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crypto: fix undefined behavior in shamir unbitslice (#1219)

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Andrew Kozlik 2020-08-24 14:25:43 +02:00 committed by GitHub
parent db020c7a47
commit 5429acdb7f
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 2 additions and 2 deletions
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4
crypto/shamir.c
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@ -48,7 +48,7 @@ static void bitslice(uint32_t r[8], const uint8_t *x, size_t len) {
for (arr_idx = 0; arr_idx < len; arr_idx++) { for (arr_idx = 0; arr_idx < len; arr_idx++) {
cur = (uint32_t)x[arr_idx]; cur = (uint32_t)x[arr_idx];
for (bit_idx = 0; bit_idx < 8; bit_idx++) { for (bit_idx = 0; bit_idx < 8; bit_idx++) {
r[bit_idx] |= ((cur & (1 << bit_idx)) >> bit_idx) << arr_idx; r[bit_idx] |= ((cur >> bit_idx) & 1) << arr_idx;
} }
} }
} }
@ -61,7 +61,7 @@ static void unbitslice(uint8_t *r, const uint32_t x[8], size_t len) {
for (bit_idx = 0; bit_idx < 8; bit_idx++) { for (bit_idx = 0; bit_idx < 8; bit_idx++) {
cur = (uint32_t)x[bit_idx]; cur = (uint32_t)x[bit_idx];
for (arr_idx = 0; arr_idx < len; arr_idx++) { for (arr_idx = 0; arr_idx < len; arr_idx++) {
r[arr_idx] |= ((cur & (1 << arr_idx)) >> arr_idx) << bit_idx; r[arr_idx] |= ((cur >> arr_idx) & 1) << bit_idx;
} }
} }
} }