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Use an actual type for the EC key rather than a capsule

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Kovid Goyal 2022-08-04 11:01:14 +05:30
parent cc297a8984
commit adf47bed89
No known key found for this signature in database
GPG key ID: 06BC317B515ACE7C
1 changed files with 60 additions and 31 deletions
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91
kitty/crypto.c
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@ -13,7 +13,12 @@
#include <openssl/pem.h>
#include <openssl/bio.h>
#define EC_KEY_CAPSULE_NAME "EC-key-capsule"
typedef struct {
PyObject_HEAD
EVP_PKEY *key;
} EllipticCurveKey;
static PyObject*
set_error_from_openssl(const char *prefix) {
@ -28,16 +33,13 @@ set_error_from_openssl(const char *prefix) {
return NULL;
}
static void
destroy_ec_key_capsule(PyObject *cap) {
EVP_PKEY *key = PyCapsule_GetPointer(cap, EC_KEY_CAPSULE_NAME);
if (key) EVP_PKEY_free(key);
}
static PyObject*
elliptic_curve_key_create(PyObject *self UNUSED, PyObject *args) {
static PyObject *
new_ec_key(PyTypeObject *type, PyObject UNUSED *args, PyObject UNUSED *kwds) {
EllipticCurveKey *self;
static const char* kwlist[] = {"curve_name", NULL};
const char *curve_name = "X25519";
if (!PyArg_ParseTuple(args, "|s", &curve_name)) return NULL;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|s", (char**)kwlist, &curve_name)) return NULL;
int nid = NID_X25519;
if (strcmp(curve_name, "X25519") != 0) { PyErr_Format(PyExc_KeyError, "Unknown curve: %s", curve_name); return NULL; }
EVP_PKEY *key = NULL;
@ -49,44 +51,68 @@ elliptic_curve_key_create(PyObject *self UNUSED, PyObject *args) {
if(1 != EVP_PKEY_keygen_init(pctx)) ssl_error("Failed to initialize keygen context");
if (1 != EVP_PKEY_keygen(pctx, &key)) ssl_error("Failed to generate key");
PyObject *ans = PyCapsule_New(key, EC_KEY_CAPSULE_NAME, destroy_ec_key_capsule);
if (ans) key = NULL;
self = (EllipticCurveKey *)type->tp_alloc(type, 0);
if (self) {
self->key = key; key = NULL;
}
cleanup();
return ans;
return (PyObject*) self;
#undef cleanup
#undef ssl_error
}
static PyObject*
elliptic_curve_key_public(PyObject *self UNUSED, PyObject *key_capsule) {
if (!PyCapsule_IsValid(key_capsule, EC_KEY_CAPSULE_NAME)) { PyErr_SetString(PyExc_TypeError, "Not a valid elliptic curve key capsule"); return NULL; }
EVP_PKEY *pkey = PyCapsule_GetPointer(key_capsule, EC_KEY_CAPSULE_NAME);
/* PEM_write_PUBKEY(stdout, pkey); */
size_t len = 0;
if (1 != EVP_PKEY_get_raw_public_key(pkey, NULL, &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
PyObject *ans = PyBytes_FromStringAndSize(NULL, len);
if (!ans) return NULL;
if (1 != EVP_PKEY_get_raw_public_key(pkey, (unsigned char*)PyBytes_AS_STRING(ans), &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
return ans;
static void
dealloc_ec_key(EllipticCurveKey* self) {
if (self->key) EVP_PKEY_free(self->key);
Py_TYPE(self)->tp_free((PyObject*)self);
}
static PyObject*
elliptic_curve_key_private(PyObject *self UNUSED, PyObject *key_capsule) {
if (!PyCapsule_IsValid(key_capsule, EC_KEY_CAPSULE_NAME)) { PyErr_SetString(PyExc_TypeError, "Not a valid elliptic curve key capsule"); return NULL; }
EVP_PKEY *pkey = PyCapsule_GetPointer(key_capsule, EC_KEY_CAPSULE_NAME);
elliptic_curve_key_get_public(EllipticCurveKey *self, void UNUSED *closure) {
/* PEM_write_PUBKEY(stdout, pkey); */
size_t len = 0;
if (1 != EVP_PKEY_get_raw_private_key(pkey, NULL, &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
if (1 != EVP_PKEY_get_raw_public_key(self->key, NULL, &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
PyObject *ans = PyBytes_FromStringAndSize(NULL, len);
if (!ans) return NULL;
if (1 != EVP_PKEY_get_raw_private_key(pkey, (unsigned char*)PyBytes_AS_STRING(ans), &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
if (1 != EVP_PKEY_get_raw_public_key(self->key, (unsigned char*)PyBytes_AS_STRING(ans), &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
return ans;
}
static PyObject*
elliptic_curve_key_get_private(EllipticCurveKey *self, void UNUSED *closure) {
size_t len = 0;
if (1 != EVP_PKEY_get_raw_private_key(self->key, NULL, &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
PyObject *ans = PyBytes_FromStringAndSize(NULL, len);
if (!ans) return NULL;
if (1 != EVP_PKEY_get_raw_private_key(self->key, (unsigned char*)PyBytes_AS_STRING(ans), &len)) return set_error_from_openssl("Could not get public key from EVP_KEY");
return ans;
}
static PyGetSetDef getsetters[] = {
{"public", (getter)elliptic_curve_key_get_public, NULL, "Get the public key as raw bytes", NULL},
{"private", (getter)elliptic_curve_key_get_private, NULL, "Get the private key as raw bytes", NULL},
{NULL} /* Sentinel */
};
PyTypeObject EllipticCurveKey_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
.tp_name = "fast_data_types.EllipticCurveKey",
.tp_basicsize = sizeof(EllipticCurveKey),
.tp_dealloc = (destructor)dealloc_ec_key,
.tp_flags = Py_TPFLAGS_DEFAULT,
.tp_doc = "Keys for use with Elliptic Curve crypto",
.tp_new = new_ec_key,
.tp_getset = getsetters,
};
static PyMethodDef module_methods[] = {
METHODB(elliptic_curve_key_create, METH_VARARGS),
METHODB(elliptic_curve_key_public, METH_O),
METHODB(elliptic_curve_key_private, METH_O),
{NULL, NULL, 0, NULL} /* Sentinel */
};
@ -94,5 +120,8 @@ static PyMethodDef module_methods[] = {
bool
init_crypto_library(PyObject *module) {
if (PyModule_AddFunctions(module, module_methods) != 0) return false;
if (PyType_Ready(&EllipticCurveKey_Type) < 0) return false;
if (PyModule_AddObject(module, "EllipticCurveKey", (PyObject *)&EllipticCurveKey_Type) != 0) return false;
Py_INCREF(&EllipticCurveKey_Type);
return true;
}