GF Validate Field Hook for

gf_validate_edit_account.php

<?php

// change the number suffix to the one corresponding to your form and field's id!
add_filter( 'gform_field_validation_1_1', 'wp_doin_validate_password_field', 10, 4 );

/**
 * @hook gform_field_validation_4
 * 
 * This function is assigned to the old password field, and then iterates over all form fields
 * if it hits a field with the pass-confirm class assigned it then compares it's value
 * with the value of the old password field and validates it. If the passwords match
 * it returns valid result!
 */
function wp_doin_validate_password_field( $result, $value, $form, $field ) {

	// iterate over gravity forms fields
	foreach ( $form['fields'] as &$field ) {

		// continue unless confirm password field was found
		if ( strpos( $field['cssClass'], 'repeat-pass' ) === false ) {
			continue;
		}

		// verify password field have the same value
		$confirm_value = rgpost( "input_{$field['id']}" );
		if ( $value !== $confirm_value ) {

			// set up validation variables
			$validation_result['is_valid'] = false;
			$field['failed_validation'] = true;
			$field['validation_message'] = 'The passwords do not match.';

			// return new validation result
			$validation_result['form'] = $form;
			return $validation_result;
		} else {
			continue;
		}
	}

	return $result;
}

// change the number suffix to the one corresponding to your form and field's id!
add_filter( 'gform_field_validation_1_2', 'wp_doin_validate_old_password_field', 10, 4 );

/**
 * This function is assigned to the old password field and checks if the old password
 * provided is the one registered with the current user account
 */
function wp_doin_validate_old_password_field($result, $value, $form, $field) {

	// iterate over gravity forms fields
	foreach ( $form['fields'] as &$field ) {

		// continue unless confirm password field was found
		if ( strpos( $field['cssClass'], 'old-pass' ) === false ) {
			continue;
		}

		$user = wp_get_current_user();

		// verify password field have the same value
		$confirm_value = rgpost( "input_{$field['id']}" );

		if ( !wp_check_password( $value, $user->data->user_pass, $user->ID ) ) {

			// mark the result as invalid
			$result["is_valid"] = false;
			$result["message"] = "Wrong password provided.";
		}
	}

	return $result;
}