From aacf29bf1bf133f6219e6f8969d4ebc2ac76458f Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 13 Sep 2012 13:09:33 +0100 Subject: MPILIB: Provide count_leading/trailing_zeros() based on arch functions Provide count_leading/trailing_zeros() macros based on extant arch bit scanning functions rather than reimplementing from scratch in MPILIB. Whilst we're at it, turn count_foo_zeros(n, x) into n = count_foo_zeros(x). Also move the definition to asm-generic as other people may be interested in using it. Signed-off-by: David Howells Cc: David S. Miller Cc: Dmitry Kasatkin Cc: Arnd Bergmann Signed-off-by: Rusty Russell --- lib/mpi/longlong.h | 138 +---------------------------------------------------- lib/mpi/mpi-bit.c | 2 +- lib/mpi/mpi-pow.c | 4 +- 3 files changed, 5 insertions(+), 139 deletions(-) (limited to 'lib/mpi') diff --git a/lib/mpi/longlong.h b/lib/mpi/longlong.h index 29f98624ef93..678ce4f1e124 100644 --- a/lib/mpi/longlong.h +++ b/lib/mpi/longlong.h @@ -19,6 +19,8 @@ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, * MA 02111-1307, USA. */ +#include + /* You have to define the following before including this file: * * UWtype -- An unsigned type, default type for operations (typically a "word") @@ -146,12 +148,6 @@ do { \ : "1" ((USItype)(n1)), \ "r" ((USItype)(n0)), \ "r" ((USItype)(d))) - -#define count_leading_zeros(count, x) \ - __asm__ ("clz %0,%1" \ - : "=r" ((USItype)(count)) \ - : "r" ((USItype)(x))) -#define COUNT_LEADING_ZEROS_0 32 #endif /* __a29k__ */ #if defined(__alpha) && W_TYPE_SIZE == 64 @@ -298,11 +294,6 @@ extern UDItype __udiv_qrnnd(); : "1" ((USItype)(nh)), \ "0" ((USItype)(nl)), \ "g" ((USItype)(d))) -#define count_leading_zeros(count, x) \ - __asm__ ("bsch/1 %1,%0" \ - : "=g" (count) \ - : "g" ((USItype)(x)), \ - "0" ((USItype)0)) #endif /*************************************** @@ -354,27 +345,6 @@ do { USItype __r; \ } while (0) extern USItype __udiv_qrnnd(); #endif /* LONGLONG_STANDALONE */ -#define count_leading_zeros(count, x) \ -do { \ - USItype __tmp; \ - __asm__ ( \ - "ldi 1,%0\n" \ - "extru,= %1,15,16,%%r0 ; Bits 31..16 zero?\n" \ - "extru,tr %1,15,16,%1 ; No. Shift down, skip add.\n" \ - "ldo 16(%0),%0 ; Yes. Perform add.\n" \ - "extru,= %1,23,8,%%r0 ; Bits 15..8 zero?\n" \ - "extru,tr %1,23,8,%1 ; No. Shift down, skip add.\n" \ - "ldo 8(%0),%0 ; Yes. Perform add.\n" \ - "extru,= %1,27,4,%%r0 ; Bits 7..4 zero?\n" \ - "extru,tr %1,27,4,%1 ; No. Shift down, skip add.\n" \ - "ldo 4(%0),%0 ; Yes. Perform add.\n" \ - "extru,= %1,29,2,%%r0 ; Bits 3..2 zero?\n" \ - "extru,tr %1,29,2,%1 ; No. Shift down, skip add.\n" \ - "ldo 2(%0),%0 ; Yes. Perform add.\n" \ - "extru %1,30,1,%1 ; Extract bit 1.\n" \ - "sub %0,%1,%0 ; Subtract it. " \ - : "=r" (count), "=r" (__tmp) : "1" (x)); \ -} while (0) #endif /* hppa */ /*************************************** @@ -457,15 +427,6 @@ do { \ : "0" ((USItype)(n0)), \ "1" ((USItype)(n1)), \ "rm" ((USItype)(d))) -#define count_leading_zeros(count, x) \ -do { \ - USItype __cbtmp; \ - __asm__ ("bsrl %1,%0" \ - : "=r" (__cbtmp) : "rm" ((USItype)(x))); \ - (count) = __cbtmp ^ 31; \ -} while (0) -#define count_trailing_zeros(count, x) \ - __asm__ ("bsfl %1,%0" : "=r" (count) : "rm" ((USItype)(x))) #ifndef UMUL_TIME #define UMUL_TIME 40 #endif @@ -536,15 +497,6 @@ do { \ "dI" ((USItype)(d))); \ (r) = __rq.__i.__l; (q) = __rq.__i.__h; \ } while (0) -#define count_leading_zeros(count, x) \ -do { \ - USItype __cbtmp; \ - __asm__ ("scanbit %1,%0" \ - : "=r" (__cbtmp) \ - : "r" ((USItype)(x))); \ - (count) = __cbtmp ^ 31; \ -} while (0) -#define COUNT_LEADING_ZEROS_0 (-32) /* sic */ #if defined(__i960mx) /* what is the proper symbol to test??? */ #define rshift_rhlc(r, h, l, c) \ do { \ @@ -603,11 +555,6 @@ do { \ : "0" ((USItype)(n0)), \ "1" ((USItype)(n1)), \ "dmi" ((USItype)(d))) -#define count_leading_zeros(count, x) \ - __asm__ ("bfffo %1{%b2:%b2},%0" \ - : "=d" ((USItype)(count)) \ - : "od" ((USItype)(x)), "n" (0)) -#define COUNT_LEADING_ZEROS_0 32 #else /* not mc68020 */ #define umul_ppmm(xh, xl, a, b) \ do { USItype __umul_tmp1, __umul_tmp2; \ @@ -664,15 +611,6 @@ do { USItype __umul_tmp1, __umul_tmp2; \ "rJ" ((USItype)(bh)), \ "rJ" ((USItype)(al)), \ "rJ" ((USItype)(bl))) -#define count_leading_zeros(count, x) \ -do { \ - USItype __cbtmp; \ - __asm__ ("ff1 %0,%1" \ - : "=r" (__cbtmp) \ - : "r" ((USItype)(x))); \ - (count) = __cbtmp ^ 31; \ -} while (0) -#define COUNT_LEADING_ZEROS_0 63 /* sic */ #if defined(__m88110__) #define umul_ppmm(wh, wl, u, v) \ do { \ @@ -779,12 +717,6 @@ do { \ : "0" (__xx.__ll), \ "g" ((USItype)(d))); \ (r) = __xx.__i.__l; (q) = __xx.__i.__h; }) -#define count_trailing_zeros(count, x) \ -do { \ - __asm__("ffsd %2,%0" \ - : "=r"((USItype) (count)) \ - : "0"((USItype) 0), "r"((USItype) (x))); \ - } while (0) #endif /* __ns32000__ */ /*************************************** @@ -855,11 +787,6 @@ do { \ "rI" ((USItype)(al)), \ "r" ((USItype)(bl))); \ } while (0) -#define count_leading_zeros(count, x) \ - __asm__ ("{cntlz|cntlzw} %0,%1" \ - : "=r" ((USItype)(count)) \ - : "r" ((USItype)(x))) -#define COUNT_LEADING_ZEROS_0 32 #if defined(_ARCH_PPC) #define umul_ppmm(ph, pl, m0, m1) \ do { \ @@ -1001,19 +928,6 @@ do { \ } while (0) #define UMUL_TIME 20 #define UDIV_TIME 200 -#define count_leading_zeros(count, x) \ -do { \ - if ((x) >= 0x10000) \ - __asm__ ("clz %0,%1" \ - : "=r" ((USItype)(count)) \ - : "r" ((USItype)(x) >> 16)); \ - else { \ - __asm__ ("clz %0,%1" \ - : "=r" ((USItype)(count)) \ - : "r" ((USItype)(x))); \ - (count) += 16; \ - } \ -} while (0) #endif /* RT/ROMP */ /*************************************** @@ -1142,13 +1056,6 @@ do { \ "rI" ((USItype)(d)) \ : "%g1" __AND_CLOBBER_CC) #define UDIV_TIME 37 -#define count_leading_zeros(count, x) \ - __asm__ ("scan %1,0,%0" \ - : "=r" ((USItype)(x)) \ - : "r" ((USItype)(count))) -/* Early sparclites return 63 for an argument of 0, but they warn that future - implementations might change this. Therefore, leave COUNT_LEADING_ZEROS_0 - undefined. */ #endif /* __sparclite__ */ #endif /* __sparc_v8__ */ /* Default to sparc v7 versions of umul_ppmm and udiv_qrnnd. */ @@ -1454,47 +1361,6 @@ do { \ #define udiv_qrnnd __udiv_qrnnd_c #endif -#undef count_leading_zeros -#if !defined(count_leading_zeros) - extern -#ifdef __STDC__ - const -#endif - unsigned char __clz_tab[]; -#define count_leading_zeros(count, x) \ -do { \ - UWtype __xr = (x); \ - UWtype __a; \ - \ - if (W_TYPE_SIZE <= 32) { \ - __a = __xr < ((UWtype) 1 << 2*__BITS4) \ - ? (__xr < ((UWtype) 1 << __BITS4) ? 0 : __BITS4) \ - : (__xr < ((UWtype) 1 << 3*__BITS4) ? 2*__BITS4 : 3*__BITS4); \ - } \ - else { \ - for (__a = W_TYPE_SIZE - 8; __a > 0; __a -= 8) \ - if (((__xr >> __a) & 0xff) != 0) \ - break; \ - } \ - \ - (count) = W_TYPE_SIZE - (__clz_tab[__xr >> __a] + __a); \ -} while (0) - /* This version gives a well-defined value for zero. */ -#define COUNT_LEADING_ZEROS_0 W_TYPE_SIZE -#endif - -#if !defined(count_trailing_zeros) -/* Define count_trailing_zeros using count_leading_zeros. The latter might be - defined in asm, but if it is not, the C version above is good enough. */ -#define count_trailing_zeros(count, x) \ -do { \ - UWtype __ctz_x = (x); \ - UWtype __ctz_c; \ - count_leading_zeros(__ctz_c, __ctz_x & -__ctz_x); \ - (count) = W_TYPE_SIZE - 1 - __ctz_c; \ -} while (0) -#endif - #ifndef UDIV_NEEDS_NORMALIZATION #define UDIV_NEEDS_NORMALIZATION 0 #endif diff --git a/lib/mpi/mpi-bit.c b/lib/mpi/mpi-bit.c index 568724804f29..503537e08436 100644 --- a/lib/mpi/mpi-bit.c +++ b/lib/mpi/mpi-bit.c @@ -45,7 +45,7 @@ unsigned mpi_get_nbits(MPI a) if (a->nlimbs) { mpi_limb_t alimb = a->d[a->nlimbs - 1]; if (alimb) - count_leading_zeros(n, alimb); + n = count_leading_zeros(alimb); else n = BITS_PER_MPI_LIMB; n = BITS_PER_MPI_LIMB - n + (a->nlimbs - 1) * BITS_PER_MPI_LIMB; diff --git a/lib/mpi/mpi-pow.c b/lib/mpi/mpi-pow.c index 67f3e79af914..5464c8744ea9 100644 --- a/lib/mpi/mpi-pow.c +++ b/lib/mpi/mpi-pow.c @@ -77,7 +77,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) mp = mp_marker = mpi_alloc_limb_space(msize); if (!mp) goto enomem; - count_leading_zeros(mod_shift_cnt, mod->d[msize - 1]); + mod_shift_cnt = count_leading_zeros(mod->d[msize - 1]); if (mod_shift_cnt) mpihelp_lshift(mp, mod->d, msize, mod_shift_cnt); else @@ -169,7 +169,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) i = esize - 1; e = ep[i]; - count_leading_zeros(c, e); + c = count_leading_zeros(e); e = (e << c) << 1; /* shift the exp bits to the left, lose msb */ c = BITS_PER_MPI_LIMB - 1 - c; -- cgit From 12f008b6dc5ff1c822fdb2198d20e3dbdc92f3f5 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 21 Sep 2012 23:25:22 +0100 Subject: MPILIB: Reinstate mpi_cmp[_ui]() and export for RSA signature verification Reinstate and export mpi_cmp() and mpi_cmp_ui() from the MPI library for use by RSA signature verification as per RFC3447 section 5.2.2 step 1. Signed-off-by: David Howells Signed-off-by: Rusty Russell --- lib/mpi/Makefile | 1 + lib/mpi/mpi-cmp.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 71 insertions(+) create mode 100644 lib/mpi/mpi-cmp.c (limited to 'lib/mpi') diff --git a/lib/mpi/Makefile b/lib/mpi/Makefile index 45ca90a8639c..019a68c90144 100644 --- a/lib/mpi/Makefile +++ b/lib/mpi/Makefile @@ -14,6 +14,7 @@ mpi-y = \ generic_mpih-add1.o \ mpicoder.o \ mpi-bit.o \ + mpi-cmp.o \ mpih-cmp.o \ mpih-div.o \ mpih-mul.o \ diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c new file mode 100644 index 000000000000..1871e7b61ca0 --- /dev/null +++ b/lib/mpi/mpi-cmp.c @@ -0,0 +1,70 @@ +/* mpi-cmp.c - MPI functions + * Copyright (C) 1998, 1999 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GnuPG 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include "mpi-internal.h" + +int mpi_cmp_ui(MPI u, unsigned long v) +{ + mpi_limb_t limb = v; + + mpi_normalize(u); + if (!u->nlimbs && !limb) + return 0; + if (u->sign) + return -1; + if (u->nlimbs > 1) + return 1; + + if (u->d[0] == limb) + return 0; + else if (u->d[0] > limb) + return 1; + else + return -1; +} +EXPORT_SYMBOL_GPL(mpi_cmp_ui); + +int mpi_cmp(MPI u, MPI v) +{ + mpi_size_t usize, vsize; + int cmp; + + mpi_normalize(u); + mpi_normalize(v); + usize = u->nlimbs; + vsize = v->nlimbs; + if (!u->sign && v->sign) + return 1; + if (u->sign && !v->sign) + return -1; + if (usize != vsize && !u->sign && !v->sign) + return usize - vsize; + 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) == (u->sign ? 1 : 0)) + return 1; + return -1; +} +EXPORT_SYMBOL_GPL(mpi_cmp); -- cgit From e1045992949160b56309b730b8bdc428f2f8b69e Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 24 Sep 2012 17:11:27 +0100 Subject: MPILIB: Provide a function to read raw data into an MPI Provide a function to read raw data of a predetermined size into an MPI rather than expecting the size to be encoded within the data. The data is assumed to represent an unsigned integer, and the resulting MPI will be positive. The function looks like this: MPI mpi_read_raw_data(const void *, size_t); This is useful for reading ASN.1 integer primitives where the length is encoded in the ASN.1 metadata. Signed-off-by: David Howells Signed-off-by: Rusty Russell --- lib/mpi/mpicoder.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'lib/mpi') diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index f0fa65995800..3962b7f7fe3f 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -18,10 +18,65 @@ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ +#include +#include #include "mpi-internal.h" #define MAX_EXTERN_MPI_BITS 16384 +/** + * mpi_read_raw_data - Read a raw byte stream as a positive integer + * @xbuffer: The data to read + * @nbytes: The amount of data to read + */ +MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) +{ + const uint8_t *buffer = xbuffer; + int i, j; + unsigned nbits, nlimbs; + mpi_limb_t a; + MPI val = NULL; + + while (nbytes >= 0 && buffer[0] == 0) { + buffer++; + nbytes--; + } + + nbits = nbytes * 8; + if (nbits > MAX_EXTERN_MPI_BITS) { + pr_info("MPI: mpi too large (%u bits)\n", nbits); + return NULL; + } + if (nbytes > 0) + nbits -= count_leading_zeros(buffer[0]); + else + nbits = 0; + + nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; + val = mpi_alloc(nlimbs); + if (!val) + return NULL; + val->nbits = nbits; + val->sign = 0; + val->nlimbs = nlimbs; + + if (nbytes > 0) { + i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; + i %= BYTES_PER_MPI_LIMB; + for (j = nlimbs; j > 0; j--) { + a = 0; + for (; i < BYTES_PER_MPI_LIMB; i++) { + a <<= 8; + a |= *buffer++; + } + i = 0; + val->d[j - 1] = a; + } + } + return val; +} +EXPORT_SYMBOL_GPL(mpi_read_raw_data); + MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) { const uint8_t *buffer = xbuffer; -- cgit