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author | Yves-Alexis Perez <corsac@debian.org> | 2013-08-25 15:37:26 +0200 |
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committer | Yves-Alexis Perez <corsac@debian.org> | 2013-08-25 15:37:26 +0200 |
commit | 6b99c8d9cff7b3e8ae8f3204b99e7ea40f791349 (patch) | |
tree | 009fc492961e13860d2a4bc2de8caf2bbe2975e7 /src/libstrongswan/plugins/rc2/rc2_crypter.c | |
parent | c83921a2b566aa9d55d8ccc7258f04fca6292ee6 (diff) | |
download | vyos-strongswan-6b99c8d9cff7b3e8ae8f3204b99e7ea40f791349.tar.gz vyos-strongswan-6b99c8d9cff7b3e8ae8f3204b99e7ea40f791349.zip |
Imported Upstream version 5.1.0
Diffstat (limited to 'src/libstrongswan/plugins/rc2/rc2_crypter.c')
-rw-r--r-- | src/libstrongswan/plugins/rc2/rc2_crypter.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/rc2/rc2_crypter.c b/src/libstrongswan/plugins/rc2/rc2_crypter.c new file mode 100644 index 000000000..256acf817 --- /dev/null +++ b/src/libstrongswan/plugins/rc2/rc2_crypter.c @@ -0,0 +1,349 @@ +/* + * Copyright (C) 2013 Tobias Brunner + * Hochschule fuer Technik Rapperswil + * + * This program 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. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program 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. + */ + +#include "rc2_crypter.h" + +typedef struct private_rc2_crypter_t private_rc2_crypter_t; + +#define RC2_BLOCK_SIZE 8 + +#define ROL16(x, k) ({ u_int16_t _x = (x); (_x << (k)) | (_x >> (16 - (k))); }) +#define ROR16(x, k) ({ u_int16_t _x = (x); (_x >> (k)) | (_x << (16 - (k))); }) + +#define GET16(x) ({ u_char *_x = (x); (u_int16_t)_x[0] | ((u_int16_t)_x[1] << 8); }) +#define PUT16(x, v) ({ u_char *_x = (x); u_int16_t _v = (v); _x[0] = _v, _x[1] = _v >> 8; }) + +/** + * Private data of rc2_crypter_t + */ +struct private_rc2_crypter_t { + + /** + * Public interface + */ + rc2_crypter_t public; + + /** + * The expanded key in 16-bit words + */ + u_int16_t K[64]; + + /** + * Key size in bytes + */ + size_t T; + + /** + * Effective key size in bits + */ + size_t T1; +}; + +/** + * PITABLE + */ +static const u_char PITABLE[256] = +{ + 0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, + 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d, + 0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e, + 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2, + 0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13, + 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32, + 0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, + 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82, + 0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c, + 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc, + 0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, + 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26, + 0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57, + 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03, + 0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7, + 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7, + 0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, + 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a, + 0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74, + 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec, + 0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, + 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39, + 0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a, + 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31, + 0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae, + 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9, + 0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, + 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9, + 0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0, + 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e, + 0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, + 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad, +}; + +/** + * Encrypt a single block of data + */ +static void encrypt_block(private_rc2_crypter_t *this, u_char R[]) +{ + register u_int16_t R0, R1, R2, R3, *Kj; + int rounds = 3, mix = 5; + + R0 = GET16(R); + R1 = GET16(R + 2); + R2 = GET16(R + 4); + R3 = GET16(R + 6); + Kj = &this->K[0]; + + /* 5 mix, mash, 6 mix, mash, 5 mix */ + while (TRUE) + { + /* mix */ + R0 = ROL16(R0 + *(Kj++) + (R3 & R2) + (~R3 & R1), 1); + R1 = ROL16(R1 + *(Kj++) + (R0 & R3) + (~R0 & R2), 2); + R2 = ROL16(R2 + *(Kj++) + (R1 & R0) + (~R1 & R3), 3); + R3 = ROL16(R3 + *(Kj++) + (R2 & R1) + (~R2 & R0), 5); + + if (--mix == 0) + { + if (--rounds == 0) + { + break; + } + mix = (rounds == 2) ? 6 : 5; + /* mash */ + R0 += this->K[R3 & 63]; + R1 += this->K[R0 & 63]; + R2 += this->K[R1 & 63]; + R3 += this->K[R2 & 63]; + } + } + + PUT16(R, R0); + PUT16(R + 2, R1); + PUT16(R + 4, R2); + PUT16(R + 6, R3); +} + +/** + * Decrypt a single block of data. + */ +static void decrypt_block(private_rc2_crypter_t *this, u_char R[]) +{ + register u_int16_t R0, R1, R2, R3, *Kj; + int rounds = 3, mix = 5; + + R0 = GET16(R); + R1 = GET16(R + 2); + R2 = GET16(R + 4); + R3 = GET16(R + 6); + Kj = &this->K[63]; + + /* 5 r-mix, r-mash, 6 r-mix, r-mash, 5 r-mix */ + while (TRUE) + { + /* r-mix */ + R3 = ROR16(R3, 5); + R3 = R3 - *(Kj--) - (R2 & R1) - (~R2 & R0); + R2 = ROR16(R2, 3); + R2 = R2 - *(Kj--) - (R1 & R0) - (~R1 & R3); + R1 = ROR16(R1, 2); + R1 = R1 - *(Kj--) - (R0 & R3) - (~R0 & R2); + R0 = ROR16(R0, 1); + R0 = R0 - *(Kj--) - (R3 & R2) - (~R3 & R1); + + if (--mix == 0) + { + if (--rounds == 0) + { + break; + } + mix = (rounds == 2) ? 6 : 5; + /* r-mash */ + R3 -= this->K[R2 & 63]; + R2 -= this->K[R1 & 63]; + R1 -= this->K[R0 & 63]; + R0 -= this->K[R3 & 63]; + } + } + + PUT16(R, R0); + PUT16(R + 2, R1); + PUT16(R + 4, R2); + PUT16(R + 6, R3); +} + +METHOD(crypter_t, decrypt, bool, + private_rc2_crypter_t *this, chunk_t data, chunk_t iv, chunk_t *decrypted) +{ + u_int8_t *in, *out, *prev; + + if (data.len % RC2_BLOCK_SIZE || iv.len != RC2_BLOCK_SIZE) + { + return FALSE; + } + + in = data.ptr + data.len - RC2_BLOCK_SIZE; + out = data.ptr; + if (decrypted) + { + *decrypted = chunk_alloc(data.len); + out = decrypted->ptr; + } + out += data.len - RC2_BLOCK_SIZE; + + prev = in; + for (; in >= data.ptr; in -= RC2_BLOCK_SIZE, out -= RC2_BLOCK_SIZE) + { + if (decrypted) + { + memcpy(out, in, RC2_BLOCK_SIZE); + } + decrypt_block(this, out); + prev -= RC2_BLOCK_SIZE; + if (prev < data.ptr) + { + prev = iv.ptr; + } + memxor(out, prev, RC2_BLOCK_SIZE); + } + return TRUE; +} + +METHOD(crypter_t, encrypt, bool, + private_rc2_crypter_t *this, chunk_t data, chunk_t iv, chunk_t *encrypted) +{ + u_int8_t *in, *out, *end, *prev; + + if (data.len % RC2_BLOCK_SIZE || iv.len != RC2_BLOCK_SIZE) + { + return FALSE; + } + + in = data.ptr; + end = data.ptr + data.len; + out = data.ptr; + if (encrypted) + { + *encrypted = chunk_alloc(data.len); + out = encrypted->ptr; + } + + prev = iv.ptr; + for (; in < end; in += RC2_BLOCK_SIZE, out += RC2_BLOCK_SIZE) + { + if (encrypted) + { + memcpy(out, in, RC2_BLOCK_SIZE); + } + memxor(out, prev, RC2_BLOCK_SIZE); + encrypt_block(this, out); + prev = out; + } + return TRUE; +} + +METHOD(crypter_t, get_block_size, size_t, + private_rc2_crypter_t *this) +{ + return RC2_BLOCK_SIZE; +} + +METHOD(crypter_t, get_iv_size, size_t, + private_rc2_crypter_t *this) +{ + return RC2_BLOCK_SIZE; +} + +METHOD(crypter_t, get_key_size, size_t, + private_rc2_crypter_t *this) +{ + return this->T; +} + +METHOD(crypter_t, set_key, bool, + private_rc2_crypter_t *this, chunk_t key) +{ + u_int8_t L[128], T8, TM, idx; + int i; + + if (key.len != this->T) + { + return FALSE; + } + for (i = 0; i < key.len; i++) + { + L[i] = key.ptr[i]; + } + for (; i < 128; i++) + { + idx = L[i-1] + L[i-key.len]; + L[i] = PITABLE[idx]; + } + T8 = (this->T1 + 7) / 8; + TM = ~(0xff << (8 - (8*T8 - this->T1))); + L[128-T8] = PITABLE[L[128-T8] & TM]; + for (i = 127-T8; i >= 0; i--) + { + idx = L[i+1] ^ L[i+T8]; + L[i] = PITABLE[idx]; + } + for (i = 0; i < 64; i++) + { + this->K[i] = GET16(&L[i << 1]); + } + memwipe(L, sizeof(L)); + return TRUE; +} + +METHOD(crypter_t, destroy, void, + private_rc2_crypter_t *this) +{ + memwipe(this->K, sizeof(this->K)); + free(this); +} + +/* + * Described in header + */ +rc2_crypter_t *rc2_crypter_create(encryption_algorithm_t algo, size_t key_size) +{ + private_rc2_crypter_t *this; + size_t effective; + + if (algo != ENCR_RC2_CBC) + { + return NULL; + } + key_size = max(1, key_size); + effective = RC2_EFFECTIVE_KEY_LEN(key_size); + key_size = min(128, RC2_KEY_LEN(key_size)); + effective = max(1, min(1024, effective ?: key_size * 8)); + + INIT(this, + .public = { + .crypter = { + .encrypt = _encrypt, + .decrypt = _decrypt, + .get_block_size = _get_block_size, + .get_iv_size = _get_iv_size, + .get_key_size = _get_key_size, + .set_key = _set_key, + .destroy = _destroy, + }, + }, + .T = key_size, + .T1 = effective, + ); + + return &this->public; +} |