From a8ea8bdd9df92a0e5db5b43900abb7a288b8a53e Mon Sep 17 00:00:00 2001 From: Tianjia Zhang Date: Mon, 21 Sep 2020 00:20:55 +0800 Subject: lib/mpi: Extend the MPI library Expand the mpi library based on libgcrypt, and the ECC algorithm of mpi based on libgcrypt requires these functions. Some other algorithms will be developed based on mpi ecc, such as SM2. Signed-off-by: Tianjia Zhang Tested-by: Xufeng Zhang Signed-off-by: Herbert Xu --- lib/mpi/mpi-div.c | 238 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 lib/mpi/mpi-div.c (limited to 'lib/mpi/mpi-div.c') diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c new file mode 100644 index 000000000000..21332dab97d4 --- /dev/null +++ b/lib/mpi/mpi-div.c @@ -0,0 +1,238 @@ +/* mpi-div.c - MPI functions + * Copyright (C) 1994, 1996, 1998, 2001, 2002, + * 2003 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + */ + +#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); + +void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor) +{ + int divisor_sign = divisor->sign; + MPI temp_divisor = NULL; + + /* 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 + * the same variable as REM. + */ + if (rem == divisor) { + temp_divisor = mpi_copy(divisor); + divisor = temp_divisor; + } + + mpi_tdiv_r(rem, dividend, divisor); + + if (((divisor_sign?1:0) ^ (dividend->sign?1:0)) && rem->nlimbs) + mpi_add(rem, rem, divisor); + + if (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); +} + +/* If den == quot, den needs temporary storage. + * If den == rem, den needs temporary storage. + * If num == quot, num needs temporary storage. + * If den has temporary storage, it can be normalized while being copied, + * i.e no extra storage should be allocated. + */ + +void mpi_tdiv_r(MPI rem, MPI num, MPI den) +{ + mpi_tdiv_qr(NULL, rem, num, den); +} + +void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) +{ + mpi_ptr_t np, dp; + mpi_ptr_t qp, rp; + mpi_size_t nsize = num->nlimbs; + mpi_size_t dsize = den->nlimbs; + mpi_size_t qsize, rsize; + mpi_size_t sign_remainder = num->sign; + mpi_size_t sign_quotient = num->sign ^ den->sign; + unsigned int normalization_steps; + mpi_limb_t q_limb; + mpi_ptr_t marker[5]; + unsigned int marker_nlimbs[5]; + int markidx = 0; + + /* 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); + + qsize = rsize - dsize; /* qsize cannot be bigger than this. */ + if (qsize <= 0) { + if (num != rem) { + rem->nlimbs = num->nlimbs; + rem->sign = num->sign; + MPN_COPY(rem->d, num->d, nsize); + } + if (quot) { + /* This needs to follow the assignment to rem, in case the + * numerator and quotient are the same. + */ + quot->nlimbs = 0; + quot->sign = 0; + } + return; + } + + if (quot) + mpi_resize(quot, qsize); + + /* Read pointers here, when reallocation is finished. */ + np = num->d; + dp = den->d; + rp = rem->d; + + /* Optimize division by a single-limb divisor. */ + if (dsize == 1) { + mpi_limb_t rlimb; + if (quot) { + qp = quot->d; + rlimb = mpihelp_divmod_1(qp, np, nsize, dp[0]); + qsize -= qp[qsize - 1] == 0; + quot->nlimbs = qsize; + quot->sign = sign_quotient; + } else + rlimb = mpihelp_mod_1(np, nsize, dp[0]); + rp[0] = rlimb; + rsize = rlimb != 0?1:0; + rem->nlimbs = rsize; + rem->sign = sign_remainder; + return; + } + + + if (quot) { + qp = quot->d; + /* Make sure QP and NP point to different objects. Otherwise the + * numerator would be gradually overwritten by the quotient limbs. + */ + if (qp == np) { /* Copy NP object to temporary space. */ + marker_nlimbs[markidx] = nsize; + np = marker[markidx++] = mpi_alloc_limb_space(nsize); + MPN_COPY(np, qp, nsize); + } + } else /* Put quotient at top of remainder. */ + qp = rp + dsize; + + normalization_steps = count_leading_zeros(dp[dsize - 1]); + + /* Normalize the denominator, i.e. make its most significant bit set by + * shifting it NORMALIZATION_STEPS bits to the left. Also shift the + * numerator the same number of steps (to keep the quotient the same!). + */ + if (normalization_steps) { + mpi_ptr_t tp; + mpi_limb_t nlimb; + + /* Shift up the denominator setting the most significant bit of + * the most significant word. Use temporary storage not to clobber + * the original contents of the denominator. + */ + marker_nlimbs[markidx] = dsize; + tp = marker[markidx++] = mpi_alloc_limb_space(dsize); + mpihelp_lshift(tp, dp, dsize, normalization_steps); + dp = tp; + + /* Shift up the numerator, possibly introducing a new most + * significant word. Move the shifted numerator in the remainder + * meanwhile. + */ + nlimb = mpihelp_lshift(rp, np, nsize, normalization_steps); + if (nlimb) { + rp[nsize] = nlimb; + rsize = nsize + 1; + } else + rsize = nsize; + } else { + /* The denominator is already normalized, as required. Copy it to + * temporary space if it overlaps with the quotient or remainder. + */ + if (dp == rp || (quot && (dp == qp))) { + mpi_ptr_t tp; + + marker_nlimbs[markidx] = dsize; + tp = marker[markidx++] = mpi_alloc_limb_space(dsize); + MPN_COPY(tp, dp, dsize); + dp = tp; + } + + /* Move the numerator to the remainder. */ + if (rp != np) + MPN_COPY(rp, np, nsize); + + rsize = nsize; + } + + q_limb = mpihelp_divrem(qp, 0, rp, rsize, dp, dsize); + + if (quot) { + qsize = rsize - dsize; + if (q_limb) { + qp[qsize] = q_limb; + qsize += 1; + } + + quot->nlimbs = qsize; + quot->sign = sign_quotient; + } + + rsize = dsize; + MPN_NORMALIZE(rp, rsize); + + if (normalization_steps && rsize) { + mpihelp_rshift(rp, rp, rsize, normalization_steps); + rsize -= rp[rsize - 1] == 0?1:0; + } + + rem->nlimbs = rsize; + rem->sign = sign_remainder; + while (markidx) { + markidx--; + mpi_free_limb_space(marker[markidx]); + } +} -- cgit v1.2.3 From ae6ee6ae2b4f4534664561161ef8087e08aff2d9 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 25 Sep 2020 18:19:55 +1000 Subject: lib/mpi: Fix unused variable warnings This patch removes a number of unused variables and marks others as unused in order to silence compiler warnings about them. Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library") Signed-off-by: Herbert Xu Tested-by: Tianjia Zhang Signed-off-by: Herbert Xu --- lib/mpi/mpi-div.c | 4 ---- lib/mpi/mpi-internal.h | 2 +- lib/mpi/mpi-mul.c | 3 --- lib/mpi/mpih-div.c | 4 ++-- 4 files changed, 3 insertions(+), 10 deletions(-) (limited to 'lib/mpi/mpi-div.c') diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c index 21332dab97d4..45beab8b9e9e 100644 --- a/lib/mpi/mpi-div.c +++ b/lib/mpi/mpi-div.c @@ -92,7 +92,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) unsigned int normalization_steps; mpi_limb_t q_limb; mpi_ptr_t marker[5]; - unsigned int marker_nlimbs[5]; int markidx = 0; /* Ensure space is enough for quotient and remainder. @@ -152,7 +151,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) * numerator would be gradually overwritten by the quotient limbs. */ if (qp == np) { /* Copy NP object to temporary space. */ - marker_nlimbs[markidx] = nsize; np = marker[markidx++] = mpi_alloc_limb_space(nsize); MPN_COPY(np, qp, nsize); } @@ -173,7 +171,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) * the most significant word. Use temporary storage not to clobber * the original contents of the denominator. */ - marker_nlimbs[markidx] = dsize; tp = marker[markidx++] = mpi_alloc_limb_space(dsize); mpihelp_lshift(tp, dp, dsize, normalization_steps); dp = tp; @@ -195,7 +192,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den) if (dp == rp || (quot && (dp == qp))) { mpi_ptr_t tp; - marker_nlimbs[markidx] = dsize; tp = marker[markidx++] = mpi_alloc_limb_space(dsize); MPN_COPY(tp, dp, dsize); dp = tp; diff --git a/lib/mpi/mpi-internal.h b/lib/mpi/mpi-internal.h index d29c4537c3a3..554002182db1 100644 --- a/lib/mpi/mpi-internal.h +++ b/lib/mpi/mpi-internal.h @@ -114,7 +114,7 @@ typedef int mpi_size_t; /* (must be a signed type) */ */ #define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \ do { \ - mpi_limb_t _ql; \ + mpi_limb_t _ql __maybe_unused; \ mpi_limb_t _q, _r; \ mpi_limb_t _xh, _xl; \ umul_ppmm(_q, _ql, (nh), (di)); \ diff --git a/lib/mpi/mpi-mul.c b/lib/mpi/mpi-mul.c index 587e6335cc12..8f5fa200f297 100644 --- a/lib/mpi/mpi-mul.c +++ b/lib/mpi/mpi-mul.c @@ -21,7 +21,6 @@ void mpi_mul(MPI w, MPI u, MPI v) int usign, vsign, sign_product; int assign_wp = 0; mpi_ptr_t tmp_limb = NULL; - unsigned int tmp_limb_nlimbs = 0; if (u->nlimbs < v->nlimbs) { /* Swap U and V. */ @@ -55,7 +54,6 @@ void mpi_mul(MPI w, MPI u, MPI v) } else { /* Make U and V not overlap with W. */ if (wp == up) { /* W and U are identical. Allocate temporary space for U. */ - tmp_limb_nlimbs = usize; up = tmp_limb = mpi_alloc_limb_space(usize); /* Is V identical too? Keep it identical with U. */ if (wp == vp) @@ -64,7 +62,6 @@ void mpi_mul(MPI w, MPI u, MPI v) MPN_COPY(up, wp, usize); } else if (wp == vp) { /* W and V are identical. Allocate temporary space for V. */ - tmp_limb_nlimbs = vsize; vp = tmp_limb = mpi_alloc_limb_space(vsize); /* Copy to the temporary space. */ MPN_COPY(vp, wp, vsize); diff --git a/lib/mpi/mpih-div.c b/lib/mpi/mpih-div.c index 182a656a1ba0..be70ee2e42d3 100644 --- a/lib/mpi/mpih-div.c +++ b/lib/mpi/mpih-div.c @@ -31,7 +31,7 @@ mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size, { mpi_size_t i; mpi_limb_t n1, n0, r; - mpi_limb_t dummy; + mpi_limb_t dummy __maybe_unused; /* Botch: Should this be handled at all? Rely on callers? */ if (!dividend_size) @@ -382,7 +382,7 @@ mpihelp_divmod_1(mpi_ptr_t quot_ptr, { mpi_size_t i; mpi_limb_t n1, n0, r; - mpi_limb_t dummy; + mpi_limb_t dummy __maybe_unused; if (!dividend_size) return 0; -- cgit v1.2.3