SECURE BIOS PASSWORD METHOD IN SERVER COMPUTER TECHNICAL FIELD [0001] The present application relates to user privilege control operations. In particular, the present application relates to methods and systems for securing Basic Input/Output System (BIOS) passwords in a server computer under user privilege control operations, and the server computer thereof. BACKGROUND [0002] In a server computer, the traditional BIOS User Privilege Control operation runs on a system processor, which uses BIOS to perform user authentications. BIOS User Privilege Control comprises User Privilege and User Authentication. User privilege can be read from Non-volatile random- access memory (NVRAM) or written to NVRAM by BIOS. User Authentication depends on saved User Privilege. [0003] In traditional methods, BIOS reads the valid passwords from an NVRAM and the user inputs the passwords from a keyboard. The passwords may be a single string of a password or a list of passwords. The BIOS compares the inputted passwords with the valid passwords. When the user changes the passwords, the BIOS saves the new passwords and sets the user privilege on the BIOS NVRAM. [0004] Such traditional methods handle the user privilege in an unsecured way due to the lack of anti-spy mechanism or encryption over the network. Any spy software may crack the BIOS passwords and then get power on or administration privileges, such that the hacker may obtain the control privilege of a server computer. In a server group, which uses one global set of passwords for all server computers, if the hacker steals the passwords from a server computer in the server group, he/she can then obtain the control privilege of all of the server computers in the group and steal any data in the whole group. BRIEF DESCRIPTION OF THE DRAWINGS [0005] Various features and advantages of the disclosed embodiments will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the disclosed embodiments. [0006] Figures 1 A and 1B illustrate a block diagram of the firmware components for user privilege authentication in a server computer. [0007] Figures 2A to 2C illustrate a flow chart of user privilege

authentication. [0008] Figure 3 illustrates a flow chart of user privilege authentication handled by a Baseboard Management Controller (BMC). [0009] Figure 4 illustrates a flow chart of three types of user privilege operation. [0010] Figure 5 illustrates a flow chart for the BIOS keyboard driver under user privilege operation mode. DETAILED DESCRIPTION [0011] As described above, the traditional BIOS User Privilege Control operation applies an unsecured method to handle the user privilege for the password authentication, such that a hacker may easily obtain the control privilege of server computers. The present invention aims to solve the aforesaid issue and provides a different structure over the traditional methods in order to avoid that the BIOS passwords and the control privilege of the server computers being hacked. [0012] The present application proposes methods and systems for securing BIOS passwords in a server computer under user privilege control operations. According to the present invention, the BIOS, system processor and system memory cannot access the actual passwords, so the spy software has no chance to discover the BIOS passwords. According to the present invention, the hacker cannot steal the passwords with any cracking methods, such as applying unauthorized applications or unauthorized option ROM (Read-Only Memory), to read the passwords from the BIOS NVRAM storage. [0013] The proposed invention handles the BIOS User Privilege Control operation by a BMC firmware running in a baseboard management controller (BMC) instead of a BIOS firmware running in a system processor of a server computer. From the hardware’s aspect, the proposed invention comprises a server computer system with a BMC. From the firmware’s aspect, the proposed invention comprises BIOS, BMC firmware and option ROM, which supports the Human Interface Infrastructure (HII) Configuration. The passwords are stored by the BMC, so the BIOS does not need to keep, save or compare them. [0014] Figure 1 illustrates a block diagram (100) of software components of BIOS, BMC firmware (150) and option ROM under user privilege operation mode (password mode). The BIOS loads an HII configuration driver (120) embedded in the BIOS or the option ROM. The HII configuration driver (120) provides an interface between the BIOS and the input devices controlled by a user, and communicates activities initiated by the user. The HII configuration driver (120) initiates an HII setup browser (110), which provides the user with a visual browser including system setup options, and enables a keyboard driver (130) for the user to input instructions in order to check whether the user requests a BIOS user privilege control operation. When the system runs in a normal mode instead of a password mode, the BIOS firmware runs on a system processor (170). However, if the user enters instructions to request a BIOS user privilege control operation, the system will then enter the password mode for user privilege authentication. The BIOS first loads a password mode driver (140) and requests the BMC firmware (150) to enter a password authentication mode for user privilege authentication. The BMC firmware (150) runs on a BMC (180) instead of the system processor (170). The BMC (180) is a specialized microcontroller embedded on a motherboard of a computer, generally a server, which supports the Intelligent Platform Management Interface (IPMI) architecture. The BMC (180) manages the interface between system management software and platform hardware. In the password mode, the keyboard driver (130) redirects keyboard events and scan codes to the BMC firmware (150), such that the BIOS and the system processor (170) do not acquire the actual scan codes and cannot access the actual passwords. The BMC firmware (150) may further comprise a keyboard controller firmware, which processes the keyboard events inputted locally or remotely from an integrated remote console (160). [0015] Under the aforesaid structure, when the user requests the password check operation locally, authentication operation will be handled by the BMC firmware (150) instead of the BIOS firmware running in a system processor of the server computer. When the user requests the password check operation and inputs the passwords remotely from the integrated remote console (160), the inputted passwords sent from the remote console (160) will be encrypted over a network. [0016] Figure 2 illustrates a detailed flow chart (200) for the BIOS requesting the BMC firmware to enter a password authentication mode for user privilege authentication. According to the present invention, a user opens the password input box in an HII setup browser (201). The BIOS gets the user’s instructions, chooses the UI operation and notifies the BMC to enter a password authentication mode (202). The BMC enters the password authentication mode (203) and notifies the BIOS keyboard driver to also enter a password authentication mode (204). The BIOS keyboard driver enters the password authentication mode and redirects keyboard events to the BMC instead of the BIOS (205). The BMC receives and processes the keyboard events and the scan codes of the inputted strings (206). After the user completes the input of the passwords, the BMC exits the password input mode (207). The BMC checks the passwords inputted by the user, compares the inputted passwords with valid passwords and sets the user privilege (208). The BMC then notifies the BIOS of the authentication result and notifies the BIOS keyboard driver to exit the password authentication mode (208). The BIOS keyboard driver exits the password authentication mode (209) and resumes the normal mode (210). The BMC exits the password authentication mode and runs in the normal mode (211 ). The BIOS processes the following UI operation in response to the user (212) and may inquire into the user’s privilege with the BMC if required (213). [0017] Figure 3 illustrates a flow chart (300) of user privilege

authentication handled by a BMC. The method for user privilege

authentication can be processed locally by a BMC or remotely from an integrated remote console. The integrated remote console module provided by the BMC can be operated over a network via the integrated remote console. If a user enters instructions for set up user privilege in the BIOS of a server computer, the BIOS requests a BMC to enter a password

authentication mode (310). The BMC receives all of the keyboard events and passes fake scan codes to the BIOS, such that the BIOS cannot access the actual input scan codes (320). When the user completes the input of the passwords, the BMC encrypts the passwords and compares the inputted passwords with valid passwords stored in the BMC (330). The BMC decides an authentication result after the aforesaid comparison and saves the authentication result (340). Finally, the BMC exits the password authentication mode and notifies the BIOS of the authentication result (350). [0018] Figure 4 illustrates three types of the authentication results under a BIOS user privilege control operation. When the BIOS requests the BMC for user privilege authentication, the BIOS needs to indicate the type of the user privilege to be processed by a unique number, usually a GUID used by the UEFI BIOS. The specified user privilege mechanism provides the option ROM with the ability to process the user privilege authentication. The user privilege can be categorized as one of the followings (for example and not limited to): BIOS power on user privilege; BIOS administrator user privilege; BMC access user privilege; and specified option ROM user privilege. Different privileges provide different authorities for the control of the computer. The BIOS power on user privilege enables an authority for setting a specific time by a user, such that the computer can be automatically powered on at the aforesaid specific time. The BIOS administrator user privilege enables an authority for a user to change the system setup options in the BIOS. The BMC access user privilege enables an authority for a user to access the setting stored in the BMC. The specified option ROM user privilege enables an authority for a user to change the setup options stored in the option ROM. The authentication results (401) under a BIOS user privilege control operation may be“no password”,“password denied”, or“password granted”. If the user privilege is “no password” (402), the BIOS and BMC will process to set up the passwords (405). If the user privilege is“password denied” (403), the BIOS and BMC will process to verify the passwords (406). If the user privilege is“password granted” (404), the BIOS and BMC will process to change or clear the passwords (407). [0019] Figure 5 illustrates a flow chart (500) for the process of the BIOS keyboard driver under user privilege operation mode. According to the present invention, when the BMC enters the password authentication mode, the BMC notifies a BIOS keyboard driver to enter the password authentication mode (510). The BIOS keyboard driver enters the password authentication mode (520) and redirects keyboard events to the BMC instead of the BIOS, such that the BIOS does not receive the key strings of the keyboard events (530). Upon the BMC exiting the password authentication mode, the BMC notifies the BIOS keyboard driver to exit the password authentication mode (540). The BIOS keyboard driver then resumes the normal mode (550). [0020] According to the illustrated operations for BIOS user privilege authentication, any server computers and systems including the disclosed functionality of the BIOS and BMC may also secure the BIOS passwords and are also claimed by the present application. According to the present invention, BIOS, system processor and system memory cannot access the actual passwords, so the spy software has no chance to discover the BIOS passwords. According to the present invention, the hacker cannot steal the passwords with any codecrack methods, such as applying unauthorized applications or unauthorized option ROM, to read the passwords from the BIOS NVRAM storage. Accordingly, the present invention secures the user privilege for server computers and systems. [0021] The aforesaid detailed descriptions illustrate the preferred embodiments of the present application. However, the scope of the claimed invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.