feat(detectors): GCP, Azure, Twilio, SendGrid, OpenAI-style keys, and DB URL passwords

.gitignore

@@ -22,3 +22,5 @@ htmlcov/
 # ctxguard local config (the example ships instead)
 .ctxguard.toml
 
+# local task notes
+goal.md

README.md

@@ -91,6 +91,14 @@ Run the synthetic demonstration with `python3 scripts/demo.py`. See
 - GitHub classic and fine-grained personal access tokens
 - Slack tokens
 - Stripe live and test secret keys
+- GCP API keys (`AIza...`) and service-account JSON (content marker plus the filename rule)
+- Azure storage, Service Bus, Event Hub, and IoT Hub connection string keys
+  (`AccountKey=...`, `SharedAccessKey=...`)
+- Twilio API key SIDs and SendGrid API keys
+- OpenAI-style keys (`sk-...`, `sk-proj-...`) and Anthropic keys (`sk-ant-...`)
+- Database URLs with inline passwords: Postgres, MySQL/MariaDB (including
+  SQLAlchemy dialect+driver and Rails `mysql2://` schemes), MongoDB, Redis,
+  AMQP, and MSSQL
 - private key blocks and JWT-shaped strings
 - credential-like assignments that pass length, digit, and entropy thresholds
 - high-entropy values assigned to names containing `key`, `secret`, `token`,
@@ -145,6 +153,19 @@ ctxguard --version
   preserves availability but means a broken hook does not provide protection.
 - Native Windows compatibility is not claimed; current testing covers the
   Python package and hook contract on Unix-like CI runners.
+- Any non-placeholder password inline in a database URL is flagged, including
+  weak or "demo" ones (`hunter2`, `letmein123`). This is intentional: a weak
+  credential is still a working credential, and ctxguard can't judge which
+  ones are safe to expose. Allowlist known-safe fixtures in `.ctxguard.toml`
+  instead.
+- GCP `AIza...`-style API keys are flagged even though some (notably Firebase
+  web config keys) are designed to be usable client-side. Restrict such keys
+  by API and referrer in the Google Cloud Console rather than relying on
+  ctxguard to tell intent apart; allowlist the specific file if it's noisy.
+- A handful of well-known, publicly documented development constants (e.g.
+  the Azurite/Azure Storage Emulator default key) are excluded by name since
+  they're identical on every machine and not secrets. This list is small and
+  only grows for equally unambiguous cases.
 
 Use layered controls: least-privilege credentials, a secrets manager,
 `.gitignore`, repository secret scanning, short-lived tokens, and revocation.

ctxguard/detectors.py

@@ -142,6 +142,11 @@ def shannon_entropy(value: str) -> float:
     "unset",
     "disabled",
     "string",
+    "pass",
+    "pwd",
+    "1234",
+    "12345",
+    "123456",
 }
 
 _PLACEHOLDER_SUBSTRINGS = (
@@ -163,13 +168,27 @@ def shannon_entropy(value: str) -> float:
     "****",
 )
 
-_PLACEHOLDER_WRAPPED = re.compile(r"^(<.*>|\$\{.*\}|\{\{.*\}\}|%.*%|__.*__|\[.*\])$")
+_PLACEHOLDER_WRAPPED = re.compile(r"^(<.*>|\$\{.*\}|\{.*\}|%.*%|__.*__|\[.*\]|\$\w+)$")
+
+# Well-known, publicly documented development keys that are constant across
+# every install and are not secrets. Checked from is_placeholder() so every
+# detector (not just the one whose regex happens to capture them) rejects
+# them consistently, regardless of which pattern matches the surrounding text.
+_KNOWN_BENIGN_VALUES = {
+    # Azurite / Azure Storage Emulator default account key (Microsoft docs)
+    (
+        "Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/"
+        "K1SZFPTOtr/KBHBeksoGMGw=="
+    ).lower(),
+}
 
 
 def is_placeholder(value: str) -> bool:
     v = value.strip().strip("\"'").lower()
     if not v or v in _PLACEHOLDER_EXACT:
         return True
+    if v in _KNOWN_BENIGN_VALUES:
+        return True
     if _PLACEHOLDER_WRAPPED.match(v):
         return True
     if any(s in v for s in _PLACEHOLDER_SUBSTRINGS):
@@ -216,6 +235,31 @@ def _plausible_env_value(value: str, m: "re.Match") -> bool:
     return shannon_entropy(v) >= 3.0
 
 
+def _plausible_db_password(value: str, m: "re.Match") -> bool:
+    # any real inline password in a connection URL is worth flagging, even a
+    # weak one: the point is that no credential (strong or not) belongs
+    # inline in a URL that might enter an AI's context. only obvious docs
+    # placeholders (user:password@, user:pass@, ${VAR}) get a pass.
+    if is_placeholder(value):
+        return False
+    return shannon_entropy(value) >= 2.0
+
+
+def _plausible_azure_key(value: str, m: "re.Match") -> bool:
+    if is_placeholder(value):
+        return False
+    return _plausible_token(value, m)
+
+
+def _plausible_gcp_service_account(value: str, m: "re.Match") -> bool:
+    # the bare service-account type marker alone also appears in docs and
+    # example snippets; require a private key nearby, which every real GCP
+    # service-account credential file has right next to it.
+    text = m.string
+    window = text[max(0, m.start() - 2000) : m.start() + 4000]
+    return "private_key" in window
+
+
 def _high_entropy_value(value: str, m: "re.Match") -> bool:
     v = value.strip()
     if len(v) < 16 or is_placeholder(v):
@@ -283,6 +327,68 @@ class _Spec:
         1,
         _plausible_token,
     ),
+    _Spec(
+        "gcp_api_key",
+        re.compile(r"\b(AIza[0-9A-Za-z_\-]{35})(?![0-9A-Za-z_\-])"),
+        "high",
+        1,
+        _plausible_token,
+    ),
+    _Spec(
+        "gcp_service_account",
+        re.compile(r"[\"']type[\"']\s*:\s*[\"']service_account[\"']"),
+        "high",
+        0,
+        _plausible_gcp_service_account,
+    ),
+    _Spec(
+        "azure_storage_account_key",
+        re.compile(r"(?i)\b(?:Account|SharedAccess)Key=([A-Za-z0-9+/]{40,}={0,2})"),
+        "high",
+        1,
+        _plausible_azure_key,
+    ),
+    _Spec(
+        "twilio_api_key",
+        re.compile(r"\b(SK[0-9a-fA-F]{32})(?![0-9a-fA-F])"),
+        "high",
+        1,
+        _plausible_token,
+    ),
+    _Spec(
+        "sendgrid_api_key",
+        re.compile(r"\b(SG\.[A-Za-z0-9_\-]{22}\.[A-Za-z0-9_\-]{43})(?![A-Za-z0-9_\-])"),
+        "high",
+        1,
+        _plausible_token,
+    ),
+    _Spec(
+        "anthropic_api_key",
+        re.compile(r"\b(sk-ant-[A-Za-z0-9_\-]{32,})\b"),
+        "high",
+        1,
+        _plausible_token,
+    ),
+    _Spec(
+        "openai_api_key",
+        re.compile(
+            r"\b(sk-(?:proj|svcacct|admin)-[A-Za-z0-9_\-]{32,}"
+            r"|sk-[A-Za-z0-9]{48}(?![A-Za-z0-9]))"
+        ),
+        "high",
+        1,
+        _plausible_token,
+    ),
+    _Spec(
+        "database_url_password",
+        re.compile(
+            r"(?i)\b(?:postgres(?:ql)?|mysql2?|mariadb|mongodb(?:\+srv)?|rediss?"
+            r"|amqps?|mssql)(?:\+[a-z0-9_]+)?://[^\s:@/]*:([^\s:@/]{4,})@"
+        ),
+        "high",
+        1,
+        _plausible_db_password,
+    ),
     _Spec(
         "private_key_block",
         re.compile(r"-----BEGIN [A-Z ]*PRIVATE KEY(?: BLOCK)?-----"),

tests/conftest.py

@@ -36,6 +36,20 @@
 API_TOKEN_VAL = "8fk2mZpQ7wR4" + "xV1bN6cY3sD5"
 STRIPE_KEY_VAL = "whsec_F8kL2mP9" + "qR4sT7vX1yZ3bC6d"
 
+GCP_API_VAL = "AIzaSyQ9w8E7r6T5y4U3i2" + "O1p0Q9w8E7r6T5y0k"
+AZURE_ACCOUNT_VAL = (
+    "aB1cD2eF3gH4iJ5kL6mN7oP8qR9sT0uVwX1yZ2aB3cD4eF5g"
+    + "H6iJ7kL8mN9oP0qR1sT2uV3wX4yZ5aB6cD7eF8g=="
+)
+TWILIO_VAL = "SK9f8e7d6c5b4a3928" + "1706f5e4d3c2b1a0"
+SENDGRID_VAL = (
+    "SG.aB1cD2eF3gH4iJ5kL6mN7o" + ".pQ8rS9tU0vW1xY2zA3bC4dE5fG6hI7jK8lM9nO0pQ1r"
+)
+OPENAI_VAL = "sk-aB1cD2eF3gH4iJ5kL6mN7oP8" + "qR9sT0uV1wX2yZ3aB4cD5eF6"
+ANTHROPIC_VAL = "sk-ant-api03-qW3eR5tY7uI9oP1a" + "S2dF4gH6jK8lZ0xC5vB7nM9q"
+PG_URL_PW = "v8Kq2Lw9" + "Xt4z"
+MONGO_URL_PW = "Zp4tK9qX" + "2mR7w"
+
 RAW_SECRETS = [
     AWS_ID,
     AWS_SECRET,
@@ -49,11 +63,21 @@
     DB_PASSWORD_VAL,
     API_TOKEN_VAL,
     STRIPE_KEY_VAL,
+    GCP_API_VAL,
+    AZURE_ACCOUNT_VAL,
+    TWILIO_VAL,
+    SENDGRID_VAL,
+    OPENAI_VAL,
+    ANTHROPIC_VAL,
+    PG_URL_PW,
+    MONGO_URL_PW,
 ]
 
 # Expected totals when scanning tests/fixtures/secrets:
 #   aws.txt 2, github.txt 2, slack.txt 1, stripe.txt 2, keys.txt 1, jwt.txt 1,
 #   dotenv/.env 4 (1 filename + 3 env), settings.py 1,
-#   dummy.pem 1, credentials.json 1, id_rsa 1 (filename-only)
-EXPECTED_SECRET_FINDINGS = 17
-EXPECTED_FLAGGED_FILES = 11
+#   dummy.pem 1, credentials.json 1, id_rsa 1 (filename-only),
+#   gcp_sa.json 2 (type marker + private_key_id), cloud.txt 2 (gcp + azure),
+#   saas.txt 4 (twilio, sendgrid, openai, anthropic), dburls.txt 2
+EXPECTED_SECRET_FINDINGS = 27
+EXPECTED_FLAGGED_FILES = 15

tests/fixtures/clean/placeholders.env

@@ -9,3 +9,8 @@ AWS_ACCESS_KEY_ID=AKIAIOSFODNN7EXAMPLE
 AWS_SECRET_ACCESS_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
 STRIPE_KEY=sk_live_XXXXXXXXXXXXXXXXXXXXXXXX
 GITHUB_TOKEN=ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+GOOGLE_API_KEY=AIzaXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+TWILIO_API_KEY=SK00000000000000000000000000000000
+SENDGRID_API_KEY=SG.XXXXXXXXXXXXXXXXXXXXXX.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+OPENAI_API_KEY=sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+DATABASE_URL=postgres://user:password@localhost:5432/dev

tests/fixtures/secrets/cloud.txt

@@ -0,0 +1,3 @@
+cloud credentials (fixture, fake but format-valid)
+google maps key for staging: AIzaSyQ9w8E7r6T5y4U3i2O1p0Q9w8E7r6T5y0k
+AZURE_STORAGE_CONNECTION_STRING=DefaultEndpointsProtocol=https;AccountName=fixtureacct;AccountKey=aB1cD2eF3gH4iJ5kL6mN7oP8qR9sT0uVwX1yZ2aB3cD4eF5gH6iJ7kL8mN9oP0qR1sT2uV3wX4yZ5aB6cD7eF8g==;EndpointSuffix=core.windows.net

tests/fixtures/secrets/dburls.txt

@@ -0,0 +1,3 @@
+connection strings (fixture, fake credentials)
+DATABASE_URL=postgres://svc_app:v8Kq2Lw9Xt4z@db.internal:5432/appdb
+MONGO_URI=mongodb+srv://appuser:Zp4tK9qX2mR7w@cluster0.fixture.mongodb.net/prod

tests/fixtures/secrets/gcp_sa.json

@@ -0,0 +1,6 @@
+{
+  "type": "service_account",
+  "project_id": "fixture-project",
+  "private_key_id": "0f1e2d3c4b5a69788796a5b4c3d2e1f001234567",
+  "client_email": "svc@fixture-project.iam.gserviceaccount.com"
+}

tests/fixtures/secrets/saas.txt

@@ -0,0 +1,5 @@
+saas api keys (fixture, fake but format-valid)
+twilio api key sid SK9f8e7d6c5b4a39281706f5e4d3c2b1a0
+sendgrid mailer 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
+openai for the bot sk-aB1cD2eF3gH4iJ5kL6mN7oP8qR9sT0uV1wX2yZ3aB4cD5eF6
+anthropic for eval sk-ant-api03-qW3eR5tY7uI9oP1aS2dF4gH6jK8lZ0xC5vB7nM9q