Validate origin header #771
+1,810
−38
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,132 @@ | ||
| /* | ||
| * Copyright 2026-2026 the original author or authors. | ||
| */ | ||
|
|
||
| package io.modelcontextprotocol.server.transport; | ||
|
|
||
| import java.util.ArrayList; | ||
| import java.util.List; | ||
| import java.util.Map; | ||
|
|
||
| import io.modelcontextprotocol.util.Assert; | ||
|
|
||
| /** | ||
| * Default implementation of {@link ServerTransportSecurityValidator} that validates the | ||
| * Origin header against a list of allowed origins. | ||
| * | ||
| * <p> | ||
| * Supports exact matches and wildcard port patterns (e.g., "http://example.com:*"). | ||
| * | ||
| * @author Daniel Garnier-Moiroux | ||
| * @see ServerTransportSecurityValidator | ||
| * @see ServerTransportSecurityException | ||
| */ | ||
| public class DefaultServerTransportSecurityValidator implements ServerTransportSecurityValidator { | ||
|
|
||
| private static final String ORIGIN_HEADER = "Origin"; | ||
|
|
||
| private static final ServerTransportSecurityException INVALID_ORIGIN = new ServerTransportSecurityException(403, | ||
| "Invalid Origin header"); | ||
|
|
||
| private final List<String> allowedOrigins; | ||
|
|
||
| /** | ||
| * Creates a new validator with the specified allowed origins. | ||
| * @param allowedOrigins List of allowed origin patterns. Supports exact matches | ||
| * (e.g., "http://example.com:8080") and wildcard ports (e.g., "http://example.com:*") | ||
| */ | ||
| public DefaultServerTransportSecurityValidator(List<String> allowedOrigins) { | ||
| Assert.notNull(allowedOrigins, "allowedOrigins must not be null"); | ||
| this.allowedOrigins = allowedOrigins; | ||
| } | ||
|
|
||
| @Override | ||
| public void validateHeaders(Map<String, List<String>> headers) throws ServerTransportSecurityException { | ||
| for (Map.Entry<String, List<String>> entry : headers.entrySet()) { | ||
| if (ORIGIN_HEADER.equalsIgnoreCase(entry.getKey())) { | ||
| List<String> values = entry.getValue(); | ||
| if (values != null && !values.isEmpty()) { | ||
| validateOrigin(values.get(0)); | ||
| } | ||
| break; | ||
| } | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * Validates a single origin value against the allowed origins. Subclasses can | ||
| * override this method to customize origin validation logic. | ||
| * @param origin The origin header value, or null if not present | ||
| * @throws ServerTransportSecurityException if the origin is not allowed | ||
| */ | ||
| protected void validateOrigin(String origin) throws ServerTransportSecurityException { | ||
| // Origin absent = no validation needed (same-origin request) | ||
| if (origin == null || origin.isBlank()) { | ||
| return; | ||
| } | ||
|
|
||
| for (String allowed : allowedOrigins) { | ||
| if (allowed.equals(origin)) { | ||
| return; | ||
| } | ||
| else if (allowed.endsWith(":*")) { | ||
| // Wildcard port pattern: "http://example.com:*" | ||
| String baseOrigin = allowed.substring(0, allowed.length() - 2); | ||
| if (origin.equals(baseOrigin) || origin.startsWith(baseOrigin + ":")) { | ||
| return; | ||
| } | ||
| } | ||
|
|
||
| } | ||
|
|
||
| throw INVALID_ORIGIN; | ||
|
Member
There was a problem hiding this comment. Due to the exception being a static, the stack trace is inaccurate with regards to where it is raised. I understand the optimization, however it might make it harder to investigate where the issue happened. Perhaps we can create an instance each time it's raised? |
||
| } | ||
|
|
||
| /** | ||
| * Creates a new builder for constructing a DefaultServerTransportSecurityValidator. | ||
| * @return A new builder instance | ||
| */ | ||
| public static Builder builder() { | ||
| return new Builder(); | ||
| } | ||
|
|
||
| /** | ||
| * Builder for creating instances of {@link DefaultServerTransportSecurityValidator}. | ||
| */ | ||
| public static class Builder { | ||
|
|
||
| private final List<String> allowedOrigins = new ArrayList<>(); | ||
|
|
||
| /** | ||
| * Adds an allowed origin pattern. | ||
| * @param origin The origin to allow (e.g., "http://localhost:8080" or | ||
| * "http://example.com:*") | ||
| * @return this builder instance | ||
| */ | ||
| public Builder allowedOrigin(String origin) { | ||
| this.allowedOrigins.add(origin); | ||
| return this; | ||
| } | ||
|
|
||
| /** | ||
| * Adds multiple allowed origin patterns. | ||
| * @param origins The origins to allow | ||
| * @return this builder instance | ||
| */ | ||
| public Builder allowedOrigins(List<String> origins) { | ||
| Assert.notNull(origins, "origins must not be null"); | ||
| this.allowedOrigins.addAll(origins); | ||
| return this; | ||
| } | ||
|
|
||
| /** | ||
| * Builds the validator instance. | ||
| * @return A new DefaultServerTransportSecurityValidator | ||
| */ | ||
| public DefaultServerTransportSecurityValidator build() { | ||
| return new DefaultServerTransportSecurityValidator(allowedOrigins); | ||
| } | ||
|
|
||
| } | ||
|
|
||
| } | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
There are two ways to create the validator - either via a constructor or via the builder. I'd vouch for a single version. The builder makes sense with no inheritance, but since users are encouraged to customize by inheriting from this class, perhaps we can skip the builder?