RequestValidator (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- net.i2p.i2ptunnel.RequestValidator

```
public class RequestValidator
extends Object
```
Validates HTTP requests for security and policy compliance.
This class encapsulates all request validation logic for I2PTunnelHTTPServer, including hostname validation (detecting attempts to access localhost/loopback), inproxy rejection, referer validation, and user-agent filtering.
Validations are performed based on configuration options set in the tunnel's client options properties.

Nested Class Summary
Nested Classes
Modifier and Type Class and Description
static class RequestValidator.ValidationResult
Encapsulates the result of hostname validation.

Nested Classes
Modifier and Type	Class and Description
`static class`	`RequestValidator.ValidationResult` Encapsulates the result of hostname validation.

Constructor Summary
Constructors
Constructor and Description
RequestValidator(Log log, String peerB32, Properties opts, BlocklistManager blocklistManager)
Creates a new RequestValidator.

Constructors
Constructor and Description
`RequestValidator(Log log, String peerB32, Properties opts, BlocklistManager blocklistManager)` Creates a new RequestValidator.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`String`	`buildInproxyRejectLog(Map<String,List<String>> headers)` Builds a detailed log message for inproxy rejection.
`String`	`getRefererForLog(Map<String,List<String>> headers)` Extracts the referer URL for logging purposes.
`String`	`getUserAgentForCheck(Map<String,List<String>> headers)` Extracts the user agent for blacklisting checks.
`boolean`	`shouldRejectInproxy(Map<String,List<String>> headers)` Checks if the request should be rejected based on inproxy headers.
`boolean`	`shouldRejectReferer(Map<String,List<String>> headers)` Checks if the request should be rejected based on referer header.
`boolean`	`shouldRejectUserAgent(Map<String,List<String>> headers)` Checks if the request should be rejected based on user-agent header.
`RequestValidator.ValidationResult`	`validateHostname(String hostname, StringBuilder command)` Validates a hostname from an HTTP request.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - RequestValidator
```
public RequestValidator(Log log,
                        String peerB32,
                        Properties opts,
                        BlocklistManager blocklistManager)
```
    Creates a new RequestValidator.
    Parameters:
    log - the Log instance for logging validation events
    peerB32 - the Base32-encoded peer destination for logging
    opts - the tunnel client options for validation configuration
    blocklistManager - the BlocklistManager for logging blocked destinations; may be null
- Method Detail
  - buildInproxyRejectLog
```
public String buildInproxyRejectLog(Map<String,List<String>> headers)
```
    Builds a detailed log message for inproxy rejection.
    This method extracts all relevant headers for logging purposes when an inproxy request is rejected.
    Parameters:
    headers - the HTTP request headers
    Returns:
    a formatted string suitable for logging
  - getRefererForLog
```
public String getRefererForLog(Map<String,List<String>> headers)
```
    Extracts the referer URL for logging purposes.
    Strips the "Referer: " prefix from the header value.
    Parameters:
    headers - the HTTP request headers
    Returns:
    the referer URL without the header prefix, or null if not available
  - getUserAgentForCheck
```
public String getUserAgentForCheck(Map<String,List<String>> headers)
```
    Extracts the user agent for blacklisting checks.
    Parameters:
    headers - the HTTP request headers
    Returns:
    the user agent string, or null if not present
  - shouldRejectInproxy
```
public boolean shouldRejectInproxy(Map<String,List<String>> headers)
```
    Checks if the request should be rejected based on inproxy headers.
    When the OPT_REJECT_INPROXY option is enabled, requests containing X-Forwarded-For, X-Forwarded-Server, Forwarded, or X-Forwarded-Host headers are rejected to prevent proxy abuse.
    Parameters:
    headers - the HTTP request headers
    Returns:
    true if the request should be rejected, false otherwise
  - shouldRejectReferer
```
public boolean shouldRejectReferer(Map<String,List<String>> headers)
```
    Checks if the request should be rejected based on referer header.
    When the OPT_REJECT_REFERER option is enabled, requests with absolute URIs (starting with http:// or https://) in the Referer header are rejected to prevent information leakage.
    Parameters:
    headers - the HTTP request headers
    Returns:
    true if the request should be rejected, false otherwise
  - shouldRejectUserAgent
```
public boolean shouldRejectUserAgent(Map<String,List<String>> headers)
```
    Checks if the request should be rejected based on user-agent header.
    When the OPT_REJECT_USER_AGENTS option is enabled, requests with blacklisted user agents are rejected. The blacklist is configured via the OPT_USER_AGENTS option as a comma-separated list.
    A special case is made for user agents starting with "MYOB" which are always allowed. Also, if the blacklist contains "none", requests without a User-Agent header are rejected.
    Parameters:
    headers - the HTTP request headers
    Returns:
    true if the request should be rejected, false otherwise
  - validateHostname
```
public RequestValidator.ValidationResult validateHostname(String hostname,
                                                          StringBuilder command)
```
    Validates a hostname from an HTTP request.
    This method checks for several security issues:
    - Attempts to access localhost or loopback addresses
    - DNS blocking (0.0.0.0 or :: responses)
    - Non-I2P/non-onion hostnames that resolve to private addresses
    Valid hostnames ending in .i2p or .onion are passed through without validation, as these are expected I2P/eepSite or Tor addresses.
    Parameters:
    hostname - the Host header value from the request; may be null
    command - the full request command for blocklist checking
    Returns:
    a ValidationResult containing the validation outcome and any error response

Class RequestValidator

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

RequestValidator

Method Detail

buildInproxyRejectLog

getRefererForLog

getUserAgentForCheck

shouldRejectInproxy

shouldRejectReferer

shouldRejectUserAgent

validateHostname