/* * Copyright (c) 2014 Dag-Erling Smørgrav * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "cryb/impl.h" #include <stdint.h> #include <stdlib.h> #include <string.h> #include <cryb/mpi.h> /* n rounded up to nearest multiple of p */ #define RUP(n, p) ((((n) + (p) - 1) / (p)) * (p)) /* * Compare absolute values */ int mpi_cmp_abs(cryb_mpi *X, cryb_mpi *Y) { int i; /* check width first */ if (X->msb > Y->msb) return (1); if (X->msb < Y->msb) return (-1); /* no luck, compare word by word */ for (i = X->msb / 32; i >= 0; --i) { if (X->words[i] > Y->words[i]) return (1); if (X->words[i] < Y->words[i]) return (-1); } return (0); } /* * Compare signed values */ int mpi_cmp(cryb_mpi *X, cryb_mpi *Y) { if (X->neg) { if (Y->neg) return (-mpi_cmp_abs(X, Y)); else return (-1); } else { if (Y->neg) return (1); else return (mpi_cmp_abs(X, Y)); } } /* * Compare for equality */ int mpi_eq_abs(cryb_mpi *A, cryb_mpi *B) { return (A->msb == B->msb && memcmp(A->words, B->words, (A->msb + 31) / 32) == 0); } /* * Compare for equality */ int mpi_eq(cryb_mpi *A, cryb_mpi *B) { return (A->neg == B->neg && A->msb == B->msb && memcmp(A->words, B->words, (A->msb + 31) / 32) == 0); }