botan.pk_pad.emsa1_bsi source code

1 /**
2 * EMSA1 BSI Variant
3 * 
4 * Copyright:
5 * (C) 1999-2008 Jack Lloyd
6 * (C) 2014-2015 Etienne Cimon
7 *      2007 FlexSecure GmbH
8 *
9 * License:
10 * Botan is released under the Simplified BSD License (see LICENSE.md)
11 */
12 module botan.pk_pad.emsa1_bsi;
13 
14 import botan.constants;
15 static if (BOTAN_HAS_EMSA1_BSI):
16 import botan.pk_pad.emsa1;
17 import botan.hash.hash;
18 import botan.utils.types;
19 
20 /**
21 * EMSA1_BSI is a variant of EMSA1 specified by the BSI. It accepts
22 * only hash values which are less or equal than the maximum key
23 * length. The implementation comes from InSiTo
24 */
25 final class EMSA1BSI : EMSA1, EMSA
26 {
27 public:
28     /**
29     * Params:
30     *  hash = the hash object to use
31     */
32     this(HashFunction hash)
33     {
34         super(hash);
35     }
36 
37     /*
38     * EMSA1 BSI Encode Operation
39     */
40     override SecureVector!ubyte encodingOf(const ref SecureVector!ubyte msg,
41                                             size_t output_bits,
42                                                RandomNumberGenerator rng)
43     {
44         //logDebug("EMSA1BSI Encode");
45         if (msg.length != hashOutputLength())
46             throw new EncodingError("EMSA1_BSI::encodingOf: Invalid size for input");
47         
48         if (8*msg.length <= output_bits)
49             return msg.dup;
50         
51         throw new EncodingError("EMSA1_BSI::encodingOf: max key input size exceeded");
52     }
53 
54     // Interface fallthrough
55     override SecureVector!ubyte rawData() { return super.rawData(); }
56     override bool verify(const ref SecureVector!ubyte coded,
57                          const ref SecureVector!ubyte raw, size_t key_bits)
58     {
59         return super.verify(coded, raw, key_bits);
60     }
61     override void update(const(ubyte)* input, size_t length)
62     {
63         super.update(input, length);
64     }
65 }
66