crypto: lib - Move mpi into lib/crypto

[linux-2.6-block.git] / lib / mpi / mpi-mod.c

diff --git a/lib/mpi/mpi-mod.c b/lib/mpi/mpi-mod.c
deleted file mode 100644 (file)
index 54fcc01..0000000
--- a/lib/mpi/mpi-mod.c
+++ /dev/null
@@ -1,157 +0,0 @@
-/* mpi-mod.c -  Modular reduction
- * Copyright (C) 1998, 1999, 2001, 2002, 2003,
- *               2007  Free Software Foundation, Inc.
- *
- * 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);
-}