X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/07bdda1fdf877d00dd63d53ebd5159b5edd1df29..26936c8341691d67655a055956656f2506d53a63:/server/dh.c

diff --git a/server/dh.c b/server/dh.c
index 314da5e4..5c27a079 100644
--- a/server/dh.c
+++ b/server/dh.c
@@ -639,6 +639,172 @@ static const char *ecdh_gestr(const dhgrp *gg, const dhge *YY)
 static void ecdh_freege(const dhgrp *gg, dhge *YY)
   { ecdh_ge *Y = (ecdh_ge *)YY; EC_DESTROY(&Y->Q); DESTROY(Y); }
 
+/*----- The X25519 and similar groups -------------------------------------*/
+
+#define XDHS(_)								\
+  _(x25519, X25519, "curve25519", 252, 255)				\
+  _(x448, X448, "ed448-goldilocks", 446, 448)
+
+#ifdef NTRACE
+#  define XDHTRACE(xdh, XDH, gname)
+#else
+
+   static const char *binstr(const octet *p, size_t sz)
+   {
+     char *q;
+
+     for (q = (char *)buf_u; sz--; p++, q += 2) sprintf(q, "%02x", *p);
+     return ((const char *)buf_u);
+   }
+
+#  define XDHTRACE(xdh, XDH, gname)					\
+     static void xdh##_tracegrp(const dhgrp *g)				\
+       { trace(T_CRYPTO, "crypto: group type `" gname "'"); }		\
+									\
+     static const char *xdh##_scstr(const dhgrp *g, const dhsc *xx)	\
+     {									\
+       const xdh##_sc *x = (const xdh##_sc *)xx;			\
+       return (binstr(x->x, XDH##_KEYSZ));				\
+     }									\
+									\
+     static const char *xdh##_gestr(const dhgrp *g, const dhge *YY)	\
+     {									\
+       const xdh##_ge *Y = (const xdh##_ge *)YY;			\
+       return (binstr(Y->X, XDH##_PUBSZ));				\
+     }
+#endif
+
+#define XDHDEF(xdh, XDH, gname, groupbits, fieldbits)			\
+									\
+  typedef struct xdh##_sc { octet x[XDH##_KEYSZ]; } xdh##_sc;		\
+  typedef struct xdh##_ge { octet X[XDH##_PUBSZ]; } xdh##_ge;		\
+									\
+  XDHTRACE(xdh, XDH, gname)						\
+									\
+  static dhsc *xdh##_bintosc(const key_bin *b)				\
+  {									\
+    xdh##_sc *x;							\
+									\
+    if (b->sz != XDH##_KEYSZ) return (0);				\
+    x = CREATE(xdh##_sc);						\
+    memcpy(x->x, b->k, XDH##_KEYSZ);					\
+    return ((dhsc *)x);							\
+  }									\
+									\
+  static dhge *xdh##_bintoge(const key_bin *b)				\
+  {									\
+    xdh##_ge *Y;							\
+									\
+    if (b->sz != XDH##_PUBSZ) return (0);				\
+    Y = CREATE(xdh##_ge);						\
+    memcpy(Y->X, b->k, XDH##_PUBSZ);					\
+    return ((dhge *)Y);							\
+  }									\
+									\
+  KLOAD(xdh, xdh, XDH,							\
+	{ kd->grp = CREATE(dhgrp); kd->grp->scsz = 32; },		\
+	{ if ((kd->k = xdh##_bintosc(&p.priv)) == 0) {			\
+	    a_format(e, "bad-private-key", A_END);			\
+	    goto fail;							\
+	  }								\
+	},								\
+	{ if ((kd->K = xdh##_bintoge(&p.pub)) == 0) {			\
+	    a_format(e, "bad-public-vector", A_END);			\
+	    goto fail;							\
+	  }								\
+	})								\
+									\
+  static const char *xdh##_checkgrp(const dhgrp *g)			\
+    { return (0); }							\
+									\
+  static void xdh##_grpinfo(const dhgrp *g, admin *adm)			\
+  {									\
+    a_info(adm,								\
+	   "kx-group=" gname,						\
+	   "kx-group-order-bits=%d", (groupbits),			\
+	   "kx-group-elt-bits=%d", (fieldbits),				\
+	   A_END);							\
+  }									\
+									\
+  static int xdh##_samegrpp(const dhgrp *g, const dhgrp *hh)		\
+    { return (1); }							\
+									\
+  static void xdh##_freegrp(dhgrp *g)					\
+    { DESTROY(g); }							\
+									\
+  static dhsc *xdh##_ldsc(const dhgrp *g, const void *p, size_t sz)	\
+  {									\
+    xdh##_sc *x;							\
+    if (sz != XDH##_KEYSZ) return (0);					\
+    x = CREATE(xdh##_sc);						\
+    memcpy(x->x, p, XDH##_KEYSZ);					\
+    return ((dhsc *)x);							\
+  }									\
+									\
+  static int xdh##_stsc(const dhgrp *g, void *p, size_t sz,		\
+			const dhsc *xx)					\
+  {									\
+    const xdh##_sc *x = (const xdh##_sc *)xx;				\
+    if (sz != XDH##_KEYSZ) return (-1);					\
+    memcpy(p, x->x, XDH##_KEYSZ);					\
+    return (0);								\
+  }									\
+									\
+  static dhsc *xdh##_randsc(const dhgrp *g)				\
+  {									\
+    xdh##_sc *x = CREATE(xdh##_sc);					\
+    rand_get(RAND_GLOBAL, x->x, XDH##_KEYSZ);				\
+    return ((dhsc *)x);							\
+  }									\
+									\
+  static void xdh##_freesc(const dhgrp *g, dhsc *xx)			\
+    { xdh##_sc *x = (xdh##_sc *)xx; DESTROY(x); }			\
+									\
+  static dhge *xdh##_ldge(const dhgrp *g, buf *b, int fmt)		\
+  {									\
+    xdh##_ge *Y;							\
+    const octet *p;							\
+									\
+    if ((p = buf_get(b, XDH##_PUBSZ)) == 0) return (0);			\
+    Y = CREATE(xdh##_ge); memcpy(Y->X, p, XDH##_PUBSZ);			\
+    return ((dhge *)Y);							\
+  }									\
+									\
+  static int xdh##_stge(const dhgrp *g, buf *b,				\
+			const dhge *YY, int fmt)			\
+  {									\
+    const xdh##_ge *Y = (const xdh##_ge *)YY;				\
+    return (buf_put(b, Y->X, XDH##_PUBSZ));				\
+  }									\
+									\
+  static int xdh##_checkge(const dhgrp *g, const dhge *YY)		\
+    { return (0); }							\
+									\
+  static int xdh##_eq(const dhgrp *g, const dhge *YY, const dhge *ZZ)	\
+  {									\
+    const xdh##_ge							\
+      *Y = (const xdh##_ge *)YY, *Z = (const xdh##_ge *)ZZ;		\
+    return (ct_memeq(Y->X, Z->X, XDH##_PUBSZ));				\
+  }									\
+									\
+  static dhge *xdh##_mul(const dhgrp *g,				\
+			 const dhsc *xx, const dhge *YY)		\
+  {									\
+    const xdh##_sc *x = (const xdh##_sc *)xx;				\
+    const xdh##_ge *Y = (const xdh##_ge *)YY;				\
+    xdh##_ge *Z = CREATE(xdh##_ge);					\
+									\
+    xdh(Z->X, x->x, Y ? Y->X : xdh##_base);				\
+    return ((dhge *)Z);							\
+  }									\
+									\
+  static void xdh##_freege(const dhgrp *g, dhge *YY)			\
+    { xdh##_ge *Y = (xdh##_ge *)YY; DESTROY(Y); }
+
+XDHS(XDHDEF)
+
+#undef XDHDEF
+
 /*----- Diffie--Hellman group table ---------------------------------------*/
 
 const dhops dhtab[] = {
@@ -657,6 +823,10 @@ const dhops dhtab[] = {
   DH("dh", intdh)
   DH("ec", ecdh)
 
+#define XDHDH(xdh, XDH, gname, groupbits, fieldbits) DH(#xdh, xdh)
+  XDHS(XDHDH)
+#undef XDHDH
+
 #undef DH
 
   { 0 }