Diffstat (limited to 'pwmanager/libcrypt/cipher/arcfour.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | pwmanager/libcrypt/cipher/arcfour.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/cipher/arcfour.c b/pwmanager/libcrypt/cipher/arcfour.c new file mode 100644 index 0000000..6bb0555 --- a/dev/null +++ b/pwmanager/libcrypt/cipher/arcfour.c @@ -0,0 +1,156 @@ +/* arcfour.c - The arcfour stream cipher + * Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Libgcrypt 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. + * + * Libgcrypt 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + * + * For a description of the algorithm, see: + * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1996. + * ISBN 0-471-11709-9. Pages 397 ff. + */ + + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "types.h" +#include "g10lib.h" +#include "cipher.h" + +static const char *selftest(void); + +typedef struct { + int idx_i, idx_j; + byte sbox[256]; +} ARCFOUR_context; + +static void +do_encrypt_stream( ARCFOUR_context *ctx, + byte *outbuf, const byte *inbuf, unsigned int length ) +{ + register int i = ctx->idx_i; + register int j = ctx->idx_j; + register byte *sbox = ctx->sbox; + register int t; + + while ( length-- ) + { + i++; + i = i & 255; /* The and-op seems to be faster than the mod-op. */ + j += sbox[i]; + j &= 255; + t = sbox[i]; sbox[i] = sbox[j]; sbox[j] = t; + *outbuf++ = *inbuf++ ^ sbox[(sbox[i] + sbox[j]) & 255]; + } + + ctx->idx_i = i; + ctx->idx_j = j; +} + +static void +encrypt_stream (void *context, + byte *outbuf, const byte *inbuf, unsigned int length) +{ + ARCFOUR_context *ctx = (ARCFOUR_context *) context; + do_encrypt_stream (ctx, outbuf, inbuf, length ); + _gcry_burn_stack (64); +} + + +static gcry_err_code_t +do_arcfour_setkey (void *context, const byte *key, unsigned int keylen) +{ + static int initialized; + static const char* selftest_failed; + int i, j; + byte karr[256]; + ARCFOUR_context *ctx = (ARCFOUR_context *) context; + + if (!initialized ) + { + initialized = 1; + selftest_failed = selftest(); + if( selftest_failed ) + log_error ("ARCFOUR selftest failed (%s)\n", selftest_failed ); + } + if( selftest_failed ) + return GPG_ERR_SELFTEST_FAILED; + + if( keylen < 40/8 ) /* we want at least 40 bits */ + return GPG_ERR_INV_KEYLEN; + + ctx->idx_i = ctx->idx_j = 0; + for (i=0; i < 256; i++ ) + ctx->sbox[i] = i; + for (i=0; i < 256; i++ ) + karr[i] = key[i%keylen]; + for (i=j=0; i < 256; i++ ) + { + int t; + j = (j + ctx->sbox[i] + karr[i]) % 256; + t = ctx->sbox[i]; + ctx->sbox[i] = ctx->sbox[j]; + ctx->sbox[j] = t; + } + memset( karr, 0, 256 ); + + return GPG_ERR_NO_ERROR; +} + +static gcry_err_code_t +arcfour_setkey ( void *context, const byte *key, unsigned int keylen ) +{ + ARCFOUR_context *ctx = (ARCFOUR_context *) context; + gcry_err_code_t rc = do_arcfour_setkey (ctx, key, keylen ); + _gcry_burn_stack (300); + return rc; +} + + +static const char* +selftest(void) +{ + ARCFOUR_context ctx; + byte scratch[16]; + + /* Test vector from Cryptlib labeled there: "from the + State/Commerce Department". */ + static byte key_1[] = + { 0x61, 0x8A, 0x63, 0xD2, 0xFB }; + static byte plaintext_1[] = + { 0xDC, 0xEE, 0x4C, 0xF9, 0x2C }; + static const byte ciphertext_1[] = + { 0xF1, 0x38, 0x29, 0xC9, 0xDE }; + + arcfour_setkey( &ctx, key_1, sizeof(key_1)); + encrypt_stream( &ctx, scratch, plaintext_1, sizeof(plaintext_1)); + if ( memcmp (scratch, ciphertext_1, sizeof (ciphertext_1))) + return "Arcfour encryption test 1 failed."; + arcfour_setkey( &ctx, key_1, sizeof(key_1)); + encrypt_stream(&ctx, scratch, scratch, sizeof(plaintext_1)); /* decrypt */ + if ( memcmp (scratch, plaintext_1, sizeof (plaintext_1))) + return "Arcfour decryption test 1 failed."; + return NULL; +} + + +gcry_cipher_spec_t _gcry_cipher_spec_arcfour = + { + "ARCFOUR", NULL, NULL, 1, 128, sizeof (ARCFOUR_context), + arcfour_setkey, NULL, NULL, encrypt_stream, encrypt_stream, + }; + |