diff options
Diffstat (limited to 'roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/bn/bn_shift.c')
| -rw-r--r-- | roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/bn/bn_shift.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/bn/bn_shift.c b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/bn/bn_shift.c new file mode 100644 index 000000000..210a83f58 --- /dev/null +++ b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/bn/bn_shift.c @@ -0,0 +1,216 @@ +/* + * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +#include <assert.h> +#include "internal/cryptlib.h" +#include "bn_local.h" + +int BN_lshift1(BIGNUM *r, const BIGNUM *a) +{ + register BN_ULONG *ap, *rp, t, c; + int i; + + bn_check_top(r); + bn_check_top(a); + + if (r != a) { + r->neg = a->neg; + if (bn_wexpand(r, a->top + 1) == NULL) + return 0; + r->top = a->top; + } else { + if (bn_wexpand(r, a->top + 1) == NULL) + return 0; + } + ap = a->d; + rp = r->d; + c = 0; + for (i = 0; i < a->top; i++) { + t = *(ap++); + *(rp++) = ((t << 1) | c) & BN_MASK2; + c = t >> (BN_BITS2 - 1); + } + *rp = c; + r->top += c; + bn_check_top(r); + return 1; +} + +int BN_rshift1(BIGNUM *r, const BIGNUM *a) +{ + BN_ULONG *ap, *rp, t, c; + int i; + + bn_check_top(r); + bn_check_top(a); + + if (BN_is_zero(a)) { + BN_zero(r); + return 1; + } + i = a->top; + ap = a->d; + if (a != r) { + if (bn_wexpand(r, i) == NULL) + return 0; + r->neg = a->neg; + } + rp = r->d; + r->top = i; + t = ap[--i]; + rp[i] = t >> 1; + c = t << (BN_BITS2 - 1); + r->top -= (t == 1); + while (i > 0) { + t = ap[--i]; + rp[i] = ((t >> 1) & BN_MASK2) | c; + c = t << (BN_BITS2 - 1); + } + if (!r->top) + r->neg = 0; /* don't allow negative zero */ + bn_check_top(r); + return 1; +} + +int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) +{ + int ret; + + if (n < 0) { + BNerr(BN_F_BN_LSHIFT, BN_R_INVALID_SHIFT); + return 0; + } + + ret = bn_lshift_fixed_top(r, a, n); + + bn_correct_top(r); + bn_check_top(r); + + return ret; +} + +/* + * In respect to shift factor the execution time is invariant of + * |n % BN_BITS2|, but not |n / BN_BITS2|. Or in other words pre-condition + * for constant-time-ness is |n < BN_BITS2| or |n / BN_BITS2| being + * non-secret. + */ +int bn_lshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n) +{ + int i, nw; + unsigned int lb, rb; + BN_ULONG *t, *f; + BN_ULONG l, m, rmask = 0; + + assert(n >= 0); + + bn_check_top(r); + bn_check_top(a); + + nw = n / BN_BITS2; + if (bn_wexpand(r, a->top + nw + 1) == NULL) + return 0; + + if (a->top != 0) { + lb = (unsigned int)n % BN_BITS2; + rb = BN_BITS2 - lb; + rb %= BN_BITS2; /* say no to undefined behaviour */ + rmask = (BN_ULONG)0 - rb; /* rmask = 0 - (rb != 0) */ + rmask |= rmask >> 8; + f = &(a->d[0]); + t = &(r->d[nw]); + l = f[a->top - 1]; + t[a->top] = (l >> rb) & rmask; + for (i = a->top - 1; i > 0; i--) { + m = l << lb; + l = f[i - 1]; + t[i] = (m | ((l >> rb) & rmask)) & BN_MASK2; + } + t[0] = (l << lb) & BN_MASK2; + } else { + /* shouldn't happen, but formally required */ + r->d[nw] = 0; + } + if (nw != 0) + memset(r->d, 0, sizeof(*t) * nw); + + r->neg = a->neg; + r->top = a->top + nw + 1; + r->flags |= BN_FLG_FIXED_TOP; + + return 1; +} + +int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) +{ + int ret = 0; + + if (n < 0) { + BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT); + return 0; + } + + ret = bn_rshift_fixed_top(r, a, n); + + bn_correct_top(r); + bn_check_top(r); + + return ret; +} + +/* + * In respect to shift factor the execution time is invariant of + * |n % BN_BITS2|, but not |n / BN_BITS2|. Or in other words pre-condition + * for constant-time-ness for sufficiently[!] zero-padded inputs is + * |n < BN_BITS2| or |n / BN_BITS2| being non-secret. + */ +int bn_rshift_fixed_top(BIGNUM *r, const BIGNUM *a, int n) +{ + int i, top, nw; + unsigned int lb, rb; + BN_ULONG *t, *f; + BN_ULONG l, m, mask; + + bn_check_top(r); + bn_check_top(a); + + assert(n >= 0); + + nw = n / BN_BITS2; + if (nw >= a->top) { + /* shouldn't happen, but formally required */ + BN_zero(r); + return 1; + } + + rb = (unsigned int)n % BN_BITS2; + lb = BN_BITS2 - rb; + lb %= BN_BITS2; /* say no to undefined behaviour */ + mask = (BN_ULONG)0 - lb; /* mask = 0 - (lb != 0) */ + mask |= mask >> 8; + top = a->top - nw; + if (r != a && bn_wexpand(r, top) == NULL) + return 0; + + t = &(r->d[0]); + f = &(a->d[nw]); + l = f[0]; + for (i = 0; i < top - 1; i++) { + m = f[i + 1]; + t[i] = (l >> rb) | ((m << lb) & mask); + l = m; + } + t[i] = l >> rb; + + r->neg = a->neg; + r->top = top; + r->flags |= BN_FLG_FIXED_TOP; + + return 1; +} |