| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * AEAD schemes based on Salsa20/ChaCha and Poly1305 |
| 4 | * |
| 5 | * (c) 2018 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Catacomb. |
| 11 | * |
| 12 | * Catacomb is free software: you can redistribute it and/or modify it |
| 13 | * under the terms of the GNU Library General Public License as published |
| 14 | * by the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * Catacomb is distributed in the hope that it will be useful, but |
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 20 | * Library General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with Catacomb. If not, write to the Free Software |
| 24 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
| 25 | * USA. |
| 26 | */ |
| 27 | |
| 28 | #ifndef CATACOMB_LATINPOLY_DEF_H |
| 29 | #define CATACOMB_LATINPOLY_DEF_H |
| 30 | |
| 31 | #ifdef __cplusplus |
| 32 | extern "C" { |
| 33 | #endif |
| 34 | |
| 35 | /*----- Header files ------------------------------------------------------*/ |
| 36 | |
| 37 | #include <mLib/bits.h> |
| 38 | #include <mLib/buf.h> |
| 39 | #include <mLib/sub.h> |
| 40 | |
| 41 | #ifndef CATACOMB_ARENA_H |
| 42 | # include "arena.h" |
| 43 | #endif |
| 44 | |
| 45 | #ifndef CATACOMB_CT_H |
| 46 | # include "ct.h" |
| 47 | #endif |
| 48 | |
| 49 | #ifndef CATACOMB_GAEAD_H |
| 50 | # include "gaead.h" |
| 51 | #endif |
| 52 | |
| 53 | #ifndef CATACOMB_KEYSZ_H |
| 54 | # include "keysz.h" |
| 55 | #endif |
| 56 | |
| 57 | #ifndef CATACOMB_LATINPOLY_H |
| 58 | # include "latinpoly.h" |
| 59 | #endif |
| 60 | |
| 61 | #ifndef CATACOMB_PARANOIA_H |
| 62 | # include "paranoia.h" |
| 63 | #endif |
| 64 | |
| 65 | #ifndef CATACOMB_POLY1305_H |
| 66 | # include "poly1305.h" |
| 67 | #endif |
| 68 | |
| 69 | #ifndef CATACOMB_SALSA20_H |
| 70 | # include "salsa20.h" |
| 71 | #endif |
| 72 | |
| 73 | /*----- Data structures ---------------------------------------------------*/ |
| 74 | |
| 75 | typedef struct latinpoly_aad { |
| 76 | gaead_aad a; |
| 77 | poly1305_ctx poly; |
| 78 | } latinpoly_aad; |
| 79 | |
| 80 | typedef struct latinpoly_key { |
| 81 | gaead_key k; |
| 82 | octet key[SALSA20_KEYSZ]; |
| 83 | size_t ksz; |
| 84 | } latinpoly_key; |
| 85 | |
| 86 | /*----- Common definitions ------------------------------------------------*/ |
| 87 | |
| 88 | /* Tables. */ |
| 89 | extern const octet latinpoly_noncesz[], latinpoly_tagsz[]; |
| 90 | |
| 91 | /* AAD methods. */ |
| 92 | extern void latinpoly_aadhash(gaead_aad */*a*/, |
| 93 | const void */*h*/, size_t /*hsz*/); |
| 94 | extern void latinpoly_aaddestroy(gaead_aad */*a*/); |
| 95 | |
| 96 | /* --- @latinpoly_tag@ --- * |
| 97 | * |
| 98 | * Arguments: @const poly1305_ctx *aad@ = Poly1305 context hashing AAD |
| 99 | * @poly1305_ctx *ct@ = Poly1305 context hashing ciphertext |
| 100 | * @void *tag@ = where to write the tag |
| 101 | * |
| 102 | * Returns: --- |
| 103 | * |
| 104 | * Use: Completes a Latin-dance-Poly1305 tag, combining the AAD and |
| 105 | * ciphertext hashes, appending their lengths, and writing the |
| 106 | * final masked hash to @tag@. The @ct@ context is clobbered. |
| 107 | */ |
| 108 | |
| 109 | extern void latinpoly_tag(const poly1305_ctx */*aad*/, |
| 110 | poly1305_ctx */*ct*/, void */*tag*/); |
| 111 | |
| 112 | /*----- Macros ------------------------------------------------------------*/ |
| 113 | |
| 114 | #define LATINPOLY_DEF(latin, base, name) \ |
| 115 | \ |
| 116 | /* Utilities. */ \ |
| 117 | \ |
| 118 | /* Reinitialize the stream cipher and hash state given a new nonce. */ \ |
| 119 | static int reinit_##latin(x##latin##_ctx *ctx, \ |
| 120 | poly1305_ctx *aadpoly, poly1305_ctx *ctpoly, \ |
| 121 | const void *n, size_t nsz) \ |
| 122 | { \ |
| 123 | poly1305_key pk; \ |
| 124 | octet b[POLY1305_KEYSZ + POLY1305_MASKSZ]; \ |
| 125 | \ |
| 126 | switch (nsz) { \ |
| 127 | case SALSA20_NONCESZ: \ |
| 128 | memcpy(ctx->s.a, ctx->k, sizeof(ctx->k)); \ |
| 129 | base##_setnonce(&ctx->s, n); \ |
| 130 | break; \ |
| 131 | case SALSA20_IETF_NONCESZ: \ |
| 132 | memcpy(ctx->s.a, ctx->k, sizeof(ctx->k)); \ |
| 133 | base##_setnonce_ietf(&ctx->s, n); \ |
| 134 | break; \ |
| 135 | case XSALSA20_NONCESZ: \ |
| 136 | x##latin##_setnonce(ctx, n); \ |
| 137 | break; \ |
| 138 | default: \ |
| 139 | return (-1); \ |
| 140 | } \ |
| 141 | \ |
| 142 | latin##_encrypt(&ctx->s, 0, b, sizeof(b)); \ |
| 143 | poly1305_keyinit(&pk, b, POLY1305_KEYSZ); \ |
| 144 | poly1305_macinit(aadpoly, &pk, b + POLY1305_KEYSZ); \ |
| 145 | poly1305_macinit(ctpoly, &pk, b + POLY1305_KEYSZ); \ |
| 146 | latin##_encrypt(&ctx->s, 0, 0, SALSA20_OUTSZ - sizeof(b)); \ |
| 147 | return (0); \ |
| 148 | } \ |
| 149 | \ |
| 150 | /* AAD operations. */ \ |
| 151 | \ |
| 152 | static const gaead_aadops gaops_##latin = \ |
| 153 | { &latin##_poly1305, 0, latinpoly_aadhash, latinpoly_aaddestroy }; \ |
| 154 | \ |
| 155 | /* Encryption operations. */ \ |
| 156 | \ |
| 157 | typedef struct gectx_##latin { \ |
| 158 | gaead_enc e; \ |
| 159 | latinpoly_aad aad; \ |
| 160 | x##latin##_ctx ctx; \ |
| 161 | poly1305_ctx poly; \ |
| 162 | } gectx_##latin; \ |
| 163 | \ |
| 164 | static gaead_aad *geaad_##latin(gaead_enc *e) \ |
| 165 | { gectx_##latin *enc = (gectx_##latin *)e; return (&enc->aad.a); } \ |
| 166 | \ |
| 167 | static int gereinit_##latin(gaead_enc *e, const void *n, size_t nsz, \ |
| 168 | size_t hsz, size_t msz, size_t tsz) \ |
| 169 | { \ |
| 170 | gectx_##latin *enc = (gectx_##latin *)e; \ |
| 171 | return (reinit_##latin(&enc->ctx, &enc->aad.poly, &enc->poly, n, nsz)); \ |
| 172 | } \ |
| 173 | \ |
| 174 | static int geenc_##latin(gaead_enc *e, \ |
| 175 | const void *m, size_t msz, buf *b) \ |
| 176 | { \ |
| 177 | gectx_##latin *enc = (gectx_##latin *)e; \ |
| 178 | void *q; \ |
| 179 | \ |
| 180 | if (msz) { q = buf_get(b, msz); if (!q) return (-1); } \ |
| 181 | else q = 0; \ |
| 182 | latin##_encrypt(&enc->ctx.s, m, q, msz); \ |
| 183 | poly1305_hash(&enc->poly, q, msz); \ |
| 184 | return (0); \ |
| 185 | } \ |
| 186 | \ |
| 187 | static int gedone_##latin(gaead_enc *e, const gaead_aad *a, \ |
| 188 | buf *b, void *t, size_t tsz) \ |
| 189 | { \ |
| 190 | gectx_##latin *enc = (gectx_##latin *)e; \ |
| 191 | const latinpoly_aad *aad = (const latinpoly_aad *)a; \ |
| 192 | \ |
| 193 | if (tsz != POLY1305_TAGSZ) return (-1); \ |
| 194 | assert((!enc->aad.poly.count && !enc->aad.poly.nbuf && !a) || \ |
| 195 | a == &enc->aad.a); \ |
| 196 | if (!BOK(b)) return (-1); \ |
| 197 | latinpoly_tag(aad ? &aad->poly : 0, &enc->poly, t); \ |
| 198 | return (0); \ |
| 199 | } \ |
| 200 | \ |
| 201 | static void gedestroy_##latin(gaead_enc *e) \ |
| 202 | { gectx_##latin *enc = (gectx_##latin *)e; BURN(*enc); S_DESTROY(enc); } \ |
| 203 | \ |
| 204 | static gaead_encops geops_##latin = \ |
| 205 | { &latin##_poly1305, geaad_##latin, gereinit_##latin, \ |
| 206 | geenc_##latin, gedone_##latin, gedestroy_##latin }; \ |
| 207 | \ |
| 208 | /* Decryption operations. */ \ |
| 209 | \ |
| 210 | typedef struct gdctx_##latin { \ |
| 211 | gaead_dec d; \ |
| 212 | latinpoly_aad aad; \ |
| 213 | x##latin##_ctx ctx; \ |
| 214 | poly1305_ctx poly; \ |
| 215 | } gdctx_##latin; \ |
| 216 | \ |
| 217 | static gaead_aad *gdaad_##latin(gaead_dec *d) \ |
| 218 | { gdctx_##latin *dec = (gdctx_##latin *)d; return (&dec->aad.a); } \ |
| 219 | \ |
| 220 | static int gdreinit_##latin(gaead_dec *d, const void *n, size_t nsz, \ |
| 221 | size_t hsz, size_t msz, size_t tsz) \ |
| 222 | { \ |
| 223 | gdctx_##latin *dec = (gdctx_##latin *)d; \ |
| 224 | return (reinit_##latin(&dec->ctx, &dec->aad.poly, &dec->poly, n, nsz)); \ |
| 225 | } \ |
| 226 | \ |
| 227 | static int gddec_##latin(gaead_dec *d, \ |
| 228 | const void *c, size_t csz, buf *b) \ |
| 229 | { \ |
| 230 | gdctx_##latin *dec = (gdctx_##latin *)d; \ |
| 231 | void *q; \ |
| 232 | \ |
| 233 | if (csz) { q = buf_get(b, csz); if (!q) return (-1); } \ |
| 234 | else q = 0; \ |
| 235 | poly1305_hash(&dec->poly, c, csz); \ |
| 236 | latin##_encrypt(&dec->ctx.s, c, q, csz); \ |
| 237 | return (0); \ |
| 238 | } \ |
| 239 | \ |
| 240 | static int gddone_##latin(gaead_dec *d, const gaead_aad *a, \ |
| 241 | buf *b, const void *t, size_t tsz) \ |
| 242 | { \ |
| 243 | gdctx_##latin *dec = (gdctx_##latin *)d; \ |
| 244 | const latinpoly_aad *aad = (const latinpoly_aad *)a; \ |
| 245 | octet u[POLY1305_TAGSZ]; \ |
| 246 | \ |
| 247 | if (tsz != POLY1305_TAGSZ) return (-1); \ |
| 248 | assert((!dec->aad.poly.count && !dec->aad.poly.nbuf && !a) || \ |
| 249 | a == &dec->aad.a); \ |
| 250 | if (!BOK(b)) return (-1); \ |
| 251 | latinpoly_tag(aad ? &aad->poly : 0, &dec->poly, u); \ |
| 252 | if (ct_memeq(t, u, POLY1305_TAGSZ)) return (+1); \ |
| 253 | else return (0); \ |
| 254 | } \ |
| 255 | \ |
| 256 | static void gddestroy_##latin(gaead_dec *d) \ |
| 257 | { gdctx_##latin *dec = (gdctx_##latin *)d; BURN(*dec); S_DESTROY(dec); } \ |
| 258 | \ |
| 259 | static gaead_decops gdops_##latin = \ |
| 260 | { &latin##_poly1305, gdaad_##latin, gdreinit_##latin, \ |
| 261 | gddec_##latin, gddone_##latin, gddestroy_##latin }; \ |
| 262 | \ |
| 263 | /* Key operations. */ \ |
| 264 | \ |
| 265 | static gaead_enc *gkenc_##latin(const gaead_key *k, \ |
| 266 | const void *n, size_t nsz, \ |
| 267 | size_t hsz, size_t msz, size_t tsz) \ |
| 268 | { \ |
| 269 | latinpoly_key *key = (latinpoly_key *)k; \ |
| 270 | gectx_##latin *enc = S_CREATE(gectx_##latin); \ |
| 271 | \ |
| 272 | enc->e.ops = &geops_##latin; enc->aad.a.ops = &gaops_##latin; \ |
| 273 | x##latin##_init(&enc->ctx, key->key, key->ksz, 0); \ |
| 274 | reinit_##latin(&enc->ctx, &enc->aad.poly, &enc->poly, n, nsz); \ |
| 275 | return (&enc->e); \ |
| 276 | } \ |
| 277 | \ |
| 278 | static gaead_dec *gkdec_##latin(const gaead_key *k, \ |
| 279 | const void *n, size_t nsz, \ |
| 280 | size_t hsz, size_t msz, size_t tsz) \ |
| 281 | { \ |
| 282 | latinpoly_key *key = (latinpoly_key *)k; \ |
| 283 | gdctx_##latin *dec = S_CREATE(gdctx_##latin); \ |
| 284 | \ |
| 285 | dec->d.ops = &gdops_##latin; dec->aad.a.ops = &gaops_##latin; \ |
| 286 | x##latin##_init(&dec->ctx, key->key, key->ksz, 0); \ |
| 287 | reinit_##latin(&dec->ctx, &dec->aad.poly, &dec->poly, n, nsz); \ |
| 288 | return (&dec->d); \ |
| 289 | } \ |
| 290 | \ |
| 291 | static void gkdestroy_##latin(gaead_key *k) \ |
| 292 | { latinpoly_key *key = (latinpoly_key *)k; BURN(*key); S_DESTROY(key); } \ |
| 293 | \ |
| 294 | static const gaead_keyops gkops_##latin = \ |
| 295 | { &latin##_poly1305, 0, gkenc_##latin, gkdec_##latin, \ |
| 296 | gkdestroy_##latin }; \ |
| 297 | \ |
| 298 | /* Class definition. */ \ |
| 299 | \ |
| 300 | static gaead_key *gkey_##latin(const void *k, size_t ksz) \ |
| 301 | { \ |
| 302 | latinpoly_key *key = S_CREATE(latinpoly_key); \ |
| 303 | \ |
| 304 | key->k.ops = &gkops_##latin; \ |
| 305 | KSZ_ASSERT(latin, ksz); memcpy(key->key, k, ksz); key->ksz = ksz; \ |
| 306 | return (&key->k); \ |
| 307 | } \ |
| 308 | \ |
| 309 | const gcaead latin##_poly1305 = { \ |
| 310 | name "-poly1305", latin##_keysz, latinpoly_noncesz, latinpoly_tagsz, \ |
| 311 | 64, 0, 0, AEADF_AADNDEP, \ |
| 312 | gkey_##latin \ |
| 313 | }; |
| 314 | |
| 315 | /*----- That's all, folks -------------------------------------------------*/ |
| 316 | |
| 317 | #ifdef __cplusplus |
| 318 | } |
| 319 | #endif |
| 320 | |
| 321 | #endif |