1 files changed, 186 insertions, 0 deletions
diff --git a/src/SWIG/_dh.i b/src/SWIG/_dh.i
new file mode 100644
index 0000000..398f418
--- /dev/null
+++ b/src/SWIG/_dh.i
@@ -0,0 +1,186 @@
+/* Copyright (c) 1999 Ng Pheng Siong. All rights reserved. */
+/* $Id$ */
+
+%{
+#include <openssl/bn.h>
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#include <openssl/dh.h>
+%}
+
+%apply Pointer NONNULL { DH * };
+
+%rename(dh_new) DH_new;
+extern DH *DH_new(void);
+%rename(dh_free) DH_free;
+extern void DH_free(DH *);
+%rename(dh_size) DH_size;
+extern int DH_size(const DH *);
+%rename(dh_generate_key) DH_generate_key;
+extern int DH_generate_key(DH *);
+%rename(dhparams_print) DHparams_print;
+%threadallow DHparams_print;
+extern int DHparams_print(BIO *, const DH *);
+
+%constant int dh_check_ok             = 0;
+%constant int dh_check_p_not_prime    = DH_CHECK_P_NOT_PRIME;
+%constant int dh_check_p_not_strong   = DH_CHECK_P_NOT_STRONG_PRIME;
+%constant int dh_check_g_failed       = DH_UNABLE_TO_CHECK_GENERATOR;
+%constant int dh_check_bad_g          = DH_NOT_SUITABLE_GENERATOR;
+
+%constant DH_GENERATOR_2          = 2;
+%constant DH_GENERATOR_5          = 5;
+
+%warnfilter(454) _dh_err;
+%inline %{
+static PyObject *_dh_err;
+
+void dh_init(PyObject *dh_err) {
+    Py_INCREF(dh_err);
+    _dh_err = dh_err;
+}
+
+int dh_type_check(DH *dh) {
+    /* Our getting here means we passed Swig's type checking,
+    XXX Still need to check the pointer for sanity? */
+    return 1;
+}
+%}
+
+%threadallow dh_read_parameters;
+%inline %{
+DH *dh_read_parameters(BIO *bio) {
+    return PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
+}
+
+DH *dh_generate_parameters(int plen, int g, PyObject *pyfunc) {
+    DH *dh;
+    BN_GENCB *gencb;
+    int ret;
+
+    if ((gencb=BN_GENCB_new()) == NULL) {
+        m2_PyErr_Msg(_dh_err);
+        return NULL;
+    }
+
+    if ((dh=DH_new()) == NULL) {
+        m2_PyErr_Msg(_dh_err);
+        BN_GENCB_free(gencb);
+        return NULL;
+    }
+
+    BN_GENCB_set(gencb, bn_gencb_callback, (void *)pyfunc);
+
+    Py_INCREF(pyfunc);
+    ret = DH_generate_parameters_ex(dh, plen, g, gencb);
+    Py_DECREF(pyfunc);
+    BN_GENCB_free(gencb);
+
+    if (ret)
+        return dh;
+
+    m2_PyErr_Msg(_dh_err);
+    DH_free(dh);
+    return NULL;
+}
+
+/* Note return value shenanigan. */
+int dh_check(DH *dh) {
+    int err;
+
+    return (DH_check(dh, &err)) ? 0 : err;
+}
+
+PyObject *dh_compute_key(DH *dh, PyObject *pubkey) {
+    const void *pkbuf;
+    int pklen = 0, klen;
+    void *key;
+    BIGNUM *pk;
+    PyObject *ret;
+
+    if (m2_PyObject_AsReadBufferInt(pubkey, &pkbuf, &pklen) == -1)
+        return NULL;
+
+    if (!(pk = BN_mpi2bn((unsigned char *)pkbuf, pklen, NULL))) {
+        m2_PyErr_Msg(_dh_err);
+        return NULL;
+    }
+    if (!(key = PyMem_Malloc(DH_size(dh)))) {
+        BN_free(pk);
+        PyErr_SetString(PyExc_MemoryError, "dh_compute_key");
+        return NULL;
+    }
+    if ((klen = DH_compute_key((unsigned char *)key, pk, dh)) == -1) {
+        BN_free(pk);
+        PyMem_Free(key);
+        m2_PyErr_Msg(_dh_err);
+        return NULL;
+    }
+
+    ret = PyBytes_FromStringAndSize((const char *)key, klen);
+
+    BN_free(pk);
+    PyMem_Free(key);
+    return ret;
+}
+
+PyObject *dh_get_p(DH *dh) {
+    const BIGNUM* p = NULL;
+    DH_get0_pqg(dh, &p, NULL, NULL);
+    if (!p) {
+        PyErr_SetString(_dh_err, "'p' is unset");
+        return NULL;
+    }
+    return bn_to_mpi(p);
+}
+
+PyObject *dh_get_g(DH *dh) {
+    const BIGNUM* g = NULL;
+    DH_get0_pqg(dh, NULL, NULL, &g);
+    if (!g) {
+        PyErr_SetString(_dh_err, "'g' is unset");
+        return NULL;
+    }
+    return bn_to_mpi(g);
+}
+
+PyObject *dh_get_pub(DH *dh) {
+    const BIGNUM* pub_key = NULL;
+    DH_get0_key(dh, &pub_key, NULL);
+    if (!pub_key) {
+        PyErr_SetString(_dh_err, "'pub' is unset");
+        return NULL;
+    }
+    return bn_to_mpi(pub_key);
+}
+
+PyObject *dh_get_priv(DH *dh) {
+    const BIGNUM* priv_key = NULL;
+    DH_get0_key(dh, NULL, &priv_key);
+    if (!priv_key) {
+        PyErr_SetString(_dh_err, "'priv' is unset");
+        return NULL;
+    }
+    return bn_to_mpi(priv_key);
+}
+
+PyObject *dh_set_pg(DH *dh, PyObject *pval, PyObject* gval) {
+    BIGNUM* p, *g;
+
+    if (!(p = m2_PyObject_AsBIGNUM(pval, _dh_err))
+        || !(g = m2_PyObject_AsBIGNUM(gval, _dh_err)))
+        return NULL;
+
+    if (!DH_set0_pqg(dh, p, NULL, g)) {
+        PyErr_SetString(_dh_err,
+            "Cannot set prime number or generator of Z_p for DH.");
+        BN_free(p);
+        BN_free(g);
+        return NULL;
+        }
+
+    Py_RETURN_NONE;
+}
+%}
+