/* SHA1 module */

/* This module provides an interface to the SHA1 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.

*/

/* SHA1 objects */

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

/*[clinic input]
module _sha1
class SHA1Type "SHA1object *" "&PyType_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=3dc9a20d1becb759]*/

/* Some useful types */

#if SIZEOF_INT == 4
typedef unsigned int SHA1_INT32; /* 32-bit integer */
typedef long long SHA1_INT64; /* 64-bit integer */
#else
/* not defined. compilation will die. */
#endif

/* The SHA1 block size and message digest sizes, in bytes */

#define SHA1_BLOCKSIZE 64
#define SHA1_DIGESTSIZE 20

/* The structure for storing SHA1 info */

struct sha1_state {
 SHA1_INT64 length;
 SHA1_INT32 state[5], curlen;
 unsigned char buf[SHA1_BLOCKSIZE];
};

typedef struct {
 PyObject_HEAD

 struct sha1_state hash_state;
} SHA1object;

#include "clinic/sha1module.c.h"

/* ------------------------------------------------------------------------
 *
 * This code for the SHA1 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 ROL(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
#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 STORE32H(x, y) \
 { (y)[0] = (unsigned char)(((x)>>24)&255); (y)[1] = (unsigned char)(((x)>>16)&255); \
 (y)[2] = (unsigned char)(((x)>>8)&255); (y)[3] = (unsigned char)((x)&255); }

#define LOAD32H(x, y) \
 { x = ((unsigned long)((y)[0] & 255)<<24) | \
 ((unsigned long)((y)[1] & 255)<<16) | \
 ((unsigned long)((y)[2] & 255)<<8) | \
 ((unsigned long)((y)[3] & 255)); }

#define STORE64H(x, y) \
 { (y)[0] = (unsigned char)(((x)>>56)&255); (y)[1] = (unsigned char)(((x)>>48)&255); \
 (y)[2] = (unsigned char)(((x)>>40)&255); (y)[3] = (unsigned char)(((x)>>32)&255); \
 (y)[4] = (unsigned char)(((x)>>24)&255); (y)[5] = (unsigned char)(((x)>>16)&255); \
 (y)[6] = (unsigned char)(((x)>>8)&255); (y)[7] = (unsigned char)((x)&255); }


/* SHA1 macros */

#define F0(x,y,z) (z ^ (x & (y ^ z)))
#define F1(x,y,z) (x ^ y ^ z)
#define F2(x,y,z) ((x & y) | (z & (x | y)))
#define F3(x,y,z) (x ^ y ^ z)

static void sha1_compress(struct sha1_state *sha1, unsigned char *buf)
{
 SHA1_INT32 a,b,c,d,e,W[80],i;

 /* copy the state into 512-bits into W[0..15] */
 for (i = 0; i < 16; i++) {
 LOAD32H(W[i], buf + (4*i));
 }

 /* copy state */
 a = sha1->state[0];
 b = sha1->state[1];
 c = sha1->state[2];
 d = sha1->state[3];
 e = sha1->state[4];

 /* expand it */
 for (i = 16; i < 80; i++) {
 W[i] = ROL(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
 }

 /* compress */
 /* round one */
 #define FF_0(a,b,c,d,e,i) e = (ROLc(a, 5) + F0(b,c,d) + e + W[i] + 0x5a827999UL); b = ROLc(b, 30);
 #define FF_1(a,b,c,d,e,i) e = (ROLc(a, 5) + F1(b,c,d) + e + W[i] + 0x6ed9eba1UL); b = ROLc(b, 30);
 #define FF_2(a,b,c,d,e,i) e = (ROLc(a, 5) + F2(b,c,d) + e + W[i] + 0x8f1bbcdcUL); b = ROLc(b, 30);
 #define FF_3(a,b,c,d,e,i) e = (ROLc(a, 5) + F3(b,c,d) + e + W[i] + 0xca62c1d6UL); b = ROLc(b, 30);

 for (i = 0; i < 20; ) {
 FF_0(a,b,c,d,e,i++);
 FF_0(e,a,b,c,d,i++);
 FF_0(d,e,a,b,c,i++);
 FF_0(c,d,e,a,b,i++);
 FF_0(b,c,d,e,a,i++);
 }

 /* round two */
 for (; i < 40; ) {
 FF_1(a,b,c,d,e,i++);
 FF_1(e,a,b,c,d,i++);
 FF_1(d,e,a,b,c,i++);
 FF_1(c,d,e,a,b,i++);
 FF_1(b,c,d,e,a,i++);
 }

 /* round three */
 for (; i < 60; ) {
 FF_2(a,b,c,d,e,i++);
 FF_2(e,a,b,c,d,i++);
 FF_2(d,e,a,b,c,i++);
 FF_2(c,d,e,a,b,i++);
 FF_2(b,c,d,e,a,i++);
 }

 /* round four */
 for (; i < 80; ) {
 FF_3(a,b,c,d,e,i++);
 FF_3(e,a,b,c,d,i++);
 FF_3(d,e,a,b,c,i++);
 FF_3(c,d,e,a,b,i++);
 FF_3(b,c,d,e,a,i++);
 }

 #undef FF_0
 #undef FF_1
 #undef FF_2
 #undef FF_3

 /* store */
 sha1->state[0] = sha1->state[0] + a;
 sha1->state[1] = sha1->state[1] + b;
 sha1->state[2] = sha1->state[2] + c;
 sha1->state[3] = sha1->state[3] + d;
 sha1->state[4] = sha1->state[4] + e;
}

/**
 Initialize the hash state
 @param sha1 The hash state you wish to initialize
*/
static void
sha1_init(struct sha1_state *sha1)
{
 assert(sha1 != NULL);
 sha1->state[0] = 0x67452301UL;
 sha1->state[1] = 0xefcdab89UL;
 sha1->state[2] = 0x98badcfeUL;
 sha1->state[3] = 0x10325476UL;
 sha1->state[4] = 0xc3d2e1f0UL;
 sha1->curlen = 0;
 sha1->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
sha1_process(struct sha1_state *sha1,
 const unsigned char *in, Py_ssize_t inlen)
{
 Py_ssize_t n;

 assert(sha1 != NULL);
 assert(in != NULL);
 assert(sha1->curlen <= sizeof(sha1->buf));

 while (inlen > 0) {
 if (sha1->curlen == 0 && inlen >= SHA1_BLOCKSIZE) {
 sha1_compress(sha1, (unsigned char *)in);
 sha1->length += SHA1_BLOCKSIZE * 8;
 in += SHA1_BLOCKSIZE;
 inlen -= SHA1_BLOCKSIZE;
 } else {
 n = Py_MIN(inlen, (Py_ssize_t)(SHA1_BLOCKSIZE - sha1->curlen));
 memcpy(sha1->buf + sha1->curlen, in, (size_t)n);
 sha1->curlen += (SHA1_INT32)n;
 in += n;
 inlen -= n;
 if (sha1->curlen == SHA1_BLOCKSIZE) {
 sha1_compress(sha1, sha1->buf);
 sha1->length += 8*SHA1_BLOCKSIZE;
 sha1->curlen = 0;
 }
 }
 }
}

/**
 Terminate the hash to get the digest
 @param sha1 The hash state
 @param out [out] The destination of the hash (20 bytes)
*/
static void
sha1_done(struct sha1_state *sha1, unsigned char *out)
{
 int i;

 assert(sha1 != NULL);
 assert(out != NULL);
 assert(sha1->curlen < sizeof(sha1->buf));

 /* increase the length of the message */
 sha1->length += sha1->curlen * 8;

 /* append the '1' bit */
 sha1->buf[sha1->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 (sha1->curlen > 56) {
 while (sha1->curlen < 64) {
 sha1->buf[sha1->curlen++] = (unsigned char)0;
 }
 sha1_compress(sha1, sha1->buf);
 sha1->curlen = 0;
 }

 /* pad upto 56 bytes of zeroes */
 while (sha1->curlen < 56) {
 sha1->buf[sha1->curlen++] = (unsigned char)0;
 }

 /* store length */
 STORE64H(sha1->length, sha1->buf+56);
 sha1_compress(sha1, sha1->buf);

 /* copy output */
 for (i = 0; i < 5; i++) {
 STORE32H(sha1->state[i], out+(4*i));
 }
}


/* .Source: /cvs/libtom/libtomcrypt/src/hashes/sha1.c,v $ */
/* .Revision: 1.10 $ */
/* .Date: 2007年05月12日 14:25:28 $ */

/*
 * End of copied SHA1 code.
 *
 * ------------------------------------------------------------------------
 */

static PyTypeObject SHA1type;


static SHA1object *
newSHA1object(void)
{
 return (SHA1object *)PyObject_New(SHA1object, &SHA1type);
}


/* Internal methods for a hash object */

static void
SHA1_dealloc(PyObject *ptr)
{
 PyObject_Del(ptr);
}


/* External methods for a hash object */

/*[clinic input]
SHA1Type.copy

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

static PyObject *
SHA1Type_copy_impl(SHA1object *self)
/*[clinic end generated code: output=b4e001264620f02a input=b7eae10df6f89b36]*/
{
 SHA1object *newobj;

 if ((newobj = newSHA1object()) == NULL)
 return NULL;

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

/*[clinic input]
SHA1Type.digest

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

static PyObject *
SHA1Type_digest_impl(SHA1object *self)
/*[clinic end generated code: output=2f05302a7aa2b5cb input=13824b35407444bd]*/
{
 unsigned char digest[SHA1_DIGESTSIZE];
 struct sha1_state temp;

 temp = self->hash_state;
 sha1_done(&temp, digest);
 return PyBytes_FromStringAndSize((const char *)digest, SHA1_DIGESTSIZE);
}

/*[clinic input]
SHA1Type.hexdigest

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

static PyObject *
SHA1Type_hexdigest_impl(SHA1object *self)
/*[clinic end generated code: output=4161fd71e68c6659 input=97691055c0c74ab0]*/
{
 unsigned char digest[SHA1_DIGESTSIZE];
 struct sha1_state temp;

 /* Get the raw (binary) digest value */
 temp = self->hash_state;
 sha1_done(&temp, digest);

 return _Py_strhex((const char *)digest, SHA1_DIGESTSIZE);
}

/*[clinic input]
SHA1Type.update

 obj: object
 /

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

static PyObject *
SHA1Type_update(SHA1object *self, PyObject *obj)
/*[clinic end generated code: output=d9902f0e5015e9ae input=aad8e07812edbba3]*/
{
 Py_buffer buf;

 GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);

 sha1_process(&self->hash_state, buf.buf, buf.len);

 PyBuffer_Release(&buf);
 Py_RETURN_NONE;
}

static PyMethodDef SHA1_methods[] = {
 SHA1TYPE_COPY_METHODDEF
 SHA1TYPE_DIGEST_METHODDEF
 SHA1TYPE_HEXDIGEST_METHODDEF
 SHA1TYPE_UPDATE_METHODDEF
 {NULL, NULL} /* sentinel */
};

static PyObject *
SHA1_get_block_size(PyObject *self, void *closure)
{
 return PyLong_FromLong(SHA1_BLOCKSIZE);
}

static PyObject *
SHA1_get_name(PyObject *self, void *closure)
{
 return PyUnicode_FromStringAndSize("sha1", 4);
}

static PyObject *
sha1_get_digest_size(PyObject *self, void *closure)
{
 return PyLong_FromLong(SHA1_DIGESTSIZE);
}


static PyGetSetDef SHA1_getseters[] = {
 {"block_size",
 (getter)SHA1_get_block_size, NULL,
 NULL,
 NULL},
 {"name",
 (getter)SHA1_get_name, NULL,
 NULL,
 NULL},
 {"digest_size",
 (getter)sha1_get_digest_size, NULL,
 NULL,
 NULL},
 {NULL} /* Sentinel */
};

static PyTypeObject SHA1type = {
 PyVarObject_HEAD_INIT(NULL, 0)
 "_sha1.sha1", /*tp_name*/
 sizeof(SHA1object), /*tp_basicsize*/
 0, /*tp_itemsize*/
 /* methods */
 SHA1_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*/
 SHA1_methods, /* tp_methods */
 NULL, /* tp_members */
 SHA1_getseters, /* tp_getset */
};


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

/*[clinic input]
_sha1.sha1

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

Return a new SHA1 hash object; optionally initialized with a string.
[clinic start generated code]*/

static PyObject *
_sha1_sha1_impl(PyObject *module, PyObject *string)
/*[clinic end generated code: output=e5982830d1dece51 input=27ea54281d995ec2]*/
{
 SHA1object *new;
 Py_buffer buf;

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

 if ((new = newSHA1object()) == NULL) {
 if (string)
 PyBuffer_Release(&buf);
 return NULL;
 }

 sha1_init(&new->hash_state);

 if (PyErr_Occurred()) {
 Py_DECREF(new);
 if (string)
 PyBuffer_Release(&buf);
 return NULL;
 }
 if (string) {
 sha1_process(&new->hash_state, buf.buf, buf.len);
 PyBuffer_Release(&buf);
 }

 return (PyObject *)new;
}


/* List of functions exported by this module */

static struct PyMethodDef SHA1_functions[] = {
 _SHA1_SHA1_METHODDEF
 {NULL, NULL} /* Sentinel */
};


/* Initialize this module. */

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


static struct PyModuleDef _sha1module = {
 PyModuleDef_HEAD_INIT,
 "_sha1",
 NULL,
 -1,
 SHA1_functions,
 NULL,
 NULL,
 NULL,
 NULL
};

PyMODINIT_FUNC
PyInit__sha1(void)
{
 PyObject *m;

 Py_TYPE(&SHA1type) = &PyType_Type;
 if (PyType_Ready(&SHA1type) < 0)
 return NULL;

 m = PyModule_Create(&_sha1module);
 if (m == NULL)
 return NULL;

 Py_INCREF((PyObject *)&SHA1type);
 PyModule_AddObject(m, "SHA1Type", (PyObject *)&SHA1type);
 return m;
}