+/* -*-c-*-
+ *
+ * AEAD schemes based on Salsa20/ChaCha and Poly1305
+ *
+ * (c) 2018 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.
+ */
+
+#ifndef CATACOMB_LATINPOLY_DEF_H
+#define CATACOMB_LATINPOLY_DEF_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/bits.h>
+#include <mLib/buf.h>
+#include <mLib/sub.h>
+
+#ifndef CATACOMB_ARENA_H
+# include "arena.h"
+#endif
+
+#ifndef CATACOMB_CT_H
+# include "ct.h"
+#endif
+
+#ifndef CATACOMB_GAEAD_H
+# include "gaead.h"
+#endif
+
+#ifndef CATACOMB_KEYSZ_H
+# include "keysz.h"
+#endif
+
+#ifndef CATACOMB_LATINPOLY_H
+# include "latinpoly.h"
+#endif
+
+#ifndef CATACOMB_PARANOIA_H
+# include "paranoia.h"
+#endif
+
+#ifndef CATACOMB_POLY1305_H
+# include "poly1305.h"
+#endif
+
+#ifndef CATACOMB_SALSA20_H
+# include "salsa20.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct latinpoly_aad {
+ gaead_aad a;
+ poly1305_ctx poly;
+} latinpoly_aad;
+
+typedef struct latinpoly_key {
+ gaead_key k;
+ octet key[SALSA20_KEYSZ];
+ size_t ksz;
+} latinpoly_key;
+
+/*----- Common definitions ------------------------------------------------*/
+
+/* Tables. */
+extern const octet latinpoly_noncesz[], latinpoly_tagsz[];
+
+/* AAD methods. */
+extern void latinpoly_aadhash(gaead_aad */*a*/,
+ const void */*h*/, size_t /*hsz*/);
+extern void latinpoly_aaddestroy(gaead_aad */*a*/);
+
+/* --- @latinpoly_tag@ --- *
+ *
+ * Arguments: @const poly1305_ctx *aad@ = Poly1305 context hashing AAD
+ * @poly1305_ctx *ct@ = Poly1305 context hashing ciphertext
+ * @void *tag@ = where to write the tag
+ *
+ * Returns: ---
+ *
+ * Use: Completes a Latin-dance-Poly1305 tag, combining the AAD and
+ * ciphertext hashes, appending their lengths, and writing the
+ * final masked hash to @tag@. The @ct@ context is clobbered.
+ */
+
+extern void latinpoly_tag(const poly1305_ctx */*aad*/,
+ poly1305_ctx */*ct*/, void */*tag*/);
+
+/*----- Macros ------------------------------------------------------------*/
+
+#define LATINPOLY_DEF(latin, base, name) \
+ \
+/* Utilities. */ \
+ \
+/* Reinitialize the stream cipher and hash state given a new nonce. */ \
+static int reinit_##latin(x##latin##_ctx *ctx, \
+ poly1305_ctx *aadpoly, poly1305_ctx *ctpoly, \
+ const void *n, size_t nsz) \
+{ \
+ poly1305_key pk; \
+ octet b[POLY1305_KEYSZ + POLY1305_MASKSZ]; \
+ \
+ switch (nsz) { \
+ case SALSA20_NONCESZ: \
+ memcpy(ctx->s.a, ctx->k, sizeof(ctx->k)); \
+ base##_setnonce(&ctx->s, n); \
+ break; \
+ case SALSA20_IETF_NONCESZ: \
+ memcpy(ctx->s.a, ctx->k, sizeof(ctx->k)); \
+ base##_setnonce_ietf(&ctx->s, n); \
+ break; \
+ case XSALSA20_NONCESZ: \
+ x##latin##_setnonce(ctx, n); \
+ break; \
+ default: \
+ return (-1); \
+ } \
+ \
+ latin##_encrypt(&ctx->s, 0, b, sizeof(b)); \
+ poly1305_keyinit(&pk, b, POLY1305_KEYSZ); \
+ poly1305_macinit(aadpoly, &pk, b + POLY1305_KEYSZ); \
+ poly1305_macinit(ctpoly, &pk, b + POLY1305_KEYSZ); \
+ latin##_encrypt(&ctx->s, 0, 0, SALSA20_OUTSZ - sizeof(b)); \
+ return (0); \
+} \
+ \
+/* AAD operations. */ \
+ \
+static const gaead_aadops gaops_##latin = \
+ { &latin##_poly1305, 0, latinpoly_aadhash, latinpoly_aaddestroy }; \
+ \
+/* Encryption operations. */ \
+ \
+typedef struct gectx_##latin { \
+ gaead_enc e; \
+ latinpoly_aad aad; \
+ x##latin##_ctx ctx; \
+ poly1305_ctx poly; \
+} gectx_##latin; \
+ \
+static gaead_aad *geaad_##latin(gaead_enc *e) \
+ { gectx_##latin *enc = (gectx_##latin *)e; return (&enc->aad.a); } \
+ \
+static int gereinit_##latin(gaead_enc *e, const void *n, size_t nsz, \
+ size_t hsz, size_t msz, size_t tsz) \
+{ \
+ gectx_##latin *enc = (gectx_##latin *)e; \
+ return (reinit_##latin(&enc->ctx, &enc->aad.poly, &enc->poly, n, nsz)); \
+} \
+ \
+static int geenc_##latin(gaead_enc *e, \
+ const void *m, size_t msz, buf *b) \
+{ \
+ gectx_##latin *enc = (gectx_##latin *)e; \
+ void *q; \
+ \
+ if (msz) { q = buf_get(b, msz); if (!q) return (-1); } \
+ else q = 0; \
+ latin##_encrypt(&enc->ctx.s, m, q, msz); \
+ poly1305_hash(&enc->poly, q, msz); \
+ return (0); \
+} \
+ \
+static int gedone_##latin(gaead_enc *e, const gaead_aad *a, \
+ buf *b, void *t, size_t tsz) \
+{ \
+ gectx_##latin *enc = (gectx_##latin *)e; \
+ const latinpoly_aad *aad = (const latinpoly_aad *)a; \
+ \
+ if (tsz != POLY1305_TAGSZ) return (-1); \
+ assert((!enc->aad.poly.count && !enc->aad.poly.nbuf && !a) || \
+ a == &enc->aad.a); \
+ if (!BOK(b)) return (-1); \
+ latinpoly_tag(aad ? &aad->poly : 0, &enc->poly, t); \
+ return (0); \
+} \
+ \
+static void gedestroy_##latin(gaead_enc *e) \
+ { gectx_##latin *enc = (gectx_##latin *)e; BURN(*enc); S_DESTROY(enc); } \
+ \
+static gaead_encops geops_##latin = \
+ { &latin##_poly1305, geaad_##latin, gereinit_##latin, \
+ geenc_##latin, gedone_##latin, gedestroy_##latin }; \
+ \
+/* Decryption operations. */ \
+ \
+typedef struct gdctx_##latin { \
+ gaead_dec d; \
+ latinpoly_aad aad; \
+ x##latin##_ctx ctx; \
+ poly1305_ctx poly; \
+} gdctx_##latin; \
+ \
+static gaead_aad *gdaad_##latin(gaead_dec *d) \
+ { gdctx_##latin *dec = (gdctx_##latin *)d; return (&dec->aad.a); } \
+ \
+static int gdreinit_##latin(gaead_dec *d, const void *n, size_t nsz, \
+ size_t hsz, size_t msz, size_t tsz) \
+{ \
+ gdctx_##latin *dec = (gdctx_##latin *)d; \
+ return (reinit_##latin(&dec->ctx, &dec->aad.poly, &dec->poly, n, nsz)); \
+} \
+ \
+static int gddec_##latin(gaead_dec *d, \
+ const void *c, size_t csz, buf *b) \
+{ \
+ gdctx_##latin *dec = (gdctx_##latin *)d; \
+ void *q; \
+ \
+ if (csz) { q = buf_get(b, csz); if (!q) return (-1); } \
+ else q = 0; \
+ poly1305_hash(&dec->poly, c, csz); \
+ latin##_encrypt(&dec->ctx.s, c, q, csz); \
+ return (0); \
+} \
+ \
+static int gddone_##latin(gaead_dec *d, const gaead_aad *a, \
+ buf *b, const void *t, size_t tsz) \
+{ \
+ gdctx_##latin *dec = (gdctx_##latin *)d; \
+ const latinpoly_aad *aad = (const latinpoly_aad *)a; \
+ octet u[POLY1305_TAGSZ]; \
+ \
+ if (tsz != POLY1305_TAGSZ) return (-1); \
+ assert((!dec->aad.poly.count && !dec->aad.poly.nbuf && !a) || \
+ a == &dec->aad.a); \
+ if (!BOK(b)) return (-1); \
+ latinpoly_tag(aad ? &aad->poly : 0, &dec->poly, u); \
+ if (ct_memeq(t, u, POLY1305_TAGSZ)) return (+1); \
+ else return (0); \
+} \
+ \
+static void gddestroy_##latin(gaead_dec *d) \
+ { gdctx_##latin *dec = (gdctx_##latin *)d; BURN(*dec); S_DESTROY(dec); } \
+ \
+static gaead_decops gdops_##latin = \
+ { &latin##_poly1305, gdaad_##latin, gdreinit_##latin, \
+ gddec_##latin, gddone_##latin, gddestroy_##latin }; \
+ \
+/* Key operations. */ \
+ \
+static gaead_enc *gkenc_##latin(const gaead_key *k, \
+ const void *n, size_t nsz, \
+ size_t hsz, size_t msz, size_t tsz) \
+{ \
+ latinpoly_key *key = (latinpoly_key *)k; \
+ gectx_##latin *enc = S_CREATE(gectx_##latin); \
+ \
+ enc->e.ops = &geops_##latin; enc->aad.a.ops = &gaops_##latin; \
+ x##latin##_init(&enc->ctx, key->key, key->ksz, 0); \
+ reinit_##latin(&enc->ctx, &enc->aad.poly, &enc->poly, n, nsz); \
+ return (&enc->e); \
+} \
+ \
+static gaead_dec *gkdec_##latin(const gaead_key *k, \
+ const void *n, size_t nsz, \
+ size_t hsz, size_t msz, size_t tsz) \
+{ \
+ latinpoly_key *key = (latinpoly_key *)k; \
+ gdctx_##latin *dec = S_CREATE(gdctx_##latin); \
+ \
+ dec->d.ops = &gdops_##latin; dec->aad.a.ops = &gaops_##latin; \
+ x##latin##_init(&dec->ctx, key->key, key->ksz, 0); \
+ reinit_##latin(&dec->ctx, &dec->aad.poly, &dec->poly, n, nsz); \
+ return (&dec->d); \
+} \
+ \
+static void gkdestroy_##latin(gaead_key *k) \
+ { latinpoly_key *key = (latinpoly_key *)k; BURN(*key); S_DESTROY(key); } \
+ \
+static const gaead_keyops gkops_##latin = \
+ { &latin##_poly1305, 0, gkenc_##latin, gkdec_##latin, \
+ gkdestroy_##latin }; \
+ \
+/* Class definition. */ \
+ \
+static gaead_key *gkey_##latin(const void *k, size_t ksz) \
+{ \
+ latinpoly_key *key = S_CREATE(latinpoly_key); \
+ \
+ key->k.ops = &gkops_##latin; \
+ KSZ_ASSERT(latin, ksz); memcpy(key->key, k, ksz); key->ksz = ksz; \
+ return (&key->k); \
+} \
+ \
+const gcaead latin##_poly1305 = { \
+ name "-poly1305", latin##_keysz, latinpoly_noncesz, latinpoly_tagsz, \
+ 64, 0, 0, AEADF_AADNDEP, \
+ gkey_##latin \
+};
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif