From 0e752a6e215aee21dc73da097c3225495d54a5b6 Mon Sep 17 00:00:00 2001 From: SoniEx2 Date: Fri, 9 Apr 2021 07:19:03 -0300 Subject: Add libotr/etc sources --- libotr/libgcrypt-1.8.7/cipher/cipher-cbc.c | 214 +++++++++++++++++++++++++++++ 1 file changed, 214 insertions(+) create mode 100644 libotr/libgcrypt-1.8.7/cipher/cipher-cbc.c (limited to 'libotr/libgcrypt-1.8.7/cipher/cipher-cbc.c') diff --git a/libotr/libgcrypt-1.8.7/cipher/cipher-cbc.c b/libotr/libgcrypt-1.8.7/cipher/cipher-cbc.c new file mode 100644 index 0000000..95c49b2 --- /dev/null +++ b/libotr/libgcrypt-1.8.7/cipher/cipher-cbc.c @@ -0,0 +1,214 @@ +/* cipher-cbc.c - Generic CBC mode implementation + * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 + * 2005, 2007, 2008, 2009, 2011 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, see . + */ + +#include +#include +#include +#include +#include + +#include "g10lib.h" +#include "cipher.h" +#include "./cipher-internal.h" +#include "bufhelp.h" + + + +gcry_err_code_t +_gcry_cipher_cbc_encrypt (gcry_cipher_hd_t c, + unsigned char *outbuf, size_t outbuflen, + const unsigned char *inbuf, size_t inbuflen) +{ + size_t n; + unsigned char *ivp; + int i; + size_t blocksize = c->spec->blocksize; + gcry_cipher_encrypt_t enc_fn = c->spec->encrypt; + size_t nblocks = inbuflen / blocksize; + unsigned int burn, nburn; + + /* Tell compiler that we require a cipher with a 64bit or 128 bit block + * length, to allow better optimization of this function. */ + if (blocksize > 16 || blocksize < 8 || blocksize & (8 - 1)) + return GPG_ERR_INV_LENGTH; + + if (outbuflen < ((c->flags & GCRY_CIPHER_CBC_MAC)? blocksize : inbuflen)) + return GPG_ERR_BUFFER_TOO_SHORT; + + if ((inbuflen % blocksize) + && !(inbuflen > blocksize + && (c->flags & GCRY_CIPHER_CBC_CTS))) + return GPG_ERR_INV_LENGTH; + + burn = 0; + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize) + { + if ((inbuflen % blocksize) == 0) + nblocks--; + } + + if (c->bulk.cbc_enc) + { + c->bulk.cbc_enc (&c->context.c, c->u_iv.iv, outbuf, inbuf, nblocks, + (c->flags & GCRY_CIPHER_CBC_MAC)); + inbuf += nblocks * blocksize; + if (!(c->flags & GCRY_CIPHER_CBC_MAC)) + outbuf += nblocks * blocksize; + } + else + { + ivp = c->u_iv.iv; + + for (n=0; n < nblocks; n++ ) + { + buf_xor (outbuf, inbuf, ivp, blocksize); + nburn = enc_fn ( &c->context.c, outbuf, outbuf ); + burn = nburn > burn ? nburn : burn; + ivp = outbuf; + inbuf += blocksize; + if (!(c->flags & GCRY_CIPHER_CBC_MAC)) + outbuf += blocksize; + } + + if (ivp != c->u_iv.iv) + buf_cpy (c->u_iv.iv, ivp, blocksize ); + } + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize) + { + /* We have to be careful here, since outbuf might be equal to + inbuf. */ + size_t restbytes; + unsigned char b; + + if ((inbuflen % blocksize) == 0) + restbytes = blocksize; + else + restbytes = inbuflen % blocksize; + + outbuf -= blocksize; + for (ivp = c->u_iv.iv, i = 0; i < restbytes; i++) + { + b = inbuf[i]; + outbuf[blocksize + i] = outbuf[i]; + outbuf[i] = b ^ *ivp++; + } + for (; i < blocksize; i++) + outbuf[i] = 0 ^ *ivp++; + + nburn = enc_fn (&c->context.c, outbuf, outbuf); + burn = nburn > burn ? nburn : burn; + buf_cpy (c->u_iv.iv, outbuf, blocksize); + } + + if (burn > 0) + _gcry_burn_stack (burn + 4 * sizeof(void *)); + + return 0; +} + + +gcry_err_code_t +_gcry_cipher_cbc_decrypt (gcry_cipher_hd_t c, + unsigned char *outbuf, size_t outbuflen, + const unsigned char *inbuf, size_t inbuflen) +{ + size_t n; + int i; + size_t blocksize = c->spec->blocksize; + gcry_cipher_decrypt_t dec_fn = c->spec->decrypt; + size_t nblocks = inbuflen / blocksize; + unsigned int burn, nburn; + + /* Tell compiler that we require a cipher with a 64bit or 128 bit block + * length, to allow better optimization of this function. */ + if (blocksize > 16 || blocksize < 8 || blocksize & (8 - 1)) + return GPG_ERR_INV_LENGTH; + + if (outbuflen < inbuflen) + return GPG_ERR_BUFFER_TOO_SHORT; + + if ((inbuflen % blocksize) + && !(inbuflen > blocksize + && (c->flags & GCRY_CIPHER_CBC_CTS))) + return GPG_ERR_INV_LENGTH; + + burn = 0; + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize) + { + nblocks--; + if ((inbuflen % blocksize) == 0) + nblocks--; + buf_cpy (c->lastiv, c->u_iv.iv, blocksize); + } + + if (c->bulk.cbc_dec) + { + c->bulk.cbc_dec (&c->context.c, c->u_iv.iv, outbuf, inbuf, nblocks); + inbuf += nblocks * blocksize; + outbuf += nblocks * blocksize; + } + else + { + for (n=0; n < nblocks; n++ ) + { + /* Because outbuf and inbuf might be the same, we must not overwrite + the original ciphertext block. We use LASTIV as intermediate + storage here because it is not used otherwise. */ + nburn = dec_fn ( &c->context.c, c->lastiv, inbuf ); + burn = nburn > burn ? nburn : burn; + buf_xor_n_copy_2(outbuf, c->lastiv, c->u_iv.iv, inbuf, blocksize); + inbuf += blocksize; + outbuf += blocksize; + } + } + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize) + { + size_t restbytes; + + if ((inbuflen % blocksize) == 0) + restbytes = blocksize; + else + restbytes = inbuflen % blocksize; + + buf_cpy (c->lastiv, c->u_iv.iv, blocksize ); /* Save Cn-2. */ + buf_cpy (c->u_iv.iv, inbuf + blocksize, restbytes ); /* Save Cn. */ + + nburn = dec_fn ( &c->context.c, outbuf, inbuf ); + burn = nburn > burn ? nburn : burn; + buf_xor(outbuf, outbuf, c->u_iv.iv, restbytes); + + buf_cpy (outbuf + blocksize, outbuf, restbytes); + for(i=restbytes; i < blocksize; i++) + c->u_iv.iv[i] = outbuf[i]; + nburn = dec_fn (&c->context.c, outbuf, c->u_iv.iv); + burn = nburn > burn ? nburn : burn; + buf_xor(outbuf, outbuf, c->lastiv, blocksize); + /* c->lastiv is now really lastlastiv, does this matter? */ + } + + if (burn > 0) + _gcry_burn_stack (burn + 4 * sizeof(void *)); + + return 0; +} -- cgit 1.4.1