diff options
| -rw-r--r-- | hal.h | 56 | ||||
| -rw-r--r-- | modexp.c | 104 | ||||
| -rw-r--r-- | rsa.c | 20 | ||||
| -rw-r--r-- | tests/test-rsa.c | 4 |
4 files changed, 92 insertions, 92 deletions
@@ -390,39 +390,33 @@ * MATH segment. */ -/* Modexp core */ -#define MODEXP_ADDR_BASE (SEGMENT_OFFSET_MATH + (0x00 * CORE_SIZE)) -#define MODEXP_ADDR_NAME0 (MODEXP_ADDR_BASE + ADDR_NAME0) -#define MODEXP_ADDR_NAME1 (MODEXP_ADDR_BASE + ADDR_NAME1) -#define MODEXP_ADDR_VERSION (MODEXP_ADDR_BASE + ADDR_VERSION) -#define MODEXP_ADDR_CTRL (MODEXP_ADDR_BASE + ADDR_CTRL) -#define MODEXP_CTRL_INIT_BIT (1) -#define MODEXP_CTRL_NEXT_BIT (2) -#define MODEXP_ADDR_STATUS (MODEXP_ADDR_BASE + ADDR_STATUS) +#define MATH_CORE_SIZE (0x400) -#define MODEXP_ADDR_DELAY (MODEXP_ADDR_BASE + 0x13) -#define MODEXP_STATUS_READY (1) - -#define MODEXP_MODULUS_LENGTH (MODEXP_ADDR_BASE + 0x20) -#define MODEXP_EXPONENT_LENGTH (MODEXP_ADDR_BASE + 0x21) -#define MODEXP_LENGTH (MODEXP_ADDR_BASE + 0x22) - -#define MODEXP_MODULUS_PTR_RST (MODEXP_ADDR_BASE + 0x30) -#define MODEXP_MODULUS_DATA (MODEXP_ADDR_BASE + 0x31) - -#define MODEXP_EXPONENT_PTR_RST (MODEXP_ADDR_BASE + 0x40) -#define MODEXP_EXPONENT_DATA (MODEXP_ADDR_BASE + 0x41) - -#define MODEXP_MESSAGE_PTR_RST (MODEXP_ADDR_BASE + 0x50) -#define MODEXP_MESSAGE_DATA (MODEXP_ADDR_BASE + 0x51) - -#define MODEXP_RESULT_PTR_RST (MODEXP_ADDR_BASE + 0x60) -#define MODEXP_RESULT_DATA (MODEXP_ADDR_BASE + 0x61) - -#define MODEXP_NAME0 "mode" -#define MODEXP_NAME1 "xp " -#define MODEXP_VERSION "0.51" +/* + * ModExpS6 core. MODEXPS6_OPERAND_BITS is size in bits of largest + * supported modulus. + */ +#define MODEXPS6_ADDR_BASE (SEGMENT_OFFSET_MATH + (0x00 * MATH_CORE_SIZE)) +#define MODEXPS6_OPERAND_BITS (4096) +#define MODEXPS6_OPERAND_WORDS (MODEXPS6_OPERAND_BITS/32) +#define MODEXPS6_ADDR_REGISTERS (MODEXPS6_ADDR_BASE + 0*MODEXPS6_OPERAND_WORDS) +#define MODEXPS6_ADDR_OPERANDS (MODEXPS6_ADDR_BASE + 4*MODEXPS6_OPERAND_WORDS) +#define MODEXPS6_ADDR_NAME0 (MODEXPS6_ADDR_REGISTERS + ADDR_NAME0) +#define MODEXPS6_ADDR_NAME1 (MODEXPS6_ADDR_REGISTERS + ADDR_NAME1) +#define MODEXPS6_ADDR_VERSION (MODEXPS6_ADDR_REGISTERS + ADDR_VERSION) +#define MODEXPS6_ADDR_CTRL (MODEXPS6_ADDR_REGISTERS + ADDR_CTRL) +#define MODEXPS6_ADDR_STATUS (MODEXPS6_ADDR_REGISTERS + ADDR_STATUS) +#define MODEXPS6_ADDR_MODE (MODEXPS6_ADDR_REGISTERS + 0x10) +#define MODEXPS6_ADDR_MODULUS_WIDTH (MODEXPS6_ADDR_REGISTERS + 0x11) +#define MODEXPS6_ADDR_EXPONENT_WIDTH (MODEXPS6_ADDR_REGISTERS + 0x12) +#define MODEXPS6_ADDR_MODULUS (MODEXPS6_ADDR_OPERANDS + 0*MODEXPS6_OPERAND_WORDS) +#define MODEXPS6_ADDR_MESSAGE (MODEXPS6_ADDR_OPERANDS + 1*MODEXPS6_OPERAND_WORDS) +#define MODEXPS6_ADDR_EXPONENT (MODEXPS6_ADDR_OPERANDS + 2*MODEXPS6_OPERAND_WORDS) +#define MODEXPS6_ADDR_RESULT (MODEXPS6_ADDR_OPERANDS + 3*MODEXPS6_OPERAND_WORDS) +#define MODEXPS6_NAME0 "mode" +#define MODEXPS6_NAME1 "xps6" +#define MODEXPS6_VERSION "0.10" /* * C API error codes. Defined in this form so we can keep the tokens @@ -91,60 +91,41 @@ static hal_error_t set_register(const off_t addr, } /* - * Get value of a block memory. + * Get value of a data buffer. We reverse the order of 32-bit words + * in the buffer during the transfer to match what the modexps6 core + * expects. */ -static hal_error_t get_blockmem(const off_t reset_addr, - const off_t data_addr, - uint8_t *value, - const size_t length, - const size_t io_len) +static hal_error_t get_buffer(const off_t data_addr, + uint8_t *value, + const size_t length) { - uint8_t discard[4]; size_t i; assert(value != NULL && length % 4 == 0); - assert(io_len >= length && io_len % 4 == 0); - - check(set_register(reset_addr, 1)); - - for (i = 0; i < io_len - length; i += 4) { - check(hal_io_read(data_addr, discard, 4)); - if (discard[0] != 0 || discard[1] != 0 || discard[2] != 0 || discard[3] != 0) - return HAL_ERROR_IO_UNEXPECTED; - } - for (i = 0; i < length; i += 4) - check(hal_io_read(data_addr, &value[i], 4)); + check(hal_io_read(data_addr + i/4, &value[length - 4 - i], 4)); return HAL_OK; } /* - * Set value of a block memory. + * Set value of a data buffer. We reverse the order of 32-bit words + * in the buffer during the transfer to match what the modexps6 core + * expects. */ -static hal_error_t set_blockmem(const off_t reset_addr, - const off_t data_addr, - const uint8_t * const value, - const size_t length, - const size_t io_len) +static hal_error_t set_buffer(const off_t data_addr, + const uint8_t * const value, + const size_t length) { - const uint8_t zero[4] = { 0, 0, 0, 0 }; size_t i; assert(value != NULL && length % 4 == 0); - assert(io_len >= length && io_len % 4 == 0); - - check(set_register(reset_addr, 1)); - - for (i = 0; i < io_len - length; i += 4) - check(hal_io_write(data_addr, zero, 4)); - for (i = 0; i < length; i += 4) - check(hal_io_write(data_addr, &value[i], 4)); + check(hal_io_write(data_addr + i/4, &value[length - 4 - i], 4)); return HAL_OK; } @@ -175,35 +156,52 @@ hal_error_t hal_modexp(const uint8_t * const msg, const size_t msg_len, /* Messa return HAL_ERROR_BAD_ARGUMENTS; /* - * This insanity is a work-around for a current bug in the ModExp - * core: we have to zero-pad everything out to the size of the - * modulus plus 32-bits. Some kind of overflow issue. All of this - * "io_len" nonsense can go away once that's fixed. + * We probably ought to take the mode (fast vs constant-time) as an + * argument, but for the moment we just guess that really short + * exponent means we're using the public key and can use fast mode, + * all other cases are something to do with the private key and + * therefore must use constant-time mode. + * + * Unclear whether it's worth trying to figure out exactly how long + * the operands are: assuming a multiple of eight is safe, but makes + * a bit more work for the core; checking to see how many bits are + * really set leaves the core sitting idle while the main CPU does + * these checks. No way to know which is faster without testing; + * take simple approach for the moment. */ - const size_t io_len = mod_len + 4; - assert((io_len & 3) == 0); + /* Select mode (1 = fast, 0 = safe) */ + check(set_register(MODEXPS6_ADDR_MODE, (exp_len <= 4))); - check(set_blockmem(MODEXP_MODULUS_PTR_RST, MODEXP_MODULUS_DATA, mod, mod_len, io_len)); - check(set_blockmem(MODEXP_MESSAGE_PTR_RST, MODEXP_MESSAGE_DATA, msg, msg_len, io_len)); - check(set_register(MODEXP_MODULUS_LENGTH, /* mod_len */ io_len / 4)); + /* Set modulus size in bits */ + check(set_register(MODEXPS6_ADDR_MODULUS_WIDTH, mod_len * 8)); - check(set_blockmem(MODEXP_EXPONENT_PTR_RST, MODEXP_EXPONENT_DATA, exp, exp_len, exp_len)); - check(set_register(MODEXP_EXPONENT_LENGTH, exp_len / 4)); + /* Write new modulus */ + check(set_buffer(MODEXPS6_ADDR_MODULUS, mod, mod_len)); - check(hal_io_wait_ready(MODEXP_ADDR_STATUS)); + /* Pre-calcuate speed-up coefficient */ + check(hal_io_init(MODEXPS6_ADDR_CTRL)); - check(set_register(MODEXP_ADDR_CTRL, 1)); + /* Wait for calculation to complete */ + check(hal_io_wait_ready(MODEXPS6_ADDR_STATUS)); - /* - * ModExp core is not very fast (yet), so wait a long time for a - * response, but not forever. - */ + /* Write new message */ + check(set_buffer(MODEXPS6_ADDR_MESSAGE, msg, msg_len)); + + /* Set new exponent length in bits */ + check(set_register(MODEXPS6_ADDR_EXPONENT_WIDTH, exp_len * 8)); + + /* Set new exponent */ + check(set_buffer(MODEXPS6_ADDR_EXPONENT, exp, exp_len)); + + /* Start calculation */ + check(hal_io_next(MODEXPS6_ADDR_CTRL)); - int timeout = 0x7FFFFFFF; - check(hal_io_wait(MODEXP_ADDR_STATUS, STATUS_READY, &timeout)); + /* Wait for result */ + check(hal_io_wait_valid(MODEXPS6_ADDR_STATUS)); - check(get_blockmem(MODEXP_RESULT_PTR_RST, MODEXP_RESULT_DATA, result, mod_len, io_len)); + /* Extract result */ + check(get_buffer(MODEXPS6_ADDR_RESULT, result, mod_len)); return HAL_OK; } @@ -55,7 +55,7 @@ */ #ifndef HAL_RSA_USE_MODEXP -#define HAL_RSA_USE_MODEXP 0 +#define HAL_RSA_USE_MODEXP 1 #endif /* @@ -170,13 +170,21 @@ static hal_error_t modexp(fp_int *msg, fp_int *exp, fp_int *mod, fp_int *res) assert(msg != NULL && exp != NULL && mod != NULL && res != NULL); - const size_t msg_len = fp_unsigned_bin_size(msg); - const size_t exp_len = fp_unsigned_bin_size(exp); - const size_t mod_len = fp_unsigned_bin_size(mod); + fp_int reduced_msg; - const size_t len = (MAX(MAX(msg_len, exp_len), mod_len) + 3) & ~3; + if (fp_cmp_mag(msg, mod) != FP_LT) { + fp_init(&reduced_msg); + fp_mod(msg, mod, &reduced_msg); + msg = &reduced_msg; + } + + const size_t exp_len = (fp_unsigned_bin_size(exp) + 3) & ~3; + const size_t mod_len = (fp_unsigned_bin_size(mod) + 3) & ~3; - uint8_t msgbuf[len], expbuf[len], modbuf[len], resbuf[len]; + uint8_t msgbuf[mod_len]; + uint8_t expbuf[exp_len]; + uint8_t modbuf[mod_len]; + uint8_t resbuf[mod_len]; if ((err = unpack_fp(msg, msgbuf, sizeof(msgbuf))) != HAL_OK || (err = unpack_fp(exp, expbuf, sizeof(expbuf))) != HAL_OK || diff --git a/tests/test-rsa.c b/tests/test-rsa.c index 0fd2002..f6bf55c 100644 --- a/tests/test-rsa.c +++ b/tests/test-rsa.c @@ -287,8 +287,8 @@ int main(int argc, char *argv[]) * Initialize EIM and report what core we're running. */ - if ((err = hal_io_read(MODEXP_ADDR_NAME0, name, sizeof(name))) != HAL_OK || - (err = hal_io_read(MODEXP_ADDR_VERSION, version, sizeof(version))) != HAL_OK) { + if ((err = hal_io_read(MODEXPS6_ADDR_NAME0, name, sizeof(name))) != HAL_OK || + (err = hal_io_read(MODEXPS6_ADDR_VERSION, version, sizeof(version))) != HAL_OK) { printf("Initialization failed: %s\n", hal_error_string(err)); return 1; } |