| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: pss.h,v 1.1 2000/07/20 20:13:38 mdw Exp $ |
| 4 | * |
| 5 | * Probabistic signature scheme |
| 6 | * |
| 7 | * (c) 2000 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Catacomb. |
| 13 | * |
| 14 | * Catacomb is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU Library General Public License as |
| 16 | * published by the Free Software Foundation; either version 2 of the |
| 17 | * License, or (at your option) any later version. |
| 18 | * |
| 19 | * Catacomb is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU Library General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU Library General Public |
| 25 | * License along with Catacomb; if not, write to the Free |
| 26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 27 | * MA 02111-1307, USA. |
| 28 | */ |
| 29 | |
| 30 | /*----- Revision history --------------------------------------------------* |
| 31 | * |
| 32 | * $Log: pss.h,v $ |
| 33 | * Revision 1.1 2000/07/20 20:13:38 mdw |
| 34 | * Added Bellare and Rogaway's PSS encoding for RSA signatures. |
| 35 | * |
| 36 | */ |
| 37 | |
| 38 | /*----- Notes on PSS ------------------------------------------------------* |
| 39 | * |
| 40 | * Applying PSS before RSA signing renders the construction provably secure, |
| 41 | * in that the difficulty of forging a signature is directly related to the |
| 42 | * difficulty of inverting the RSA function, in the random oracle model. |
| 43 | * This is a good thing. PSS was designed by Bellare and Rogaway. This |
| 44 | * particular variant is the one specified in draft 1 of PKCS#1 version 2.1. |
| 45 | * |
| 46 | * Stanford University have a patent claim on PSS, although if (as seems |
| 47 | * likely) PSS is included in IEEE P1363, they'll grant a free world-wide |
| 48 | * licence to use the scheme for signatures with appendix (rather than |
| 49 | * signatures with message recovery). |
| 50 | */ |
| 51 | |
| 52 | #ifndef CATACOMB_PSS_H |
| 53 | #define CATACOMB_PSS_H |
| 54 | |
| 55 | #ifdef __cplusplus |
| 56 | extern "C" { |
| 57 | #endif |
| 58 | |
| 59 | /*----- Header files ------------------------------------------------------*/ |
| 60 | |
| 61 | #include <mLib/bits.h> |
| 62 | #include <mLib/dstr.h> |
| 63 | |
| 64 | #ifndef CATACOMB_GCIPHER_H |
| 65 | # include "gcipher.h" |
| 66 | #endif |
| 67 | |
| 68 | #ifndef CATACOMB_GHASH_H |
| 69 | # include "ghash.h" |
| 70 | #endif |
| 71 | |
| 72 | #ifndef CATACOMB_GRAND_H |
| 73 | # include "grand.h" |
| 74 | #endif |
| 75 | |
| 76 | /*----- Data structures ---------------------------------------------------*/ |
| 77 | |
| 78 | typedef struct pss { |
| 79 | const gccipher *cc; /* Cipher class for masking */ |
| 80 | const gchash *ch; /* Hash class for choosing a seed */ |
| 81 | grand *r; /* Random number source */ |
| 82 | void *salt; /* Pointer to the salt */ |
| 83 | } pss; |
| 84 | |
| 85 | /*----- Functions provided ------------------------------------------------*/ |
| 86 | |
| 87 | /* --- @pss_presign@ --- * |
| 88 | * |
| 89 | * Arguments: @pss *pp@ = pointer to PSS parameter block |
| 90 | * |
| 91 | * Returns: An initialized generic hash context. |
| 92 | * |
| 93 | * Use: Initializes a hash function for signing with PSS. A salt is |
| 94 | * chosen and written into the parameter block. |
| 95 | */ |
| 96 | |
| 97 | extern ghash *pss_presign(pss */*pp*/); |
| 98 | |
| 99 | /* --- @pss_encode@ --- * |
| 100 | * |
| 101 | * Arguments: @const void *msg@ = pointer to message (hash) data |
| 102 | * @size_t msz@ = size of message data |
| 103 | * @void *buf@ = pointer to output buffer |
| 104 | * @size_t sz@ = size of the output buffer |
| 105 | * @void *p@ = pointer to PSS parameter block |
| 106 | * |
| 107 | * Returns: Zero of all went well, negative on failure. |
| 108 | * |
| 109 | * Use: Implements the operation @EMSA-PSS-ENCODE@, as defined in |
| 110 | * PKCS#1 v. 2.1 draft 1. |
| 111 | */ |
| 112 | |
| 113 | extern int pss_encode(const void */*msg*/, size_t /*msz*/, |
| 114 | void */*buf*/, size_t /*sz*/, void */*p*/); |
| 115 | |
| 116 | /* --- @pss_decode@ --- * |
| 117 | * |
| 118 | * Arguments: @const void *buf@ = pointer to encoded buffer |
| 119 | * @size_t sz@ = size of the encoded byffer |
| 120 | * @dstr *d@ = pointer to destination string |
| 121 | * @void *p@ = pointer to PSS parameter block |
| 122 | * |
| 123 | * Returns: The length of the output string (hash) if successful, |
| 124 | * negative on failure. |
| 125 | * |
| 126 | * Use: Implements most of the operation @EMSA_PSS_VERIFY@, as |
| 127 | * defined in PCSK#1 v. 2.1 draft 1. The salt value is filled |
| 128 | * in ready for hashing of the data to start. |
| 129 | */ |
| 130 | |
| 131 | extern int pss_decode(const void */*buf*/, size_t /*sz*/, |
| 132 | dstr */*d*/, void */*p*/); |
| 133 | |
| 134 | /* --- @pss_preverify@ --- * |
| 135 | * |
| 136 | * Arguments: @pss *pp@ = pointer to PSS parameter block |
| 137 | * |
| 138 | * Returns: An initialized generic hash context. |
| 139 | * |
| 140 | * Use: Initializes a hash function for use with PSS. A salt is |
| 141 | * read from the parameter block, where @pss_decode@ should have |
| 142 | * left it. |
| 143 | */ |
| 144 | |
| 145 | extern ghash *pss_presign(pss */*pp*/); |
| 146 | |
| 147 | /* --- @pss_done@ --- * |
| 148 | * |
| 149 | * Arguments: @pss *pp@ = pointer to PSS parameter block |
| 150 | * |
| 151 | * Returns: --- |
| 152 | * |
| 153 | * Use: Disposes of a PSS parameter block once it's finished with. |
| 154 | */ |
| 155 | |
| 156 | extern void pss_done(pss */*pp*/); |
| 157 | |
| 158 | /*----- That's all, folks -------------------------------------------------*/ |
| 159 | |
| 160 | #ifdef __cplusplus |
| 161 | } |
| 162 | #endif |
| 163 | |
| 164 | #endif |