diff options
Diffstat (limited to 'lib/crypto/mpi/mpi-div.c')
-rw-r--r-- | lib/crypto/mpi/mpi-div.c | 82 |
1 files changed, 39 insertions, 43 deletions
diff --git a/lib/crypto/mpi/mpi-div.c b/lib/crypto/mpi/mpi-div.c index 45beab8b9e9e..6e5044e72595 100644 --- a/lib/crypto/mpi/mpi-div.c +++ b/lib/crypto/mpi/mpi-div.c @@ -14,13 +14,13 @@ #include "mpi-internal.h" #include "longlong.h" -void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den); -void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor); +int mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den); -void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor) +int mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor) { int divisor_sign = divisor->sign; MPI temp_divisor = NULL; + int err; /* We need the original value of the divisor after the remainder has been * preliminary calculated. We have to copy it to temporary space if it's @@ -28,44 +28,22 @@ void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor) */ if (rem == divisor) { temp_divisor = mpi_copy(divisor); + if (!temp_divisor) + return -ENOMEM; divisor = temp_divisor; } - mpi_tdiv_r(rem, dividend, divisor); + err = mpi_tdiv_r(rem, dividend, divisor); + if (err) + goto free_temp_divisor; if (((divisor_sign?1:0) ^ (dividend->sign?1:0)) && rem->nlimbs) - mpi_add(rem, rem, divisor); + err = mpi_add(rem, rem, divisor); - if (temp_divisor) - mpi_free(temp_divisor); -} +free_temp_divisor: + mpi_free(temp_divisor); -void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor) -{ - MPI tmp = mpi_alloc(mpi_get_nlimbs(quot)); - mpi_fdiv_qr(quot, tmp, dividend, divisor); - mpi_free(tmp); -} - -void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor) -{ - int divisor_sign = divisor->sign; - MPI temp_divisor = NULL; - - if (quot == divisor || rem == divisor) { - temp_divisor = mpi_copy(divisor); - divisor = temp_divisor; - } - - mpi_tdiv_qr(quot, rem, dividend, divisor); - - if ((divisor_sign ^ dividend->sign) && rem->nlimbs) { - mpi_sub_ui(quot, quot, 1); - mpi_add(rem, rem, divisor); - } - - if (temp_divisor) - mpi_free(temp_divisor); + return err; } /* If den == quot, den needs temporary storage. @@ -75,12 +53,12 @@ void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor) * i.e no extra storage should be allocated. */ -void mpi_tdiv_r(MPI rem, MPI num, MPI den) +int mpi_tdiv_r(MPI rem, MPI num, MPI den) { - mpi_tdiv_qr(NULL, rem, num, den); + return mpi_tdiv_qr(NULL, rem, num, den); } -void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) +int mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) { mpi_ptr_t np, dp; mpi_ptr_t qp, rp; @@ -93,13 +71,16 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) mpi_limb_t q_limb; mpi_ptr_t marker[5]; int markidx = 0; + int err; /* Ensure space is enough for quotient and remainder. * We need space for an extra limb in the remainder, because it's * up-shifted (normalized) below. */ rsize = nsize + 1; - mpi_resize(rem, rsize); + err = mpi_resize(rem, rsize); + if (err) + return err; qsize = rsize - dsize; /* qsize cannot be bigger than this. */ if (qsize <= 0) { @@ -115,11 +96,14 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) quot->nlimbs = 0; quot->sign = 0; } - return; + return 0; } - if (quot) - mpi_resize(quot, qsize); + if (quot) { + err = mpi_resize(quot, qsize); + if (err) + return err; + } /* Read pointers here, when reallocation is finished. */ np = num->d; @@ -141,10 +125,10 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) rsize = rlimb != 0?1:0; rem->nlimbs = rsize; rem->sign = sign_remainder; - return; + return 0; } - + err = -ENOMEM; if (quot) { qp = quot->d; /* Make sure QP and NP point to different objects. Otherwise the @@ -152,6 +136,8 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) */ if (qp == np) { /* Copy NP object to temporary space. */ np = marker[markidx++] = mpi_alloc_limb_space(nsize); + if (!np) + goto out_free_marker; MPN_COPY(np, qp, nsize); } } else /* Put quotient at top of remainder. */ @@ -172,6 +158,8 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) * the original contents of the denominator. */ tp = marker[markidx++] = mpi_alloc_limb_space(dsize); + if (!tp) + goto out_free_marker; mpihelp_lshift(tp, dp, dsize, normalization_steps); dp = tp; @@ -193,6 +181,8 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) mpi_ptr_t tp; tp = marker[markidx++] = mpi_alloc_limb_space(dsize); + if (!tp) + goto out_free_marker; MPN_COPY(tp, dp, dsize); dp = tp; } @@ -227,8 +217,14 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) rem->nlimbs = rsize; rem->sign = sign_remainder; + + err = 0; + +out_free_marker: while (markidx) { markidx--; mpi_free_limb_space(marker[markidx]); } + + return err; } |