*
* This file is part of Trivial IP Encryption (TrIPE).
*
- * TrIPE is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * TrIPE is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
*
- * TrIPE 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 General Public License for more details.
+ * TrIPE 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 General Public License
+ * for more details.
*
* You should have received a copy of the GNU General Public License
- * along with TrIPE; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with TrIPE. If not, see <https://www.gnu.org/licenses/>.
*/
/*----- Header files ------------------------------------------------------*/
trace_block(T_CRYPTO, "crypto: expected MAC", (pmac), (tagsz)); \
}) } while (0)
+/*----- Common functionality for generic-composition transforms -----------*/
+
#define CHECK_MAC(h, pmac, tagsz) do { \
ghash *_h = (h); \
const octet *_pmac = (pmac); \
} \
} while (0)
+typedef struct gencomp_algs {
+ const gccipher *c; size_t cksz;
+ const gcmac *m; size_t mksz; size_t tagsz;
+} gencomp_algs;
+
+typedef struct gencomp_chal {
+ bulkchal _b;
+ gmac *m;
+} gencomp_chal;
+
+static int gencomp_getalgs(gencomp_algs *a, const algswitch *asw,
+ dstr *e, key_file *kf, key *k)
+{
+ const char *p;
+ char *q, *qq;
+ unsigned long n;
+ dstr d = DSTR_INIT;
+ int rc = -1;
+
+ /* --- Symmetric encryption --- */
+
+ if ((p = key_getattr(kf, k, "cipher")) == 0) p = "blowfish-cbc";
+ if ((a->c = gcipher_byname(p)) == 0) {
+ a_format(e, "unknown-cipher", "%s", p, A_END);
+ goto done;
+ }
+
+ /* --- Message authentication --- */
+
+ if ((p = key_getattr(kf, k, "mac")) != 0) {
+ dstr_reset(&d);
+ dstr_puts(&d, p);
+ if ((q = strrchr(d.buf, '/')) != 0)
+ *q++ = 0;
+ if ((a->m = gmac_byname(d.buf)) == 0) {
+ a_format(e, "unknown-mac", "%s", d.buf, A_END);
+ goto done;
+ }
+ if (!q)
+ a->tagsz = a->m->hashsz;
+ else {
+ n = strtoul(q, &qq, 0);
+ if (*qq) {
+ a_format(e, "bad-tag-length-string", "%s", q, A_END);
+ goto done;
+ }
+ if (n%8 || n/8 > a->m->hashsz) {
+ a_format(e, "bad-tag-length", "%lu", n, A_END);
+ goto done;
+ }
+ a->tagsz = n/8;
+ }
+ } else {
+ dstr_reset(&d);
+ dstr_putf(&d, "%s-hmac", asw->h->name);
+ if ((a->m = gmac_byname(d.buf)) == 0) {
+ a_format(e, "no-hmac-for-hash", "%s", asw->h->name, A_END);
+ goto done;
+ }
+ a->tagsz = asw->h->hashsz/2;
+ }
+
+ rc = 0;
+done:
+ dstr_destroy(&d);
+ return (rc);
+}
+
+#ifndef NTRACE
+static void gencomp_tracealgs(const gencomp_algs *a)
+{
+ trace(T_CRYPTO, "crypto: cipher = %s", a->c->name);
+ trace(T_CRYPTO, "crypto: mac = %s/%lu",
+ a->m->name, (unsigned long)a->tagsz * 8);
+}
+#endif
+
+static int gencomp_checkalgs(gencomp_algs *a, const algswitch *asw, dstr *e)
+{
+ /* --- Derive the key sizes --- *
+ *
+ * Must ensure that we have non-empty keys. This isn't ideal, but it
+ * provides a handy sanity check. Also must be based on a 64- or 128-bit
+ * block cipher or we can't do the data expiry properly.
+ */
+
+ if ((a->cksz = keysz(asw->hashsz, a->c->keysz)) == 0) {
+ a_format(e, "cipher", "%s", a->c->name,
+ "no-key-size", "%lu", (unsigned long)asw->hashsz,
+ A_END);
+ return (-1);
+ }
+ if ((a->mksz = keysz(asw->hashsz, a->m->keysz)) == 0) {
+ a_format(e, "mac", "%s", a->m->name,
+ "no-key-size", "%lu", (unsigned long)asw->hashsz,
+ A_END);
+ return (-1);
+ }
+
+ return (0);
+}
+
+static void gencomp_alginfo(const gencomp_algs *a, admin *adm)
+{
+ a_info(adm,
+ "cipher=%s", a->c->name,
+ "cipher-keysz=%lu", (unsigned long)a->cksz,
+ "cipher-blksz=%lu", (unsigned long)a->c->blksz,
+ A_END);
+ a_info(adm,
+ "mac=%s", a->m->name,
+ "mac-keysz=%lu", (unsigned long)a->mksz,
+ "mac-tagsz=%lu", (unsigned long)a->tagsz,
+ A_END);
+}
+
+static int gencomp_samealgsp(const gencomp_algs *a, const gencomp_algs *aa)
+{
+ return (a->c == aa->c &&
+ a->m == aa->m && a->tagsz == aa->tagsz);
+}
+
+static size_t gencomp_expsz(const gencomp_algs *a)
+ { return (a->c->blksz < 16 ? MEG(64) : MEG(2048)); }
+
+static bulkchal *gencomp_genchal(const gencomp_algs *a)
+{
+ gencomp_chal *gc = CREATE(gencomp_chal);
+
+ rand_get(RAND_GLOBAL, buf_t, a->mksz);
+ gc->m = GM_KEY(a->m, buf_t, a->mksz);
+ gc->_b.tagsz = a->tagsz;
+ IF_TRACING(T_CHAL, {
+ trace(T_CHAL, "chal: generated new challenge key");
+ trace_block(T_CRYPTO, "chal: new key", buf_t, a->mksz);
+ })
+ return (&gc->_b);
+}
+
+static int gencomp_chaltag(bulkchal *bc, const void *m, size_t msz, void *t)
+{
+ gencomp_chal *gc = (gencomp_chal *)bc;
+ ghash *h = GM_INIT(gc->m);
+
+ GH_HASH(h, m, msz);
+ memcpy(t, GH_DONE(h, 0), bc->tagsz);
+ GH_DESTROY(h);
+ return (0);
+}
+
+static int gencomp_chalvrf(bulkchal *bc, const void *m, size_t msz,
+ const void *t)
+{
+ gencomp_chal *gc = (gencomp_chal *)bc;
+ ghash *h = GM_INIT(gc->m);
+ int ok;
+
+ GH_HASH(h, m, msz);
+ ok = ct_memeq(GH_DONE(h, 0), t, gc->_b.tagsz);
+ GH_DESTROY(h);
+ return (ok ? 0 : -1);
+}
+
+static void gencomp_freechal(bulkchal *bc)
+ { gencomp_chal *gc = (gencomp_chal *)bc; GM_DESTROY(gc->m); DESTROY(gc); }
+
/*----- The original transform --------------------------------------------*
*
* We generate a random initialization vector (if the cipher needs one). We
* ciphertext and extracts the sequence number.
*/
-static int v0_check(const algswitch *a, dstr *e)
- { return (0); }
+typedef struct v0_algs {
+ bulkalgs _b;
+ gencomp_algs ga;
+} v0_algs;
+
+typedef struct v0_ctx {
+ bulkctx _b;
+ size_t tagsz;
+ struct {
+ gcipher *c;
+ gmac *m;
+ } d[NDIR];
+} v0_ctx;
+
+static bulkalgs *v0_getalgs(const algswitch *asw, dstr *e,
+ key_file *kf, key *k)
+{
+ v0_algs *a = CREATE(v0_algs);
+ if (gencomp_getalgs(&a->ga, asw, e, kf, k)) { DESTROY(a); return (0); }
+ return (&a->_b);
+}
+
+#ifndef NTRACE
+static void v0_tracealgs(const bulkalgs *aa)
+ { const v0_algs *a = (const v0_algs *)aa; gencomp_tracealgs(&a->ga); }
+#endif
+
+static int v0_checkalgs(bulkalgs *aa, const algswitch *asw, dstr *e)
+{
+ v0_algs *a = (v0_algs *)aa;
+ if (gencomp_checkalgs(&a->ga, asw, e)) return (-1);
+ return (0);
+}
+
+static int v0_samealgsp(const bulkalgs *aa, const bulkalgs *bb)
+{
+ const v0_algs *a = (const v0_algs *)aa, *b = (const v0_algs *)bb;
+ return (gencomp_samealgsp(&a->ga, &b->ga));
+}
-static size_t v0_overhead(const algswitch *a)
- { return a->tagsz + SEQSZ + a->c->blksz; }
+static void v0_alginfo(const bulkalgs *aa, admin *adm)
+ { const v0_algs *a = (const v0_algs *)aa; gencomp_alginfo(&a->ga, adm); }
-static int v0_encrypt(keyset *ks, unsigned ty, buf *b, buf *bb)
+static size_t v0_overhead(const bulkalgs *aa)
{
+ const v0_algs *a = (const v0_algs *)aa;
+ return (a->ga.tagsz + SEQSZ + a->ga.c->blksz);
+}
+
+static size_t v0_expsz(const bulkalgs *aa)
+ { const v0_algs *a = (const v0_algs *)aa; return (gencomp_expsz(&a->ga)); }
+
+static bulkctx *v0_genkeys(const bulkalgs *aa, const struct rawkey *rk)
+{
+ const v0_algs *a = (const v0_algs *)aa;
+ v0_ctx *bc = CREATE(v0_ctx);
+ octet k[MAXHASHSZ];
+ int i;
+
+ bc->tagsz = a->ga.tagsz;
+ for (i = 0; i < NDIR; i++) {
+ ks_derivekey(k, a->ga.cksz, rk, i, "encryption");
+ bc->d[i].c = GC_INIT(a->ga.c, k, a->ga.cksz);
+ ks_derivekey(k, a->ga.mksz, rk, i, "integrity");
+ bc->d[i].m = GM_KEY(a->ga.m, k, a->ga.mksz);
+ }
+ return (&bc->_b);
+}
+
+static bulkchal *v0_genchal(const bulkalgs *aa)
+{
+ const v0_algs *a = (const v0_algs *)aa;
+ return (gencomp_genchal(&a->ga));
+}
+#define v0_chaltag gencomp_chaltag
+#define v0_chalvrf gencomp_chalvrf
+#define v0_freechal gencomp_freechal
+
+static void v0_freealgs(bulkalgs *aa)
+ { v0_algs *a = (v0_algs *)aa; DESTROY(a); }
+
+static void v0_freectx(bulkctx *bbc)
+{
+ v0_ctx *bc = (v0_ctx *)bbc;
+ int i;
+
+ for (i = 0; i < NDIR; i++) {
+ GC_DESTROY(bc->d[i].c);
+ GM_DESTROY(bc->d[i].m);
+ }
+ DESTROY(bc);
+}
+
+static int v0_encrypt(bulkctx *bbc, unsigned ty,
+ buf *b, buf *bb, uint32 seq)
+{
+ v0_ctx *bc = (v0_ctx *)bbc;
ghash *h;
- gcipher *c = ks->out.c;
+ gcipher *c = bc->d[DIR_OUT].c;
const octet *p = BCUR(b);
size_t sz = BLEFT(b);
octet *qmac, *qseq, *qiv, *qpk;
- uint32 oseq;
size_t ivsz = GC_CLASS(c)->blksz;
- size_t tagsz = ks->tagsz;
+ size_t tagsz = bc->tagsz;
octet t[4];
/* --- Determine the ciphertext layout --- */
/* --- Store the sequence number --- */
- oseq = ks->oseq++;
- STORE32(qseq, oseq);
+ STORE32(qseq, seq);
/* --- Establish an initialization vector if necessary --- */
/* --- Compute a MAC over type, sequence number, IV, and ciphertext --- */
if (tagsz) {
- h = GM_INIT(ks->out.m);
+ h = GM_INIT(bc->d[DIR_OUT].m);
GH_HASH(h, t, sizeof(t));
GH_HASH(h, qseq, SEQSZ + ivsz + sz);
memcpy(qmac, GH_DONE(h, 0), tagsz);
return (0);
}
-static int v0_decrypt(keyset *ks, unsigned ty, buf *b, buf *bb, uint32 *seq)
+static int v0_decrypt(bulkctx *bbc, unsigned ty,
+ buf *b, buf *bb, uint32 *seq)
{
+ v0_ctx *bc = (v0_ctx *)bbc;
const octet *pmac, *piv, *pseq, *ppk;
size_t psz = BLEFT(b);
size_t sz;
octet *q = BCUR(bb);
ghash *h;
- gcipher *c = ks->in.c;
+ gcipher *c = bc->d[DIR_IN].c;
size_t ivsz = GC_CLASS(c)->blksz;
- size_t tagsz = ks->tagsz;
+ size_t tagsz = bc->tagsz;
octet t[4];
/* --- Break up the packet into its components --- */
if (psz < ivsz + SEQSZ + tagsz) {
- T( trace(T_KEYSET, "keyset: block too small for keyset %u", ks->seq); )
+ T( trace(T_KEYSET, "keyset: block too small for keyset"); )
return (KSERR_MALFORMED);
}
sz = psz - ivsz - SEQSZ - tagsz;
/* --- Verify the MAC on the packet --- */
if (tagsz) {
- h = GM_INIT(ks->in.m);
+ h = GM_INIT(bc->d[DIR_IN].m);
GH_HASH(h, t, sizeof(t));
GH_HASH(h, pseq, SEQSZ + ivsz + sz);
CHECK_MAC(h, pmac, tagsz);
* tagsz 32 sz
*/
-static int iiv_check(const algswitch *a, dstr *e)
+typedef struct iiv_algs {
+ bulkalgs _b;
+ gencomp_algs ga;
+ const gccipher *b; size_t bksz;
+} iiv_algs;
+
+typedef struct iiv_ctx {
+ bulkctx _b;
+ size_t tagsz;
+ struct {
+ gcipher *c, *b;
+ gmac *m;
+ } d[NDIR];
+} iiv_ctx;
+
+
+static bulkalgs *iiv_getalgs(const algswitch *asw, dstr *e,
+ key_file *kf, key *k)
{
- if (a->b->blksz < a->c->blksz) {
+ iiv_algs *a = CREATE(iiv_algs);
+ dstr d = DSTR_INIT, dd = DSTR_INIT;
+ const char *p;
+ char *q;
+
+ if (gencomp_getalgs(&a->ga, asw, e, kf, k)) goto fail;
+
+ if ((p = key_getattr(kf, k, "blkc")) == 0) {
+ dstr_puts(&dd, a->ga.c->name);
+ if ((q = strrchr(dd.buf, '-')) != 0) *q = 0;
+ p = dd.buf;
+ }
+ dstr_putf(&d, "%s-ecb", p);
+ if ((a->b = gcipher_byname(d.buf)) == 0) {
+ a_format(e, "unknown-blkc", "%s", p, A_END);
+ goto fail;
+ }
+
+ dstr_destroy(&d); dstr_destroy(&dd);
+ return (&a->_b);
+fail:
+ dstr_destroy(&d); dstr_destroy(&dd);
+ DESTROY(a);
+ return (0);
+}
+
+#ifndef NTRACE
+static void iiv_tracealgs(const bulkalgs *aa)
+{
+ const iiv_algs *a = (const iiv_algs *)aa;
+
+ gencomp_tracealgs(&a->ga);
+ trace(T_CRYPTO,
+ "crypto: blkc = %.*s", (int)strlen(a->b->name) - 4, a->b->name);
+}
+#endif
+
+static int iiv_checkalgs(bulkalgs *aa, const algswitch *asw, dstr *e)
+{
+ iiv_algs *a = (iiv_algs *)aa;
+
+ if (gencomp_checkalgs(&a->ga, asw, e)) return (-1);
+
+ if ((a->bksz = keysz(asw->hashsz, a->b->keysz)) == 0) {
+ a_format(e, "blkc", "%.*s", strlen(a->b->name) - 4, a->b->name,
+ "no-key-size", "%lu", (unsigned long)asw->hashsz,
+ A_END);
+ return (-1);
+ }
+ if (a->b->blksz < a->ga.c->blksz) {
a_format(e, "blkc", "%.*s", strlen(a->b->name) - 4, a->b->name,
"blksz-insufficient", A_END);
return (-1);
return (0);
}
-static size_t iiv_overhead(const algswitch *a)
- { return a->tagsz + SEQSZ; }
+static int iiv_samealgsp(const bulkalgs *aa, const bulkalgs *bb)
+{
+ const iiv_algs *a = (const iiv_algs *)aa, *b = (const iiv_algs *)bb;
+ return (gencomp_samealgsp(&a->ga, &b->ga) && a->b == b->b);
+}
+
+static void iiv_alginfo(const bulkalgs *aa, admin *adm)
+{
+ const iiv_algs *a = (const iiv_algs *)aa;
+ gencomp_alginfo(&a->ga, adm);
+ a_info(adm,
+ "blkc=%.*s", strlen(a->b->name) - 4, a->b->name,
+ "blkc-keysz=%lu", (unsigned long)a->bksz,
+ "blkc-blksz=%lu", (unsigned long)a->b->blksz,
+ A_END);
+}
+
+static size_t iiv_overhead(const bulkalgs *aa)
+ { const iiv_algs *a = (const iiv_algs *)aa; return (a->ga.tagsz + SEQSZ); }
+
+static size_t iiv_expsz(const bulkalgs *aa)
+{
+ const iiv_algs *a = (const iiv_algs *)aa;
+ return (gencomp_expsz(&a->ga));
+}
+
+static bulkctx *iiv_genkeys(const bulkalgs *aa, const struct rawkey *rk)
+{
+ const iiv_algs *a = (const iiv_algs *)aa;
+ iiv_ctx *bc = CREATE(iiv_ctx);
+ octet k[MAXHASHSZ];
+ int i;
+
+ bc->tagsz = a->ga.tagsz;
+ for (i = 0; i < NDIR; i++) {
+ ks_derivekey(k, a->ga.cksz, rk, i, "encryption");
+ bc->d[i].c = GC_INIT(a->ga.c, k, a->ga.cksz);
+ ks_derivekey(k, a->bksz, rk, i, "blkc");
+ bc->d[i].b = GC_INIT(a->b, k, a->bksz);
+ ks_derivekey(k, a->ga.mksz, rk, i, "integrity");
+ bc->d[i].m = GM_KEY(a->ga.m, k, a->ga.mksz);
+ }
+ return (&bc->_b);
+}
+
+static bulkchal *iiv_genchal(const bulkalgs *aa)
+{
+ const iiv_algs *a = (const iiv_algs *)aa;
+ return (gencomp_genchal(&a->ga));
+}
+#define iiv_chaltag gencomp_chaltag
+#define iiv_chalvrf gencomp_chalvrf
+#define iiv_freechal gencomp_freechal
+
+static void iiv_freealgs(bulkalgs *aa)
+ { iiv_algs *a = (iiv_algs *)aa; DESTROY(a); }
+
+static void iiv_freectx(bulkctx *bbc)
+{
+ iiv_ctx *bc = (iiv_ctx *)bbc;
+ int i;
+
+ for (i = 0; i < NDIR; i++) {
+ GC_DESTROY(bc->d[i].c);
+ GC_DESTROY(bc->d[i].b);
+ GM_DESTROY(bc->d[i].m);
+ }
+ DESTROY(bc);
+}
#define TRACE_PRESEQ(qseq, ivsz) do { IF_TRACING(T_KEYSET, { \
trace_block(T_CRYPTO, "crypto: IV derivation input", (qseq), (ivsz)); \
}) } while (0)
-static int iiv_encrypt(keyset *ks, unsigned ty, buf *b, buf *bb)
+static int iiv_encrypt(bulkctx *bbc, unsigned ty,
+ buf *b, buf *bb, uint32 seq)
{
+ iiv_ctx *bc = (iiv_ctx *)bbc;
ghash *h;
- gcipher *c = ks->out.c, *blkc = ks->out.b;
+ gcipher *c = bc->d[DIR_OUT].c, *blkc = bc->d[DIR_OUT].b;
const octet *p = BCUR(b);
size_t sz = BLEFT(b);
octet *qmac, *qseq, *qpk;
- uint32 oseq;
size_t ivsz = GC_CLASS(c)->blksz, blkcsz = GC_CLASS(blkc)->blksz;
- size_t tagsz = ks->tagsz;
+ size_t tagsz = bc->tagsz;
octet t[4];
/* --- Determine the ciphertext layout --- */
/* --- Store the sequence number --- */
- oseq = ks->oseq++;
- STORE32(qseq, oseq);
+ STORE32(qseq, seq);
/* --- Establish an initialization vector if necessary --- */
/* --- Compute a MAC over type, sequence number, and ciphertext --- */
if (tagsz) {
- h = GM_INIT(ks->out.m);
+ h = GM_INIT(bc->d[DIR_OUT].m);
GH_HASH(h, t, sizeof(t));
GH_HASH(h, qseq, SEQSZ + sz);
memcpy(qmac, GH_DONE(h, 0), tagsz);
return (0);
}
-static int iiv_decrypt(keyset *ks, unsigned ty, buf *b, buf *bb, uint32 *seq)
+static int iiv_decrypt(bulkctx *bbc, unsigned ty,
+ buf *b, buf *bb, uint32 *seq)
{
+ iiv_ctx *bc = (iiv_ctx *)bbc;
const octet *pmac, *pseq, *ppk;
size_t psz = BLEFT(b);
size_t sz;
octet *q = BCUR(bb);
ghash *h;
- gcipher *c = ks->in.c, *blkc = ks->in.b;
+ gcipher *c = bc->d[DIR_IN].c, *blkc = bc->d[DIR_IN].b;
size_t ivsz = GC_CLASS(c)->blksz, blkcsz = GC_CLASS(blkc)->blksz;
- size_t tagsz = ks->tagsz;
+ size_t tagsz = bc->tagsz;
octet t[4];
/* --- Break up the packet into its components --- */
if (psz < SEQSZ + tagsz) {
- T( trace(T_KEYSET, "keyset: block too small for keyset %u", ks->seq); )
+ T( trace(T_KEYSET, "keyset: block too small for keyset"); )
return (KSERR_MALFORMED);
}
sz = psz - SEQSZ - tagsz;
/* --- Verify the MAC on the packet --- */
if (tagsz) {
- h = GM_INIT(ks->in.m);
+ h = GM_INIT(bc->d[DIR_IN].m);
GH_HASH(h, t, sizeof(t));
GH_HASH(h, pseq, SEQSZ + sz);
CHECK_MAC(h, pmac, tagsz);
return (0);
}
+/*----- The NaCl box transform --------------------------------------------*
+ *
+ * This transform is very similar to the NaCl `crypto_secretbox' transform
+ * described in Bernstein, `Cryptography in NaCl', with the difference that,
+ * rather than using XSalsa20, we use either Salsa20/r or ChaChar, because we
+ * have no need of XSalsa20's extended nonce. The default cipher is Salsa20.
+ *
+ * Salsa20 and ChaCha accept a 64-bit nonce. The low 32 bits are the
+ * sequence number, and the high 32 bits are the type, both big-endian.
+ *
+ * +------+------+
+ * | seq | type |
+ * +------+------+
+ * 32 32
+ *
+ * A stream is generated by concatenating the raw output blocks generated
+ * with this nonce and successive counter values starting from zero. The
+ * first 32 bytes of the stream are used as a key for Poly1305: the first 16
+ * bytes are the universal hash key r, and the second 16 bytes are the mask
+ * value s.
+ *
+ * +------+------+ +------...------+
+ * | r | s | | keystream |
+ * +------+------+ +------...------+
+ * 128 128 sz
+ *
+ * The remainder of the stream is XORed with the incoming plaintext to form a
+ * ciphertext with the same length. The ciphertext (only) is then tagged
+ * using Poly1305. The tag, sequence number, and ciphertext are concatenated
+ * in this order, and transmitted.
+ *
+ *
+ * +---...---+------+------...------+
+ * | tag | seq | ciphertext |
+ * +---...---+------+------...------+
+ * 128 32 sz
+ *
+ * Note that there is no need to authenticate the type separately, since it
+ * was used to select the cipher nonce, and hence the Poly1305 key. The
+ * Poly1305 tag length is fixed.
+ */
+
+typedef struct naclbox_algs {
+ bulkalgs _b;
+ const gccipher *c; size_t cksz;
+} naclbox_algs;
+
+typedef struct naclbox_ctx {
+ bulkctx _b;
+ struct { gcipher *c; } d[NDIR];
+} naclbox_ctx;
+
+
+static bulkalgs *naclbox_getalgs(const algswitch *asw, dstr *e,
+ key_file *kf, key *k)
+{
+ naclbox_algs *a = CREATE(naclbox_algs);
+ const char *p;
+ char *qq;
+ unsigned long n;
+
+ /* --- Collect the selected cipher and check that it's supported --- */
+
+ p = key_getattr(kf, k, "cipher");
+ if (!p || strcmp(p, "salsa20") == 0) a->c = &salsa20;
+ else if (strcmp(p, "salsa20/12") == 0) a->c = &salsa2012;
+ else if (strcmp(p, "salsa20/8") == 0) a->c = &salsa208;
+ else if (strcmp(p, "chacha20") == 0) a->c = &chacha20;
+ else if (strcmp(p, "chacha12") == 0) a->c = &chacha12;
+ else if (strcmp(p, "chacha8") == 0) a->c = &chacha8;
+ else {
+ a_format(e, "unknown-cipher", "%s", p, A_END);
+ goto fail;
+ }
+
+ /* --- Collect the selected MAC, and check the tag length --- */
+
+ p = key_getattr(kf, k, "mac");
+ if (!p)
+ ;
+ else if (strncmp(p, "poly1305", 8) != 0 || (p[8] && p[8] != '/')) {
+ a_format(e, "unknown-mac", "%s", p, A_END);
+ goto fail;
+ } else if (p[8] == '/') {
+ n = strtoul(p + 9, &qq, 0);
+ if (*qq) {
+ a_format(e, "bad-tag-length-string", "%s", p + 9, A_END);
+ goto fail;
+ }
+ if (n != 128) {
+ a_format(e, "bad-tag-length", "%lu", n, A_END);
+ goto fail;
+ }
+ }
+
+ return (&a->_b);
+fail:
+ DESTROY(a);
+ return (0);
+}
+
+#ifndef NTRACE
+static void naclbox_tracealgs(const bulkalgs *aa)
+{
+ const naclbox_algs *a = (const naclbox_algs *)aa;
+
+ trace(T_CRYPTO, "crypto: cipher = %s", a->c->name);
+ trace(T_CRYPTO, "crypto: mac = poly1305/128");
+}
+#endif
+
+static int naclbox_checkalgs(bulkalgs *aa, const algswitch *asw, dstr *e)
+{
+ naclbox_algs *a = (naclbox_algs *)aa;
+
+ if ((a->cksz = keysz(asw->hashsz, a->c->keysz)) == 0) {
+ a_format(e, "cipher", "%s", a->c->name,
+ "no-key-size", "%lu", (unsigned long)asw->hashsz,
+ A_END);
+ return (-1);
+ }
+ return (0);
+}
+
+static int naclbox_samealgsp(const bulkalgs *aa, const bulkalgs *bb)
+{
+ const naclbox_algs *a = (const naclbox_algs *)aa,
+ *b = (const naclbox_algs *)bb;
+ return (a->c == b->c);
+}
+
+static void naclbox_alginfo(const bulkalgs *aa, admin *adm)
+{
+ const naclbox_algs *a = (const naclbox_algs *)aa;
+ a_info(adm, "cipher=%s", a->c->name, "cipher-keysz=32", A_END);
+ a_info(adm, "mac=poly1305", "mac-tagsz=16", A_END);
+}
+
+static size_t naclbox_overhead(const bulkalgs *aa)
+ { return (POLY1305_TAGSZ + SEQSZ); }
+
+static size_t naclbox_expsz(const bulkalgs *aa)
+ { return (MEG(2048)); }
+
+static bulkctx *naclbox_genkeys(const bulkalgs *aa, const struct rawkey *rk)
+{
+ const naclbox_algs *a = (const naclbox_algs *)aa;
+ naclbox_ctx *bc = CREATE(naclbox_ctx);
+ octet k[MAXHASHSZ];
+ int i;
+
+ for (i = 0; i < NDIR; i++) {
+ ks_derivekey(k, a->cksz, rk, i, "encryption");
+ bc->d[i].c = GC_INIT(a->c, k, a->cksz);
+ }
+ return (&bc->_b);
+}
+
+typedef struct naclbox_chal {
+ bulkchal _b;
+ gcipher *c;
+} naclbox_chal;
+
+static bulkchal *naclbox_genchal(const bulkalgs *aa)
+{
+ const naclbox_algs *a = (const naclbox_algs *)aa;
+ naclbox_chal *c = CREATE(naclbox_chal);
+ rand_get(RAND_GLOBAL, buf_t, a->cksz);
+ c->c = GC_INIT(a->c, buf_t, a->cksz);
+ IF_TRACING(T_CHAL, {
+ trace(T_CHAL, "chal: generated new challenge key");
+ trace_block(T_CRYPTO, "chal: new key", buf_t, a->cksz);
+ })
+ c->_b.tagsz = 16;
+ return (&c->_b);
+}
+
+static int naclbox_chaltag(bulkchal *bc, const void *m, size_t msz, void *t)
+{
+ naclbox_chal *c = (naclbox_chal *)bc;
+ octet b0[SALSA20_NONCESZ];
+ assert(msz <= sizeof(b0));
+ memcpy(b0, m, msz); memset(b0 + msz, 0, sizeof(b0) - msz);
+ GC_SETIV(c->c, b0);
+ GC_ENCRYPT(c->c, 0, t, c->_b.tagsz);
+ return (0);
+}
+
+static int naclbox_chalvrf(bulkchal *bc, const void *m, size_t msz,
+ const void *t)
+{
+ naclbox_chal *c = (naclbox_chal *)bc;
+ octet b0[SALSA20_NONCESZ], b1[16];
+ assert(msz <= sizeof(b0)); assert(c->_b.tagsz <= sizeof(b1));
+ memcpy(b0, m, msz); memset(b0 + msz, 0, sizeof(b0) - msz);
+ GC_SETIV(c->c, b0);
+ GC_ENCRYPT(c->c, 0, b1, c->_b.tagsz);
+ return (ct_memeq(t, b1, c->_b.tagsz) ? 0 : -1);
+}
+
+static void naclbox_freechal(bulkchal *bc)
+ { naclbox_chal *c = (naclbox_chal *)bc; GC_DESTROY(c->c); DESTROY(c); }
+
+static void naclbox_freealgs(bulkalgs *aa)
+ { naclbox_algs *a = (naclbox_algs *)aa; DESTROY(a); }
+
+static void naclbox_freectx(bulkctx *bbc)
+{
+ naclbox_ctx *bc = (naclbox_ctx *)bbc;
+ int i;
+
+ for (i = 0; i < NDIR; i++) GC_DESTROY(bc->d[i].c);
+ DESTROY(bc);
+}
+
+static int naclbox_encrypt(bulkctx *bbc, unsigned ty,
+ buf *b, buf *bb, uint32 seq)
+{
+ naclbox_ctx *bc = (naclbox_ctx *)bbc;
+ gcipher *c = bc->d[DIR_OUT].c;
+ poly1305_key polyk;
+ poly1305_ctx poly;
+ const octet *p = BCUR(b);
+ size_t sz = BLEFT(b);
+ octet *qmac, *qseq, *qpk;
+
+ /* --- Determine the ciphertext layout --- */
+
+ if (buf_ensure(bb, POLY1305_TAGSZ + SEQSZ + sz)) return (0);
+ qmac = BCUR(bb); qseq = qmac + POLY1305_TAGSZ; qpk = qseq + SEQSZ;
+ BSTEP(bb, POLY1305_TAGSZ + SEQSZ + sz);
+
+ /* --- Construct and set the nonce --- */
+
+ STORE32(qseq, seq);
+ memcpy(buf_u, qseq, SEQSZ); STORE32(buf_u + SEQSZ, ty);
+ GC_SETIV(c, buf_u);
+ TRACE_IV(buf_u, SALSA20_NONCESZ);
+
+ /* --- Determine the MAC key --- */
+
+ GC_ENCRYPT(c, 0, buf_u, POLY1305_KEYSZ + POLY1305_MASKSZ);
+ poly1305_keyinit(&polyk, buf_u, POLY1305_KEYSZ);
+ poly1305_macinit(&poly, &polyk, buf_u + POLY1305_KEYSZ);
+
+ /* --- Encrypt the message --- */
+
+ GC_ENCRYPT(c, p, qpk, sz);
+ TRACE_CT(qpk, sz);
+
+ /* --- Compute the MAC --- */
+
+ poly1305_hash(&poly, qpk, sz);
+ poly1305_done(&poly, qmac);
+ TRACE_MAC(qmac, POLY1305_TAGSZ);
+
+ /* --- We're done --- */
+
+ return (0);
+}
+
+static int naclbox_decrypt(bulkctx *bbc, unsigned ty,
+ buf *b, buf *bb, uint32 *seq)
+{
+ naclbox_ctx *bc = (naclbox_ctx *)bbc;
+ gcipher *c = bc->d[DIR_IN].c;
+ poly1305_key polyk;
+ poly1305_ctx poly;
+ const octet *pmac, *pseq, *ppk;
+ size_t psz = BLEFT(b);
+ size_t sz;
+ octet *q = BCUR(bb);
+
+ /* --- Break up the packet into its components --- */
+
+ if (psz < SEQSZ + POLY1305_TAGSZ) {
+ T( trace(T_KEYSET, "keyset: block too small for keyset"); )
+ return (KSERR_MALFORMED);
+ }
+ sz = psz - SEQSZ - POLY1305_TAGSZ;
+ pmac = BCUR(b); pseq = pmac + POLY1305_TAGSZ; ppk = pseq + SEQSZ;
+
+ /* --- Construct and set the nonce --- */
+
+ memcpy(buf_u, pseq, SEQSZ); STORE32(buf_u + SEQSZ, ty);
+ GC_SETIV(c, buf_u);
+ TRACE_IV(buf_u, SALSA20_NONCESZ);
+
+ /* --- Determine the MAC key --- */
+
+ GC_ENCRYPT(c, 0, buf_u, POLY1305_KEYSZ + POLY1305_MASKSZ);
+ poly1305_keyinit(&polyk, buf_u, POLY1305_KEYSZ);
+ poly1305_macinit(&poly, &polyk, buf_u + POLY1305_KEYSZ);
+
+ /* --- Verify the MAC on the packet --- */
+
+ poly1305_hash(&poly, ppk, sz);
+ poly1305_done(&poly, buf_u);
+ TRACE_MAC(buf_u, POLY1305_TAGSZ);
+ if (!ct_memeq(buf_u, pmac, POLY1305_TAGSZ)) {
+ TRACE_MACERR(pmac, POLY1305_TAGSZ);
+ return (KSERR_DECRYPT);
+ }
+
+ /* --- Decrypt the packet --- */
+
+ GC_DECRYPT(c, ppk, q, sz);
+
+ /* --- Finished --- */
+
+ *seq = LOAD32(pseq);
+ BSTEP(bb, sz);
+ return (0);
+}
+
/*----- Bulk crypto transform table ---------------------------------------*/
const bulkops bulktab[] = {
-#define BULK(name, pre, prim) \
- { name, prim, pre##_check, pre##_overhead, pre##_encrypt, pre##_decrypt }
+#define COMMA ,
+
+#define BULK(name, pre) \
+ { name, pre##_getalgs, T( pre##_tracealgs COMMA ) \
+ pre##_checkalgs, pre##_samealgsp, \
+ pre##_alginfo, pre##_overhead, pre##_expsz, \
+ pre##_genkeys, pre##_genchal, pre##_freealgs, \
+ pre##_encrypt, pre##_decrypt, pre##_freectx, \
+ pre##_chaltag, pre##_chalvrf, pre##_freechal }
- BULK("v0", v0, BCP_CIPHER | BCP_MAC),
- BULK("iiv", iiv, BCP_CIPHER | BCP_MAC | BCP_BLKC),
+ BULK("v0", v0),
+ BULK("iiv", iiv),
+ BULK("naclbox", naclbox),
#undef BULK
{ 0 }