[Go] Support HTTP signature

bin/openapi3/go-experimental-petstore.sh

@@ -25,7 +25,11 @@ then
   mvn -B clean package
 fi
 
-SPEC="modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml"
+#SPEC="modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml"
+# petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml is the same as the above file, with
+# the addition of the HTTP signature security scheme. Ideally, this would have been directly added to
+# petstore-with-fake-endpoints-models-for-testing.yaml, but this cannot be done until issue #5025 is resolved.
+SPEC="modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml"
 GENERATOR="go-experimental"
 STUB_DIR="samples/openapi3/client/petstore/go-experimental/go-petstore"
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoClientExperimentalCodegen.java

@@ -16,11 +16,14 @@
 
 package org.openapitools.codegen.languages;
 
+import io.swagger.v3.oas.models.security.SecurityScheme;
 import org.openapitools.codegen.CodegenModel;
 import org.openapitools.codegen.CodegenProperty;
+import org.openapitools.codegen.CodegenSecurity;
 import org.openapitools.codegen.SupportingFile;
 import org.openapitools.codegen.meta.GeneratorMetadata;
 import org.openapitools.codegen.meta.Stability;
+import org.openapitools.codegen.utils.ProcessUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -67,6 +70,15 @@ public String getHelp() {
     public void processOpts() {
         super.processOpts();
         supportingFiles.add(new SupportingFile("utils.mustache", "", "utils.go"));
+
+        // Generate the 'signing.py' module, but only if the 'HTTP signature' security scheme is specified in the OAS.
+        Map<String, SecurityScheme> securitySchemeMap = openAPI != null ?
+           (openAPI.getComponents() != null ? openAPI.getComponents().getSecuritySchemes() : null) : null;
+        List<CodegenSecurity> authMethods = fromSecurity(securitySchemeMap);
+        if (ProcessUtils.hasHttpSignatureMethods(authMethods)) {
+            supportingFiles.add(new SupportingFile("signing.mustache", "", "signing.go"));
+            supportingFiles.add(new SupportingFile("http_signature_test.mustache", "", "http_signature_test.go"));
+        }
     }
 
     @Override

modules/openapi-generator/src/main/resources/go-experimental/README.mustache

@@ -104,7 +104,9 @@ Class | Method | HTTP request | Description
 Note, each API key must be added to a map of `map[string]APIKey` where the key is: {{keyParamName}} and passed in as the auth context for each request.
 
 {{/isApiKey}}
-{{#isBasic}}- **Type**: HTTP basic authentication
+{{#isBasic}}
+{{#isBasicBasic}}
+- **Type**: HTTP basic authentication
 
 Example
 
@@ -116,6 +118,38 @@ auth := context.WithValue(context.Background(), sw.ContextBasicAuth, sw.BasicAut
 r, err := client.Service.Operation(auth, args)
 ```
 
+{{/isBasicBasic}}
+{{#isHttpSignature}}
+- **Type**: HTTP signature authentication
+
+Example
+
+```golang
+	authConfig := sw.HttpSignatureAuth{
+		KeyId:                "my-key-id",
+		PrivateKeyPath:       "rsa.pem",
+		Passphrase:           "my-passphrase",
+		SigningScheme:        sw.HttpSigningSchemeHs2019,
+		SignedHeaders:        []string{
+			sw.HttpSignatureParameterRequestTarget, // The special (request-target) parameter expresses the HTTP request target.
+			sw.HttpSignatureParameterCreated,       // Time when request was signed, formatted as a Unix timestamp integer value.
+			"Host",                                 // The Host request header specifies the domain name of the server, and optionally the TCP port number.
+			"Date",                                 // The date and time at which the message was originated.
+			"Content-Type",                         // The Media type of the body of the request.
+			"Digest",                               // A cryptographic digest of the request body.
+		},
+		SigningAlgorithm:     sw.HttpSigningAlgorithmRsaPSS,
+		SignatureMaxValidity: 5 * time.Minute,
+	}
+	var authCtx context.Context
+	var err error
+	if authCtx, err = authConfig.ContextWithValue(context.Background()); err != nil {
+		// Process error
+	}
+	r, err = client.Service.Operation(auth, args)
+
+```
+{{/isHttpSignature}}
 {{/isBasic}}
 {{#isOAuth}}
 

modules/openapi-generator/src/main/resources/go-experimental/client.mustache

@@ -351,7 +351,18 @@ func (c *APIClient) prepareRequest(
 	for header, value := range c.cfg.DefaultHeader {
 		localVarRequest.Header.Add(header, value)
 	}
-
+{{#hasHttpSignatureMethods}}
+	if ctx != nil {
+		// HTTP Signature Authentication. All request headers must be set (including default headers)
+		// because the headers may be included in the signature.
+		if auth, ok := ctx.Value(ContextHttpSignatureAuth).(HttpSignatureAuth); ok {
+			err = SignRequest(ctx, localVarRequest, auth)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+{{/hasHttpSignatureMethods}}
 	return localVarRequest, nil
 }
 

modules/openapi-generator/src/main/resources/go-experimental/configuration.mustache

@@ -31,6 +31,9 @@ var (
 	// ContextAPIKeys takes a string apikey as authentication for the request
 	ContextAPIKeys = contextKey("apiKeys")
 
+	// ContextHttpSignatureAuth takes HttpSignatureAuth as authentication for the request.
+	ContextHttpSignatureAuth = contextKey("httpsignature")
+
 	// ContextServerIndex uses a server configuration from the index.
 	ContextServerIndex = contextKey("serverIndex")