feat: add passwordless passkey-only account support (#254)

Enable users to register without a password and go fully passwordless
by removing their password after adding passkeys. Adds new DTOs
(PasswordlessRegistrationDto, SetPasswordDto, AuthMethodsResponse),
new UserService methods (hasPassword, removeUserPassword,
setInitialPassword, registerPasswordlessAccount), and new API endpoints
(GET /user/auth-methods, POST /user/registration/passwordless,
POST /user/setPassword, DELETE /user/webauthn/password).

Author: devondragon

src/main/java/com/digitalsanctuary/spring/user/api/UserAPI.java

@@ -4,6 +4,7 @@
 import java.util.Locale;
 import java.util.Optional;
 import jakarta.validation.Valid;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.context.MessageSource;
@@ -12,14 +13,18 @@
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 import com.digitalsanctuary.spring.user.audit.AuditEvent;
+import com.digitalsanctuary.spring.user.dto.AuthMethodsResponse;
 import com.digitalsanctuary.spring.user.dto.PasswordDto;
 import com.digitalsanctuary.spring.user.dto.PasswordResetRequestDto;
+import com.digitalsanctuary.spring.user.dto.PasswordlessRegistrationDto;
 import com.digitalsanctuary.spring.user.dto.SavePasswordDto;
+import com.digitalsanctuary.spring.user.dto.SetPasswordDto;
 import com.digitalsanctuary.spring.user.dto.UserDto;
 import com.digitalsanctuary.spring.user.dto.UserProfileUpdateDto;
 import com.digitalsanctuary.spring.user.event.OnRegistrationCompleteEvent;
@@ -30,6 +35,7 @@
 import com.digitalsanctuary.spring.user.service.PasswordPolicyService;
 import com.digitalsanctuary.spring.user.service.UserEmailService;
 import com.digitalsanctuary.spring.user.service.UserService;
+import com.digitalsanctuary.spring.user.service.WebAuthnCredentialManagementService;
 import com.digitalsanctuary.spring.user.util.JSONResponse;
 import com.digitalsanctuary.spring.user.util.UserUtils;
 import jakarta.servlet.ServletException;
@@ -61,6 +67,9 @@ public class UserAPI {
 	private final ApplicationEventPublisher eventPublisher;
 	private final PasswordPolicyService passwordPolicyService;
 
+	@Autowired(required = false)
+	private WebAuthnCredentialManagementService webAuthnCredentialManagementService;
+
 	@Value("${user.security.registrationPendingURI}")
 	private String registrationPendingURI;
 
@@ -337,6 +346,112 @@ public ResponseEntity<JSONResponse> deleteAccount(@AuthenticationPrincipal DSUse
 		return buildSuccessResponse("Account Deleted", null);
 	}
 
+	/**
+	 * Returns the authentication methods configured for the current user.
+	 *
+	 * @param userDetails the authenticated user details
+	 * @return a ResponseEntity containing the auth methods response
+	 */
+	@GetMapping("/auth-methods")
+	public ResponseEntity<JSONResponse> getAuthMethods(@AuthenticationPrincipal DSUserDetails userDetails) {
+		validateAuthenticatedUser(userDetails);
+		User user = userService.findUserByEmail(userDetails.getUser().getEmail());
+		if (user == null) {
+			return buildErrorResponse("User not found", 1, HttpStatus.BAD_REQUEST);
+		}
+
+		boolean hasPasskeys = false;
+		int passkeysCount = 0;
+		if (webAuthnCredentialManagementService != null) {
+			long count = webAuthnCredentialManagementService.getCredentialCount(user);
+			hasPasskeys = count > 0;
+			passkeysCount = (int) count;
+		}
+
+		AuthMethodsResponse authMethods = AuthMethodsResponse.builder()
+				.hasPassword(userService.hasPassword(user))
+				.hasPasskeys(hasPasskeys)
+				.passkeysCount(passkeysCount)
+				.provider(user.getProvider())
+				.build();
+
+		return ResponseEntity.ok(JSONResponse.builder().success(true).data(authMethods).build());
+	}
+
+	/**
+	 * Registers a new passwordless user account (passkey-only).
+	 *
+	 * @param dto the passwordless registration DTO
+	 * @param request the HTTP servlet request
+	 * @return a ResponseEntity containing a JSONResponse with the registration result
+	 */
+	@PostMapping("/registration/passwordless")
+	public ResponseEntity<JSONResponse> registerPasswordlessAccount(@Valid @RequestBody PasswordlessRegistrationDto dto,
+			HttpServletRequest request) {
+		try {
+			User registeredUser = userService.registerPasswordlessAccount(dto);
+			publishRegistrationEvent(registeredUser, request);
+			logAuditEvent("PasswordlessRegistration", "Success", "Passwordless registration successful", registeredUser, request);
+
+			String nextURL = registeredUser.isEnabled() ? handleAutoLogin(registeredUser) : registrationPendingURI;
+
+			return buildSuccessResponse("Registration Successful!", nextURL);
+		} catch (UserAlreadyExistException ex) {
+			log.warn("User already exists with email: {}", dto.getEmail());
+			logAuditEvent("PasswordlessRegistration", "Failure", "User Already Exists", null, request);
+			return buildErrorResponse("An account already exists for the email address", 2, HttpStatus.CONFLICT);
+		} catch (Exception ex) {
+			log.error("Unexpected error during passwordless registration.", ex);
+			logAuditEvent("PasswordlessRegistration", "Failure", ex.getMessage(), null, request);
+			return buildErrorResponse("System Error!", 5, HttpStatus.INTERNAL_SERVER_ERROR);
+		}
+	}
+
+	/**
+	 * Sets an initial password for a passwordless account.
+	 *
+	 * @param userDetails the authenticated user details
+	 * @param setPasswordDto the set password DTO
+	 * @param request the HTTP servlet request
+	 * @param locale the locale
+	 * @return a ResponseEntity containing a JSONResponse with the result
+	 */
+	@PostMapping("/setPassword")
+	public ResponseEntity<JSONResponse> setPassword(@AuthenticationPrincipal DSUserDetails userDetails,
+			@Valid @RequestBody SetPasswordDto setPasswordDto, HttpServletRequest request, Locale locale) {
+		validateAuthenticatedUser(userDetails);
+		User user = userService.findUserByEmail(userDetails.getUser().getEmail());
+		if (user == null) {
+			return buildErrorResponse("User not found", 1, HttpStatus.BAD_REQUEST);
+		}
+
+		try {
+			if (userService.hasPassword(user)) {
+				return buildErrorResponse("User already has a password. Use the change password feature instead.", 1, HttpStatus.BAD_REQUEST);
+			}
+
+			if (!setPasswordDto.getNewPassword().equals(setPasswordDto.getConfirmPassword())) {
+				return buildErrorResponse(messages.getMessage("message.password.mismatch", null, "Passwords do not match", locale), 2,
+						HttpStatus.BAD_REQUEST);
+			}
+
+			List<String> errors = passwordPolicyService.validate(user, setPasswordDto.getNewPassword(), user.getEmail(), locale);
+			if (!errors.isEmpty()) {
+				log.warn("Password validation failed for user {}: {}", user.getEmail(), errors);
+				return buildErrorResponse(String.join(" ", errors), 3, HttpStatus.BAD_REQUEST);
+			}
+
+			userService.setInitialPassword(user, setPasswordDto.getNewPassword());
+			logAuditEvent("SetPassword", "Success", "Initial password set for passwordless account", user, request);
+
+			return buildSuccessResponse(messages.getMessage("message.set-password.success", null, "Password set successfully", locale), null);
+		} catch (Exception ex) {
+			log.error("Unexpected error during set password.", ex);
+			logAuditEvent("SetPassword", "Failure", ex.getMessage(), user, request);
+			return buildErrorResponse("System Error!", 5, HttpStatus.INTERNAL_SERVER_ERROR);
+		}
+	}
+
 	// Helper Methods
 	/**
 	 * Validates the user data transfer object.

src/main/java/com/digitalsanctuary/spring/user/api/WebAuthnManagementAPI.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.security.core.userdetails.UserDetails;
@@ -12,16 +13,21 @@
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
+import com.digitalsanctuary.spring.user.audit.AuditEvent;
 import com.digitalsanctuary.spring.user.dto.WebAuthnCredentialInfo;
+import com.digitalsanctuary.spring.user.exceptions.WebAuthnException;
 import com.digitalsanctuary.spring.user.exceptions.WebAuthnUserNotFoundException;
 import com.digitalsanctuary.spring.user.persistence.model.User;
 import com.digitalsanctuary.spring.user.service.UserService;
 import com.digitalsanctuary.spring.user.service.WebAuthnCredentialManagementService;
 import com.digitalsanctuary.spring.user.util.GenericResponse;
+import com.digitalsanctuary.spring.user.util.UserUtils;
+import jakarta.servlet.http.HttpServletRequest;
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.Size;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.validation.annotation.Validated;
 
 /**
@@ -42,6 +48,7 @@
  * <li>DELETE /user/webauthn/credentials/{id} - Delete a passkey</li>
  * </ul>
  */
+@Slf4j
 @RestController
 @RequestMapping("/user/webauthn")
 @ConditionalOnProperty(name = "user.webauthn.enabled", havingValue = "true", matchIfMissing = false)
@@ -51,6 +58,7 @@ public class WebAuthnManagementAPI {
 
 	private final WebAuthnCredentialManagementService credentialManagementService;
 	private final UserService userService;
+	private final ApplicationEventPublisher eventPublisher;
 
 	/**
 	 * Get user's registered passkeys.
@@ -127,6 +135,44 @@ public ResponseEntity<GenericResponse> deleteCredential(@PathVariable @NotBlank
 		return ResponseEntity.ok(new GenericResponse("Passkey deleted successfully"));
 	}
 
+	/**
+	 * Remove the user's password, making the account passwordless (passkey-only).
+	 *
+	 * <p>
+	 * Requires the user to have at least one passkey registered. This ensures
+	 * the user can still authenticate after the password is removed.
+	 * </p>
+	 *
+	 * @param userDetails the authenticated user details
+	 * @param request the HTTP servlet request
+	 * @return ResponseEntity with success message or error
+	 */
+	@DeleteMapping("/password")
+	public ResponseEntity<GenericResponse> removePassword(@AuthenticationPrincipal UserDetails userDetails,
+			HttpServletRequest request) {
+		User user = findAuthenticatedUser(userDetails);
+
+		if (!userService.hasPassword(user)) {
+			throw new WebAuthnException("User does not have a password to remove");
+		}
+
+		if (!credentialManagementService.hasCredentials(user)) {
+			throw new WebAuthnException("Cannot remove password. Please register a passkey first.");
+		}
+
+		userService.removeUserPassword(user);
+
+		AuditEvent event = AuditEvent.builder().source(this).user(user).sessionId(request.getSession().getId())
+				.ipAddress(UserUtils.getClientIP(request))
+				.userAgent(request.getHeader("User-Agent")).action("PasswordRemoval").actionStatus("Success")
+				.message("Password removed for passwordless account").build();
+		eventPublisher.publishEvent(event);
+
+		log.info("User {} removed their password", user.getEmail());
+
+		return ResponseEntity.ok(new GenericResponse("Password removed successfully"));
+	}
+
 	private User findAuthenticatedUser(UserDetails userDetails) throws WebAuthnUserNotFoundException {
 		User user = userService.findUserByEmail(userDetails.getUsername());
 		if (user == null) {

src/main/java/com/digitalsanctuary/spring/user/dto/AuthMethodsResponse.java

@@ -0,0 +1,31 @@
+package com.digitalsanctuary.spring.user.dto;
+
+import com.digitalsanctuary.spring.user.persistence.model.User;
+import lombok.Builder;
+import lombok.Data;
+
+/**
+ * Response DTO for the auth-methods endpoint.
+ * <p>
+ * Provides information about which authentication methods are configured
+ * for the current user, enabling the UI to show/hide relevant options.
+ * </p>
+ *
+ * @author Devon Hillard
+ */
+@Data
+@Builder
+public class AuthMethodsResponse {
+
+	/** Whether the user has a password set. */
+	private boolean hasPassword;
+
+	/** Whether the user has any passkeys registered. */
+	private boolean hasPasskeys;
+
+	/** The number of passkeys registered. */
+	private int passkeysCount;
+
+	/** The user's authentication provider. */
+	private User.Provider provider;
+}

src/main/java/com/digitalsanctuary/spring/user/dto/PasswordlessRegistrationDto.java

@@ -0,0 +1,38 @@
+package com.digitalsanctuary.spring.user.dto;
+
+import jakarta.validation.constraints.Email;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+import lombok.Data;
+
+/**
+ * Data Transfer Object for passwordless user registration.
+ * <p>
+ * Used for registering users who will authenticate exclusively with passkeys,
+ * without setting an initial password. Contains only the user's name and email.
+ * </p>
+ *
+ * @author Devon Hillard
+ */
+@Data
+public class PasswordlessRegistrationDto {
+
+	/** The first name. */
+	@NotBlank(message = "First name is required")
+	@Size(max = 50, message = "First name must not exceed 50 characters")
+	private String firstName;
+
+	/** The last name. */
+	@NotBlank(message = "Last name is required")
+	@Size(max = 50, message = "Last name must not exceed 50 characters")
+	private String lastName;
+
+	/** The email. */
+	@NotBlank(message = "Email is required")
+	@Email(message = "Please provide a valid email address")
+	@Size(max = 100, message = "Email must not exceed 100 characters")
+	private String email;
+
+	/** The role. */
+	private Integer role;
+}

src/main/java/com/digitalsanctuary/spring/user/dto/SetPasswordDto.java

@@ -0,0 +1,30 @@
+package com.digitalsanctuary.spring.user.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+import lombok.Data;
+import lombok.ToString;
+
+/**
+ * Data Transfer Object for setting an initial password on a passwordless account.
+ * <p>
+ * Used when a user who registered without a password (passkey-only) wants to add
+ * a password to their account. Contains the new password and confirmation.
+ * </p>
+ *
+ * @author Devon Hillard
+ */
+@Data
+public class SetPasswordDto {
+
+	/** The new password to set. */
+	@ToString.Exclude
+	@NotBlank(message = "Password is required")
+	@Size(min = 8, max = 128, message = "Password must be between 8 and 128 characters")
+	private String newPassword;
+
+	/** Confirmation of the new password (must match newPassword). */
+	@ToString.Exclude
+	@NotBlank(message = "Password confirmation is required")
+	private String confirmPassword;
+}

src/main/java/com/digitalsanctuary/spring/user/persistence/repository/PasswordHistoryRepository.java

@@ -33,4 +33,12 @@ public interface PasswordHistoryRepository extends JpaRepository<PasswordHistory
      * @return list of password history entries
      */
     List<PasswordHistoryEntry> findByUserOrderByEntryDateDesc(User user);
+
+    /**
+     * Delete all password history entries for a user.
+     * Used when removing a user's password for passwordless accounts.
+     *
+     * @param user the user whose history should be deleted
+     */
+    void deleteByUser(User user);
 }