Fix reduce.c's overflowing multiplication

This commit is contained in:
Thom Wiggers 2020-03-09 17:57:43 -04:00
parent 9b06aedefe
commit 39fa1ccfc7
No known key found for this signature in database
GPG Key ID: 001BB0A7CE26E363
6 changed files with 6 additions and 6 deletions

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@ -18,7 +18,7 @@ int16_t PQCLEAN_KYBER102490S_CLEAN_montgomery_reduce(int32_t a) {
int32_t t; int32_t t;
int16_t u; int16_t u;
u = (int16_t)(a * QINV); u = (int16_t)(a * (int64_t)QINV);
t = (int32_t)u * KYBER_Q; t = (int32_t)u * KYBER_Q;
t = a - t; t = a - t;
t >>= 16; t >>= 16;

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@ -18,7 +18,7 @@ int16_t PQCLEAN_KYBER1024_CLEAN_montgomery_reduce(int32_t a) {
int32_t t; int32_t t;
int16_t u; int16_t u;
u = (int16_t)(a * QINV); u = (int16_t)(a * (int64_t)QINV);
t = (int32_t)u * KYBER_Q; t = (int32_t)u * KYBER_Q;
t = a - t; t = a - t;
t >>= 16; t >>= 16;

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@ -18,7 +18,7 @@ int16_t PQCLEAN_KYBER51290S_CLEAN_montgomery_reduce(int32_t a) {
int32_t t; int32_t t;
int16_t u; int16_t u;
u = (int16_t)(a * QINV); u = (int16_t)(a * (int64_t)QINV);
t = (int32_t)u * KYBER_Q; t = (int32_t)u * KYBER_Q;
t = a - t; t = a - t;
t >>= 16; t >>= 16;

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@ -18,7 +18,7 @@ int16_t PQCLEAN_KYBER512_CLEAN_montgomery_reduce(int32_t a) {
int32_t t; int32_t t;
int16_t u; int16_t u;
u = (int16_t)(a * QINV); u = (int16_t)(a * (int64_t)QINV);
t = (int32_t)u * KYBER_Q; t = (int32_t)u * KYBER_Q;
t = a - t; t = a - t;
t >>= 16; t >>= 16;

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@ -18,7 +18,7 @@ int16_t PQCLEAN_KYBER76890S_CLEAN_montgomery_reduce(int32_t a) {
int32_t t; int32_t t;
int16_t u; int16_t u;
u = (int16_t)(a * QINV); u = (int16_t)(a * (int64_t)QINV);
t = (int32_t)u * KYBER_Q; t = (int32_t)u * KYBER_Q;
t = a - t; t = a - t;
t >>= 16; t >>= 16;

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@ -18,7 +18,7 @@ int16_t PQCLEAN_KYBER768_CLEAN_montgomery_reduce(int32_t a) {
int32_t t; int32_t t;
int16_t u; int16_t u;
u = (int16_t)(a * QINV); u = (int16_t)(a * (int64_t)QINV);
t = (int32_t)u * KYBER_Q; t = (int32_t)u * KYBER_Q;
t = a - t; t = a - t;
t >>= 16; t >>= 16;