[CORE] Add support for HTTP signature (OpenAPITools#4993)

* Add support for HTTP signature

* Add http-signature security scheme

* add http_signature_test to security scheme

* Add separate OAS file with support for HTTP signature

* change URL of apache license to use https

* add log warning to indicate the 'http signature' security scheme is still a draft

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

@@ -29,8 +29,11 @@ public class CodegenSecurity {
     public String type;
     public String scheme;
     public Boolean hasMore, isBasic, isOAuth, isApiKey;
-    // is Basic is true for all http authentication type. Those are to differentiate basic and bearer authentication
-    public Boolean isBasicBasic, isBasicBearer;
+    // is Basic is true for all http authentication type.
+    // Those are to differentiate basic and bearer authentication
+    // isHttpSignature is to support HTTP signature authorization scheme.
+    // https://datatracker.ietf.org/doc/draft-cavage-http-signatures/
+    public Boolean isBasicBasic, isBasicBearer, isHttpSignature;
     public String bearerFormat;
     public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
     // ApiKey specific
@@ -50,6 +53,7 @@ public CodegenSecurity filterByScopeNames(List<String> filterScopes) {
         filteredSecurity.hasMore = false;
         filteredSecurity.isBasic = isBasic;
         filteredSecurity.isBasicBasic = isBasicBasic;
+        filteredSecurity.isHttpSignature = isHttpSignature;
         filteredSecurity.isBasicBearer = isBasicBearer;
         filteredSecurity.isApiKey = isApiKey;
         filteredSecurity.isOAuth = isOAuth;
@@ -97,6 +101,7 @@ public boolean equals(Object o) {
                 Objects.equals(isOAuth, that.isOAuth) &&
                 Objects.equals(isApiKey, that.isApiKey) &&
                 Objects.equals(isBasicBasic, that.isBasicBasic) &&
+                Objects.equals(isHttpSignature, that.isHttpSignature) &&
                 Objects.equals(isBasicBearer, that.isBasicBearer) &&
                 Objects.equals(bearerFormat, that.bearerFormat) &&
                 Objects.equals(vendorExtensions, that.vendorExtensions) &&
@@ -117,8 +122,9 @@ public boolean equals(Object o) {
     @Override
     public int hashCode() {
 
-        return Objects.hash(name, type, scheme, hasMore, isBasic, isOAuth, isApiKey, isBasicBasic, isBasicBearer,
-                bearerFormat, vendorExtensions, keyParamName, isKeyInQuery, isKeyInHeader, isKeyInCookie, flow,
+        return Objects.hash(name, type, scheme, hasMore, isBasic, isOAuth, isApiKey,
+                isBasicBasic, isHttpSignature, isBasicBearer, bearerFormat, vendorExtensions,
+                keyParamName, isKeyInQuery, isKeyInHeader, isKeyInCookie, flow,
                 authorizationUrl, tokenUrl, scopes, isCode, isPassword, isApplication, isImplicit);
     }
 
@@ -133,6 +139,7 @@ public String toString() {
         sb.append(", isOAuth=").append(isOAuth);
         sb.append(", isApiKey=").append(isApiKey);
         sb.append(", isBasicBasic=").append(isBasicBasic);
+        sb.append(", isHttpSignature=").append(isHttpSignature);
         sb.append(", isBasicBearer=").append(isBasicBearer);
         sb.append(", bearerFormat='").append(bearerFormat).append('\'');
         sb.append(", vendorExtensions=").append(vendorExtensions);

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

@@ -3617,6 +3617,7 @@ public List<CodegenSecurity> fromSecurity(Map<String, SecurityScheme> securitySc
             cs.name = key;
             cs.type = securityScheme.getType().toString();
             cs.isCode = cs.isPassword = cs.isApplication = cs.isImplicit = false;
+            cs.isHttpSignature = false;
             cs.isBasicBasic = cs.isBasicBearer = false;
             cs.scheme = securityScheme.getScheme();
             if (securityScheme.getExtensions() != null) {
@@ -3638,6 +3639,14 @@ public List<CodegenSecurity> fromSecurity(Map<String, SecurityScheme> securitySc
                 } else if ("bearer".equals(securityScheme.getScheme())) {
                     cs.isBasicBearer = true;
                     cs.bearerFormat = securityScheme.getBearerFormat();
+                } else if ("signature".equals(securityScheme.getScheme())) {
+                    // HTTP signature as defined in https://datatracker.ietf.org/doc/draft-cavage-http-signatures/
+                    // The registry of security schemes is maintained by IANA.
+                    // https://www.iana.org/assignments/http-authschemes/http-authschemes.xhtml
+                    // As of January 2020, the "signature" scheme has not been registered with IANA yet.
+                    // This scheme may have to be changed when it is officially registered with IANA.
+                    cs.isHttpSignature = true;
+                    LOGGER.warn("Security scheme 'HTTP signature' is a draft IETF RFC and subject to change.");
                 }
             } else if (SecurityScheme.Type.OAUTH2.equals(securityScheme.getType())) {
                 cs.isKeyInHeader = cs.isKeyInQuery = cs.isKeyInCookie = cs.isApiKey = cs.isBasic = false;

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

@@ -42,6 +42,7 @@
 import org.openapitools.codegen.templating.MustacheEngineAdapter;
 import org.openapitools.codegen.utils.ImplementationVersion;
 import org.openapitools.codegen.utils.ModelUtils;
+import org.openapitools.codegen.utils.ProcessUtils;
 import org.openapitools.codegen.utils.URLPathUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -851,6 +852,9 @@ private Map<String, Object> buildSupportFileBundle(List<Object> allOperations, L
             if (hasBearerMethods(authMethods)) {
                 bundle.put("hasBearerMethods", true);
             }
+            if (ProcessUtils.hasHttpSignatureMethods(authMethods)) {
+                bundle.put("hasHttpSignatureMethods", true);
+            }
         }
 
         List<CodegenServer> servers = config.fromServers(openAPI.getServers());

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ProcessUtils.java

@@ -94,4 +94,22 @@ public static boolean hasBearerMethods(Map<String, Object> objs) {
         return false;
     }
 
+    /**
+     * Returns true if the specified OAS model has at least one operation with the HTTP signature
+     * security scheme.
+     * The HTTP signature scheme is defined in https://datatracker.ietf.org/doc/draft-cavage-http-signatures/
+     * 
+     * @param authMethods List of auth methods.
+     * @return True if at least one operation has HTTP signature security schema defined
+     */
+    public static boolean hasHttpSignatureMethods(List<CodegenSecurity> authMethods) {
+        if (authMethods != null && !authMethods.isEmpty()) {
+          for (CodegenSecurity cs : authMethods) {
+              if (Boolean.TRUE.equals(cs.isHttpSignature)) {
+                  return true;
+              }
+          }
+        }
+        return false;
+    }
 }