diff options
Diffstat (limited to 'lib/crypto/mpi/mpi-add.c')
-rw-r--r-- | lib/crypto/mpi/mpi-add.c | 89 |
1 files changed, 26 insertions, 63 deletions
diff --git a/lib/crypto/mpi/mpi-add.c b/lib/crypto/mpi/mpi-add.c index 9056fc5167fc..3015140d4860 100644 --- a/lib/crypto/mpi/mpi-add.c +++ b/lib/crypto/mpi/mpi-add.c @@ -13,62 +13,12 @@ #include "mpi-internal.h" -/**************** - * Add the unsigned integer V to the mpi-integer U and store the - * result in W. U and V may be the same. - */ -void mpi_add_ui(MPI w, MPI u, unsigned long v) -{ - mpi_ptr_t wp, up; - mpi_size_t usize, wsize; - int usign, wsign; - - usize = u->nlimbs; - usign = u->sign; - wsign = 0; - - /* If not space for W (and possible carry), increase space. */ - wsize = usize + 1; - if (w->alloced < wsize) - mpi_resize(w, wsize); - - /* These must be after realloc (U may be the same as W). */ - up = u->d; - wp = w->d; - - if (!usize) { /* simple */ - wp[0] = v; - wsize = v ? 1:0; - } else if (!usign) { /* mpi is not negative */ - mpi_limb_t cy; - cy = mpihelp_add_1(wp, up, usize, v); - wp[usize] = cy; - wsize = usize + cy; - } else { - /* The signs are different. Need exact comparison to determine - * which operand to subtract from which. - */ - if (usize == 1 && up[0] < v) { - wp[0] = v - up[0]; - wsize = 1; - } else { - mpihelp_sub_1(wp, up, usize, v); - /* Size can decrease with at most one limb. */ - wsize = usize - (wp[usize-1] == 0); - wsign = 1; - } - } - - w->nlimbs = wsize; - w->sign = wsign; -} - - -void mpi_add(MPI w, MPI u, MPI v) +int mpi_add(MPI w, MPI u, MPI v) { mpi_ptr_t wp, up, vp; mpi_size_t usize, vsize, wsize; int usign, vsign, wsign; + int err; if (u->nlimbs < v->nlimbs) { /* Swap U and V. */ usize = v->nlimbs; @@ -76,7 +26,9 @@ void mpi_add(MPI w, MPI u, MPI v) vsize = u->nlimbs; vsign = u->sign; wsize = usize + 1; - RESIZE_IF_NEEDED(w, wsize); + err = RESIZE_IF_NEEDED(w, wsize); + if (err) + return err; /* These must be after realloc (u or v may be the same as w). */ up = v->d; vp = u->d; @@ -86,7 +38,9 @@ void mpi_add(MPI w, MPI u, MPI v) vsize = v->nlimbs; vsign = v->sign; wsize = usize + 1; - RESIZE_IF_NEEDED(w, wsize); + err = RESIZE_IF_NEEDED(w, wsize); + if (err) + return err; /* These must be after realloc (u or v may be the same as w). */ up = u->d; vp = v->d; @@ -128,28 +82,37 @@ void mpi_add(MPI w, MPI u, MPI v) w->nlimbs = wsize; w->sign = wsign; + return 0; } EXPORT_SYMBOL_GPL(mpi_add); -void mpi_sub(MPI w, MPI u, MPI v) +int mpi_sub(MPI w, MPI u, MPI v) { - MPI vv = mpi_copy(v); + int err; + MPI vv; + + vv = mpi_copy(v); + if (!vv) + return -ENOMEM; + vv->sign = !vv->sign; - mpi_add(w, u, vv); + err = mpi_add(w, u, vv); mpi_free(vv); + + return err; } EXPORT_SYMBOL_GPL(mpi_sub); -void mpi_addm(MPI w, MPI u, MPI v, MPI m) +int mpi_addm(MPI w, MPI u, MPI v, MPI m) { - mpi_add(w, u, v); - mpi_mod(w, w, m); + return mpi_add(w, u, v) ?: + mpi_mod(w, w, m); } EXPORT_SYMBOL_GPL(mpi_addm); -void mpi_subm(MPI w, MPI u, MPI v, MPI m) +int mpi_subm(MPI w, MPI u, MPI v, MPI m) { - mpi_sub(w, u, v); - mpi_mod(w, w, m); + return mpi_sub(w, u, v) ?: + mpi_mod(w, w, m); } EXPORT_SYMBOL_GPL(mpi_subm); |