crypto: GnuPG based MPI lib - header files (part 2)

Adds the multi-precision-integer maths library which was originally taken
from GnuPG and ported to the kernel by (among others) David Howells.
This version is taken from Fedora kernel 2.6.32-71.14.1.el6.
The difference is that checkpatch reported errors and warnings have been fixed.

This library is used to implemenet RSA digital signature verification
used in IMA/EVM integrity protection subsystem.

Due to patch size limitation, the patch is divided into 4 parts.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>

include/linux/mpi.h

+/* mpi.h  -  Multi Precision Integers
+ *	Copyright (C) 1994, 1996, 1998, 1999,
+ *                    2000, 2001 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
+ *
+ * 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.
+ *	 The GNU MP Library itself is published under the LGPL;
+ *	 however I decided to publish this code under the plain GPL.
+ */
+
+#ifndef G10_MPI_H
+#define G10_MPI_H
+
+#include <linux/types.h>
+
+/* DSI defines */
+
+#define SHA1_DIGEST_LENGTH   20
+
+/*end of DSI defines */
+
+#define BYTES_PER_MPI_LIMB	(BITS_PER_LONG / 8)
+#define BITS_PER_MPI_LIMB	BITS_PER_LONG
+
+typedef unsigned long int mpi_limb_t;
+typedef signed long int mpi_limb_signed_t;
+
+struct gcry_mpi {
+	int alloced;		/* array size (# of allocated limbs) */
+	int nlimbs;		/* number of valid limbs */
+	int nbits;		/* the real number of valid bits (info only) */
+	int sign;		/* indicates a negative number */
+	unsigned flags;		/* bit 0: array must be allocated in secure memory space */
+	/* bit 1: not used */
+	/* bit 2: the limb is a pointer to some m_alloced data */
+	mpi_limb_t *d;		/* array with the limbs */
+};
+
+typedef struct gcry_mpi *MPI;
+
+#define MPI_NULL NULL
+
+#define mpi_get_nlimbs(a)     ((a)->nlimbs)
+#define mpi_is_neg(a)	      ((a)->sign)
+
+/*-- mpiutil.c --*/
+MPI mpi_alloc(unsigned nlimbs);
+MPI mpi_alloc_secure(unsigned nlimbs);
+MPI mpi_alloc_like(MPI a);
+void mpi_free(MPI a);
+int mpi_resize(MPI a, unsigned nlimbs);
+int mpi_copy(MPI *copy, const MPI a);
+void mpi_clear(MPI a);
+int mpi_set(MPI w, MPI u);
+int mpi_set_ui(MPI w, ulong u);
+MPI mpi_alloc_set_ui(unsigned long u);
+void mpi_m_check(MPI a);
+void mpi_swap(MPI a, MPI b);
+
+/*-- mpicoder.c --*/
+MPI do_encode_md(const void *sha_buffer, unsigned nbits);
+MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread);
+int mpi_fromstr(MPI val, const char *str);
+u32 mpi_get_keyid(MPI a, u32 *keyid);
+void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign);
+void *mpi_get_secure_buffer(MPI a, unsigned *nbytes, int *sign);
+int mpi_set_buffer(MPI a, const void *buffer, unsigned nbytes, int sign);
+
+#define log_mpidump g10_log_mpidump
+
+/*-- mpi-add.c --*/
+int mpi_add_ui(MPI w, MPI u, ulong v);
+int mpi_add(MPI w, MPI u, MPI v);
+int mpi_addm(MPI w, MPI u, MPI v, MPI m);
+int mpi_sub_ui(MPI w, MPI u, ulong v);
+int mpi_sub(MPI w, MPI u, MPI v);
+int mpi_subm(MPI w, MPI u, MPI v, MPI m);
+
+/*-- mpi-mul.c --*/
+int mpi_mul_ui(MPI w, MPI u, ulong v);
+int mpi_mul_2exp(MPI w, MPI u, ulong cnt);
+int mpi_mul(MPI w, MPI u, MPI v);
+int mpi_mulm(MPI w, MPI u, MPI v, MPI m);
+
+/*-- mpi-div.c --*/
+ulong mpi_fdiv_r_ui(MPI rem, MPI dividend, ulong divisor);
+int mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor);
+int mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor);
+int mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor);
+int mpi_tdiv_r(MPI rem, MPI num, MPI den);
+int mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den);
+int mpi_tdiv_q_2exp(MPI w, MPI u, unsigned count);
+int mpi_divisible_ui(const MPI dividend, ulong divisor);
+
+/*-- mpi-gcd.c --*/
+int mpi_gcd(MPI g, const MPI a, const MPI b);
+
+/*-- mpi-pow.c --*/
+int mpi_pow(MPI w, MPI u, MPI v);
+int mpi_powm(MPI res, MPI base, MPI exp, MPI mod);
+
+/*-- mpi-mpow.c --*/
+int mpi_mulpowm(MPI res, MPI *basearray, MPI *exparray, MPI mod);
+
+/*-- mpi-cmp.c --*/
+int mpi_cmp_ui(MPI u, ulong v);
+int mpi_cmp(MPI u, MPI v);
+
+/*-- mpi-scan.c --*/
+int mpi_getbyte(MPI a, unsigned idx);
+void mpi_putbyte(MPI a, unsigned idx, int value);
+unsigned mpi_trailing_zeros(MPI a);
+
+/*-- mpi-bit.c --*/
+void mpi_normalize(MPI a);
+unsigned mpi_get_nbits(MPI a);
+int mpi_test_bit(MPI a, unsigned n);
+int mpi_set_bit(MPI a, unsigned n);
+int mpi_set_highbit(MPI a, unsigned n);
+void mpi_clear_highbit(MPI a, unsigned n);
+void mpi_clear_bit(MPI a, unsigned n);
+int mpi_rshift(MPI x, MPI a, unsigned n);
+
+/*-- mpi-inv.c --*/
+int mpi_invm(MPI x, MPI u, MPI v);
+
+#endif /*G10_MPI_H */

lib/mpi/mpi-inline.h

+/* mpi-inline.h  -  Internal to the Multi Precision Integers
+ *	Copyright (C) 1994, 1996, 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
+ *
+ * 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.
+ *	 The GNU MP Library itself is published under the LGPL;
+ *	 however I decided to publish this code under the plain GPL.
+ */
+
+#ifndef G10_MPI_INLINE_H
+#define G10_MPI_INLINE_H
+
+#ifndef G10_MPI_INLINE_DECL
+#define G10_MPI_INLINE_DECL  extern inline
+#endif
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+	      mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+	mpi_limb_t x;
+
+	x = *s1_ptr++;
+	s2_limb += x;
+	*res_ptr++ = s2_limb;
+	if (s2_limb < x) {	/* sum is less than the left operand: handle carry */
+		while (--s1_size) {
+			x = *s1_ptr++ + 1;	/* add carry */
+			*res_ptr++ = x;	/* and store */
+			if (x)	/* not 0 (no overflow): we can stop */
+				goto leave;
+		}
+		return 1;	/* return carry (size of s1 to small) */
+	}
+
+leave:
+	if (res_ptr != s1_ptr) {	/* not the same variable */
+		mpi_size_t i;	/* copy the rest */
+		for (i = 0; i < s1_size - 1; i++)
+			res_ptr[i] = s1_ptr[i];
+	}
+	return 0;		/* no carry */
+}
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+	    mpi_ptr_t s2_ptr, mpi_size_t s2_size)
+{
+	mpi_limb_t cy = 0;
+
+	if (s2_size)
+		cy = mpihelp_add_n(res_ptr, s1_ptr, s2_ptr, s2_size);
+
+	if (s1_size - s2_size)
+		cy = mpihelp_add_1(res_ptr + s2_size, s1_ptr + s2_size,
+				   s1_size - s2_size, cy);
+	return cy;
+}
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+	      mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+	mpi_limb_t x;
+
+	x = *s1_ptr++;
+	s2_limb = x - s2_limb;
+	*res_ptr++ = s2_limb;
+	if (s2_limb > x) {
+		while (--s1_size) {
+			x = *s1_ptr++;
+			*res_ptr++ = x - 1;
+			if (x)
+				goto leave;
+		}
+		return 1;
+	}
+
+leave:
+	if (res_ptr != s1_ptr) {
+		mpi_size_t i;
+		for (i = 0; i < s1_size - 1; i++)
+			res_ptr[i] = s1_ptr[i];
+	}
+	return 0;
+}
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+	    mpi_ptr_t s2_ptr, mpi_size_t s2_size)
+{
+	mpi_limb_t cy = 0;
+
+	if (s2_size)
+		cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size);
+
+	if (s1_size - s2_size)
+		cy = mpihelp_sub_1(res_ptr + s2_size, s1_ptr + s2_size,
+				   s1_size - s2_size, cy);
+	return cy;
+}
+
+#endif /*G10_MPI_INLINE_H */

lib/mpi/mpi-internal.h

+/* mpi-internal.h  -  Internal to the Multi Precision Integers
+ *	Copyright (C) 1994, 1996 Free Software Foundation, Inc.
+ *	Copyright (C) 1998, 2000 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
+ *
+ * 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.
+ *	 The GNU MP Library itself is published under the LGPL;
+ *	 however I decided to publish this code under the plain GPL.
+ */
+
+#ifndef G10_MPI_INTERNAL_H
+#define G10_MPI_INTERNAL_H
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/mpi.h>
+#include <linux/errno.h>
+
+#define log_debug printk
+#define log_bug printk
+
+#define assert(x) \
+	do { \
+		if (!x) \
+			log_bug("failed assertion\n"); \
+	} while (0);
+
+/* If KARATSUBA_THRESHOLD is not already defined, define it to a
+ * value which is good on most machines.  */
+
+/* tested 4, 16, 32 and 64, where 16 gave the best performance when
+ * checking a 768 and a 1024 bit ElGamal signature.
+ * (wk 22.12.97) */
+#ifndef KARATSUBA_THRESHOLD
+#define KARATSUBA_THRESHOLD 16
+#endif
+
+/* The code can't handle KARATSUBA_THRESHOLD smaller than 2.  */
+#if KARATSUBA_THRESHOLD < 2
+#undef KARATSUBA_THRESHOLD
+#define KARATSUBA_THRESHOLD 2
+#endif
+
+typedef mpi_limb_t *mpi_ptr_t;	/* pointer to a limb */
+typedef int mpi_size_t;		/* (must be a signed type) */
+
+#define ABS(x) (x >= 0 ? x : -x)
+#define MIN(l, o) ((l) < (o) ? (l) : (o))
+#define MAX(h, i) ((h) > (i) ? (h) : (i))
+
+static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
+{
+	if (a->alloced < b)
+		return mpi_resize(a, b);
+	return 0;
+}
+
+/* Copy N limbs from S to D.  */
+#define MPN_COPY(d, s, n) \
+	do {					\
+		mpi_size_t _i;			\
+		for (_i = 0; _i < (n); _i++)	\
+			(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] = (d)[_i];	\
+	} while (0)
+
+#define MPN_COPY_DECR(d, s, n) \
+	do {					\
+		mpi_size_t _i;			\
+		for (_i = (n)-1; _i >= 0; _i--) \
+			(d)[_i] = (s)[_i];	\
+	} while (0)
+
+/* Zero N limbs at D */
+#define MPN_ZERO(d, n) \
+	do {					\
+		int  _i;			\
+		for (_i = 0; _i < (n); _i++)	\
+			(d)[_i] = 0;		\
+	} while (0)
+
+#define MPN_NORMALIZE(d, n)  \
+	do {					\
+		while ((n) > 0) {		\
+			if ((d)[(n)-1])		\
+				break;		\
+			(n)--;			\
+		}				\
+	} while (0)
+
+#define MPN_NORMALIZE_NOT_ZERO(d, n) \
+	do {				\
+		for (;;) {		\
+			if ((d)[(n)-1])	\
+				break;	\
+			(n)--;		\
+		}			\
+	} while (0)
+
+#define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
+	do {							\
+		if ((size) < KARATSUBA_THRESHOLD)		\
+			mul_n_basecase(prodp, up, vp, size);	\
+		else						\
+			mul_n(prodp, up, vp, size, tspace);	\
+	} while (0);
+
+/* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
+ * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
+ * If this would yield overflow, DI should be the largest possible number
+ * (i.e., only ones).  For correct operation, the most significant bit of D
+ * has to be set.  Put the quotient in Q and the remainder in R.
+ */
+#define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
+	do {								\
+		mpi_limb_t _q, _ql, _r;					\
+		mpi_limb_t _xh, _xl;					\
+		umul_ppmm(_q, _ql, (nh), (di));				\
+		_q += (nh);	/* DI is 2**BITS_PER_MPI_LIMB too small */ \
+		umul_ppmm(_xh, _xl, _q, (d));				\
+		sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl);		\
+		if (_xh) {						\
+			sub_ddmmss(_xh, _r, _xh, _r, 0, (d));		\
+			_q++;						\
+			if (_xh) {					\
+				sub_ddmmss(_xh, _r, _xh, _r, 0, (d));	\
+				_q++;					\
+			}						\
+		}							\
+		if (_r >= (d)) {					\
+			_r -= (d);					\
+			_q++;						\
+		}							\
+		(r) = _r;						\
+		(q) = _q;						\
+	} while (0)
+
+/*-- mpiutil.c --*/
+mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
+void mpi_free_limb_space(mpi_ptr_t a);
+void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
+
+/*-- mpi-bit.c --*/
+void mpi_rshift_limbs(MPI a, unsigned int count);
+int mpi_lshift_limbs(MPI a, unsigned int count);
+
+/*-- mpihelp-add.c --*/
+mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			 mpi_size_t s1_size, mpi_limb_t s2_limb);
+mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			 mpi_ptr_t s2_ptr, mpi_size_t size);
+mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+		       mpi_ptr_t s2_ptr, mpi_size_t s2_size);
+
+/*-- mpihelp-sub.c --*/
+mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			 mpi_size_t s1_size, mpi_limb_t s2_limb);
+mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			 mpi_ptr_t s2_ptr, mpi_size_t size);
+mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+		       mpi_ptr_t s2_ptr, mpi_size_t s2_size);
+
+/*-- mpihelp-cmp.c --*/
+int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
+
+/*-- mpihelp-mul.c --*/
+
+struct karatsuba_ctx {
+	struct karatsuba_ctx *next;
+	mpi_ptr_t tspace;
+	mpi_size_t tspace_size;
+	mpi_ptr_t tp;
+	mpi_size_t tp_size;
+};
+
+void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
+
+mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			    mpi_size_t s1_size, mpi_limb_t s2_limb);
+mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			    mpi_size_t s1_size, mpi_limb_t s2_limb);
+int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
+int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
+		mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
+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);
+
+int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
+			       mpi_ptr_t up, mpi_size_t usize,
+			       mpi_ptr_t vp, mpi_size_t vsize,
+			       struct karatsuba_ctx *ctx);
+
+/*-- mpihelp-mul_1.c (or xxx/cpu/ *.S) --*/
+mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+			 mpi_size_t s1_size, mpi_limb_t s2_limb);
+
+/*-- mpihelp-div.c --*/
+mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+			 mpi_limb_t divisor_limb);
+mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
+			  mpi_ptr_t np, mpi_size_t nsize,
+			  mpi_ptr_t dp, mpi_size_t dsize);
+mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
+			    mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+			    mpi_limb_t divisor_limb);
+
+/*-- mpihelp-shift.c --*/
+mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
+			  unsigned cnt);
+mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
+			  unsigned cnt);
+
+/* Define stuff for longlong.h.  */
+#define W_TYPE_SIZE BITS_PER_MPI_LIMB
+typedef mpi_limb_t UWtype;
+typedef unsigned int UHWtype;
+#if defined(__GNUC__)
+typedef unsigned int UQItype __attribute__ ((mode(QI)));
+typedef int SItype __attribute__ ((mode(SI)));
+typedef unsigned int USItype __attribute__ ((mode(SI)));
+typedef int DItype __attribute__ ((mode(DI)));
+typedef unsigned int UDItype __attribute__ ((mode(DI)));
+#else
+typedef unsigned char UQItype;
+typedef long SItype;
+typedef unsigned long USItype;
+#endif
+
+#ifdef __GNUC__
+#include "mpi-inline.h"
+#endif
+
+#endif /*G10_MPI_INTERNAL_H */