wolfSSL 3.11.1 for TLS1.3 beta
Fork of wolfSSL by
wolfcrypt/src/idea.c
- Committer:
- wolfSSL
- Date:
- 2017-05-02
- Revision:
- 7:481bce714567
File content as of revision 7:481bce714567:
/* idea.c * * Copyright (C) 2006-2016 wolfSSL Inc. * * This file is part of wolfSSL. * * wolfSSL is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * wolfSSL 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <wolfssl/wolfcrypt/settings.h> #ifdef HAVE_IDEA #include <wolfssl/wolfcrypt/idea.h> #include <wolfssl/wolfcrypt/error-crypt.h> #include <wolfssl/wolfcrypt/logging.h> #ifdef NO_INLINE #include <wolfssl/wolfcrypt/misc.h> #else #define WOLFSSL_MISC_INCLUDED #include <wolfcrypt/src/misc.c> #endif /* multiplication of x and y modulo 2^16+1 * IDEA specify a special case when an entry value is 0 ( x or y) * then it must be replaced by 2^16 */ static INLINE word16 idea_mult(word16 x, word16 y) { long mul, res; mul = (long)x * (long)y; if (mul) { res = (mul & IDEA_MASK) - ((word32)mul >> 16); if (res <= 0) res += IDEA_MODULO; return (word16) (res & IDEA_MASK); } if (!x) return ((IDEA_MODULO - y) & IDEA_MASK); /* !y */ return ((IDEA_MODULO - x) & IDEA_MASK); } /* compute 1/a modulo 2^16+1 using Extended euclidean algorithm * adapted from fp_invmod */ static INLINE word16 idea_invmod(word16 x) { int u, v, b, d; if (x <= 1) return x; u = IDEA_MODULO; v = x; d = 1; b = 0; do { while (!(u & 1)) { u >>= 1; if (b & 1) b -= IDEA_MODULO; b >>= 1; } while (!(v & 1)) { v >>= 1; if (d & 1) { d -= IDEA_MODULO; } d >>= 1; } if (u >= v) { u -= v; b -= d; } else { v -= u; d -= b; } } while (u != 0); /* d is now the inverse, put positive value if required */ while (d < 0) d += IDEA_MODULO; /* d must be < IDEA_MODULO */ while (d >= (int)IDEA_MODULO) d -= IDEA_MODULO; return (word16)(d & IDEA_MASK); } /* generate the 52 16-bits key sub-blocks from the 128 key */ int wc_IdeaSetKey(Idea *idea, const byte* key, word16 keySz, const byte *iv, int dir) { word16 idx = 0; word32 t; short i; if (idea == NULL || key == NULL || keySz != IDEA_KEY_SIZE || (dir != IDEA_ENCRYPTION && dir != IDEA_DECRYPTION)) return BAD_FUNC_ARG; /* initial key schedule for 0 -> 7 */ for (i = 0; i < IDEA_ROUNDS; i++) { idea->skey[i] = (word16)key[idx++] << 8; idea->skey[i] |= (word16)key[idx++]; } /* shift phase key schedule for 8 -> 51 */ for (i = IDEA_ROUNDS; i < IDEA_SK_NUM; i++) { t = (word32)idea->skey[((i+1) & 7) ? i-7 : i-15] << 9; t |= (word32)idea->skey[((i+2) & 7) < 2 ? i-14 : i-6] >> 7; idea->skey[i] = (word16)(t & IDEA_MASK); } /* compute decryption key from encryption key */ if (dir == IDEA_DECRYPTION) { word16 enckey[IDEA_SK_NUM]; /* put encryption key in tmp buffer */ XMEMCPY(enckey, idea->skey, sizeof(idea->skey)); idx = 0; idea->skey[6*IDEA_ROUNDS] = idea_invmod(enckey[idx++]); idea->skey[6*IDEA_ROUNDS+1] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK; idea->skey[6*IDEA_ROUNDS+2] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK; idea->skey[6*IDEA_ROUNDS+3] = idea_invmod(enckey[idx++]); for (i = 6*(IDEA_ROUNDS-1); i >= 0; i -= 6) { idea->skey[i+4] = enckey[idx++]; idea->skey[i+5] = enckey[idx++]; idea->skey[i] = idea_invmod(enckey[idx++]); if (i) { idea->skey[i+2] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK; idea->skey[i+1] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK; } else { idea->skey[1] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK; idea->skey[2] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK; } idea->skey[i+3] = idea_invmod(enckey[idx++]); } /* erase temporary buffer */ ForceZero(enckey, sizeof(enckey)); } /* set the iv */ return wc_IdeaSetIV(idea, iv); } /* set the IV in the Idea key structure */ int wc_IdeaSetIV(Idea *idea, const byte* iv) { if (idea == NULL) return BAD_FUNC_ARG; if (iv != NULL) XMEMCPY(idea->reg, iv, IDEA_BLOCK_SIZE); else XMEMSET(idea->reg, 0, IDEA_BLOCK_SIZE); return 0; } /* encryption/decryption for a block (64 bits) */ void wc_IdeaCipher(Idea *idea, byte* out, const byte* in) { word32 t1, t2; word16 i, skey_idx = 0, idx = 0; word16 x[4]; /* put input byte block in word16 */ for (i = 0; i < IDEA_BLOCK_SIZE/2; i++) { x[i] = (word16)in[idx++] << 8; x[i] |= (word16)in[idx++]; } for (i = 0; i < IDEA_ROUNDS; i++) { x[0] = idea_mult(x[0], idea->skey[skey_idx++]); x[1] = ((word32)x[1] + (word32)idea->skey[skey_idx++]) & IDEA_MASK; x[2] = ((word32)x[2] + (word32)idea->skey[skey_idx++]) & IDEA_MASK; x[3] = idea_mult(x[3], idea->skey[skey_idx++]); t2 = x[0] ^ x[2]; t2 = idea_mult((word16)t2, idea->skey[skey_idx++]); t1 = (t2 + (x[1] ^ x[3])) & IDEA_MASK; t1 = idea_mult((word16)t1, idea->skey[skey_idx++]); t2 = (t1 + t2) & IDEA_MASK; x[0] ^= t1; x[3] ^= t2; t2 ^= x[1]; x[1] = x[2] ^ (word16)t1; x[2] = (word16)t2; } x[0] = idea_mult(x[0], idea->skey[skey_idx++]); out[0] = (x[0] >> 8) & 0xFF; out[1] = x[0] & 0xFF; x[2] = ((word32)x[2] + (word32)idea->skey[skey_idx++]) & IDEA_MASK; out[2] = (x[2] >> 8) & 0xFF; out[3] = x[2] & 0xFF; x[1] = ((word32)x[1] + (word32)idea->skey[skey_idx++]) & IDEA_MASK; out[4] = (x[1] >> 8) & 0xFF; out[5] = x[1] & 0xFF; x[3] = idea_mult(x[3], idea->skey[skey_idx++]); out[6] = (x[3] >> 8) & 0xFF; out[7] = x[3] & 0xFF; } int wc_IdeaCbcEncrypt(Idea *idea, byte* out, const byte* in, word32 len) { int blocks; if (idea == NULL || out == NULL || in == NULL) return BAD_FUNC_ARG; blocks = len / IDEA_BLOCK_SIZE; while (blocks--) { xorbuf((byte*)idea->reg, in, IDEA_BLOCK_SIZE); wc_IdeaCipher(idea, (byte*)idea->reg, (byte*)idea->reg); XMEMCPY(out, idea->reg, IDEA_BLOCK_SIZE); out += IDEA_BLOCK_SIZE; in += IDEA_BLOCK_SIZE; } return 0; } int wc_IdeaCbcDecrypt(Idea *idea, byte* out, const byte* in, word32 len) { int blocks; if (idea == NULL || out == NULL || in == NULL) return BAD_FUNC_ARG; blocks = len / IDEA_BLOCK_SIZE; while (blocks--) { XMEMCPY((byte*)idea->tmp, in, IDEA_BLOCK_SIZE); wc_IdeaCipher(idea, out, (byte*)idea->tmp); xorbuf(out, (byte*)idea->reg, IDEA_BLOCK_SIZE); XMEMCPY(idea->reg, idea->tmp, IDEA_BLOCK_SIZE); out += IDEA_BLOCK_SIZE; in += IDEA_BLOCK_SIZE; } return 0; } #endif /* HAVE_IDEA */