From fea9a197c6ca55a1c3c57798e0dc59949c59633c Mon Sep 17 00:00:00 2001 From: mdw Date: Sat, 17 Jun 2000 11:33:11 +0000 Subject: [PATCH] MGF-1 support, as defined in PKCS#1. --- mgf-def.h | 468 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ mgf.h | 172 +++++++++++++++++++++++ 2 files changed, 640 insertions(+) create mode 100644 mgf-def.h create mode 100644 mgf.h diff --git a/mgf-def.h b/mgf-def.h new file mode 100644 index 0000000..9565093 --- /dev/null +++ b/mgf-def.h @@ -0,0 +1,468 @@ +/* -*-c-*- + * + * $Id: mgf-def.h,v 1.1 2000/06/17 11:33:11 mdw Exp $ + * + * Definitions for the MGF-1 mask generator + * + * (c) 2000 Straylight/Edgeware + */ + +/*----- Licensing notice --------------------------------------------------* + * + * This file is part of Catacomb. + * + * Catacomb is free software; you can redistribute it and/or modify + * it under the terms of the GNU Library General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * Catacomb 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 Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with Catacomb; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +/*----- Revision history --------------------------------------------------* + * + * $Log: mgf-def.h,v $ + * Revision 1.1 2000/06/17 11:33:11 mdw + * MGF-1 support, as defined in PKCS#1. + * + */ + +#ifndef CATACOMB_MGF_DEF_H +#define CATACOMB_MGF_DEF_H + +#ifdef __cplusplus + extern "C" { +#endif + +/*----- Header files ------------------------------------------------------*/ + +#include +#include +#include + +#include +#include + +#ifndef CATACOMB_ARENA_H +# include "arena.h" +#endif + +#ifndef CATACOMB_GCIPHER_H +# include "gcipher.h" +#endif + +#ifndef CATACOMB_GRAND_H +# include "grand.h" +#endif + +#ifndef CATACOMB_PARANOIA_H +# include "paranoia.h" +#endif + +/*----- Macros ------------------------------------------------------------*/ + +#define MGF_DEF(PRE, pre) \ + \ +/* --- Useful constants --- */ \ + \ +const octet pre##_mgfkeysz[] = { KSZ_ANY, PRE##_HASHSZ }; \ + \ +/* --- @pre_mgfkeybegin@, @pre_mgfkeyadd@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \ + * @const void *p@ = pointer to data to contribute \ + * \ + * Returns: --- \ + * \ + * Use: A multi-step keying procedure for initializing an MGF \ + * context. The data is contributed to a hashing context \ + * which is then used for mask generation. If you only \ + * have a fixed buffer, you can save a lot of effort by \ + * simply calling @pre_mgfinit@. \ + */ \ + \ +void pre##_mgfkeybegin(pre##_mgfctx *k) \ +{ \ + k->c = 0; \ + k->bsz = 0; \ + pre##_init(&k->k); \ +} \ + \ +void pre##_mgfkeyadd(pre##_mgfctx *k, const void *p, size_t sz) \ +{ \ + pre##_hash(&k->k, p, sz); \ +} \ + \ +/* ---- @pre_mgfinit@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \ + * @const void *p@ = pointer to data to contribute \ + * @size_t sz@ = size of data to contribute \ + * \ + * Returns: --- \ + * \ + * Use: A simpler interface to initialization if all of your \ + * keying material is in one place. \ + */ \ + \ +void pre##_mgfinit(pre##_mgfctx *k, const void *p, size_t sz) \ +{ \ + k->c = 0; \ + k->bsz = 0; \ + pre##_init(&k->k); \ + pre##_hash(&k->k, p, sz); \ +} \ + \ +/* --- @pre_mgfencrypt@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to masking context \ + * @const void *s@ = pointer to source buffer \ + * @void *d@ = pointer to destination buffer \ + * @size_t sz@ = size of buffers \ + * \ + * Returns: --- \ + * \ + * Use: Outputs pseudorandom data, or masks an input buffer. \ + * \ + * If @s@ is nonzero, the source material is exclusive- \ + * orred with the generated mask. If @d@ is zero, the \ + * generator is simply spun around for a while, which \ + * isn't very useful. \ + */ \ + \ +void pre##_mgfencrypt(pre##_mgfctx *k, const void *s, \ + void *d, size_t sz) \ +{ \ + const octet *ss = s; \ + octet *dd = d; \ + \ + /* --- Empty the buffer if there's anything there --- */ \ + \ + if (k->bsz) { \ + const octet *p = k->buf + PRE##_HASHSZ - k->bsz; \ + size_t n = sz > k->bsz ? k->bsz : sz; \ + sz -= n; \ + k->bsz -= n; \ + if (dd) { \ + if (!ss) { \ + memcpy(dd, p, n); \ + dd += n; \ + } else { \ + while (n) { \ + *dd++ = *ss++ ^ *p++; \ + n--; \ + } \ + } \ + } \ + } \ + \ + /* --- While necessary, generate some more mask --- */ \ + \ + while (sz) { \ + pre##_ctx c = k->k; /* Not quick! */ \ + size_t n; \ + \ + STORE32(k->buf, k->c); \ + k->c++; \ + pre##_hash(&c, k->buf, 4); \ + pre##_done(&c, k->buf); \ + n = sz > PRE##_HASHSZ ? PRE##_HASHSZ : sz; \ + k->bsz = PRE##_HASHSZ - n; \ + sz -= n; \ + if (dd) { \ + const octet *p = k->buf; \ + if (!ss) { \ + memcpy(dd, p, n); \ + dd += n; \ + } else { \ + while (n) { \ + *dd++ = *ss++ ^ *p++; \ + n--; \ + } \ + } \ + } \ + } \ +} \ + \ +/* --- @pre_mgfsetindex@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to masking context \ + * @uint32 *c@ = new index to set \ + * \ + * Returns: --- \ + * \ + * Use: Sets a new index. This may be used to step around the \ + * output stream in a rather crude way. \ + */ \ + \ +void pre##_mgfsetindex(pre##_mgfctx *k, uint32 c) \ +{ \ + k->c = c; \ + k->bsz = 0; \ +} \ + \ +/* --- Generic cipher interface --- */ \ + \ +static const gcipher_ops gops; \ + \ +typedef struct gctx { \ + gcipher c; \ + pre##_mgfctx k; \ +} gctx; \ + \ +static gcipher *ginit(const void *k, size_t sz) \ +{ \ + gctx *g = S_CREATE(gctx); \ + g->c.ops = &gops; \ + pre##_mgfinit(&g->k, k, sz); \ + return (&g->c); \ +} \ + \ +static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ +{ \ + gctx *g = (gctx *)c; \ + pre##_mgfencrypt(&g->k, s, t, sz); \ +} \ + \ +static void gdestroy(gcipher *c) \ +{ \ + gctx *g = (gctx *)c; \ + BURN(*g); \ + S_DESTROY(g); \ +} \ + \ +static const gcipher_ops gops = { \ + &pre##_mgf, \ + gencrypt, gencrypt, gdestroy, 0, 0 \ +}; \ + \ +const gccipher pre##_mgf = { \ + #pre "-mgf", pre##_mgfkeysz, 0, \ + ginit \ +}; \ + \ +/* --- Generic random number generator interface --- */ \ + \ +typedef struct grctx { \ + grand r; \ + pre##_mgfctx k; \ +} grctx; \ + \ +static void grdestroy(grand *r) \ +{ \ + grctx *g = (grctx *)r; \ + BURN(*g); \ + S_DESTROY(g); \ +} \ + \ +static int grmisc(grand *r, unsigned op, ...) \ +{ \ + grctx *g = (grctx *)r; \ + va_list ap; \ + int rc = 0; \ + va_start(ap, op); \ + \ + switch (op) { \ + case GRAND_CHECK: \ + switch (va_arg(ap, unsigned)) { \ + case GRAND_CHECK: \ + case GRAND_SEEDINT: \ + case GRAND_SEEDUINT32: \ + case GRAND_SEEDBLOCK: \ + case GRAND_SEEDRAND: \ + rc = 1; \ + break; \ + default: \ + rc = 0; \ + break; \ + } \ + break; \ + case GRAND_SEEDINT: \ + pre##_mgfsetindex(&g->k, va_arg(ap, unsigned)); \ + break; \ + case GRAND_SEEDUINT32: \ + pre##_mgfsetindex(&g->k, va_arg(ap, uint32)); \ + break; \ + case GRAND_SEEDBLOCK: { \ + const void *p = va_arg(ap, const void *); \ + size_t sz = va_arg(ap, size_t); \ + pre##_hash(&g->k.k, p, sz); \ + } break; \ + case GRAND_SEEDRAND: { \ + octet buf[PRE##_BUFSZ]; \ + grand *rr = va_arg(ap, grand *); \ + rr->ops->fill(rr, buf, sizeof(buf)); \ + pre##_hash(&g->k.k, buf, sizeof(buf)); \ + } break; \ + default: \ + GRAND_BADOP; \ + break; \ + } \ + \ + va_end(ap); \ + return (rc); \ +} \ + \ +static octet grbyte(grand *r) \ +{ \ + grctx *g = (grctx *)r; \ + octet o; \ + pre##_mgfencrypt(&g->k, 0, &o, 1); \ + return (o); \ +} \ + \ +static uint32 grword(grand *r) \ +{ \ + grctx *g = (grctx *)r; \ + octet b[4]; \ + pre##_mgfencrypt(&g->k, 0, b, sizeof(b)); \ + return (LOAD32(b)); \ +} \ + \ +static void grfill(grand *r, void *p, size_t sz) \ +{ \ + grctx *g = (grctx *)r; \ + pre##_mgfencrypt(&g->k, 0, p, sz); \ +} \ + \ +static const grand_ops grops = { \ + #pre "-mgf", \ + GRAND_CRYPTO, 0, \ + grmisc, grdestroy, \ + grword, grbyte, grword, grand_range, grfill \ +}; \ + \ +/* --- @pre_mgfrand@ --- * \ + * \ + * Arguments: @const void *k@ = pointer to key material \ + * @size_t sz@ = size of key material \ + * \ + * Returns: Pointer to a generic random number generator instance. \ + * \ + * Use: Creates a random number interface wrapper around an \ + * MGF-1-mode hash function. \ + */ \ + \ +extern grand *pre##_mgfrand(const void *k, size_t sz) \ +{ \ + grctx *g = S_CREATE(grctx); \ + g->r.ops = &grops; \ + pre##_mgfinit(&g->k, k, sz); \ + return (&g->r); \ +} \ + \ +MGF_TEST(PRE, pre) + +/*----- Test rig ----------------------------------------------------------*/ + +#ifdef TEST_RIG + +#include + +#include "daftstory.h" + +/* --- @MGF_TEST@ --- * + * + * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions + * + * Use: Standard test rig for MGF functions. + */ + +#define MGF_TEST(PRE, pre) \ + \ +/* --- Initial plaintext for the test --- */ \ + \ +static const octet text[] = TEXT; \ + \ +/* --- Key and IV to use --- */ \ + \ +static const octet key[] = KEY; \ + \ +/* --- Buffers for encryption and decryption output --- */ \ + \ +static octet ct[sizeof(text)]; \ +static octet pt[sizeof(text)]; \ + \ +static void hexdump(const octet *p, size_t sz) \ +{ \ + const octet *q = p + sz; \ + for (sz = 0; p < q; p++, sz++) { \ + printf("%02x", *p); \ + if ((sz + 1) % PRE##_HASHSZ == 0) \ + putchar(':'); \ + } \ +} \ + \ +int main(void) \ +{ \ + size_t sz = 0, rest; \ + pre##_mgfctx ctx; \ + int status = 0; \ + int done = 0; \ + \ + size_t keysz = strlen((const char *)key); \ + \ + fputs(#pre "-mgf: ", stdout); \ + \ + pre##_mgfinit(&ctx, key, keysz); \ + \ + while (sz <= sizeof(text)) { \ + rest = sizeof(text) - sz; \ + memcpy(ct, text, sizeof(text)); \ + pre##_mgfsetindex(&ctx, 0); \ + pre##_mgfencrypt(&ctx, ct, ct, sz); \ + pre##_mgfencrypt(&ctx, ct + sz, ct + sz, rest); \ + memcpy(pt, ct, sizeof(text)); \ + pre##_mgfsetindex(&ctx, 0); \ + pre##_mgfencrypt(&ctx, pt, pt, rest); \ + pre##_mgfencrypt(&ctx, pt + rest, pt + rest, sz); \ + if (memcmp(pt, text, sizeof(text)) == 0) { \ + done++; \ + if (sizeof(text) < 40 || done % 8 == 0) \ + fputc('.', stdout); \ + if (done % 480 == 0) \ + fputs("\n\t", stdout); \ + fflush(stdout); \ + } else { \ + printf("\nError (sz = %lu)\n", (unsigned long)sz); \ + status = 1; \ + printf("\tplaintext = "); hexdump(text, sz); \ + printf(", "); hexdump(text + sz, rest); \ + fputc('\n', stdout); \ + printf("\tciphertext = "); hexdump(ct, sz); \ + printf(", "); hexdump(ct + sz, rest); \ + fputc('\n', stdout); \ + printf("\trecovered text = "); hexdump(pt, sz); \ + printf(", "); hexdump(pt + sz, rest); \ + fputc('\n', stdout); \ + fputc('\n', stdout); \ + } \ + if (sz < 63) \ + sz++; \ + else \ + sz += 9; \ + } \ + \ + fputs(status ? " failed\n" : " ok\n", stdout); \ + return (status); \ +} + +#else +# define MGF_TEST(PRE, pre) +#endif + +/*----- That's all, folks -------------------------------------------------*/ + +#ifdef __cplusplus + } +#endif + +#endif diff --git a/mgf.h b/mgf.h new file mode 100644 index 0000000..14d2c82 --- /dev/null +++ b/mgf.h @@ -0,0 +1,172 @@ +/* -*-c-*- + * + * $Id: mgf.h,v 1.1 2000/06/17 11:33:11 mdw Exp $ + * + * The MGF mask generation function + * + * (c) 2000 Straylight/Edgeware + */ + +/*----- Licensing notice --------------------------------------------------* + * + * This file is part of Catacomb. + * + * Catacomb is free software; you can redistribute it and/or modify + * it under the terms of the GNU Library General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * Catacomb 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 Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with Catacomb; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +/*----- Revision history --------------------------------------------------* + * + * $Log: mgf.h,v $ + * Revision 1.1 2000/06/17 11:33:11 mdw + * MGF-1 support, as defined in PKCS#1. + * + */ + +/*----- Notes on the MGF-1 mask generating function -----------------------* + * + * The idea of a mask-generating function is that given an input of arbitrary + * size, it can emit a pseudorandom output `mask' of arbitrary size. This is + * used in PKCS#1 OAEP (RFC2437). My recommendation would be to use a decent + * stream cipher instead, like RC4 or SEAL. MGF-1 isn't very fast. + */ + +#ifndef CATACOMB_MGF_H +#define CATACOMB_MGF_H + +#ifdef __cplusplus + extern "C" { +#endif + +/*----- Header files ------------------------------------------------------*/ + +#include + +#ifndef CATACOMB_GCIPHER_H +# include "gcipher.h" +#endif + +#ifndef CATACOMB_GRAND_H +# include "grand.h" +#endif + +/*----- Macros ------------------------------------------------------------*/ + +#define MGF_DECL(PRE, pre) \ + \ +/* --- An MGF generation context --- */ \ + \ +typedef struct pre##_mgfctx { \ + pre##_ctx k; /* Underlying key context */ \ + uint32 c; /* Counter */ \ + octet buf[PRE##_HASHSZ]; /* Output buffer */ \ + size_t bsz; /* Size of buffered data */ \ +} pre##_mgfctx; \ + \ +/* --- Other useful constants --- */ \ + \ +extern const octet pre##_mgfkeysz[]; \ + \ +/* --- @pre_mgfkeybegin@, @pre_mgfkeyadd@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \ + * @const void *p@ = pointer to data to contribute \ + * @size_t sz@ = size of data to contribute \ + * \ + * Returns: --- \ + * \ + * Use: A multi-step keying procedure for initializing an MGF \ + * context. The data is contributed to a hashing context \ + * which is then used for mask generation. If you only \ + * have a fixed buffer, you can save a lot of effort by \ + * simply calling @pre_mgfinit@. \ + */ \ + \ +extern void pre##_mgfkeybegin(pre##_mgfctx */*k*/); \ +extern void pre##_mgfkeyadd(pre##_mgfctx */*k*/, \ + const void */*p*/, size_t /*sz*/); \ + \ +/* ---- @pre_mgfinit@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \ + * @const void *p@ = pointer to data to contribute \ + * @size_t sz@ = size of data to contribute \ + * \ + * Returns: --- \ + * \ + * Use: A simpler interface to initialization if all of your \ + * keying material is in one place. \ + */ \ + \ +extern void pre##_mgfinit(pre##_mgfctx */*k*/, \ + const void */*p*/, size_t /*sz*/); \ + \ +/* --- @pre_mgfencrypt@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to masking context \ + * @const void *s@ = pointer to source buffer \ + * @void *d@ = pointer to destination buffer \ + * @size_t sz@ = size of buffers \ + * \ + * Returns: --- \ + * \ + * Use: Outputs pseudorandom data, or masks an input buffer. \ + * \ + * If @s@ is nonzero, the source material is exclusive- \ + * orred with the generated mask. If @d@ is zero, the \ + * generator is simply spun around for a while, which \ + * isn't very useful. \ + */ \ + \ +extern void pre##_mgfencrypt(pre##_mgfctx */*k*/, const void */*s*/, \ + void */*d*/, size_t /*sz*/); \ + \ +/* --- @pre_mgfsetindex@ --- * \ + * \ + * Arguments: @pre_mgfctx *k@ = pointer to masking context \ + * @uint32 *c@ = new index to set \ + * \ + * Returns: --- \ + * \ + * Use: Sets a new index. This may be used to step around the \ + * output stream in a rather crude way. \ + */ \ + \ +extern void pre##_mgfsetindex(pre##_mgfctx */*k*/, uint32 /*c*/); \ + \ +/* --- @pre_mgfrand@ --- * \ + * \ + * Arguments: @const void *k@ = pointer to key material \ + * @size_t sz@ = size of key material \ + * \ + * Returns: Pointer to a generic random number generator instance. \ + * \ + * Use: Creates a random number interface wrapper around an \ + * MGF-1-mode hash function. \ + */ \ + \ +extern grand *pre##_mgfrand(const void */*k*/, size_t /*sz*/); \ + \ +/* --- Generic cipher interface --- */ \ + \ +extern const gccipher pre##_mgf; + +/*----- That's all, folks -------------------------------------------------*/ + +#ifdef __cplusplus + } +#endif + +#endif -- 2.11.0