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Revert "lib/mpi: Extend the MPI library"
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This partially reverts commit a8ea8bd.

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>
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@herbertx
herbertx committed Aug 17, 2024
1 parent f235bc1 commit fca5cb4
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Showing 12 changed files with 10 additions and 1,165 deletions.
65 changes: 0 additions & 65 deletions include/linux/mpi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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);
Expand All @@ -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 */

Expand Down
1 change: 0 additions & 1 deletion lib/crypto/mpi/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -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 \
Expand Down
51 changes: 0 additions & 51 deletions lib/crypto/mpi/mpi-add.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
143 changes: 0 additions & 143 deletions lib/crypto/mpi/mpi-bit.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down Expand Up @@ -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.
*/
Expand Down Expand Up @@ -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);
}
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