diff options
Diffstat (limited to 'rsa.c')
| -rw-r--r-- | rsa.c | 18 |
1 files changed, 9 insertions, 9 deletions
@@ -175,18 +175,18 @@ static hal_error_t modexp_fp(fp_int *msg, fp_int *exp, fp_int *mod, fp_int *res) assert(msg != NULL && exp != NULL && mod != NULL && res != NULL); - uint8_t msgbuf[(fp_unsigned_bin_size(msg) + 3) & ~3]; - uint8_t expbuf[(fp_unsigned_bin_size(exp) + 3) & ~3]; - uint8_t modbuf[(fp_unsigned_bin_size(mod) + 3) & ~3]; + 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); - if ((err = unpack_fp(msg, msgbuf, sizeof(msgbuf))) != HAL_OK || - (err = unpack_fp(exp, expbuf, sizeof(expbuf))) != HAL_OK || - (err = unpack_fp(mod, modbuf, sizeof(modbuf))) != HAL_OK) - goto fail; + const size_t len = (MAX(MAX(msg_len, exp_len), mod_len) + 3) & ~3; - uint8_t resbuf[FP_MAX_SIZE/8]; + uint8_t msgbuf[len], expbuf[len], modbuf[len], resbuf[len]; - if ((err = hal_modexp(msgbuf, sizeof(msgbuf), + if ((err = unpack_fp(msg, msgbuf, sizeof(msgbuf))) != HAL_OK || + (err = unpack_fp(exp, expbuf, sizeof(expbuf))) != HAL_OK || + (err = unpack_fp(mod, modbuf, sizeof(modbuf))) != HAL_OK || + (err = hal_modexp(msgbuf, sizeof(msgbuf), expbuf, sizeof(expbuf), modbuf, sizeof(modbuf), resbuf, sizeof(resbuf))) != HAL_OK) |