Merge pull request #3408 from AndrzejKurek/hamming-distance-improvements
Hamming distance improvements
diff --git a/include/tinycrypt/ecc.h b/include/tinycrypt/ecc.h
index 6a85a55..57aa508 100644
--- a/include/tinycrypt/ecc.h
+++ b/include/tinycrypt/ecc.h
@@ -155,7 +155,8 @@
* @param random OUT -- random integer in the range 0 < random < top
* @param top IN -- upper limit
* @param num_words IN -- number of words
- * @return a random integer in the range 0 < random < top
+ * @return UECC_SUCCESS in case of success
+ * @return UECC_FAILURE upon failure
*/
int uECC_generate_random_int(uECC_word_t *random, const uECC_word_t *top,
wordcount_t num_words);
@@ -163,9 +164,9 @@
/* uECC_RNG_Function type
* The RNG function should fill 'size' random bytes into 'dest'. It should
- * return 1 if 'dest' was filled with random data, or 0 if the random data could
- * not be generated. The filled-in values should be either truly random, or from
- * a cryptographically-secure PRNG.
+ * return 'size' if 'dest' was filled with random data of 'size' length, or 0
+ * if the random data could not be generated. The filled-in values should be
+ * either truly random, or from a cryptographically-secure PRNG.
*
* A correctly functioning RNG function must be set (using uECC_set_rng())
* before calling uECC_make_key() or uECC_sign().
@@ -181,8 +182,8 @@
/*
* @brief Set the function that will be used to generate random bytes. The RNG
- * function should return 1 if the random data was generated, or 0 if the random
- * data could not be generated.
+ * function should return 'size' if the random data of length 'size' was
+ * generated, or 0 if the random data could not be generated.
*
* @note On platforms where there is no predefined RNG function, this must be
* called before uECC_make_key() or uECC_sign() are used.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 9851560..4f41ac9 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -56,6 +56,8 @@
#include "mbedtls/oid.h"
#endif
+#define PROPER_HS_FRAGMENT 0x75555555
+
#if defined(MBEDTLS_USE_TINYCRYPT)
static int uecc_rng_wrapper( uint8_t *dest, unsigned int size )
{
@@ -4736,7 +4738,7 @@
mbedtls_platform_memcmp( ssl->in_msg + 6, "\0\0\0", 3 ) != 0 ||
mbedtls_platform_memcmp( ssl->in_msg + 9, ssl->in_msg + 1, 3 ) != 0 )
{
- return( 1 );
+ return( PROPER_HS_FRAGMENT );
}
return( 0 );
}
@@ -4929,7 +4931,7 @@
* messages; the commonality is that both handshake fragments and
* future messages cannot be forwarded immediately to the
* handshake logic layer. */
- if( ssl_hs_is_proper_fragment( ssl ) == 1 )
+ if( ssl_hs_is_proper_fragment( ssl ) == PROPER_HS_FRAGMENT )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) );
return( MBEDTLS_ERR_SSL_EARLY_MESSAGE );
@@ -6053,7 +6055,7 @@
size_t reassembly_buf_sz;
hs_buf->is_fragmented =
- ( ssl_hs_is_proper_fragment( ssl ) == 1 );
+ ( ssl_hs_is_proper_fragment( ssl ) == PROPER_HS_FRAGMENT );
/* We copy the message back into the input buffer
* after reassembly, so check that it's not too large.
diff --git a/tinycrypt/ecc.c b/tinycrypt/ecc.c
index b3e3ed3..ca91e12 100644
--- a/tinycrypt/ecc.c
+++ b/tinycrypt/ecc.c
@@ -1080,7 +1080,7 @@
/* If an RNG function was specified, get a random initial Z value to
* protect against side-channel attacks such as Template SPA */
if (g_rng_function) {
- if (!uECC_generate_random_int(k2[carry], curve_p, num_words)) {
+ if (uECC_generate_random_int(k2[carry], curve_p, num_words) != UECC_SUCCESS) {
r = UECC_FAILURE;
goto clear_and_out;
}
@@ -1165,21 +1165,21 @@
bitcount_t num_bits = uECC_vli_numBits(top);
if (!g_rng_function) {
- return 0;
+ return UECC_FAILURE;
}
for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) {
- if (!g_rng_function((uint8_t *)random, num_words * uECC_WORD_SIZE)) {
- return 0;
+ if (g_rng_function((uint8_t *)random, num_words * uECC_WORD_SIZE) != num_words * uECC_WORD_SIZE) {
+ return UECC_FAILURE;
}
random[num_words - 1] &=
mask >> ((bitcount_t)(num_words * uECC_WORD_SIZE * 8 - num_bits));
if (!uECC_vli_isZero(random) &&
uECC_vli_cmp(top, random) == 1) {
- return 1;
+ return UECC_SUCCESS;
}
}
- return 0;
+ return UECC_FAILURE;
}
diff --git a/tinycrypt/ecc_dh.c b/tinycrypt/ecc_dh.c
index ceabb00..a63c84b 100644
--- a/tinycrypt/ecc_dh.c
+++ b/tinycrypt/ecc_dh.c
@@ -119,7 +119,7 @@
/* Generating _private uniformly at random: */
uECC_RNG_Function rng_function = uECC_get_rng();
if (!rng_function ||
- !rng_function((uint8_t *)_random, 2 * NUM_ECC_WORDS*uECC_WORD_SIZE)) {
+ rng_function((uint8_t *)_random, 2 * NUM_ECC_WORDS*uECC_WORD_SIZE) != 2 * NUM_ECC_WORDS*uECC_WORD_SIZE) {
return UECC_FAILURE;
}
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index 230f689..bb3ed81 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -109,7 +109,7 @@
uECC_vli_clear(tmp);
tmp[0] = 1;
}
- else if (!uECC_generate_random_int(tmp, curve_n, num_n_words)) {
+ else if (uECC_generate_random_int(tmp, curve_n, num_n_words) != UECC_SUCCESS) {
return UECC_FAILURE;
}
@@ -151,7 +151,7 @@
/* Generating _random uniformly at random: */
uECC_RNG_Function rng_function = uECC_get_rng();
if (!rng_function ||
- !rng_function((uint8_t *)_random, 2*NUM_ECC_WORDS*uECC_WORD_SIZE)) {
+ rng_function((uint8_t *)_random, 2*NUM_ECC_WORDS*uECC_WORD_SIZE) != 2*NUM_ECC_WORDS*uECC_WORD_SIZE) {
return UECC_FAILURE;
}