[ sf.net patch # 1121611 ]

A new hashlib module to replace the md5 and sha modules.  It adds
support for additional secure hashes such as SHA-256 and SHA-512.  The
hashlib module uses OpenSSL for fast platform optimized
implementations of algorithms when available.  The old md5 and sha
modules still exist as wrappers around hashlib to preserve backwards
compatibility.

1 files changed, 487 insertions, 0 deletions

diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c
new file mode 100644
index 0000000..bfa180c
--- /dev/null
+++ b/Modules/_hashopenssl.c
@@ -0,0 +1,487 @@
+/* Module that wraps all OpenSSL hash algorithms */
+
+/*
+ * Copyright (C) 2005   Gregory P. Smith (greg@electricrain.com)
+ * Licensed to PSF under a Contributor Agreement.
+ *
+ * Derived from a skeleton of shamodule.c containing work performed by:
+ *
+ * Andrew Kuchling (amk@amk.ca)
+ * Greg Stein (gstein@lyra.org)
+ *
+ */
+
+#include "Python.h"
+#include "structmember.h"
+
+/* EVP is the preferred interface to hashing in OpenSSL */
+#include <openssl/evp.h>
+
+
+typedef struct {
+    PyObject_HEAD
+    PyObject            *name;  /* name of this hash algorithm */
+    EVP_MD_CTX          ctx;    /* OpenSSL message digest context */
+} EVPobject;
+
+
+static PyTypeObject EVPtype;
+
+
+#define DEFINE_CONSTS_FOR_NEW(Name)  \
+    static PyObject *CONST_ ## Name ## _name_obj; \
+    static EVP_MD_CTX CONST_new_ ## Name ## _ctx; \
+    static EVP_MD_CTX *CONST_new_ ## Name ## _ctx_p = NULL;
+
+DEFINE_CONSTS_FOR_NEW(md5);
+DEFINE_CONSTS_FOR_NEW(sha1);
+DEFINE_CONSTS_FOR_NEW(sha224);
+DEFINE_CONSTS_FOR_NEW(sha256);
+DEFINE_CONSTS_FOR_NEW(sha384);
+DEFINE_CONSTS_FOR_NEW(sha512);
+
+
+static EVPobject *
+newEVPobject(PyObject *name)
+{
+    EVPobject *retval = (EVPobject *)PyObject_New(EVPobject, &EVPtype);
+
+    /* save the name for .name to return */
+    if (retval != NULL) {
+        Py_INCREF(name);
+        retval->name = name;
+    }
+
+    return retval;
+}
+
+/* Internal methods for a hash object */
+
+static void
+EVP_dealloc(PyObject *ptr)
+{
+    EVP_MD_CTX_cleanup(&((EVPobject *)ptr)->ctx);
+    Py_XDECREF(((EVPobject *)ptr)->name);
+    PyObject_Del(ptr);
+}
+
+
+/* External methods for a hash object */
+
+PyDoc_STRVAR(EVP_copy__doc__, "Return a copy of the hash object.");
+
+static PyObject *
+EVP_copy(EVPobject *self, PyObject *args)
+{
+    EVPobject *newobj;
+
+    if (!PyArg_ParseTuple(args, ":copy"))
+        return NULL;
+
+    if ( (newobj = newEVPobject(self->name))==NULL)
+        return NULL;
+
+    EVP_MD_CTX_copy(&newobj->ctx, &self->ctx);
+    return (PyObject *)newobj;
+}
+
+PyDoc_STRVAR(EVP_digest__doc__,
+"Return the digest value as a string of binary data.");
+
+static PyObject *
+EVP_digest(EVPobject *self, PyObject *args)
+{
+    unsigned char digest[EVP_MAX_MD_SIZE];
+    EVP_MD_CTX temp_ctx;
+    PyObject *retval;
+    unsigned int digest_size;
+
+    if (!PyArg_ParseTuple(args, ":digest"))
+        return NULL;
+
+    EVP_MD_CTX_copy(&temp_ctx, &self->ctx);
+    digest_size = EVP_MD_CTX_size(&temp_ctx);
+    EVP_DigestFinal(&temp_ctx, (char *)digest, NULL);
+
+    retval = PyString_FromStringAndSize((const char *)digest, digest_size);
+    EVP_MD_CTX_cleanup(&temp_ctx);
+    return retval;
+}
+
+PyDoc_STRVAR(EVP_hexdigest__doc__,
+"Return the digest value as a string of hexadecimal digits.");
+
+static PyObject *
+EVP_hexdigest(EVPobject *self, PyObject *args)
+{
+    unsigned char digest[EVP_MAX_MD_SIZE];
+    EVP_MD_CTX temp_ctx;
+    PyObject *retval;
+    char *hex_digest;
+    unsigned int i, j, digest_size;
+
+    if (!PyArg_ParseTuple(args, ":hexdigest"))
+        return NULL;
+
+    /* Get the raw (binary) digest value */
+    EVP_MD_CTX_copy(&temp_ctx, &self->ctx);
+    digest_size = EVP_MD_CTX_size(&temp_ctx);
+    EVP_DigestFinal(&temp_ctx, digest, NULL);
+
+    EVP_MD_CTX_cleanup(&temp_ctx);
+
+    /* Create a new string */
+    /* NOTE: not thread safe! modifying an already created string object */
+    /* (not a problem because we hold the GIL by default) */
+    retval = PyString_FromStringAndSize(NULL, digest_size * 2);
+    if (!retval)
+	    return NULL;
+    hex_digest = PyString_AsString(retval);
+    if (!hex_digest) {
+	    Py_DECREF(retval);
+	    return NULL;
+    }
+
+    /* Make hex version of the digest */
+    for(i=j=0; i<digest_size; i++) {
+        char c;
+        c = (digest[i] >> 4) & 0xf;
+	c = (c>9) ? c+'a'-10 : c + '0';
+        hex_digest[j++] = c;
+        c = (digest[i] & 0xf);
+	c = (c>9) ? c+'a'-10 : c + '0';
+        hex_digest[j++] = c;
+    }
+    return retval;
+}
+
+PyDoc_STRVAR(EVP_update__doc__,
+"Update this hash object's state with the provided string.");
+
+static PyObject *
+EVP_update(EVPobject *self, PyObject *args)
+{
+    unsigned char *cp;
+    int len;
+
+    if (!PyArg_ParseTuple(args, "s#:update", &cp, &len))
+        return NULL;
+
+    EVP_DigestUpdate(&self->ctx, cp, len);
+
+    Py_INCREF(Py_None);
+    return Py_None;
+}
+
+static PyMethodDef EVP_methods[] = {
+    {"update",	  (PyCFunction)EVP_update,    METH_VARARGS, EVP_update__doc__},
+    {"digest",	  (PyCFunction)EVP_digest,    METH_VARARGS, EVP_digest__doc__},
+    {"hexdigest", (PyCFunction)EVP_hexdigest, METH_VARARGS, EVP_hexdigest__doc__},
+    {"copy",	  (PyCFunction)EVP_copy,      METH_VARARGS, EVP_copy__doc__},
+    {NULL,	  NULL}		/* sentinel */
+};
+
+static PyObject *
+EVP_get_block_size(EVPobject *self, void *closure)
+{
+    return PyInt_FromLong(EVP_MD_CTX_block_size(&((EVPobject *)self)->ctx));
+}
+
+static PyObject *
+EVP_get_digest_size(EVPobject *self, void *closure)
+{
+    return PyInt_FromLong(EVP_MD_CTX_size(&((EVPobject *)self)->ctx));
+}
+
+static PyMemberDef EVP_members[] = {
+    {"name", T_OBJECT, offsetof(EVPobject, name), READONLY, PyDoc_STR("algorithm name.")},
+    {NULL}  /* Sentinel */
+};
+
+static PyGetSetDef EVP_getseters[] = {
+    {"digest_size",
+     (getter)EVP_get_digest_size, NULL,
+     NULL,
+     NULL},
+    {"block_size",
+     (getter)EVP_get_block_size, NULL,
+     NULL,
+     NULL},
+    /* the old md5 and sha modules support 'digest_size' as in PEP 247.
+     * the old sha module also supported 'digestsize'.  ugh. */
+    {"digestsize",
+     (getter)EVP_get_digest_size, NULL,
+     NULL,
+     NULL},
+    {NULL}  /* Sentinel */
+};
+
+
+static PyObject *
+EVP_repr(PyObject *self)
+{
+    char buf[100];
+    PyOS_snprintf(buf, sizeof(buf), "<%s HASH object @ %p>",
+            PyString_AsString(((EVPobject *)self)->name), self);
+    return PyString_FromString(buf);
+}
+
+#if HASH_OBJ_CONSTRUCTOR
+static int
+EVP_tp_init(EVPobject *self, PyObject *args, PyObject *kwds)
+{
+    static char *kwlist[] = {"name", "string", NULL};
+    PyObject *name_obj = NULL;
+    char *nameStr;
+    unsigned char *cp = NULL;
+    unsigned int len;
+    const EVP_MD *digest;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|s#:HASH", kwlist,
+                                     &name_obj, &cp, &len)) {
+        return -1;
+    }
+
+    if (!PyArg_Parse(name_obj, "s", &nameStr)) {
+        PyErr_SetString(PyExc_TypeError, "name must be a string");
+        return -1;
+    }
+
+    digest = EVP_get_digestbyname(nameStr);
+    if (!digest) {
+        PyErr_SetString(PyExc_ValueError, "unknown hash function");
+        return -1;
+    }
+    EVP_DigestInit(&self->ctx, digest);
+
+    self->name = name_obj;
+    Py_INCREF(self->name);
+
+    if (cp && len)
+        EVP_DigestUpdate(&self->ctx, cp, len);
+
+    return 0;
+}
+#endif
+
+
+PyDoc_STRVAR(hashtype_doc,
+"A hash represents the object used to calculate a checksum of a\n\
+string of information.\n\
+\n\
+Methods:\n\
+\n\
+update() -- updates the current digest with an additional string\n\
+digest() -- return the current digest value\n\
+hexdigest() -- return the current digest as a string of hexadecimal digits\n\
+copy() -- return a copy of the current hash object\n\
+\n\
+Attributes:\n\
+\n\
+name -- the hash algorithm being used by this object\n\
+digest_size -- number of bytes in this hashes output\n");
+
+static PyTypeObject EVPtype = {
+    PyObject_HEAD_INIT(NULL)
+    0,			/*ob_size*/
+    "_hashlib.HASH",    /*tp_name*/
+    sizeof(EVPobject),	/*tp_basicsize*/
+    0,			/*tp_itemsize*/
+    /* methods */
+    EVP_dealloc,	/*tp_dealloc*/
+    0,			/*tp_print*/
+    0,                  /*tp_getattr*/
+    0,                  /*tp_setattr*/
+    0,                  /*tp_compare*/
+    EVP_repr,           /*tp_repr*/
+    0,                  /*tp_as_number*/
+    0,                  /*tp_as_sequence*/
+    0,                  /*tp_as_mapping*/
+    0,                  /*tp_hash*/
+    0,                  /*tp_call*/
+    0,                  /*tp_str*/
+    0,                  /*tp_getattro*/
+    0,                  /*tp_setattro*/
+    0,                  /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+    hashtype_doc,       /*tp_doc*/
+    0,                  /*tp_traverse*/
+    0,			/*tp_clear*/
+    0,			/*tp_richcompare*/
+    0,			/*tp_weaklistoffset*/
+    0,			/*tp_iter*/
+    0,			/*tp_iternext*/
+    EVP_methods,	/* tp_methods */
+    EVP_members,	/* tp_members */
+    EVP_getseters,      /* tp_getset */
+#if 1
+    0,                  /* tp_base */
+    0,                  /* tp_dict */
+    0,                  /* tp_descr_get */
+    0,                  /* tp_descr_set */
+    0,                  /* tp_dictoffset */
+#endif
+#if HASH_OBJ_CONSTRUCTOR
+    (initproc)EVP_tp_init, /* tp_init */
+#endif
+};
+
+static PyObject *
+EVPnew(PyObject *name_obj,
+       const EVP_MD *digest, const EVP_MD_CTX *initial_ctx,
+       const char *cp, unsigned int len)
+{
+    EVPobject *self;
+
+    if (!digest && !initial_ctx) {
+        PyErr_SetString(PyExc_ValueError, "unsupported hash type");
+        return NULL;
+    }
+
+    if ((self = newEVPobject(name_obj)) == NULL)
+        return NULL;
+
+    if (initial_ctx) {
+        EVP_MD_CTX_copy(&self->ctx, initial_ctx);
+    } else {
+        EVP_DigestInit(&self->ctx, digest);
+    }
+
+    if (cp && len)
+        EVP_DigestUpdate(&self->ctx, cp, len);
+
+    return (PyObject *)self;
+}
+
+
+/* The module-level function: new() */
+
+PyDoc_STRVAR(EVP_new__doc__,
+"Return a new hash object using the named algorithm.\n\
+An optional string argument may be provided and will be\n\
+automatically hashed.\n\
+\n\
+The MD5 and SHA1 algorithms are always supported.\n");
+
+static PyObject *
+EVP_new(PyObject *self, PyObject *args, PyObject *kwdict)
+{
+    static char *kwlist[] = {"name", "string", NULL};
+    PyObject *name_obj = NULL;
+    char *name;
+    const EVP_MD *digest;
+    unsigned char *cp = NULL;
+    unsigned int len;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "O|s#:new", kwlist,
+                                     &name_obj, &cp, &len)) {
+        return NULL;
+    }
+
+    if (!PyArg_Parse(name_obj, "s", &name)) {
+        PyErr_SetString(PyExc_TypeError, "name must be a string");
+        return NULL;
+    }
+
+    digest = EVP_get_digestbyname(name);
+
+    return EVPnew(name_obj, digest, NULL, cp, len);
+}
+
+/*
+ *  This macro generates constructor function definitions for specific
+ *  hash algorithms.  These constructors are much faster than calling
+ *  the generic one passing it a python string and are noticably
+ *  faster than calling a python new() wrapper.  Thats important for
+ *  code that wants to make hashes of a bunch of small strings.
+ */
+#define GEN_CONSTRUCTOR(NAME)  \
+    static PyObject * \
+    EVP_new_ ## NAME (PyObject *self, PyObject *args) \
+    { \
+        unsigned char *cp = NULL; \
+        unsigned int len; \
+     \
+        if (!PyArg_ParseTuple(args, "|s#:" #NAME , &cp, &len)) { \
+            return NULL; \
+        } \
+     \
+        return EVPnew( \
+                CONST_ ## NAME ## _name_obj, \
+                NULL, \
+                CONST_new_ ## NAME ## _ctx_p, \
+                cp, len); \
+    }
+
+/* a PyMethodDef structure for the constructor */
+#define CONSTRUCTOR_METH_DEF(NAME)  \
+    {"openssl_" #NAME, (PyCFunction)EVP_new_ ## NAME, METH_VARARGS, \
+        PyDoc_STR("Returns a " #NAME \
+                  " hash object; optionally initialized with a string") \
+    }
+
+/* used in the init function to setup a constructor */
+#define INIT_CONSTRUCTOR_CONSTANTS(NAME)  do { \
+    CONST_ ## NAME ## _name_obj = PyString_FromString(#NAME); \
+    if (EVP_get_digestbyname(#NAME)) { \
+        CONST_new_ ## NAME ## _ctx_p = &CONST_new_ ## NAME ## _ctx; \
+        EVP_DigestInit(CONST_new_ ## NAME ## _ctx_p, EVP_get_digestbyname(#NAME)); \
+    } \
+} while (0);
+
+GEN_CONSTRUCTOR(md5)
+GEN_CONSTRUCTOR(sha1)
+GEN_CONSTRUCTOR(sha224)
+GEN_CONSTRUCTOR(sha256)
+GEN_CONSTRUCTOR(sha384)
+GEN_CONSTRUCTOR(sha512)
+
+/* List of functions exported by this module */
+
+static struct PyMethodDef EVP_functions[] = {
+    {"new", (PyCFunction)EVP_new, METH_VARARGS|METH_KEYWORDS, EVP_new__doc__},
+    CONSTRUCTOR_METH_DEF(md5),
+    CONSTRUCTOR_METH_DEF(sha1),
+    CONSTRUCTOR_METH_DEF(sha224),
+    CONSTRUCTOR_METH_DEF(sha256),
+    CONSTRUCTOR_METH_DEF(sha384),
+    CONSTRUCTOR_METH_DEF(sha512),
+    {NULL,	NULL}		 /* Sentinel */
+};
+
+
+/* Initialize this module. */
+
+PyMODINIT_FUNC
+init_hashlib(void)
+{
+    PyObject *m;
+
+    OpenSSL_add_all_digests();
+
+    /* TODO build EVP_functions openssl_* entries dynamically based
+     * on what hashes are supported rather than listing many
+     * but having some be unsupported.  Only init appropriate
+     * constants. */
+
+    EVPtype.ob_type = &PyType_Type;
+    if (PyType_Ready(&EVPtype) < 0)
+        return;
+
+    m = Py_InitModule("_hashlib", EVP_functions);
+    if (m == NULL)
+        return;
+
+#if HASH_OBJ_CONSTRUCTOR
+    Py_INCREF(&EVPtype);
+    PyModule_AddObject(m, "HASH", (PyObject *)&EVPtype);
+#endif
+
+    /* these constants are used by the convenience constructors */
+    INIT_CONSTRUCTOR_CONSTANTS(md5);
+    INIT_CONSTRUCTOR_CONSTANTS(sha1);
+    INIT_CONSTRUCTOR_CONSTANTS(sha224);
+    INIT_CONSTRUCTOR_CONSTANTS(sha256);
+    INIT_CONSTRUCTOR_CONSTANTS(sha384);
+    INIT_CONSTRUCTOR_CONSTANTS(sha512);
+}