/* MD5 module */

/* This module provides an interface to the MD5 algorithm */

/* See below for information about the original code this module was
 based upon. Additional work performed by:

 Andrew Kuchling (amk@amk.ca)
 Greg Stein (gstein@lyra.org)
 Trevor Perrin (trevp@trevp.net)

 Copyright (C) 2005-2007 Gregory P. Smith (greg@krypto.org)
 Licensed to PSF under a Contributor Agreement.

*/

/* MD5 objects */

#include "Python.h"
#include "hashlib.h"
#include "pystrhex.h"

/*[clinic input]
module _md5
class MD5Type "MD5object *" "&PyType_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=6e5261719957a912]*/

/* Some useful types */

#if SIZEOF_INT == 4
typedef unsigned int MD5_INT32; /* 32-bit integer */
typedef long long MD5_INT64; /* 64-bit integer */
#else
/* not defined. compilation will die. */
#endif

/* The MD5 block size and message digest sizes, in bytes */

#define MD5_BLOCKSIZE 64
#define MD5_DIGESTSIZE 16

/* The structure for storing MD5 info */

struct md5_state {
 MD5_INT64 length;
 MD5_INT32 state[4], curlen;
 unsigned char buf[MD5_BLOCKSIZE];
};

typedef struct {
 PyObject_HEAD

 struct md5_state hash_state;
} MD5object;

#include "clinic/md5module.c.h"

/* ------------------------------------------------------------------------
 *
 * This code for the MD5 algorithm was noted as public domain. The
 * original headers are pasted below.
 *
 * Several changes have been made to make it more compatible with the
 * Python environment and desired interface.
 *
 */

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tomstdenis@gmail.com, https://www.libtom.net
 */

/* rotate the hard way (platform optimizations could be done) */
#define ROLc(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)

/* Endian Neutral macros that work on all platforms */

#define STORE32L(x, y) \
 { (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255); \
 (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }

#define LOAD32L(x, y) \
 { x = ((unsigned long)((y)[3] & 255)<<24) | \
 ((unsigned long)((y)[2] & 255)<<16) | \
 ((unsigned long)((y)[1] & 255)<<8) | \
 ((unsigned long)((y)[0] & 255)); }

#define STORE64L(x, y) \
 { (y)[7] = (unsigned char)(((x)>>56)&255); (y)[6] = (unsigned char)(((x)>>48)&255); \
 (y)[5] = (unsigned char)(((x)>>40)&255); (y)[4] = (unsigned char)(((x)>>32)&255); \
 (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255); \
 (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }


/* MD5 macros */

#define F(x,y,z) (z ^ (x & (y ^ z)))
#define G(x,y,z) (y ^ (z & (y ^ x)))
#define H(x,y,z) (x^y^z)
#define I(x,y,z) (y^(x|(~z)))

#define FF(a,b,c,d,M,s,t) \
 a = (a + F(b,c,d) + M + t); a = ROLc(a, s) + b;

#define GG(a,b,c,d,M,s,t) \
 a = (a + G(b,c,d) + M + t); a = ROLc(a, s) + b;

#define HH(a,b,c,d,M,s,t) \
 a = (a + H(b,c,d) + M + t); a = ROLc(a, s) + b;

#define II(a,b,c,d,M,s,t) \
 a = (a + I(b,c,d) + M + t); a = ROLc(a, s) + b;


static void md5_compress(struct md5_state *md5, const unsigned char *buf)
{
 MD5_INT32 i, W[16], a, b, c, d;

 assert(md5 != NULL);
 assert(buf != NULL);

 /* copy the state into 512-bits into W[0..15] */
 for (i = 0; i < 16; i++) {
 LOAD32L(W[i], buf + (4*i));
 }

 /* copy state */
 a = md5->state[0];
 b = md5->state[1];
 c = md5->state[2];
 d = md5->state[3];

 FF(a,b,c,d,W[0],7,0xd76aa478UL)
 FF(d,a,b,c,W[1],12,0xe8c7b756UL)
 FF(c,d,a,b,W[2],17,0x242070dbUL)
 FF(b,c,d,a,W[3],22,0xc1bdceeeUL)
 FF(a,b,c,d,W[4],7,0xf57c0fafUL)
 FF(d,a,b,c,W[5],12,0x4787c62aUL)
 FF(c,d,a,b,W[6],17,0xa8304613UL)
 FF(b,c,d,a,W[7],22,0xfd469501UL)
 FF(a,b,c,d,W[8],7,0x698098d8UL)
 FF(d,a,b,c,W[9],12,0x8b44f7afUL)
 FF(c,d,a,b,W[10],17,0xffff5bb1UL)
 FF(b,c,d,a,W[11],22,0x895cd7beUL)
 FF(a,b,c,d,W[12],7,0x6b901122UL)
 FF(d,a,b,c,W[13],12,0xfd987193UL)
 FF(c,d,a,b,W[14],17,0xa679438eUL)
 FF(b,c,d,a,W[15],22,0x49b40821UL)
 GG(a,b,c,d,W[1],5,0xf61e2562UL)
 GG(d,a,b,c,W[6],9,0xc040b340UL)
 GG(c,d,a,b,W[11],14,0x265e5a51UL)
 GG(b,c,d,a,W[0],20,0xe9b6c7aaUL)
 GG(a,b,c,d,W[5],5,0xd62f105dUL)
 GG(d,a,b,c,W[10],9,0x02441453UL)
 GG(c,d,a,b,W[15],14,0xd8a1e681UL)
 GG(b,c,d,a,W[4],20,0xe7d3fbc8UL)
 GG(a,b,c,d,W[9],5,0x21e1cde6UL)
 GG(d,a,b,c,W[14],9,0xc33707d6UL)
 GG(c,d,a,b,W[3],14,0xf4d50d87UL)
 GG(b,c,d,a,W[8],20,0x455a14edUL)
 GG(a,b,c,d,W[13],5,0xa9e3e905UL)
 GG(d,a,b,c,W[2],9,0xfcefa3f8UL)
 GG(c,d,a,b,W[7],14,0x676f02d9UL)
 GG(b,c,d,a,W[12],20,0x8d2a4c8aUL)
 HH(a,b,c,d,W[5],4,0xfffa3942UL)
 HH(d,a,b,c,W[8],11,0x8771f681UL)
 HH(c,d,a,b,W[11],16,0x6d9d6122UL)
 HH(b,c,d,a,W[14],23,0xfde5380cUL)
 HH(a,b,c,d,W[1],4,0xa4beea44UL)
 HH(d,a,b,c,W[4],11,0x4bdecfa9UL)
 HH(c,d,a,b,W[7],16,0xf6bb4b60UL)
 HH(b,c,d,a,W[10],23,0xbebfbc70UL)
 HH(a,b,c,d,W[13],4,0x289b7ec6UL)
 HH(d,a,b,c,W[0],11,0xeaa127faUL)
 HH(c,d,a,b,W[3],16,0xd4ef3085UL)
 HH(b,c,d,a,W[6],23,0x04881d05UL)
 HH(a,b,c,d,W[9],4,0xd9d4d039UL)
 HH(d,a,b,c,W[12],11,0xe6db99e5UL)
 HH(c,d,a,b,W[15],16,0x1fa27cf8UL)
 HH(b,c,d,a,W[2],23,0xc4ac5665UL)
 II(a,b,c,d,W[0],6,0xf4292244UL)
 II(d,a,b,c,W[7],10,0x432aff97UL)
 II(c,d,a,b,W[14],15,0xab9423a7UL)
 II(b,c,d,a,W[5],21,0xfc93a039UL)
 II(a,b,c,d,W[12],6,0x655b59c3UL)
 II(d,a,b,c,W[3],10,0x8f0ccc92UL)
 II(c,d,a,b,W[10],15,0xffeff47dUL)
 II(b,c,d,a,W[1],21,0x85845dd1UL)
 II(a,b,c,d,W[8],6,0x6fa87e4fUL)
 II(d,a,b,c,W[15],10,0xfe2ce6e0UL)
 II(c,d,a,b,W[6],15,0xa3014314UL)
 II(b,c,d,a,W[13],21,0x4e0811a1UL)
 II(a,b,c,d,W[4],6,0xf7537e82UL)
 II(d,a,b,c,W[11],10,0xbd3af235UL)
 II(c,d,a,b,W[2],15,0x2ad7d2bbUL)
 II(b,c,d,a,W[9],21,0xeb86d391UL)

 md5->state[0] = md5->state[0] + a;
 md5->state[1] = md5->state[1] + b;
 md5->state[2] = md5->state[2] + c;
 md5->state[3] = md5->state[3] + d;
}


/**
 Initialize the hash state
 @param sha1 The hash state you wish to initialize
*/
static void
md5_init(struct md5_state *md5)
{
 assert(md5 != NULL);
 md5->state[0] = 0x67452301UL;
 md5->state[1] = 0xefcdab89UL;
 md5->state[2] = 0x98badcfeUL;
 md5->state[3] = 0x10325476UL;
 md5->curlen = 0;
 md5->length = 0;
}

/**
 Process a block of memory though the hash
 @param sha1 The hash state
 @param in The data to hash
 @param inlen The length of the data (octets)
*/
static void
md5_process(struct md5_state *md5, const unsigned char *in, Py_ssize_t inlen)
{
 Py_ssize_t n;

 assert(md5 != NULL);
 assert(in != NULL);
 assert(md5->curlen <= sizeof(md5->buf));

 while (inlen > 0) {
 if (md5->curlen == 0 && inlen >= MD5_BLOCKSIZE) {
 md5_compress(md5, in);
 md5->length += MD5_BLOCKSIZE * 8;
 in += MD5_BLOCKSIZE;
 inlen -= MD5_BLOCKSIZE;
 } else {
 n = Py_MIN(inlen, (Py_ssize_t)(MD5_BLOCKSIZE - md5->curlen));
 memcpy(md5->buf + md5->curlen, in, (size_t)n);
 md5->curlen += (MD5_INT32)n;
 in += n;
 inlen -= n;
 if (md5->curlen == MD5_BLOCKSIZE) {
 md5_compress(md5, md5->buf);
 md5->length += 8*MD5_BLOCKSIZE;
 md5->curlen = 0;
 }
 }
 }
}

/**
 Terminate the hash to get the digest
 @param sha1 The hash state
 @param out [out] The destination of the hash (16 bytes)
*/
static void
md5_done(struct md5_state *md5, unsigned char *out)
{
 int i;

 assert(md5 != NULL);
 assert(out != NULL);
 assert(md5->curlen < sizeof(md5->buf));

 /* increase the length of the message */
 md5->length += md5->curlen * 8;

 /* append the '1' bit */
 md5->buf[md5->curlen++] = (unsigned char)0x80;

 /* if the length is currently above 56 bytes we append zeros
 * then compress. Then we can fall back to padding zeros and length
 * encoding like normal.
 */
 if (md5->curlen > 56) {
 while (md5->curlen < 64) {
 md5->buf[md5->curlen++] = (unsigned char)0;
 }
 md5_compress(md5, md5->buf);
 md5->curlen = 0;
 }

 /* pad up to 56 bytes of zeroes */
 while (md5->curlen < 56) {
 md5->buf[md5->curlen++] = (unsigned char)0;
 }

 /* store length */
 STORE64L(md5->length, md5->buf+56);
 md5_compress(md5, md5->buf);

 /* copy output */
 for (i = 0; i < 4; i++) {
 STORE32L(md5->state[i], out+(4*i));
 }
}

/* .Source: /cvs/libtom/libtomcrypt/src/hashes/md5.c,v $ */
/* .Revision: 1.10 $ */
/* .Date: 2007年05月12日 14:25:28 $ */

/*
 * End of copied MD5 code.
 *
 * ------------------------------------------------------------------------
 */

static PyTypeObject MD5type;


static MD5object *
newMD5object(void)
{
 return (MD5object *)PyObject_New(MD5object, &MD5type);
}


/* Internal methods for a hash object */

static void
MD5_dealloc(PyObject *ptr)
{
 PyObject_Del(ptr);
}


/* External methods for a hash object */

/*[clinic input]
MD5Type.copy

Return a copy of the hash object.
[clinic start generated code]*/

static PyObject *
MD5Type_copy_impl(MD5object *self)
/*[clinic end generated code: output=596eb36852f02071 input=2c09e6d2493f3079]*/
{
 MD5object *newobj;

 if ((newobj = newMD5object())==NULL)
 return NULL;

 newobj->hash_state = self->hash_state;
 return (PyObject *)newobj;
}

/*[clinic input]
MD5Type.digest

Return the digest value as a bytes object.
[clinic start generated code]*/

static PyObject *
MD5Type_digest_impl(MD5object *self)
/*[clinic end generated code: output=eb691dc4190a07ec input=bc0c4397c2994be6]*/
{
 unsigned char digest[MD5_DIGESTSIZE];
 struct md5_state temp;

 temp = self->hash_state;
 md5_done(&temp, digest);
 return PyBytes_FromStringAndSize((const char *)digest, MD5_DIGESTSIZE);
}

/*[clinic input]
MD5Type.hexdigest

Return the digest value as a string of hexadecimal digits.
[clinic start generated code]*/

static PyObject *
MD5Type_hexdigest_impl(MD5object *self)
/*[clinic end generated code: output=17badced1f3ac932 input=b60b19de644798dd]*/
{
 unsigned char digest[MD5_DIGESTSIZE];
 struct md5_state temp;

 /* Get the raw (binary) digest value */
 temp = self->hash_state;
 md5_done(&temp, digest);

 return _Py_strhex((const char*)digest, MD5_DIGESTSIZE);
}

/*[clinic input]
MD5Type.update

 obj: object
 /

Update this hash object's state with the provided string.
[clinic start generated code]*/

static PyObject *
MD5Type_update(MD5object *self, PyObject *obj)
/*[clinic end generated code: output=f6ad168416338423 input=6e1efcd9ecf17032]*/
{
 Py_buffer buf;

 GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);

 md5_process(&self->hash_state, buf.buf, buf.len);

 PyBuffer_Release(&buf);
 Py_RETURN_NONE;
}

static PyMethodDef MD5_methods[] = {
 MD5TYPE_COPY_METHODDEF
 MD5TYPE_DIGEST_METHODDEF
 MD5TYPE_HEXDIGEST_METHODDEF
 MD5TYPE_UPDATE_METHODDEF
 {NULL, NULL} /* sentinel */
};

static PyObject *
MD5_get_block_size(PyObject *self, void *closure)
{
 return PyLong_FromLong(MD5_BLOCKSIZE);
}

static PyObject *
MD5_get_name(PyObject *self, void *closure)
{
 return PyUnicode_FromStringAndSize("md5", 3);
}

static PyObject *
md5_get_digest_size(PyObject *self, void *closure)
{
 return PyLong_FromLong(MD5_DIGESTSIZE);
}


static PyGetSetDef MD5_getseters[] = {
 {"block_size",
 (getter)MD5_get_block_size, NULL,
 NULL,
 NULL},
 {"name",
 (getter)MD5_get_name, NULL,
 NULL,
 NULL},
 {"digest_size",
 (getter)md5_get_digest_size, NULL,
 NULL,
 NULL},
 {NULL} /* Sentinel */
};

static PyTypeObject MD5type = {
 PyVarObject_HEAD_INIT(NULL, 0)
 "_md5.md5", /*tp_name*/
 sizeof(MD5object), /*tp_basicsize*/
 0, /*tp_itemsize*/
 /* methods */
 MD5_dealloc, /*tp_dealloc*/
 0, /*tp_vectorcall_offset*/
 0, /*tp_getattr*/
 0, /*tp_setattr*/
 0, /*tp_as_async*/
 0, /*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, /*tp_flags*/
 0, /*tp_doc*/
 0, /*tp_traverse*/
 0, /*tp_clear*/
 0, /*tp_richcompare*/
 0, /*tp_weaklistoffset*/
 0, /*tp_iter*/
 0, /*tp_iternext*/
 MD5_methods, /* tp_methods */
 NULL, /* tp_members */
 MD5_getseters, /* tp_getset */
};


/* The single module-level function: new() */

/*[clinic input]
_md5.md5

 string: object(c_default="NULL") = b''

Return a new MD5 hash object; optionally initialized with a string.
[clinic start generated code]*/

static PyObject *
_md5_md5_impl(PyObject *module, PyObject *string)
/*[clinic end generated code: output=2cfd0f8c091b97e6 input=d12ef8f72d684f7b]*/
{
 MD5object *new;
 Py_buffer buf;

 if (string)
 GET_BUFFER_VIEW_OR_ERROUT(string, &buf);

 if ((new = newMD5object()) == NULL) {
 if (string)
 PyBuffer_Release(&buf);
 return NULL;
 }

 md5_init(&new->hash_state);

 if (PyErr_Occurred()) {
 Py_DECREF(new);
 if (string)
 PyBuffer_Release(&buf);
 return NULL;
 }
 if (string) {
 md5_process(&new->hash_state, buf.buf, buf.len);
 PyBuffer_Release(&buf);
 }

 return (PyObject *)new;
}


/* List of functions exported by this module */

static struct PyMethodDef MD5_functions[] = {
 _MD5_MD5_METHODDEF
 {NULL, NULL} /* Sentinel */
};


/* Initialize this module. */

#define insint(n,v) { PyModule_AddIntConstant(m,n,v); }


static struct PyModuleDef _md5module = {
 PyModuleDef_HEAD_INIT,
 "_md5",
 NULL,
 -1,
 MD5_functions,
 NULL,
 NULL,
 NULL,
 NULL
};

PyMODINIT_FUNC
PyInit__md5(void)
{
 PyObject *m;

 Py_TYPE(&MD5type) = &PyType_Type;
 if (PyType_Ready(&MD5type) < 0)
 return NULL;

 m = PyModule_Create(&_md5module);
 if (m == NULL)
 return NULL;

 Py_INCREF((PyObject *)&MD5type);
 PyModule_AddObject(m, "MD5Type", (PyObject *)&MD5type);
 return m;
}