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/* |
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curve25519.C -- diffie hellman key exchange |
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Copyright (C) 2013 Marc Lehmann <gvpe@schmorp.de> |
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|
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This file is part of GVPE. |
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|
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GVPE is free software; you can redistribute it and/or modify it |
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under the terms of the GNU General Public License as published by the |
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Free Software Foundation; either version 3 of the License, or (at your |
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option) any later version. |
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|
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This program is distributed in the hope that it will be useful, but |
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WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
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Public License for more details. |
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|
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You should have received a copy of the GNU General Public License along |
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with this program; if not, see <http://www.gnu.org/licenses/>. |
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|
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Additional permission under GNU GPL version 3 section 7 |
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|
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If you modify this Program, or any covered work, by linking or |
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combining it with the OpenSSL project's OpenSSL library (or a modified |
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version of that library), containing parts covered by the terms of the |
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OpenSSL or SSLeay licenses, the licensors of this Program grant you |
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additional permission to convey the resulting work. Corresponding |
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Source for a non-source form of such a combination shall include the |
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source code for the parts of OpenSSL used as well as that of the |
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covered work. |
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*/ |
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|
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#include "config.h" |
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|
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#include <cstring> |
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#include <openssl/rand.h> |
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|
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#include "util.h" |
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#include "curve25519.h" |
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|
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#if __GNUC__ >= 4 && __SIZEOF_LONG__ == 8 |
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#include "curve25519-donna-c64.c" |
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#else |
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#include "curve25519-donna.c" |
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#endif |
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|
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static void |
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curve25519_derive (const curve25519_key &a, curve25519_key &b) |
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{ |
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static const curve25519_key basepoint = { 9 }; |
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curve25519_donna (b, a, basepoint); |
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} |
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|
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void curve25519_generate (curve25519_key &a, curve25519_key &b) |
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{ |
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rand_fill (a); |
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|
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#if 0 |
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a [ 0] &= 0xf8; |
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a [31] &= 0x7f; |
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a [31] |= 0x40; |
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#endif |
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|
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curve25519_derive (a, b); |
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} |
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|
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void curve25519_combine (const curve25519_key &a, const curve25519_key &b, curve25519_key &s) |
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{ |
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curve25519_donna (s, a, b); |
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} |
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|
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void curve25519_verify () |
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{ |
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// NaCl test vector |
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|
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static const curve25519_key alice_private = { 0x77, 0x07, 0x6d, 0x0a, 0x73, 0x18, 0xa5, 0x7d, 0x3c, 0x16, 0xc1, 0x72, 0x51, 0xb2, 0x66, 0x45, 0xdf, 0x4c, 0x2f, 0x87, 0xeb, 0xc0, 0x99, 0x2a, 0xb1, 0x77, 0xfb, 0xa5, 0x1d, 0xb9, 0x2c, 0x2a }; |
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static const curve25519_key alice_public = { 0x85, 0x20, 0xf0, 0x09, 0x89, 0x30, 0xa7, 0x54, 0x74, 0x8b, 0x7d, 0xdc, 0xb4, 0x3e, 0xf7, 0x5a, 0x0d, 0xbf, 0x3a, 0x0d, 0x26, 0x38, 0x1a, 0xf4, 0xeb, 0xa4, 0xa9, 0x8e, 0xaa, 0x9b, 0x4e, 0x6a }; |
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static const curve25519_key bob_private = { 0x5d, 0xab, 0x08, 0x7e, 0x62, 0x4a, 0x8a, 0x4b, 0x79, 0xe1, 0x7f, 0x8b, 0x83, 0x80, 0x0e, 0xe6, 0x6f, 0x3b, 0xb1, 0x29, 0x26, 0x18, 0xb6, 0xfd, 0x1c, 0x2f, 0x8b, 0x27, 0xff, 0x88, 0xe0, 0xeb }; |
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static const curve25519_key bob_public = { 0xde, 0x9e, 0xdb, 0x7d, 0x7b, 0x7d, 0xc1, 0xb4, 0xd3, 0x5b, 0x61, 0xc2, 0xec, 0xe4, 0x35, 0x37, 0x3f, 0x83, 0x43, 0xc8, 0x5b, 0x78, 0x67, 0x4d, 0xad, 0xfc, 0x7e, 0x14, 0x6f, 0x88, 0x2b, 0x4f }; |
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static const curve25519_key alice_mult_bob = { 0x4a, 0x5d, 0x9d, 0x5b, 0xa4, 0xce, 0x2d, 0xe1, 0x72, 0x8e, 0x3b, 0xf4, 0x80, 0x35, 0x0f, 0x25, 0xe0, 0x7e, 0x21, 0xc9, 0x47, 0xd1, 0x9e, 0x33, 0x76, 0xf0, 0x9b, 0x3c, 0x1e, 0x16, 0x17, 0x42 }; |
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|
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curve25519_key a, b, s1, s2; |
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|
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curve25519_derive (alice_private, a); |
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curve25519_derive (bob_private , b); |
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curve25519_combine (alice_private, b, s1); |
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curve25519_combine (bob_private , a, s2); |
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|
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require (!memcmp (alice_public , a , sizeof a )); |
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require (!memcmp (bob_public , b , sizeof b )); |
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require (!memcmp (alice_mult_bob, s1, sizeof s1)); |
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require (!memcmp (alice_mult_bob, s2, sizeof s2)); |
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} |
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