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Revert "lib/mpi: Extend the MPI library"

Browse Source 
This partially reverts commit a8ea8bdd9d.

Most of it is no longer needed since sm2 has been removed.  However,
the following functions have been kept as they have developed other
uses:

mpi_copy

mpi_mod

mpi_test_bit
mpi_set_bit
mpi_rshift

mpi_add
mpi_sub
mpi_addm
mpi_subm

mpi_mul
mpi_mulm

mpi_tdiv_r
mpi_fdiv_r

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2024-08-10 14:20:55 +08:00
parent f235bc11cc
commit fca5cb4dd2
12 changed files with 10 additions and 1165 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

65
include/linux/mpi.h
View File

@ -40,87 +40,33 @@ struct gcry_mpi {
typedef struct gcry_mpi *MPI;
#define mpi_get_nlimbs(a) ((a)->nlimbs)
#define mpi_has_sign(a) ((a)->sign)
/*-- mpiutil.c --*/
MPI mpi_alloc(unsigned nlimbs);
void mpi_clear(MPI a);
void mpi_free(MPI a);
int mpi_resize(MPI a, unsigned nlimbs);
static inline MPI mpi_new(unsigned int nbits)
{
return mpi_alloc((nbits + BITS_PER_MPI_LIMB - 1) / BITS_PER_MPI_LIMB);
}
MPI mpi_copy(MPI a);
MPI mpi_alloc_like(MPI a);
void mpi_snatch(MPI w, MPI u);
MPI mpi_set(MPI w, MPI u);
MPI mpi_set_ui(MPI w, unsigned long u);
MPI mpi_alloc_set_ui(unsigned long u);
void mpi_swap_cond(MPI a, MPI b, unsigned long swap);
/* Constants used to return constant MPIs. See mpi_init if you
* want to add more constants.
*/
#define MPI_NUMBER_OF_CONSTANTS 6
enum gcry_mpi_constants {
MPI_C_ZERO,
MPI_C_ONE,
MPI_C_TWO,
MPI_C_THREE,
MPI_C_FOUR,
MPI_C_EIGHT
};
MPI mpi_const(enum gcry_mpi_constants no);
/*-- mpicoder.c --*/
/* Different formats of external big integer representation. */
enum gcry_mpi_format {
GCRYMPI_FMT_NONE = 0,
GCRYMPI_FMT_STD = 1, /* Twos complement stored without length. */
GCRYMPI_FMT_PGP = 2, /* As used by OpenPGP (unsigned only). */
GCRYMPI_FMT_SSH = 3, /* As used by SSH (like STD but with length). */
GCRYMPI_FMT_HEX = 4, /* Hex format. */
GCRYMPI_FMT_USG = 5, /* Like STD but unsigned. */
GCRYMPI_FMT_OPAQUE = 8 /* Opaque format (some functions only). */
};
MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes);
MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
int mpi_fromstr(MPI val, const char *str);
MPI mpi_scanval(const char *string);
MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len);
void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign);
int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
int *sign);
int mpi_write_to_sgl(MPI a, struct scatterlist *sg, unsigned nbytes,
int *sign);
int mpi_print(enum gcry_mpi_format format, unsigned char *buffer,
size_t buflen, size_t *nwritten, MPI a);
/*-- mpi-mod.c --*/
void mpi_mod(MPI rem, MPI dividend, MPI divisor);
/* Context used with Barrett reduction. */
struct barrett_ctx_s;
typedef struct barrett_ctx_s *mpi_barrett_t;
mpi_barrett_t mpi_barrett_init(MPI m, int copy);
void mpi_barrett_free(mpi_barrett_t ctx);
void mpi_mod_barrett(MPI r, MPI x, mpi_barrett_t ctx);
void mpi_mul_barrett(MPI w, MPI u, MPI v, mpi_barrett_t ctx);
/*-- mpi-pow.c --*/
int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);
/*-- mpi-cmp.c --*/
int mpi_cmp_ui(MPI u, ulong v);
int mpi_cmp(MPI u, MPI v);
int mpi_cmpabs(MPI u, MPI v);
/*-- mpi-sub-ui.c --*/
int mpi_sub_ui(MPI w, MPI u, unsigned long vval);
@ -130,16 +76,9 @@ void mpi_normalize(MPI a);
unsigned mpi_get_nbits(MPI a);
int mpi_test_bit(MPI a, unsigned int n);
void mpi_set_bit(MPI a, unsigned int n);
void mpi_set_highbit(MPI a, unsigned int n);
void mpi_clear_highbit(MPI a, unsigned int n);
void mpi_clear_bit(MPI a, unsigned int n);
void mpi_rshift_limbs(MPI a, unsigned int count);
void mpi_rshift(MPI x, MPI a, unsigned int n);
void mpi_lshift_limbs(MPI a, unsigned int count);
void mpi_lshift(MPI x, MPI a, unsigned int n);
/*-- mpi-add.c --*/
void mpi_add_ui(MPI w, MPI u, unsigned long v);
void mpi_add(MPI w, MPI u, MPI v);
void mpi_sub(MPI w, MPI u, MPI v);
void mpi_addm(MPI w, MPI u, MPI v, MPI m);
@ -152,10 +91,6 @@ void mpi_mulm(MPI w, MPI u, MPI v, MPI m);
/*-- mpi-div.c --*/
void mpi_tdiv_r(MPI rem, MPI num, MPI den);
void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor);
void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor);
/*-- mpi-inv.c --*/
int mpi_invm(MPI x, MPI a, MPI n);
/* inline functions */

1
lib/crypto/mpi/Makefile
View File

@ -19,7 +19,6 @@ mpi-y = \
mpi-cmp.o \
mpi-sub-ui.o \
mpi-div.o \
mpi-inv.o \
mpi-mod.o \
mpi-mul.o \
mpih-cmp.o \

51
lib/crypto/mpi/mpi-add.c
View File

@ -13,57 +13,6 @@
#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)
{
mpi_ptr_t wp, up, vp;

143
lib/crypto/mpi/mpi-bit.c
View File

@ -32,7 +32,6 @@ void mpi_normalize(MPI a)
for (; a->nlimbs && !a->d[a->nlimbs - 1]; a->nlimbs--)
;
}
EXPORT_SYMBOL_GPL(mpi_normalize);
/****************
* Return the number of bits in A.
@ -93,85 +92,6 @@ void mpi_set_bit(MPI a, unsigned int n)
a->d[limbno] |= (A_LIMB_1<<bitno);
}
/****************
* Set bit N of A. and clear all bits above
*/
void mpi_set_highbit(MPI a, unsigned int n)
{
unsigned int i, limbno, bitno;
limbno = n / BITS_PER_MPI_LIMB;
bitno = n % BITS_PER_MPI_LIMB;
if (limbno >= a->nlimbs) {
for (i = a->nlimbs; i < a->alloced; i++)
a->d[i] = 0;
mpi_resize(a, limbno+1);
a->nlimbs = limbno+1;
}
a->d[limbno] |= (A_LIMB_1<<bitno);
for (bitno++; bitno < BITS_PER_MPI_LIMB; bitno++)
a->d[limbno] &= ~(A_LIMB_1 << bitno);
a->nlimbs = limbno+1;
}
EXPORT_SYMBOL_GPL(mpi_set_highbit);
/****************
* clear bit N of A and all bits above
*/
void mpi_clear_highbit(MPI a, unsigned int n)
{
unsigned int limbno, bitno;
limbno = n / BITS_PER_MPI_LIMB;
bitno = n % BITS_PER_MPI_LIMB;
if (limbno >= a->nlimbs)
return; /* not allocated, therefore no need to clear bits :-) */
for ( ; bitno < BITS_PER_MPI_LIMB; bitno++)
a->d[limbno] &= ~(A_LIMB_1 << bitno);
a->nlimbs = limbno+1;
}
/****************
* Clear bit N of A.
*/
void mpi_clear_bit(MPI a, unsigned int n)
{
unsigned int limbno, bitno;
limbno = n / BITS_PER_MPI_LIMB;
bitno = n % BITS_PER_MPI_LIMB;
if (limbno >= a->nlimbs)
return; /* Don't need to clear this bit, it's far too left. */
a->d[limbno] &= ~(A_LIMB_1 << bitno);
}
EXPORT_SYMBOL_GPL(mpi_clear_bit);
/****************
* Shift A by COUNT limbs to the right
* This is used only within the MPI library
*/
void mpi_rshift_limbs(MPI a, unsigned int count)
{
mpi_ptr_t ap = a->d;
mpi_size_t n = a->nlimbs;
unsigned int i;
if (count >= n) {
a->nlimbs = 0;
return;
}
for (i = 0; i < n - count; i++)
ap[i] = ap[i+count];
ap[i] = 0;
a->nlimbs -= count;
}
/*
* Shift A by N bits to the right.
*/
@ -241,66 +161,3 @@ void mpi_rshift(MPI x, MPI a, unsigned int n)
MPN_NORMALIZE(x->d, x->nlimbs);
}
EXPORT_SYMBOL_GPL(mpi_rshift);
/****************
* Shift A by COUNT limbs to the left
* This is used only within the MPI library
*/
void mpi_lshift_limbs(MPI a, unsigned int count)
{
mpi_ptr_t ap;
int n = a->nlimbs;
int i;
if (!count || !n)
return;
RESIZE_IF_NEEDED(a, n+count);
ap = a->d;
for (i = n-1; i >= 0; i--)
ap[i+count] = ap[i];
for (i = 0; i < count; i++)
ap[i] = 0;
a->nlimbs += count;
}
/*
* Shift A by N bits to the left.
*/
void mpi_lshift(MPI x, MPI a, unsigned int n)
{
unsigned int nlimbs = (n/BITS_PER_MPI_LIMB);
unsigned int nbits = (n%BITS_PER_MPI_LIMB);
if (x == a && !n)
return; /* In-place shift with an amount of zero. */
if (x != a) {
/* Copy A to X. */
unsigned int alimbs = a->nlimbs;
int asign = a->sign;
mpi_ptr_t xp, ap;
RESIZE_IF_NEEDED(x, alimbs+nlimbs+1);
xp = x->d;
ap = a->d;
MPN_COPY(xp, ap, alimbs);
x->nlimbs = alimbs;
x->flags = a->flags;
x->sign = asign;
}
if (nlimbs && !nbits) {
/* Shift a full number of limbs. */
mpi_lshift_limbs(x, nlimbs);
} else if (n) {
/* We use a very dump approach: Shift left by the number of
* limbs plus one and than fix it up by an rshift.
*/
mpi_lshift_limbs(x, nlimbs+1);
mpi_rshift(x, x, BITS_PER_MPI_LIMB - nbits);
}
MPN_NORMALIZE(x->d, x->nlimbs);
}

46
lib/crypto/mpi/mpi-cmp.c
View File

@ -45,54 +45,28 @@ int mpi_cmp_ui(MPI u, unsigned long v)
}
EXPORT_SYMBOL_GPL(mpi_cmp_ui);
static int do_mpi_cmp(MPI u, MPI v, int absmode)
int mpi_cmp(MPI u, MPI v)
{
mpi_size_t usize;
mpi_size_t vsize;
int usign;
int vsign;
mpi_size_t usize, vsize;
int cmp;
mpi_normalize(u);
mpi_normalize(v);
usize = u->nlimbs;
vsize = v->nlimbs;
usign = absmode ? 0 : u->sign;
vsign = absmode ? 0 : v->sign;
/* Compare sign bits. */
if (!usign && vsign)
if (!u->sign && v->sign)
return 1;
if (usign && !vsign)
if (u->sign && !v->sign)
return -1;
/* U and V are either both positive or both negative. */
if (usize != vsize && !usign && !vsign)
if (usize != vsize && !u->sign && !v->sign)
return usize - vsize;
if (usize != vsize && usign && vsign)
return vsize + usize;
if (usize != vsize && u->sign && v->sign)
return vsize - usize;
if (!usize)
return 0;
cmp = mpihelp_cmp(u->d, v->d, usize);
if (!cmp)
return 0;
if ((cmp < 0?1:0) == (usign?1:0))
return 1;
return -1;
}
int mpi_cmp(MPI u, MPI v)
{
return do_mpi_cmp(u, v, 0);
if (u->sign)
return -cmp;
return cmp;
}
EXPORT_SYMBOL_GPL(mpi_cmp);
int mpi_cmpabs(MPI u, MPI v)
{
return do_mpi_cmp(u, v, 1);
}
EXPORT_SYMBOL_GPL(mpi_cmpabs);

29
lib/crypto/mpi/mpi-div.c
View File

@ -15,7 +15,6 @@
#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)
{
@ -40,34 +39,6 @@ void mpi_fdiv_r(MPI rem, MPI dividend, MPI 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.

10
lib/crypto/mpi/mpi-internal.h
View File

@ -66,14 +66,6 @@ typedef int mpi_size_t; /* (must be a signed type) */
(d)[_i] = (s)[_i]; \
} while (0)
#define MPN_COPY_INCR(d, s, n) \
do { \
mpi_size_t _i; \
for (_i = 0; _i < (n); _i++) \
(d)[_i] = (s)[_i]; \
} while (0)
#define MPN_COPY_DECR(d, s, n) \
do { \
mpi_size_t _i; \
@ -181,8 +173,6 @@ int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
mpi_ptr_t tspace);
void mpihelp_mul_n(mpi_ptr_t prodp,
mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
mpi_ptr_t up, mpi_size_t usize,

143
lib/crypto/mpi/mpi-inv.c
View File

@ -1,143 +0,0 @@
/* mpi-inv.c - MPI functions
* Copyright (C) 1998, 2001, 2002, 2003 Free Software Foundation, Inc.
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "mpi-internal.h"
/****************
* Calculate the multiplicative inverse X of A mod N
* That is: Find the solution x for
* 1 = (a*x) mod n
*/
int mpi_invm(MPI x, MPI a, MPI n)
{
/* Extended Euclid's algorithm (See TAOCP Vol II, 4.5.2, Alg X)
* modified according to Michael Penk's solution for Exercise 35
* with further enhancement
*/
MPI u, v, u1, u2 = NULL, u3, v1, v2 = NULL, v3, t1, t2 = NULL, t3;
unsigned int k;
int sign;
int odd;
if (!mpi_cmp_ui(a, 0))
return 0; /* Inverse does not exists. */
if (!mpi_cmp_ui(n, 1))
return 0; /* Inverse does not exists. */
u = mpi_copy(a);
v = mpi_copy(n);
for (k = 0; !mpi_test_bit(u, 0) && !mpi_test_bit(v, 0); k++) {
mpi_rshift(u, u, 1);
mpi_rshift(v, v, 1);
}
odd = mpi_test_bit(v, 0);
u1 = mpi_alloc_set_ui(1);
if (!odd)
u2 = mpi_alloc_set_ui(0);
u3 = mpi_copy(u);
v1 = mpi_copy(v);
if (!odd) {
v2 = mpi_alloc(mpi_get_nlimbs(u));
mpi_sub(v2, u1, u); /* U is used as const 1 */
}
v3 = mpi_copy(v);
if (mpi_test_bit(u, 0)) { /* u is odd */
t1 = mpi_alloc_set_ui(0);
if (!odd) {
t2 = mpi_alloc_set_ui(1);
t2->sign = 1;
}
t3 = mpi_copy(v);
t3->sign = !t3->sign;
goto Y4;
} else {
t1 = mpi_alloc_set_ui(1);
if (!odd)
t2 = mpi_alloc_set_ui(0);
t3 = mpi_copy(u);
}
do {
do {
if (!odd) {
if (mpi_test_bit(t1, 0) || mpi_test_bit(t2, 0)) {
/* one is odd */
mpi_add(t1, t1, v);
mpi_sub(t2, t2, u);
}
mpi_rshift(t1, t1, 1);
mpi_rshift(t2, t2, 1);
mpi_rshift(t3, t3, 1);
} else {
if (mpi_test_bit(t1, 0))
mpi_add(t1, t1, v);
mpi_rshift(t1, t1, 1);
mpi_rshift(t3, t3, 1);
}
Y4:
;
} while (!mpi_test_bit(t3, 0)); /* while t3 is even */
if (!t3->sign) {
mpi_set(u1, t1);
if (!odd)
mpi_set(u2, t2);
mpi_set(u3, t3);
} else {
mpi_sub(v1, v, t1);
sign = u->sign; u->sign = !u->sign;
if (!odd)
mpi_sub(v2, u, t2);
u->sign = sign;
sign = t3->sign; t3->sign = !t3->sign;
mpi_set(v3, t3);
t3->sign = sign;
}
mpi_sub(t1, u1, v1);
if (!odd)
mpi_sub(t2, u2, v2);
mpi_sub(t3, u3, v3);
if (t1->sign) {
mpi_add(t1, t1, v);
if (!odd)
mpi_sub(t2, t2, u);
}
} while (mpi_cmp_ui(t3, 0)); /* while t3 != 0 */
/* mpi_lshift( u3, k ); */
mpi_set(x, u1);
mpi_free(u1);
mpi_free(v1);
mpi_free(t1);
if (!odd) {
mpi_free(u2);
mpi_free(v2);
mpi_free(t2);
}
mpi_free(u3);
mpi_free(v3);
mpi_free(t3);
mpi_free(u);
mpi_free(v);
return 1;
}
EXPORT_SYMBOL_GPL(mpi_invm);

144
lib/crypto/mpi/mpi-mod.c
View File

@ -5,153 +5,9 @@
* This file is part of Libgcrypt.
*/
#include "mpi-internal.h"
#include "longlong.h"
/* Context used with Barrett reduction. */
struct barrett_ctx_s {
MPI m; /* The modulus - may not be modified. */
int m_copied; /* If true, M needs to be released. */
int k;
MPI y;
MPI r1; /* Helper MPI. */
MPI r2; /* Helper MPI. */
MPI r3; /* Helper MPI allocated on demand. */
};
void mpi_mod(MPI rem, MPI dividend, MPI divisor)
{
mpi_fdiv_r(rem, dividend, divisor);
}
/* This function returns a new context for Barrett based operations on
* the modulus M. This context needs to be released using
* _gcry_mpi_barrett_free. If COPY is true M will be transferred to
* the context and the user may change M. If COPY is false, M may not
* be changed until gcry_mpi_barrett_free has been called.
*/
mpi_barrett_t mpi_barrett_init(MPI m, int copy)
{
mpi_barrett_t ctx;
MPI tmp;
mpi_normalize(m);
ctx = kcalloc(1, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return NULL;
if (copy) {
ctx->m = mpi_copy(m);
ctx->m_copied = 1;
} else
ctx->m = m;
ctx->k = mpi_get_nlimbs(m);
tmp = mpi_alloc(ctx->k + 1);
/* Barrett precalculation: y = floor(b^(2k) / m). */
mpi_set_ui(tmp, 1);
mpi_lshift_limbs(tmp, 2 * ctx->k);
mpi_fdiv_q(tmp, tmp, m);
ctx->y = tmp;
ctx->r1 = mpi_alloc(2 * ctx->k + 1);
ctx->r2 = mpi_alloc(2 * ctx->k + 1);
return ctx;
}
void mpi_barrett_free(mpi_barrett_t ctx)
{
if (ctx) {
mpi_free(ctx->y);
mpi_free(ctx->r1);
mpi_free(ctx->r2);
if (ctx->r3)
mpi_free(ctx->r3);
if (ctx->m_copied)
mpi_free(ctx->m);
kfree(ctx);
}
}
/* R = X mod M
*
* Using Barrett reduction. Before using this function
* _gcry_mpi_barrett_init must have been called to do the
* precalculations. CTX is the context created by this precalculation
* and also conveys M. If the Barret reduction could no be done a
* straightforward reduction method is used.
*
* We assume that these conditions are met:
* Input: x =(x_2k-1 ...x_0)_b
* m =(m_k-1 ....m_0)_b with m_k-1 != 0
* Output: r = x mod m
*/
void mpi_mod_barrett(MPI r, MPI x, mpi_barrett_t ctx)
{
MPI m = ctx->m;
int k = ctx->k;
MPI y = ctx->y;
MPI r1 = ctx->r1;
MPI r2 = ctx->r2;
int sign;
mpi_normalize(x);
if (mpi_get_nlimbs(x) > 2*k) {
mpi_mod(r, x, m);
return;
}
sign = x->sign;
x->sign = 0;
/* 1. q1 = floor( x / b^k-1)
* q2 = q1 * y
* q3 = floor( q2 / b^k+1 )
* Actually, we don't need qx, we can work direct on r2
*/
mpi_set(r2, x);
mpi_rshift_limbs(r2, k-1);
mpi_mul(r2, r2, y);
mpi_rshift_limbs(r2, k+1);
/* 2. r1 = x mod b^k+1
* r2 = q3 * m mod b^k+1
* r = r1 - r2
* 3. if r < 0 then r = r + b^k+1
*/
mpi_set(r1, x);
if (r1->nlimbs > k+1) /* Quick modulo operation. */
r1->nlimbs = k+1;
mpi_mul(r2, r2, m);
if (r2->nlimbs > k+1) /* Quick modulo operation. */
r2->nlimbs = k+1;
mpi_sub(r, r1, r2);
if (mpi_has_sign(r)) {
if (!ctx->r3) {
ctx->r3 = mpi_alloc(k + 2);
mpi_set_ui(ctx->r3, 1);
mpi_lshift_limbs(ctx->r3, k + 1);
}
mpi_add(r, r, ctx->r3);
}
/* 4. while r >= m do r = r - m */
while (mpi_cmp(r, m) >= 0)
mpi_sub(r, r, m);
x->sign = sign;
}
void mpi_mul_barrett(MPI w, MPI u, MPI v, mpi_barrett_t ctx)
{
mpi_mul(w, u, v);
mpi_mod_barrett(w, w, ctx);
}

336
lib/crypto/mpi/mpicoder.c
View File

@ -25,7 +25,6 @@
#include <linux/string.h>
#include "mpi-internal.h"
#define MAX_EXTERN_SCAN_BYTES (16*1024*1024)
#define MAX_EXTERN_MPI_BITS 16384
/**
@ -110,112 +109,6 @@ MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
}
EXPORT_SYMBOL_GPL(mpi_read_from_buffer);
/****************
* Fill the mpi VAL from the hex string in STR.
*/
int mpi_fromstr(MPI val, const char *str)
{
int sign = 0;
int prepend_zero = 0;
int i, j, c, c1, c2;
unsigned int nbits, nbytes, nlimbs;
mpi_limb_t a;
if (*str == '-') {
sign = 1;
str++;
}
/* Skip optional hex prefix. */
if (*str == '0' && str[1] == 'x')
str += 2;
nbits = strlen(str);
if (nbits > MAX_EXTERN_SCAN_BYTES) {
mpi_clear(val);
return -EINVAL;
}
nbits *= 4;
if ((nbits % 8))
prepend_zero = 1;
nbytes = (nbits+7) / 8;
nlimbs = (nbytes+BYTES_PER_MPI_LIMB-1) / BYTES_PER_MPI_LIMB;
if (val->alloced < nlimbs)
mpi_resize(val, nlimbs);
i = BYTES_PER_MPI_LIMB - (nbytes % BYTES_PER_MPI_LIMB);
i %= BYTES_PER_MPI_LIMB;
j = val->nlimbs = nlimbs;
val->sign = sign;
for (; j > 0; j--) {
a = 0;
for (; i < BYTES_PER_MPI_LIMB; i++) {
if (prepend_zero) {
c1 = '0';
prepend_zero = 0;
} else
c1 = *str++;
if (!c1) {
mpi_clear(val);
return -EINVAL;
}
c2 = *str++;
if (!c2) {
mpi_clear(val);
return -EINVAL;
}
if (c1 >= '0' && c1 <= '9')
c = c1 - '0';
else if (c1 >= 'a' && c1 <= 'f')
c = c1 - 'a' + 10;
else if (c1 >= 'A' && c1 <= 'F')
c = c1 - 'A' + 10;
else {
mpi_clear(val);
return -EINVAL;
}
c <<= 4;
if (c2 >= '0' && c2 <= '9')
c |= c2 - '0';
else if (c2 >= 'a' && c2 <= 'f')
c |= c2 - 'a' + 10;
else if (c2 >= 'A' && c2 <= 'F')
c |= c2 - 'A' + 10;
else {
mpi_clear(val);
return -EINVAL;
}
a <<= 8;
a |= c;
}
i = 0;
val->d[j-1] = a;
}
return 0;
}
EXPORT_SYMBOL_GPL(mpi_fromstr);
MPI mpi_scanval(const char *string)
{
MPI a;
a = mpi_alloc(0);
if (!a)
return NULL;
if (mpi_fromstr(a, string)) {
mpi_free(a);
return NULL;
}
mpi_normalize(a);
return a;
}
EXPORT_SYMBOL_GPL(mpi_scanval);
static int count_lzeros(MPI a)
{
mpi_limb_t alimb;
@ -521,232 +414,3 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
return val;
}
EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl);
/* Perform a two's complement operation on buffer P of size N bytes. */
static void twocompl(unsigned char *p, unsigned int n)
{
int i;
for (i = n-1; i >= 0 && !p[i]; i--)
;
if (i >= 0) {
if ((p[i] & 0x01))
p[i] = (((p[i] ^ 0xfe) | 0x01) & 0xff);
else if ((p[i] & 0x02))
p[i] = (((p[i] ^ 0xfc) | 0x02) & 0xfe);
else if ((p[i] & 0x04))
p[i] = (((p[i] ^ 0xf8) | 0x04) & 0xfc);
else if ((p[i] & 0x08))
p[i] = (((p[i] ^ 0xf0) | 0x08) & 0xf8);
else if ((p[i] & 0x10))
p[i] = (((p[i] ^ 0xe0) | 0x10) & 0xf0);
else if ((p[i] & 0x20))
p[i] = (((p[i] ^ 0xc0) | 0x20) & 0xe0);
else if ((p[i] & 0x40))
p[i] = (((p[i] ^ 0x80) | 0x40) & 0xc0);
else
p[i] = 0x80;
for (i--; i >= 0; i--)
p[i] ^= 0xff;
}
}
int mpi_print(enum gcry_mpi_format format, unsigned char *buffer,
size_t buflen, size_t *nwritten, MPI a)
{
unsigned int nbits = mpi_get_nbits(a);
size_t len;
size_t dummy_nwritten;
int negative;
if (!nwritten)
nwritten = &dummy_nwritten;
/* Libgcrypt does no always care to set clear the sign if the value
* is 0. For printing this is a bit of a surprise, in particular
* because if some of the formats don't support negative numbers but
* should be able to print a zero. Thus we need this extra test
* for a negative number.
*/
if (a->sign && mpi_cmp_ui(a, 0))
negative = 1;
else
negative = 0;
len = buflen;
*nwritten = 0;
if (format == GCRYMPI_FMT_STD) {
unsigned char *tmp;
int extra = 0;
unsigned int n;
tmp = mpi_get_buffer(a, &n, NULL);
if (!tmp)
return -EINVAL;
if (negative) {
twocompl(tmp, n);
if (!(*tmp & 0x80)) {
/* Need to extend the sign. */
n++;
extra = 2;
}
} else if (n && (*tmp & 0x80)) {
/* Positive but the high bit of the returned buffer is set.
* Thus we need to print an extra leading 0x00 so that the
* output is interpreted as a positive number.
*/
n++;
extra = 1;
}
if (buffer && n > len) {
/* The provided buffer is too short. */
kfree(tmp);
return -E2BIG;
}
if (buffer) {
unsigned char *s = buffer;
if (extra == 1)
*s++ = 0;
else if (extra)
*s++ = 0xff;
memcpy(s, tmp, n-!!extra);
}
kfree(tmp);
*nwritten = n;
return 0;
} else if (format == GCRYMPI_FMT_USG) {
unsigned int n = (nbits + 7)/8;
/* Note: We ignore the sign for this format. */
/* FIXME: for performance reasons we should put this into
* mpi_aprint because we can then use the buffer directly.
*/
if (buffer && n > len)
return -E2BIG;
if (buffer) {
unsigned char *tmp;
tmp = mpi_get_buffer(a, &n, NULL);
if (!tmp)
return -EINVAL;
memcpy(buffer, tmp, n);
kfree(tmp);
}
*nwritten = n;
return 0;
} else if (format == GCRYMPI_FMT_PGP) {
unsigned int n = (nbits + 7)/8;
/* The PGP format can only handle unsigned integers. */
if (negative)
return -EINVAL;
if (buffer && n+2 > len)
return -E2BIG;
if (buffer) {
unsigned char *tmp;
unsigned char *s = buffer;
s[0] = nbits >> 8;
s[1] = nbits;
tmp = mpi_get_buffer(a, &n, NULL);
if (!tmp)
return -EINVAL;
memcpy(s+2, tmp, n);
kfree(tmp);
}
*nwritten = n+2;
return 0;
} else if (format == GCRYMPI_FMT_SSH) {
unsigned char *tmp;
int extra = 0;
unsigned int n;
tmp = mpi_get_buffer(a, &n, NULL);
if (!tmp)
return -EINVAL;
if (negative) {
twocompl(tmp, n);
if (!(*tmp & 0x80)) {
/* Need to extend the sign. */
n++;
extra = 2;
}
} else if (n && (*tmp & 0x80)) {
n++;
extra = 1;
}
if (buffer && n+4 > len) {
kfree(tmp);
return -E2BIG;
}
if (buffer) {
unsigned char *s = buffer;
*s++ = n >> 24;
*s++ = n >> 16;
*s++ = n >> 8;
*s++ = n;
if (extra == 1)
*s++ = 0;
else if (extra)
*s++ = 0xff;
memcpy(s, tmp, n-!!extra);
}
kfree(tmp);
*nwritten = 4+n;
return 0;
} else if (format == GCRYMPI_FMT_HEX) {
unsigned char *tmp;
int i;
int extra = 0;
unsigned int n = 0;
tmp = mpi_get_buffer(a, &n, NULL);
if (!tmp)
return -EINVAL;
if (!n || (*tmp & 0x80))
extra = 2;
if (buffer && 2*n + extra + negative + 1 > len) {
kfree(tmp);
return -E2BIG;
}
if (buffer) {
unsigned char *s = buffer;
if (negative)
*s++ = '-';
if (extra) {
*s++ = '0';
*s++ = '0';
}
for (i = 0; i < n; i++) {
unsigned int c = tmp[i];
*s++ = (c >> 4) < 10 ? '0'+(c>>4) : 'A'+(c>>4)-10;
c &= 15;
*s++ = c < 10 ? '0'+c : 'A'+c-10;
}
*s++ = 0;
*nwritten = s - buffer;
} else {
*nwritten = 2*n + extra + negative + 1;
}
kfree(tmp);
return 0;
} else
return -EINVAL;
}
EXPORT_SYMBOL_GPL(mpi_print);

25
lib/crypto/mpi/mpih-mul.c
View File

@ -317,31 +317,6 @@ mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size, mpi_ptr_t tspace)
}
}
void mpihelp_mul_n(mpi_ptr_t prodp,
mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size)
{
if (up == vp) {
if (size < KARATSUBA_THRESHOLD)
mpih_sqr_n_basecase(prodp, up, size);
else {
mpi_ptr_t tspace;
tspace = mpi_alloc_limb_space(2 * size);
mpih_sqr_n(prodp, up, size, tspace);
mpi_free_limb_space(tspace);
}
} else {
if (size < KARATSUBA_THRESHOLD)
mul_n_basecase(prodp, up, vp, size);
else {
mpi_ptr_t tspace;
tspace = mpi_alloc_limb_space(2 * size);
mul_n(prodp, up, vp, size, tspace);
mpi_free_limb_space(tspace);
}
}
}
int
mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
mpi_ptr_t up, mpi_size_t usize,

182
lib/crypto/mpi/mpiutil.c
View File

@ -20,63 +20,6 @@
#include "mpi-internal.h"
/* Constants allocated right away at startup. */
static MPI constants[MPI_NUMBER_OF_CONSTANTS];
/* Initialize the MPI subsystem. This is called early and allows to
* do some initialization without taking care of threading issues.
*/
static int __init mpi_init(void)
{
int idx;
unsigned long value;
for (idx = 0; idx < MPI_NUMBER_OF_CONSTANTS; idx++) {
switch (idx) {
case MPI_C_ZERO:
value = 0;
break;
case MPI_C_ONE:
value = 1;
break;
case MPI_C_TWO:
value = 2;
break;
case MPI_C_THREE:
value = 3;
break;
case MPI_C_FOUR:
value = 4;
break;
case MPI_C_EIGHT:
value = 8;
break;
default:
pr_err("MPI: invalid mpi_const selector %d\n", idx);
return -EFAULT;
}
constants[idx] = mpi_alloc_set_ui(value);
constants[idx]->flags = (16|32);
}
return 0;
}
postcore_initcall(mpi_init);
/* Return a constant MPI descripbed by NO which is one of the
* MPI_C_xxx macros. There is no need to copy this returned value; it
* may be used directly.
*/
MPI mpi_const(enum gcry_mpi_constants no)
{
if ((int)no < 0 || no > MPI_NUMBER_OF_CONSTANTS)
pr_err("MPI: invalid mpi_const selector %d\n", no);
if (!constants[no])
pr_err("MPI: MPI subsystem not initialized\n");
return constants[no];
}
EXPORT_SYMBOL_GPL(mpi_const);
/****************
* Note: It was a bad idea to use the number of limbs to allocate
* because on a alpha the limbs are large but we normally need
@ -163,15 +106,6 @@ int mpi_resize(MPI a, unsigned nlimbs)
return 0;
}
void mpi_clear(MPI a)
{
if (!a)
return;
a->nlimbs = 0;
a->flags = 0;
}
EXPORT_SYMBOL_GPL(mpi_clear);
void mpi_free(MPI a)
{
if (!a)
@ -210,121 +144,5 @@ MPI mpi_copy(MPI a)
return b;
}
/****************
* This function allocates an MPI which is optimized to hold
* a value as large as the one given in the argument and allocates it
* with the same flags as A.
*/
MPI mpi_alloc_like(MPI a)
{
MPI b;
if (a) {
b = mpi_alloc(a->nlimbs);
b->nlimbs = 0;
b->sign = 0;
b->flags = a->flags;
} else
b = NULL;
return b;
}
/* Set U into W and release U. If W is NULL only U will be released. */
void mpi_snatch(MPI w, MPI u)
{
if (w) {
mpi_assign_limb_space(w, u->d, u->alloced);
w->nlimbs = u->nlimbs;
w->sign = u->sign;
w->flags = u->flags;
u->alloced = 0;
u->nlimbs = 0;
u->d = NULL;
}
mpi_free(u);
}
MPI mpi_set(MPI w, MPI u)
{
mpi_ptr_t wp, up;
mpi_size_t usize = u->nlimbs;
int usign = u->sign;
if (!w)
w = mpi_alloc(mpi_get_nlimbs(u));
RESIZE_IF_NEEDED(w, usize);
wp = w->d;
up = u->d;
MPN_COPY(wp, up, usize);
w->nlimbs = usize;
w->flags = u->flags;
w->flags &= ~(16|32); /* Reset the immutable and constant flags. */
w->sign = usign;
return w;
}
EXPORT_SYMBOL_GPL(mpi_set);
MPI mpi_set_ui(MPI w, unsigned long u)
{
if (!w)
w = mpi_alloc(1);
/* FIXME: If U is 0 we have no need to resize and thus possible
* allocating the limbs.
*/
RESIZE_IF_NEEDED(w, 1);
w->d[0] = u;
w->nlimbs = u ? 1 : 0;
w->sign = 0;
w->flags = 0;
return w;
}
EXPORT_SYMBOL_GPL(mpi_set_ui);
MPI mpi_alloc_set_ui(unsigned long u)
{
MPI w = mpi_alloc(1);
w->d[0] = u;
w->nlimbs = u ? 1 : 0;
w->sign = 0;
return w;
}
/****************
* Swap the value of A and B, when SWAP is 1.
* Leave the value when SWAP is 0.
* This implementation should be constant-time regardless of SWAP.
*/
void mpi_swap_cond(MPI a, MPI b, unsigned long swap)
{
mpi_size_t i;
mpi_size_t nlimbs;
mpi_limb_t mask = ((mpi_limb_t)0) - swap;
mpi_limb_t x;
if (a->alloced > b->alloced)
nlimbs = b->alloced;
else
nlimbs = a->alloced;
if (a->nlimbs > nlimbs || b->nlimbs > nlimbs)
return;
for (i = 0; i < nlimbs; i++) {
x = mask & (a->d[i] ^ b->d[i]);
a->d[i] = a->d[i] ^ x;
b->d[i] = b->d[i] ^ x;
}
x = mask & (a->nlimbs ^ b->nlimbs);
a->nlimbs = a->nlimbs ^ x;
b->nlimbs = b->nlimbs ^ x;
x = mask & (a->sign ^ b->sign);
a->sign = a->sign ^ x;
b->sign = b->sign ^ x;
}
MODULE_DESCRIPTION("Multiprecision maths library");
MODULE_LICENSE("GPL");