[CORE] Add support for HTTP signature

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

@@ -29,8 +29,10 @@ 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 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 +52,7 @@ 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 +100,7 @@ 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) &&
@@ -117,7 +121,7 @@ public boolean equals(Object o) {
     @Override
     public int hashCode() {
 
-        return Objects.hash(name, type, scheme, hasMore, isBasic, isOAuth, isApiKey, isBasicBasic, isBasicBearer,
+        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 +137,7 @@ 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

@@ -3605,6 +3605,7 @@ 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) {
@@ -3626,6 +3627,13 @@ 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
+                    cs.isHttpSignature = true;
+                } else {
+                    throw new RuntimeException("Unsupported security scheme: " + securityScheme.getScheme());
                 }
             } 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

@@ -851,6 +851,9 @@ private Map<String, Object> buildSupportFileBundle(List<Object> allOperations, L
             if (hasBearerMethods(authMethods)) {
                 bundle.put("hasBearerMethods", true);
             }
+            if (hasHttpSignatureMethods(authMethods)) {
+                bundle.put("hasHttpSignatureMethods", true);
+            }
         }
 
         List<CodegenServer> servers = config.fromServers(openAPI.getServers());
@@ -1332,6 +1335,19 @@ private boolean hasBearerMethods(List<CodegenSecurity> authMethods) {
         return false;
     }
 
+    // hasHttpSignatureMethods returns true if the specified OAS model has
+    // HTTP signature methods.
+    // The HTTP signature scheme is defined in https://datatracker.ietf.org/doc/draft-cavage-http-signatures/
+    private boolean hasHttpSignatureMethods(List<CodegenSecurity> authMethods) {
+        for (CodegenSecurity cs : authMethods) {
+            if (Boolean.TRUE.equals(cs.isHttpSignature)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     private List<CodegenSecurity> getOAuthMethods(List<CodegenSecurity> authMethods) {
         List<CodegenSecurity> oauthMethods = new ArrayList<>();