feat(java): add hardcoded secret rule (#206)

rules/java/lang/hardcoded_secret.yml

@@ -0,0 +1,109 @@
+patterns:
+  - pattern: $<...>char[] $<NAME> = $<STRING_LITERAL>.toCharArray()
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+      - variable: STRING_LITERAL
+        detection: java_lang_hardcoded_secret_literal
+        scope: cursor
+  - pattern: |
+      class $<...>$<_> $<...> {
+        $<!>$<...>char[] $<NAME> = $<STRING_LITERAL>.toCharArray()
+      }
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+      - variable: STRING_LITERAL
+        detection: java_lang_hardcoded_secret_literal
+        scope: cursor
+  - pattern: $<...>char[] $<NAME> = {};
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+  - pattern: |
+      class $<...>$<_> $<...> {
+        $<!>$<...>char[] $<NAME> = {};
+      }
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+  - pattern: $<...>byte[] $<NAME> = new byte[] {};
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+  - pattern: |
+      class $<...>$<_> $<...> {
+        $<!>$<...>byte[] $<NAME> = new byte[] {};
+      }
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+  - pattern: $<...>String $<NAME> = $<STRING_LITERAL>;
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+      - variable: STRING_LITERAL
+        detection: java_lang_hardcoded_secret_literal
+        scope: cursor
+  - pattern: |
+      class $<...>$<_> $<...> {
+        $<!>$<...>String $<NAME> = $<STRING_LITERAL>;
+      }
+    filters:
+      - variable: NAME
+        detection: java_lang_hardcoded_secret_name
+        scope: cursor_strict
+      - variable: STRING_LITERAL
+        detection: java_lang_hardcoded_secret_literal
+        scope: cursor
+auxiliary:
+  - id: java_lang_hardcoded_secret_name
+    patterns:
+      - pattern: $<NAME>;
+        filters:
+          - either:
+              - variable: NAME
+                regex: (?i)(password|api_?key|api?key|secret)\b
+              - variable: NAME
+                regex: (?i)(pass|pwd|psw|cipher|crypt|des|aes|mac|private|secret|sign|cert).*
+  - id: java_lang_hardcoded_secret_literal
+    patterns:
+      - pattern: $<STRING>;
+        filters:
+          - variable: STRING
+            detection: string_literal
+            scope: cursor_strict
+          - not:
+              variable: STRING
+              string_regex: \A[*•]+\z
+          - variable: STRING
+            entropy_greater_than: 3.5
+languages:
+  - java
+severity: high
+metadata:
+  description: "Hard-coded secret detected."
+  remediation_message: |
+    ## Description
+
+    Applications should store secret values securely and not as literal values
+    in the source code.
+
+    ## Remediations
+
+    ✅ Retrieve secrets from a secure location at runtime
+
+    ## Resources
+    - [OWASP hardcoded passwords](https://owasp.org/www-community/vulnerabilities/Use_of_hard-coded_password)
+    - [OWASP secrets management cheat sheet](https://cheatsheetseries.owasp.org/cheatsheets/Secrets_Management_Cheat_Sheet.html#21-high-availability)
+  cwe_id:
+    - 798
+  id: java_lang_hardcoded_secret
+  documentation_url: https://docs.bearer.com/reference/rules/java_lang_hardcoded_secret

tests/java/lang/hardcoded_secret/test.js

@@ -0,0 +1,18 @@
+const {
+  createNewInvoker,
+  getEnvironment,
+} = require("../../../helper.js")
+const { ruleId, ruleFile, testBase } = getEnvironment(__dirname)
+
+describe(ruleId, () => {
+  const invoke = createNewInvoker(ruleId, ruleFile, testBase)
+
+  test("hardcoded_secret", () => {
+    const testCase = "main.java"
+
+    const results = invoke(testCase)
+
+    expect(results.Missing).toEqual([])
+    expect(results.Extra).toEqual([])
+  })
+})

tests/java/lang/hardcoded_secret/testdata/main.java

@@ -0,0 +1,46 @@
+package password;
+import java.util.Arrays;
+
+public class ShareTheSecrets {
+  // ok
+  private static final byte[] PUBLIC_KEY = new byte[] { 1, 2, 3, 4, 5, 6, 7 };
+  // bearer:expected java_lang_hardcoded_secret
+  final String pass2 = "f#a};!y~7VBcu<&F@[%,{b";
+  // bearer:expected java_lang_hardcoded_secret
+  private static final byte[] API_KEY = new byte[] { 1, 2, 3, 4, 5, 6, 7 };
+  // bearer:expected java_lang_hardcoded_secret
+  private static final String PWD = "hV#;N.F9j}'v5Y-XJc])P*";
+  // bearer:expected java_lang_hardcoded_secret
+  private static final char[] password = { 's', 'e', 'c', 'r', 'e', 't', '5' };
+  // bearer:expected java_lang_hardcoded_secret
+  public static final String API_KEY = ".uYikE-os3cM23rz.i6Q";
+
+  public static void bad() throws Exception {
+    // bearer:expected java_lang_hardcoded_secret
+    final String pass2 = "f#a};!y~7VBcu<&F@[%,{b";
+    // bearer:expected java_lang_hardcoded_secret
+    char[] ciphertext = "gSbDu-wAE7ZL#[tG4'jfx><HFdVk;5a".toCharArray();
+    // bearer:expected java_lang_hardcoded_secret
+    char[] secret = { 's', 'e', 'c', 'r', 'e', 't' };
+  }
+
+  public void alsoBad() throws Exception {
+    // bearer:expected java_lang_hardcoded_secret
+    char[] pwd1 = PWD.toCharArray();
+    // bearer:expected java_lang_hardcoded_secret
+    public char[] apiKey = {"s", "e", "c", "r", "e", "t"};
+    // bearer:expected java_lang_hardcoded_secret
+    char[] pwd = ".uYikE-os3cM23rz.i6Q".toCharArray();
+  }
+
+  public void good() throws Exception {
+    // test-like data
+    char[] apiKey = "my-secret-key";
+    final String API_KEY = "Enter API";
+    final String pwd = "testing";
+
+    // null data
+    public String password = null;
+    char[] apiKey =
+  }
+}