/* mpi-cmp.c - MPI functions * Copyright (C) 1998, 1999, 2001, 2002, 2005 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, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ #include <config.h> #include <stdio.h> #include <stdlib.h> #include "mpi-internal.h" int gcry_mpi_cmp_ui (gcry_mpi_t u, unsigned long v) { mpi_limb_t limb = v; _gcry_mpi_normalize (u); /* Handle the case that U contains no limb. */ if (u->nlimbs == 0) return -(limb != 0); /* Handle the case that U is negative. */ if (u->sign) return -1; if (u->nlimbs == 1) { /* Handle the case that U contains exactly one limb. */ if (u->d[0] > limb) return 1; if (u->d[0] < limb) return -1; return 0; } else /* Handle the case that U contains more than one limb. */ return 1; } int gcry_mpi_cmp (gcry_mpi_t u, gcry_mpi_t v) { mpi_size_t usize; mpi_size_t vsize; int cmp; if (mpi_is_opaque (u) || mpi_is_opaque (v)) { if (mpi_is_opaque (u) && !mpi_is_opaque (v)) return -1; if (!mpi_is_opaque (u) && mpi_is_opaque (v)) return 1; if (!u->sign && !v->sign) return 0; /* Empty buffers are identical. */ if (u->sign < v->sign) return -1; if (u->sign > v->sign) return 1; return memcmp (u->d, v->d, (u->sign+7)/8); } else { _gcry_mpi_normalize (u); _gcry_mpi_normalize (v); usize = u->nlimbs; vsize = v->nlimbs; /* Compare sign bits. */ if (!u->sign && v->sign) return 1; if (u->sign && !v->sign) return -1; /* U and V are either both positive or both negative. */ if (usize != vsize && !u->sign && !v->sign) return usize - vsize; if (usize != vsize && u->sign && v->sign) return vsize + usize; if (!usize ) return 0; if (!(cmp = _gcry_mpih_cmp (u->d, v->d, usize))) return 0; if ((cmp < 0?1:0) == (u->sign?1:0)) return 1; } return -1; }