Difference between revisions of "CW308T-ADUCM3029"

Power Supply

The Atmel SAM4L has an internal 1.8V regulator. This regulator is not used in the board, instead power for the core is supplied by an external LDO on the UFO board. Be sure to enable the 1.8V and 3.3V regulators on the UFO board for the SAM4L board to function.

Hardware AES

The SAM4L has a hardware AES module, with optional countermeasures that can be enabled. These countermeasures are described in the SAM4L datasheet as the following options:

• Type 1: Randomly add one cycle to data processing
• Type 2: Randomly add one cycle to data processing (other version)
• Type 3: Add a random number of clock cycles to data processing, subject to a maximum of 11 clock cycles for key size of 128 bits
• Type 4: Add random spurious power consumption during data processing

Interestingly they can be individually enabled/disabled. This makes the SAM4L a useful training target for power analysis attacks against various hardware countermeasures.

Programming

An external programmer is needed for this target. The SAM4L has an internal bootloader you can use via an external serial port, which is not yet supported directly by the ChipWhisperer-Capture software.

SimpleSerial Program

The SimpleSerial-AES program can be built for this target. This can use either hardware crypto or a software AES. This project is currently built via the Atmel Studio IDE, and the project file is located at hardware/victims/firmware/simpleserial-aes/ide_projects/asf/sam4l-simpleserial-aes with the ChipWhisperer release.

If an Atmel ICE is attached as above, you should be able to build and run the example in 'debug' mode:

An automatically generated makefile can be modified to built in Linux, but currently has not been integrated into the rest of the system. This makefile is checked into the GIT repository.

void aes_init(void)
{
	periclk_aesa_init();
	SCIF->SCIF_GCCTRL[AESA_GCLK_NUM].SCIF_GCCTRL = SCIF_GCCTRL_OSCSEL(GENCLK_SRC_CLK_CPU) |  SCIF_GCCTRL_CEN;

    /* AES Enable */
    AESA->AESA_CTRL = AESA_CTRL_ENABLE | AESA_CTRL_NEWMSG; /* Enable, auto-accept new messages */
	
	//Use with debugger to check PARAMETER register value
	//volatile uint32_t param = AESA->AESA_PARAMETER;
	
    /* AES Mode */
    AESA->AESA_MODE = AESA_MODE_ENCRYPT | (AESA_MODE_CTYPE(0x0F)); /* Encrypt Mode, with all countermeasures */    
	//AESA->AESA_MODE = AESA_MODE_ENCRYPT; /* Encrypt Mode, without countermeasures */   
    
    /* Setup random seed for countermeasures to work */
    AESA->AESA_DRNGSEED = 0xDEADBEEF; //A very random number        
}

Schematic

See GIT Repo for PDF of schematic.

Board Layout

See GIT Repo for gerber files.

Hardware