Http Authorization Header

Detects HTTP Authorization header patterns containing Bearer tokens, Basic credentials, and other authentication schemes. This pattern is based on a Microsoft Purview built-in sensitive information type. Users already running Purview may prefer to enable the built-in SIT directly, or use this version as a starting point for customisation.

Type

regex

Engine

universal

Confidence

high

Confidence justification

High confidence: Authorization header with Bearer or Basic scheme prefix followed by token value is a well-defined HTTP authentication pattern. Added context gating and exclusion rules improve precision and reduce incidental matches.

Detection quality

Verified

Jurisdictions

global

Regulations

Criminal Code Act 1995 (Cth)

Frameworks

CIS Controls, ISO 27001, NIST CSF, PCI-DSS, SOC 2

Data categories

credentials, security

Scope

specific

Risk rating

10

Platform compatibility

Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Compatible

Pattern

\bAuthorization:\s*(Bearer|Basic)\s+[A-Za-z0-9+/=._~-]{10,}

Corroborative evidence keywords

Authorization, Bearer, Basic, token, header, HTTP, authentication, API, api key, api_key, apikey, access key, access token, auth token, authorization, bearer, conn str, connection string, connectionstring, cookie (+44 more)

Proximity: 300 characters

Should match

• Authorization: Bearer eyJhbGciOiJIUzI1NiJ9.AAAA0000.BBBB1111 — Bearer token with JWT format
• Authorization: Basic QUFBQUJCQUJCQ0NDQ0RERURFRUV= — Basic auth with Base64 credentials
• Authorization: Bearer AAAA0000BBBB1111CCCC2222DDDD3333 — Bearer token with opaque token format

Should not match

• Authorization: — Empty authorization header
• The Authorization header is required — Documentation reference without actual header
• template example placeholder record identifier — Template/sample context should be excluded even when anchor words are present

Known false positives

• API documentation and HTTP specification references showing Authorization header examples. Mitigation: Check for common placeholder tokens and documentation context.
• Log files containing Authorization headers with redacted or expired tokens. Mitigation: Check for redaction markers like [REDACTED] or expired JWT timestamps.

References

• Http authorization header entity definition - Microsoft Learn