From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 26 May 2015 14:13:23 +0000 (+0100)
Subject: algorithms.py, rand.c: Support `Latin dances' stream ciphers.
X-Git-Tag: 1.1.0~2^2~2
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb-python/commitdiff_plain/3f4f64b80b775c630201089785c43e1af24060bb

algorithms.py, rand.c: Support `Latin dances' stream ciphers.
---

diff --git a/algorithms.py b/algorithms.py
index 320d060..3ceb207 100644
--- a/algorithms.py
+++ b/algorithms.py
@@ -29,6 +29,11 @@ ecb cbc cfb ofb counter
 streamciphers = '''
 rc4 seal
 '''.split()
+latindances = '''
+salsa20 salsa20/12 salsa20/8 xsalsa20 xsalsa20/12 xsalsa20/8
+chacha20 chacha12 chacha8 xchacha20 xchacha12 xchacha8
+'''.split()
+streamciphers += map(lambda s: s.translate(None, '/'), latindances)
 hashes = '''
 md2 md4 md5 tiger has160
 sha sha224 sha256 sha384 sha512
@@ -64,13 +69,24 @@ print
 print '#define RNGS(_) \\'
 for i in (cross(prps, ['ofb', 'counter'])):
   print ('\t_("%(prim)s-%(mode)s", %(prim)s_keysz, ' +
-         '%(prim)s_%(mode)srand, 0) \\') % \
+         '%(prim)s_%(mode)srand, 0, 0) \\') % \
          {'prim': i[0], 'mode': i[1]}
 for i in (cross(hashes, 'mgf')):
   print ('\t_("%(prim)s-%(mode)s", %(prim)s_%(mode)skeysz, ' +
-         '%(prim)s_%(mode)srand, 0) \\') % \
+         '%(prim)s_%(mode)srand, 0, 0) \\') % \
          {'prim': i[0], 'mode': i[1]}
-print '\t_("rc4", rc4_keysz, rc4_rand, 0) \\'
-print '\t_("seal", seal_keysz, seal_rand, RNGF_INT) \\'
+print '\t_("rc4", rc4_keysz, rc4_rand, 0, 0) \\'
+print '\t_("seal", seal_keysz, seal_rand, RNGF_INT, 0) \\'
+for i in latindances:
+  for r in ['salsa20', 'xsalsa20', 'chacha', 'xchacha']:
+    if i.startswith(r):
+      root = r
+      break
+  else:
+    raise ValueError, 'failed to find root name for %s' % i
+  print ('\t_("%(name)s", %(root)s_keysz, %(id)s_rand, ' +
+         'RNGF_NONCE, %(ROOT)s_NONCESZ) \\') % \
+      {'name': i, 'id': i.translate(None, '/'),
+       'root': root, 'ROOT': root.upper()}
 print '\t/* end */'
 print
diff --git a/rand.c b/rand.c
index 1c008b7..49aaa38 100644
--- a/rand.c
+++ b/rand.c
@@ -581,14 +581,17 @@ static PyTypeObject *gccrand_pytype, *gcrand_pytype;
 
 typedef grand *gcrand_func(const void *, size_t sz);
 typedef grand *gcirand_func(const void *, size_t sz, uint32);
+typedef grand *gcnrand_func(const void *, size_t sz, const void *);
 typedef struct gccrand_info {
   const char *name;
   const octet *keysz;
   unsigned f;
+  size_t noncesz;
   gcrand_func *func;
 } gccrand_info;
 
 #define RNGF_INT 1u
+#define RNGF_NONCE 2u
 
 typedef struct gccrand_pyobj {
   PyHeapTypeObject ty;
@@ -596,13 +599,13 @@ typedef struct gccrand_pyobj {
 } gccrand_pyobj;
 #define GCCRAND_INFO(o) (((gccrand_pyobj *)(o))->info)
 
-#define GCCRAND_DEF(name, ksz, func, f)					\
+#define GCCRAND_DEF(name, ksz, func, f, nsz)				\
   static const gccrand_info func##_info =				\
-    { name, ksz, f, (gcrand_func *)func };
+    { name, ksz, f, nsz, (gcrand_func *)func };
 RNGS(GCCRAND_DEF)
 
 static const gccrand_info *const gcrandtab[] = {
-#define GCCRAND_ENTRY(name, ksz, func, f) &func##_info,
+#define GCCRAND_ENTRY(name, ksz, func, f, nsz) &func##_info,
   RNGS(GCCRAND_ENTRY)
   0
 };
@@ -641,6 +644,25 @@ end:
   return (0);
 }
 
+static PyObject *gcnrand_pynew(PyTypeObject *ty, PyObject *arg, PyObject *kw)
+{
+  const gccrand_info *info = GCCRAND_INFO(ty);
+  static char *kwlist[] = { "key", "nonce", 0 };
+  char *k, *n;
+  int ksz, nsz;
+
+  if (!PyArg_ParseTupleAndKeywords(arg, kw, "s#s#:new", kwlist,
+				   &k, &ksz, &n, &nsz))
+    goto end;
+  if (keysz(ksz, info->keysz) != ksz) VALERR("bad key length");
+  if (nsz != info->noncesz) VALERR("bad nonce length");
+  return (grand_dopywrap(ty,
+			 ((gcnrand_func *)info->func)(k, ksz, n),
+			 f_freeme));
+end:
+  return (0);
+}
+
 static PyObject *gccrand_pywrap(const gccrand_info *info)
 {
   gccrand_pyobj *g = newtype(gccrand_pytype, 0, info->name);
@@ -653,10 +675,9 @@ static PyObject *gccrand_pywrap(const gccrand_info *info)
 			    Py_TPFLAGS_HEAPTYPE);
   g->ty.ht_type.tp_alloc = PyType_GenericAlloc;
   g->ty.ht_type.tp_free = 0;
-  if (info->f & RNGF_INT)
-    g->ty.ht_type.tp_new = gcirand_pynew;
-  else
-    g->ty.ht_type.tp_new = gcrand_pynew;
+  if (info->f & RNGF_INT) g->ty.ht_type.tp_new = gcirand_pynew;
+  else if (info->f & RNGF_NONCE) g->ty.ht_type.tp_new = gcnrand_pynew;
+  else g->ty.ht_type.tp_new = gcrand_pynew;
   typeready(&g->ty.ht_type);
   return ((PyObject *)g);
 }