本文整理汇总了C++中BN_usub函数的典型用法代码示例。如果您正苦于以下问题：C++ BN_usub函数的具体用法？C++ BN_usub怎么用？C++ BN_usub使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。
在下文中一共展示了BN_usub函数的15个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: BN_add
int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) {
const BIGNUM *tmp;
int a_neg = a->neg, ret;
// a + b a+b
// a + -b a-b
// -a + b b-a
// -a + -b -(a+b)
if (a_neg ^ b->neg) {
// only one is negative
if (a_neg) {
tmp = a;
a = b;
b = tmp;
}
// we are now a - b
if (BN_ucmp(a, b) < 0) {
if (!BN_usub(r, b, a)) {
return 0;
}
r->neg = 1;
} else {
if (!BN_usub(r, a, b)) {
return 0;
}
r->neg = 0;
}
return 1;
}
ret = BN_uadd(r, a, b);
r->neg = a_neg;
return ret;
}示例2: BN_sub
int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
int max;
int add = 0, neg = 0;
bn_check_top(a);
bn_check_top(b);
/*-
* a - b a-b
* a - -b a+b
* -a - b -(a+b)
* -a - -b b-a
*/
if (a->neg) {
if (b->neg) {
const BIGNUM *tmp;
tmp = a;
a = b;
b = tmp;
} else {
add = 1;
neg = 1;
}
} else {
if (b->neg) {
add = 1;
neg = 0;
}
}
if (add) {
if (!BN_uadd(r, a, b))
return 0;
r->neg = neg;
return 1;
}
/* We are actually doing a - b :-) */
max = (a->top > b->top) ? a->top : b->top;
if (bn_wexpand(r, max) == NULL)
return 0;
if (BN_ucmp(a, b) < 0) {
if (!BN_usub(r, b, a))
return 0;
r->neg = 1;
} else {
if (!BN_usub(r, a, b))
return 0;
r->neg = 0;
}
bn_check_top(r);
return 1;
}示例3: BN_div
int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
BN_CTX *ctx)
{
int i,nm,nd;
int ret = 0;
BIGNUM *D;
bn_check_top(m);
bn_check_top(d);
if (BN_is_zero(d))
{
BNerr(BN_F_BN_DIV,BN_R_DIV_BY_ZERO);
return(0);
}
if (BN_ucmp(m,d) < 0)
{
if (rem != NULL)
{ if (BN_copy(rem,m) == NULL) return(0); }
if (dv != NULL) BN_zero(dv);
return(1);
}
BN_CTX_start(ctx);
D = BN_CTX_get(ctx);
if (dv == NULL) dv = BN_CTX_get(ctx);
if (rem == NULL) rem = BN_CTX_get(ctx);
if (D == NULL || dv == NULL || rem == NULL)
goto end;
nd=BN_num_bits(d);
nm=BN_num_bits(m);
if (BN_copy(D,d) == NULL) goto end;
if (BN_copy(rem,m) == NULL) goto end;
/* The next 2 are needed so we can do a dv->d[0]|=1 later
* since BN_lshift1 will only work once there is a value :-) */
BN_zero(dv);
if(bn_wexpand(dv,1) == NULL) goto end;
dv->top=1;
if (!BN_lshift(D,D,nm-nd)) goto end;
for (i=nm-nd; i>=0; i--)
{
if (!BN_lshift1(dv,dv)) goto end;
if (BN_ucmp(rem,D) >= 0)
{
dv->d[0]|=1;
if (!BN_usub(rem,rem,D)) goto end;
}
/* CAN IMPROVE (and have now :=) */
if (!BN_rshift1(D,D)) goto end;
}
rem->neg=BN_is_zero(rem)?0:m->neg;
dv->neg=m->neg^d->neg;
ret = 1;
end:
BN_CTX_end(ctx);
return(ret);
}示例4: BN_mod_add_quick
/* BN_mod_add variant that may be used if both a and b are non-negative
* and less than m */
int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m)
{
if (!BN_uadd(r, a, b)) return 0;
if (BN_ucmp(r, m) >= 0)
return BN_usub(r, r, m);
return 1;
}示例5: BN_sub
int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) {
int add = 0, neg = 0;
const BIGNUM *tmp;
// a - b a-b
// a - -b a+b
// -a - b -(a+b)
// -a - -b b-a
if (a->neg) {
if (b->neg) {
tmp = a;
a = b;
b = tmp;
} else {
add = 1;
neg = 1;
}
} else {
if (b->neg) {
add = 1;
neg = 0;
}
}
if (add) {
if (!BN_uadd(r, a, b)) {
return 0;
}
r->neg = neg;
return 1;
}
if (BN_ucmp(a, b) < 0) {
if (!BN_usub(r, b, a)) {
return 0;
}
r->neg = 1;
} else {
if (!BN_usub(r, a, b)) {
return 0;
}
r->neg = 0;
}
return 1;
}示例6: ec_GFp_simple_invert
int ec_GFp_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
{
if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(point->Y))
/* point is its own inverse */
return 1;
return BN_usub(point->Y, group->field, point->Y);
}示例7: BN_add
/* r can == a or b */
int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
int a_neg = a->neg, ret;
bn_check_top(a);
bn_check_top(b);
/*-
* a + b a+b
* a + -b a-b
* -a + b b-a
* -a + -b -(a+b)
*/
if (a_neg ^ b->neg) {
/* only one is negative */
if (a_neg) {
const BIGNUM *tmp;
tmp = a;
a = b;
b = tmp;
}
/* we are now a - b */
if (BN_ucmp(a, b) < 0) {
if (!BN_usub(r, b, a))
return 0;
r->neg = 1;
} else {
if (!BN_usub(r, a, b))
return 0;
r->neg = 0;
}
return 1;
}
ret = BN_uadd(r, a, b);
r->neg = a_neg;
bn_check_top(r);
return ret;
}示例8: BN_add
/* r can == a or b */
int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
const BIGNUM *tmp;
bn_check_top(a);
bn_check_top(b);
/* a + b a+b
* a + -b a-b
* -a + b b-a
* -a + -b -(a+b)
*/
if (a->neg ^ b->neg)
{
/* only one is negative */
if (a->neg)
{ tmp=a; a=b; b=tmp; }
/* we are now a - b */
if (BN_ucmp(a,b) < 0)
{
if (!BN_usub(r,b,a)) return(0);
r->neg=1;
}
else
{
if (!BN_usub(r,a,b)) return(0);
r->neg=0;
}
return(1);
}
if (a->neg) /* both are neg */
r->neg=1;
else
r->neg=0;
if (!BN_uadd(r,a,b)) return(0);
return(1);
}示例9: fermat_question_ask
static RSA *
fermat_question_ask(const RSA *rsa)
{
BIGNUM
*a = BN_new(),
*b = BN_new(),
*a2 = BN_new(),
*b2 = BN_new();
BIGNUM *n = rsa->n;
BIGNUM
*tmp = BN_new(),
*rem = BN_new(),
*dssdelta = BN_new();
BN_CTX *ctx = BN_CTX_new();
RSA *ret = NULL;
BN_sqrtmod(tmp, rem, n, ctx);
/* Δ = |p - q| = |a + b - a + b| = |2b| > √N 2⁻¹⁰⁰ */
/* BN_rshift(dssdelta, tmp, 101); */
BN_one(dssdelta);
BN_lshift(dssdelta, dssdelta, BN_num_bits(n) / 4 + 10);
BN_copy(a, tmp);
BN_sqr(a2, a, ctx);
do {
/* a² += 2a + 1 */
BN_lshift1(tmp, a);
BN_uiadd1(tmp);
BN_add(a2, a2, tmp);
/* a += 1 */
BN_uiadd1(a);
/* b² = a² - N */
BN_usub(b2, a2, n);
/* b */
BN_sqrtmod(b, rem, b2, ctx);
} while (!BN_is_zero(rem) && BN_cmp(b, dssdelta) < 1);
if (BN_is_zero(rem)) {
BN_uadd(a, a, b);
ret = qa_RSA_recover(rsa, a, ctx);
}
BN_CTX_free(ctx);
BN_free(a);
BN_free(b);
BN_free(a2);
BN_free(b2);
BN_free(dssdelta);
BN_free(tmp);
BN_free(rem);
return ret;
}示例10: BN_from_montgomery
int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
BN_CTX *ctx)
{
int retn = 0;
#ifdef MONT_WORD
BIGNUM *t;
BN_CTX_start(ctx);
if ((t = BN_CTX_get(ctx)) && BN_copy(t, a)) {
retn = bn_from_montgomery_word(ret, t, mont);
bn_correct_top(ret);
bn_check_top(ret);
}
BN_CTX_end(ctx);
#else /* !MONT_WORD */
BIGNUM *t1, *t2;
BN_CTX_start(ctx);
t1 = BN_CTX_get(ctx);
t2 = BN_CTX_get(ctx);
if (t1 == NULL || t2 == NULL)
goto err;
if (!BN_copy(t1, a))
goto err;
BN_mask_bits(t1, mont->ri);
if (!BN_mul(t2, t1, &mont->Ni, ctx))
goto err;
BN_mask_bits(t2, mont->ri);
if (!BN_mul(t1, t2, &mont->N, ctx))
goto err;
if (!BN_add(t2, a, t1))
goto err;
if (!BN_rshift(ret, t2, mont->ri))
goto err;
if (BN_ucmp(ret, &(mont->N)) >= 0) {
if (!BN_usub(ret, ret, &(mont->N)))
goto err;
}
retn = 1;
bn_check_top(ret);
err:
BN_CTX_end(ctx);
#endif /* MONT_WORD */
return (retn);
}示例11: BN_nist_mod_224
int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
BN_CTX *ctx)
{
#if BN_BITS2 != 64
int top = a->top, i;
int carry = 0;
BN_ULONG *r_d, *a_d = a->d;
BN_ULONG t_d[BN_NIST_224_TOP],
buf[BN_NIST_224_TOP];
i = BN_ucmp(field, a);
if (i == 0)
{
BN_zero(r);
return 1;
}
else if (i > 0)
return (r == a)? 1 : (BN_copy(r ,a) != NULL);
if (top == BN_NIST_224_TOP)
return BN_usub(r, a, field);
if (r != a)
{
if (!bn_wexpand(r, BN_NIST_224_TOP))
return 0;
r_d = r->d;
nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
}
else
r_d = a_d;
nist_cp_bn_0(buf, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
nist_set_224(t_d, buf, 10, 9, 8, 7, 0, 0, 0);
if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
++carry;
nist_set_224(t_d, buf, 0, 13, 12, 11, 0, 0, 0);
if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
++carry;
nist_set_224(t_d, buf, 13, 12, 11, 10, 9, 8, 7);
if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
--carry;
nist_set_224(t_d, buf, 0, 0, 0, 0, 13, 12, 11);
if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
--carry;
if (carry > 0)
while (carry)
{
if (bn_sub_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP))
--carry;
}
else if (carry < 0)
while (carry)
{
if (bn_add_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP))
++carry;
}
r->top = BN_NIST_224_TOP;
bn_correct_top(r);
if (BN_ucmp(r, field) >= 0)
{
bn_sub_words(r_d, r_d, _nist_p_224, BN_NIST_224_TOP);
bn_correct_top(r);
}
bn_check_top(r);
return 1;
#else
return 0;
#endif
}示例12: ec_GFp_simple_set_compressed_coordinates
//.........这里部分代码省略.........
!group->meth->field_mul(group, tmp1, tmp2, x_, ctx)) {
goto err;
}
} else {
if (!BN_mod_sqr(tmp2, x_, &group->field, ctx) ||
!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx)) {
goto err;
}
}
/* tmp1 := tmp1 + a*x */
if (group->a_is_minus3) {
if (!BN_mod_lshift1_quick(tmp2, x, &group->field) ||
!BN_mod_add_quick(tmp2, tmp2, x, &group->field) ||
!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) {
goto err;
}
} else {
if (group->meth->field_decode) {
if (!group->meth->field_decode(group, tmp2, &group->a, ctx) ||
!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) {
goto err;
}
} else {
/* field_mul works on standard representation */
if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx)) {
goto err;
}
}
if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) {
goto err;
}
}
/* tmp1 := tmp1 + b */
if (group->meth->field_decode) {
if (!group->meth->field_decode(group, tmp2, &group->b, ctx) ||
!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) {
goto err;
}
} else {
if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) {
goto err;
}
}
if (!BN_mod_sqrt(y, tmp1, &group->field, ctx)) {
unsigned long err = ERR_peek_last_error();
if (ERR_GET_LIB(err) == ERR_LIB_BN &&
ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE) {
ERR_clear_error();
OPENSSL_PUT_ERROR(EC, ec_GFp_simple_set_compressed_coordinates, EC_R_INVALID_COMPRESSED_POINT);
} else {
OPENSSL_PUT_ERROR(EC, ec_GFp_simple_set_compressed_coordinates, ERR_R_BN_LIB);
}
goto err;
}
if (y_bit != BN_is_odd(y)) {
if (BN_is_zero(y)) {
int kron;
kron = BN_kronecker(x, &group->field, ctx);
if (kron == -2) {
goto err;
}
if (kron == 1) {
OPENSSL_PUT_ERROR(EC, ec_GFp_simple_set_compressed_coordinates,
EC_R_INVALID_COMPRESSION_BIT);
} else {
/* BN_mod_sqrt() should have cought this error (not a square) */
OPENSSL_PUT_ERROR(EC, ec_GFp_simple_set_compressed_coordinates,
EC_R_INVALID_COMPRESSED_POINT);
}
goto err;
}
if (!BN_usub(y, &group->field, y)) {
goto err;
}
}
if (y_bit != BN_is_odd(y)) {
OPENSSL_PUT_ERROR(EC, ec_GFp_simple_set_compressed_coordinates,
ERR_R_INTERNAL_ERROR);
goto err;
}
if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
goto err;
ret = 1;
err:
BN_CTX_end(ctx);
if (new_ctx != NULL)
BN_CTX_free(new_ctx);
return ret;
}示例13: BN_mod_inverse_no_branch
//.........这里部分代码省略.........
{
shift++;
if (BN_is_odd(Y))
{
if (!BN_uadd(Y, Y, n)) goto err;
}
/* now Y is even */
if (!BN_rshift1(Y, Y)) goto err;
}
if (shift > 0)
{
if (!BN_rshift(A, A, shift)) goto err;
}
/* We still have (1) and (2).
* Both A and B are odd.
* The following computations ensure that
*
* 0 <= B < |n|,
* 0 < A < |n|,
* (1) -sign*X*a == B (mod |n|),
* (2) sign*Y*a == A (mod |n|),
*
* and that either A or B is even in the next iteration.
*/
if (BN_ucmp(B, A) >= 0)
{
/* -sign*(X + Y)*a == B - A (mod |n|) */
if (!BN_uadd(X, X, Y)) goto err;
/* NB: we could use BN_mod_add_quick(X, X, Y, n), but that
* actually makes the algorithm slower */
if (!BN_usub(B, B, A)) goto err;
}
else
{
/* sign*(X + Y)*a == A - B (mod |n|) */
if (!BN_uadd(Y, Y, X)) goto err;
/* as above, BN_mod_add_quick(Y, Y, X, n) would slow things down */
if (!BN_usub(A, A, B)) goto err;
}
}
}
else
{
/* general inversion algorithm */
while (!BN_is_zero(B))
{
BIGNUM *tmp;
/*
* 0 < B < A,
* (*) -sign*X*a == B (mod |n|),
* sign*Y*a == A (mod |n|)
*/
/* (D, M) := (A/B, A%B) ... */
if (BN_num_bits(A) == BN_num_bits(B))
{
if (!BN_one(D)) goto err;
if (!BN_sub(M,A,B)) goto err;
}
else if (BN_num_bits(A) == BN_num_bits(B) + 1)
{示例14: BN_from_montgomery
//.........这里部分代码省略.........
ret->neg=r->neg;
rp=ret->d;
ap=&(r->d[ri]);
{
size_t m1,m2;
v=bn_sub_words(rp,ap,np,ri);
/* this ----------------^^ works even in al<ri case
* thanks to zealous zeroing of top of the vector in the
* beginning. */
/* if (al==ri && !v) || al>ri) nrp=rp; else nrp=ap; */
/* in other words if subtraction result is real, then
* trick unconditional memcpy below to perform in-place
* "refresh" instead of actual copy. */
m1=0-(size_t)(((al-ri)>>(sizeof(al)*8-1))&1); /* al<ri */
m2=0-(size_t)(((ri-al)>>(sizeof(al)*8-1))&1); /* al>ri */
m1|=m2; /* (al!=ri) */
m1|=(0-(size_t)v); /* (al!=ri || v) */
m1&=~m2; /* (al!=ri || v) && !al>ri */
nrp=(BN_ULONG *)(((size_t)rp&~m1)|((size_t)ap&m1));
}
/* 'i<ri' is chosen to eliminate dependency on input data, even
* though it results in redundant copy in al<ri case. */
for (i=0,ri-=4; i<ri; i+=4)
{
BN_ULONG t1,t2,t3,t4;
t1=nrp[i+0];
t2=nrp[i+1];
t3=nrp[i+2]; ap[i+0]=0;
t4=nrp[i+3]; ap[i+1]=0;
rp[i+0]=t1; ap[i+2]=0;
rp[i+1]=t2; ap[i+3]=0;
rp[i+2]=t3;
rp[i+3]=t4;
}
for (ri+=4; i<ri; i++)
rp[i]=nrp[i], ap[i]=0;
bn_correct_top(r);
bn_correct_top(ret);
# else
if (bn_wexpand(ret,al) == NULL) goto err;
ret->top=al;
ret->neg=r->neg;
rp=ret->d;
ap=&(r->d[ri]);
al-=4;
for (i=0; i<al; i+=4)
{
BN_ULONG t1,t2,t3,t4;
t1=ap[i+0];
t2=ap[i+1];
t3=ap[i+2];
t4=ap[i+3];
rp[i+0]=t1;
rp[i+1]=t2;
rp[i+2]=t3;
rp[i+3]=t4;
}
al+=4;
for (; i<al; i++)
rp[i]=ap[i];
# endif
#else /* !MONT_WORD */
BIGNUM *t1,*t2;
BN_CTX_start(ctx);
t1 = BN_CTX_get(ctx);
t2 = BN_CTX_get(ctx);
if (t1 == NULL || t2 == NULL) goto err;
if (!BN_copy(t1,a)) goto err;
BN_mask_bits(t1,mont->ri);
if (!BN_mul(t2,t1,&mont->Ni,ctx)) goto err;
BN_mask_bits(t2,mont->ri);
if (!BN_mul(t1,t2,&mont->N,ctx)) goto err;
if (!BN_add(t2,a,t1)) goto err;
if (!BN_rshift(ret,t2,mont->ri)) goto err;
#endif /* MONT_WORD */
#if !defined(BRANCH_FREE) || BRANCH_FREE==0
if (BN_ucmp(ret, &(mont->N)) >= 0)
{
if (!BN_usub(ret,ret,&(mont->N))) goto err;
}
#endif
retn=1;
bn_check_top(ret);
err:
BN_CTX_end(ctx);
return(retn);
}示例15: BN_div_recp
int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
BN_RECP_CTX *recp, BN_CTX *ctx)
{
int i, j, ret = 0;
BIGNUM *a, *b, *d, *r;
BN_CTX_start(ctx);
d = (dv != NULL) ? dv : BN_CTX_get(ctx);
r = (rem != NULL) ? rem : BN_CTX_get(ctx);
a = BN_CTX_get(ctx);
b = BN_CTX_get(ctx);
if (b == NULL)
goto err;
if (BN_ucmp(m, &(recp->N)) < 0) {
BN_zero(d);
if (!BN_copy(r, m)) {
BN_CTX_end(ctx);
return 0;
}
BN_CTX_end(ctx);
return 1;
}
/*
* We want the remainder Given input of ABCDEF / ab we need multiply
* ABCDEF by 3 digests of the reciprocal of ab
*/
/* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */
i = BN_num_bits(m);
j = recp->num_bits << 1;
if (j > i)
i = j;
/* Nr := round(2^i / N) */
if (i != recp->shift)
recp->shift = BN_reciprocal(&(recp->Nr), &(recp->N), i, ctx);
/* BN_reciprocal could have returned -1 for an error */
if (recp->shift == -1)
goto err;
/*-
* d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
* = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
* <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
* = |m/N|
*/
if (!BN_rshift(a, m, recp->num_bits))
goto err;
if (!BN_mul(b, a, &(recp->Nr), ctx))
goto err;
if (!BN_rshift(d, b, i - recp->num_bits))
goto err;
d->neg = 0;
if (!BN_mul(b, &(recp->N), d, ctx))
goto err;
if (!BN_usub(r, m, b))
goto err;
r->neg = 0;
j = 0;
while (BN_ucmp(r, &(recp->N)) >= 0) {
if (j++ > 2) {
BNerr(BN_F_BN_DIV_RECP, BN_R_BAD_RECIPROCAL);
goto err;
}
if (!BN_usub(r, r, &(recp->N)))
goto err;
if (!BN_add_word(d, 1))
goto err;
}
r->neg = BN_is_zero(r) ? 0 : m->neg;
d->neg = m->neg ^ recp->N.neg;
ret = 1;
err:
BN_CTX_end(ctx);
bn_check_top(dv);
bn_check_top(rem);
return ret;
}