diff --git a/nettle-write.h b/nettle-write.h new file mode 100644 index 0000000000000000000000000000000000000000..7287270b642e442880c2afde3b9e828d6566db06 --- /dev/null +++ b/nettle-write.h @@ -0,0 +1,44 @@ +/* nettle-write.h + * + * Prototypes for some internal functions to write out word-sized data + * to byte arrays. */ + +/* nettle, low-level cryptographics library + * + * Copyright (C) 2010 Niels M�ller + * + * The nettle library 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. + * + * The nettle library 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 the nettle library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +#ifndef NETTLE_WRITE_H_INCLUDED +#define NETTLE_WRITE_H_INCLUDED + +#include "nettle-stdint.h" + +/* Write the word array at SRC to the byte array at DST, using little + endian (le) or big endian (be) byte order, and truncating the + result to LENGTH bytes. */ +void +_nettle_write_be32(unsigned length, uint8_t *dst, + uint32_t *src); +void +_nettle_write_le32(unsigned length, uint8_t *dst, + uint32_t *src); +void +_nettle_write_be64(unsigned length, uint8_t *dst, + uint64_t *src); + +#endif /* NETTLE_WRITE_H_INCLUDED */ diff --git a/write-be32.c b/write-be32.c new file mode 100644 index 0000000000000000000000000000000000000000..e52e565f8ef32971223d3ada33e98097e6a5a041 --- /dev/null +++ b/write-be32.c @@ -0,0 +1,68 @@ +/* write-be32.c */ + +/* nettle, low-level cryptographics library + * + * Copyright (C) 2001 Niels M�ller + * + * The nettle library 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. + * + * The nettle library 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 the nettle library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +#if HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdlib.h> + +#include "nettle-write.h" + +#include "macros.h" + +void +_nettle_write_be32(unsigned length, uint8_t *dst, + uint32_t *src) +{ + unsigned i; + unsigned words; + unsigned leftover; + + words = length / 4; + leftover = length % 4; + + for (i = 0; i < words; i++, dst += 4) + WRITE_UINT32(dst, src[i]); + + if (leftover) + { + uint32_t word; + unsigned j = leftover; + + word = src[i]; + + switch (leftover) + { + default: + abort(); + case 3: + dst[--j] = (word >> 8) & 0xff; + /* Fall through */ + case 2: + dst[--j] = (word >> 16) & 0xff; + /* Fall through */ + case 1: + dst[--j] = (word >> 24) & 0xff; + } + } +}