a file. It does not currently assist with any log rotation.
 
 ## Format
 
-Each line in the audit log is a JSON object. The "type" field specifies
-what type of object it is. Currently, only two types exist: "request" and
-"response".
+Each line in the audit log is a JSON object. The `type` field specifies what type of
+object it is. Currently, only two types exist: `request` and `response`. The line contains
+all of the information for any given request and response. By default, all the sensitive
+information is first hashed before logging in the audit logs.
 
-The line contains all of the information for any given request and response.
+## Enabling
 
-If `log_raw` if false, as is default, all sensitive information is first hashed
-before logging. If explicitly enabled, all values are logged raw without hashing.
+#### Via the CLI
+
+Audit `file` backend can be enabled by the following command.
+
+```
+$ vault audit-enable file path=/var/log/vault_audit.log
+```
+
+Any number of `file` audit logs can be created by enabling it with different `id`s.
+
+```
+$ vault audit-enable -id="vault_audit_1" file path=/home/user/vault_audit.log
+```
+
+Note the difference between `audit-enable` command options and the `file` backend
+configuration options. Use `vault audit-enable -help` to see the command options.
+Following are the configuration options available for the backend.
+
+<dl class="api">
+  <dt>Backend configuration options</dt>
+  <dd>
+    <ul>
+      <li>
+        <span class="param">path</span>
+        <span class="param-flags">required</span>
+            The path to where the audit log will be written. If this
+            path exists, the audit backend will append to it.
+      </li>
+      <li>
+        <span class="param">log_raw</span>
+        <span class="param-flags">optional</span>
+            A boolean, if set, logs the security sensitive information without
+            hashing, in the raw format. Defaults to `false`.
+      </li>
+      <li>
+        <span class="param">hash_accessor</span>
+        <span class="param-flags">optional</span>
+            A boolean, if set, skips the hashing of token accessor. This option
+            is useful only when `log_raw` is `false`.
+      </li>
+    </ul>
+  </dd>
+</dl>
 

website/source/docs/audit/index.html.md

@@ -67,3 +67,41 @@ Vault will not respond to requests if audit backends are blocked because
 audit logs are critically important and ignoring blocked requests opens
 an avenue for attack. Be absolutely certain that your audit backends cannot
 block.
+
+## API
+
+### /sys/audit/[path]
+#### POST
+
+<dl class="api">
+  <dt>Description</dt>
+  <dd>
+      Enables audit backend at the specified path.
+  </dd>
+
+  <dt>Method</dt>
+  <dd>POST</dd>
+
+  <dd>
+    <ul>
+      <li>
+       <span class="param">type</span>
+        <span class="param-flags">required</span>
+            The path to where the audit log will be written. If this
+            path exists, the audit backend will append to it.
+      </li>
+      <li>
+        <span class="param">description</span>
+        <span class="param-flags">optional</span>
+            A boolean, if set, logs the security sensitive information without
+            hashing, in the raw format. Defaults to `false`.
+      </li>
+      <li>
+        <span class="param">options</span>
+        <span class="param-flags">optional</span>
+           Configuration options of the backend in JSON format.
+           Refer to `syslog` and `file` audit backend options.
+      </li>
+    </ul>
+  </dd>
+</dl>

website/source/docs/audit/syslog.html.md

@@ -8,30 +8,63 @@ description: |-
 
 # Audit Backend: Syslog
 
-Name: `syslog`
+The `syslog` audit backend writes audit logs to syslog.
 
-The "syslog" audit backend writes audit logs to syslog.
-
-It currently does not support a configurable syslog destination, and
-always sends to the local agent. This backend is only supported on Unix systems,
+It currently does not support a configurable syslog destination, and always
+sends to the local agent. This backend is only supported on Unix systems,
 and should not be enabled if any standby Vault instances do not support it.
 
-## Options
-
-When enabling this backend, the following options are accepted:
-
- * `facility` (optional) - The syslog facility to use. Defaults to "AUTH".
- * `tag` (optional) - The syslog tag to use. Defaults to "vault".
- * `log_raw` (optional) Should security sensitive information be logged raw. Defaults to "false".
-
 ## Format
 
-Each line in the audit log is a JSON object. The "type" field specifies
-what type of object it is. Currently, only two types exist: "request" and
-"response".
+Each line in the audit log is a JSON object. The `type` field specifies what type of
+object it is. Currently, only two types exist: `request` and `response`. The line contains
+all of the information for any given request and response. By default, all the sensitive
+information is first hashed before logging in the audit logs.
 
-The line contains all of the information for any given request and response.
+## Enabling
 
-If `log_raw` if false, as is default, all sensitive information is first hashed
-before logging. If explicitly enabled, all values are logged raw without hashing.
+#### Via the CLI
 
+Audit `syslog` backend can be enabled by the following command.
+
+```
+$ vault audit-enable syslog
+```
+
+Backend configuration options can also be provided from command-line.
+
+```
+$ vault audit-enable syslog tag="vault" facility="AUTH"
+```
+
+Following are the configuration options available for the backend.
+
+<dl class="api">
+  <dt>Backend configuration options</dt>
+  <dd>
+    <ul>
+      <li>
+        <span class="param">facility</span>
+        <span class="param-flags">optional</span>
+            The syslog facility to use. Defaults to `AUTH`.
+      </li>
+      <li>
+        <span class="param">tag</span>
+        <span class="param-flags">optional</span>
+            The syslog tag to use. Defaults to `vault`.
+      </li>
+      <li>
+        <span class="param">log_raw</span>
+        <span class="param-flags">optional</span>
+            A boolean, if set, logs the security sensitive information without
+            hashing, in the raw format. Defaults to `false`.
+      </li>
+      <li>
+        <span class="param">hash_accessor</span>
+        <span class="param-flags">optional</span>
+            A boolean, if set, skips the hashing of token accessor. This option
+            is useful only when `log_raw` is `false`.
+      </li>
+    </ul>
+  </dd>
+</dl>