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algos_enc: works

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This commit is contained in:
Mirek Kratochvil 2013-01-26 22:55:56 +01:00
parent 932cd938a4
commit 805df12176
2 changed files with 25 additions and 16 deletions

9
src/algorithm.h
View file

@ -28,7 +28,14 @@
class algorithm;
typedef std::map<std::string, algorithm*> algorithm_suite;
//virtual interface definition for all cryptographic algorithm instances
/*
* virtual interface definition for all cryptographic algorithm instances.
*
* Note that the whole class could be defined static, but we really enjoy
* having the tiny virtual pointers stored in some cool structure along with
* the handy algorithm name.
*/
class algorithm
{
public:

32
src/algos_enc.cpp
View file

@ -182,12 +182,12 @@ static int fo_encrypt (const bvector&plain, bvector&cipher,
//load the key
pubkey_type Pub;
if (Pub.unserialize (pubkey) ) return 1;
if (!Pub.unserialize (pubkey) ) return 1;
//verify that key parameters match our scheme
if (Pub.plain_size() != plainsize) return 1;
if (Pub.cipher_size() != ciphersize) return 1;
if (Pub.error_count() != errorcount) return 1;
if (Pub.plain_size() != plainsize) return 2;
if (Pub.cipher_size() != ciphersize) return 3;
if (Pub.error_count() != errorcount) return 4;
//create the unencrypted message part
std::vector<byte> M;
@ -217,10 +217,10 @@ static int fo_encrypt (const bvector&plain, bvector&cipher,
//prepare plaintext
bvector mce_plain;
mce_plain.resize (plainsize);
for (i = 0; i < plainsize; ++i) mce_plain[i] = 1 & (M[i >> 3] >> (i & 0x7) );
for (i = 0; i < plainsize; ++i) mce_plain[i] = 1 & (K[i >> 3] >> (i & 0x7) );
//run McEliece
if (Pub.encrypt (mce_plain, cipher, ev) ) return 2;
if (Pub.encrypt (mce_plain, cipher, ev) ) return 5;
//encrypt the message part (xor with arcfour)
arcfour<byte> arc;
@ -256,22 +256,24 @@ static int fo_decrypt (const bvector&cipher, bvector&plain,
//load the key
privkey_type Priv;
if (Priv.unserialize (privkey) ) return 1;
if (!Priv.unserialize (privkey) ) return 1;
if (Priv.prepare() ) return 100;
//verify that key parameters match the scheme
if (Priv.plain_size() != plainsize) return 1;
if (Priv.cipher_size() != ciphersize) return 1;
if (Priv.error_count() != errorcount) return 1;
if (Priv.plain_size() != plainsize) return 2;
if (Priv.cipher_size() != ciphersize) return 3;
if (Priv.error_count() != errorcount) return 4;
//get the McE part
if (cipher.size() < ciphersize) return 2;
if (cipher.size() < ciphersize) return 5;
bvector mce_cipher, mce_plain, ev;
mce_cipher.insert (mce_cipher.end(),
cipher.begin(),
cipher.begin() + ciphersize);
//decrypt the symmetric key
if (Priv.decrypt (mce_cipher, mce_plain, ev) ) return 2;
if (Priv.decrypt (mce_cipher, mce_plain, ev) ) return 6;
//convert stuff to byte vectors
std::vector<byte> K, M;
@ -280,7 +282,7 @@ static int fo_decrypt (const bvector&cipher, bvector&plain,
if (mce_plain[i]) K[i >> 3] |= 1 << (i & 0x7);
uint msize = cipher.size() - ciphersize;
if (msize & 0x7) return 2;
if (msize & 0x7) return 7;
M.resize (msize >> 3, 0);
for (i = 0; i < msize; ++i)
if (cipher[ciphersize + i]) M[i >> 3] |= 1 << (i & 0x7);
@ -318,10 +320,10 @@ static int fo_decrypt (const bvector&cipher, bvector&plain,
ev_rank.colex_unrank (ev2, ciphersize, errorcount);
//now it should match, otherwise someone mangled the message.
if (ev != ev2) return 3;
if (ev != ev2) return 8;
//if the message seems okay, unpad and return it.
if (!message_unpad (M, plain) ) return 2;
if (!message_unpad (M, plain) ) return 9;
return 0;
}