Adding possibility to supply the jwt private key as a string.

docs/src/main/asciidoc/security-oidc-code-flow-authentication.adoc

@@ -169,6 +169,15 @@ quarkus.oidc.credentials.jwt.secret-provider.key=mysecret-key
 quarkus.oidc.credentials.jwt.secret-provider.name=oidc-credentials-provider
 ----
 
+Example of `private_key_jwt` with the PEM key inlined in application.properties, and where the signature algorithm is `RS256`:
+
+[source,properties]
+----
+quarkus.oidc.auth-server-url=http://localhost:8180/realms/quarkus/
+quarkus.oidc.client-id=quarkus-app
+quarkus.oidc.credentials.jwt.key=Base64-encoded private key representation
+----
+
 Example of `private_key_jwt` with the PEM key file, and where the signature algorithm is RS256:
 
 [source,properties]

docs/src/main/asciidoc/security-openid-connect-client-reference.adoc

@@ -757,6 +757,15 @@ quarkus.oidc-client.credentials.jwt.secret-provider.key=mysecret-key
 quarkus.oidc-client.credentials.jwt.secret-provider.name=oidc-credentials-provider
 ----
 
+`private_key_jwt` with the PEM key inlined in application.properties, and where the signature algorithm is `RS256`:
+
+[source,properties]
+----
+quarkus.oidc-client.auth-server-url=http://localhost:8180/auth/realms/quarkus/
+quarkus.oidc-client.client-id=quarkus-app
+quarkus.oidc-client.credentials.jwt.key=Base64-encoded private key representation
+----
+
 `private_key_jwt` with the PEM key file, signature algorithm is `RS256`:
 
 [source,properties]

extensions/oidc-client/deployment/src/test/java/io/quarkus/oidc/client/OidcClientCredentialsJwtPrivateKeyTestCase.java

@@ -34,4 +34,14 @@ public void testClientCredentialsToken() {
                 .statusCode(200)
                 .body(equalTo("service-account-quarkus-app"));
     }
+
+    @Test
+    public void testPrivateKeyToken() {
+        String token = RestAssured.when().get("/client/token-key").body().asString();
+        RestAssured.given().auth().oauth2(token)
+                .when().get("/protected")
+                .then()
+                .statusCode(200)
+                .body(equalTo("service-account-quarkus-app"));
+    }
 }

extensions/oidc-client/deployment/src/test/java/io/quarkus/oidc/client/OidcClientResource.java

@@ -14,6 +14,16 @@ public class OidcClientResource {
     @Inject
     OidcClient client;
 
+    @Inject
+    @NamedOidcClient("key")
+    OidcClient keyClient;
+
+    @GET
+    @Path("token-key")
+    public Uni<String> tokenFromPrivateKeyUni() {
+        return keyClient.getTokens().flatMap(tokens -> Uni.createFrom().item(tokens.getAccessToken()));
+    }
+
     @GET
     @Path("token")
     public Uni<String> tokenUni() {
@@ -23,13 +33,13 @@ public Uni<String> tokenUni() {
     @GET
     @Path("tokens")
     public Uni<String> grantTokensUni() {
-        return client.getTokens().flatMap(tokens -> createTokensString(tokens));
+        return client.getTokens().flatMap(this::createTokensString);
     }
 
     @GET
     @Path("refresh-tokens")
     public Uni<String> refreshGrantTokens(@QueryParam("refreshToken") String refreshToken) {
-        return client.refreshTokens(refreshToken).flatMap(tokens -> createTokensString(tokens));
+        return client.refreshTokens(refreshToken).flatMap(this::createTokensString);
     }
 
     private Uni<String> createTokensString(Tokens tokens) {

extensions/oidc-client/deployment/src/test/java/io/quarkus/oidc/client/OidcClientsResource.java

@@ -27,7 +27,7 @@ public Uni<String> tokenUni(@PathParam("id") String oidcClientId) {
     @GET
     @Path("tokens/{id}")
     public Uni<String> grantTokensUni(@PathParam("id") String oidcClientId) {
-        return getClient(oidcClientId).getTokens().flatMap(tokens -> createTokensString(tokens));
+        return getClient(oidcClientId).getTokens().flatMap(this::createTokensString);
     }
 
     @GET

extensions/oidc-client/deployment/src/test/resources/application-oidc-client-credentials-jwt-private-key.properties

@@ -4,3 +4,7 @@ quarkus.oidc.client-id=quarkus-app
 quarkus.oidc-client.auth-server-url=${quarkus.oidc.auth-server-url}
 quarkus.oidc-client.client-id=${quarkus.oidc.client-id}
 quarkus.oidc-client.credentials.jwt.key-file=/privateKey.pem
+
+quarkus.oidc-client.key.auth-server-url=${quarkus.oidc.auth-server-url}
+quarkus.oidc-client.key.client-id=${quarkus.oidc.client-id}
+quarkus.oidc-client.key.credentials.jwt.key=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

extensions/oidc-common/runtime/src/main/java/io/quarkus/oidc/common/OidcRequestFilter.java

@@ -15,7 +15,7 @@ public interface OidcRequestFilter {
      * Filter OIDC requests
      *
      * @param request HTTP request that can have its headers customized
-     * @param body request body, will be null for HTTP GET methods, may be null for other HTTP methods
+     * @param requestBody request body, will be null for HTTP GET methods, may be null for other HTTP methods
      * @param contextProperties context properties that can be available in context of some requests
      */
     void filter(HttpRequest<Buffer> request, Buffer requestBody, OidcRequestContextProperties contextProperties);

extensions/oidc-common/runtime/src/main/java/io/quarkus/oidc/common/runtime/OidcCommonConfig.java

@@ -274,6 +274,14 @@ public static enum Source {
             @ConfigItem
             public Provider secretProvider = new Provider();
 
+            /**
+             * String representation of a private key. If provided, indicates that JWT is signed using a private key in PEM or
+             * JWK format.
+             * You can use the {@link #signatureAlgorithm} property to override the default key algorithm, `RS256`.
+             */
+            @ConfigItem
+            public Optional<String> key = Optional.empty();
+
             /**
              * If provided, indicates that JWT is signed using a private key in PEM or JWK format.
              * You can use the {@link #signatureAlgorithm} property to override the default key algorithm, `RS256`.
@@ -399,6 +407,14 @@ public void setAudience(String audience) {
                 this.audience = Optional.of(audience);
             }
 
+            public Optional<String> getKey() {
+                return key;
+            }
+
+            public void setKey(String key) {
+                this.key = Optional.of(key);
+            }
+
             public Optional<String> getKeyFile() {
                 return keyFile;
             }

extensions/oidc-common/runtime/src/main/java/io/quarkus/oidc/common/runtime/OidcCommonUtils.java

@@ -280,8 +280,8 @@ public static boolean isClientSecretBasicAuthRequired(Credentials creds) {
     }
 
     public static boolean isClientJwtAuthRequired(Credentials creds) {
-        return creds.jwt.secret.isPresent() || creds.jwt.secretProvider.key.isPresent() || creds.jwt.keyFile.isPresent()
-                || creds.jwt.keyStoreFile.isPresent();
+        return creds.jwt.secret.isPresent() || creds.jwt.secretProvider.key.isPresent() || creds.jwt.key.isPresent()
+                || creds.jwt.keyFile.isPresent() || creds.jwt.keyStoreFile.isPresent();
     }
 
     public static boolean isClientSecretPostAuthRequired(Credentials creds) {
@@ -329,7 +329,10 @@ public static Key clientJwtKey(Credentials creds) {
         } else {
             Key key = null;
             try {
-                if (creds.jwt.getKeyFile().isPresent()) {
+                if (creds.jwt.getKey().isPresent()) {
+                    key = KeyUtils.tryAsPemSigningPrivateKey(creds.jwt.getKey().get(),
+                            getSignatureAlgorithm(creds, SignatureAlgorithm.RS256));
+                } else if (creds.jwt.getKeyFile().isPresent()) {
                     key = KeyUtils.readSigningKey(creds.jwt.getKeyFile().get(), creds.jwt.keyId.orElse(null),
                             getSignatureAlgorithm(creds, SignatureAlgorithm.RS256));
                 } else if (creds.jwt.keyStoreFile.isPresent()) {