| /*********************************************************** |
| Copyright 1994 by Lance Ellinghouse, |
| Cathedral City, California Republic, United States of America. |
| |
| All Rights Reserved |
| |
| Permission to use, copy, modify, and distribute this software and its |
| documentation for any purpose and without fee is hereby granted, |
| provided that the above copyright notice appear in all copies and that |
| both that copyright notice and this permission notice appear in |
| supporting documentation, and that the name of Lance Ellinghouse |
| not be used in advertising or publicity pertaining to distribution |
| of the software without specific, written prior permission. |
| |
| LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO |
| THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE BE LIABLE FOR ANY SPECIAL, |
| INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING |
| FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, |
| NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION |
| WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| ******************************************************************/ |
| |
| /* This creates an encryption and decryption engine I am calling |
| a rotor due to the original design was a hardware rotor with |
| contacts used in Germany during WWII. |
| |
| Rotor Module: |
| |
| - rotor.newrotor('key') -> rotorobject (default of 6 rotors) |
| - rotor.newrotor('key', num_rotors) -> rotorobject |
| |
| Rotor Objects: |
| |
| - ro.setkey('string') -> None (resets the key as defined in newrotor(). |
| - ro.encrypt('string') -> encrypted string |
| - ro.decrypt('encrypted string') -> unencrypted string |
| |
| - ro.encryptmore('string') -> encrypted string |
| - ro.decryptmore('encrypted string') -> unencrypted string |
| |
| NOTE: the {en,de}cryptmore() methods use the setup that was |
| established via the {en,de}crypt calls. They will NOT |
| re-initalize the rotors unless: 1) They have not been |
| initialized with {en,de}crypt since the last setkey() call; |
| 2) {en,de}crypt has not been called for this rotor yet. |
| |
| NOTE: you MUST use the SAME key in rotor.newrotor() |
| if you wish to decrypt an encrypted string. |
| Also, the encrypted string is NOT 0-127 ASCII. |
| It is considered BINARY data. |
| |
| */ |
| |
| /* Rotor objects */ |
| |
| #include "Python.h" |
| |
| #ifndef TRUE |
| #define TRUE 1 |
| #endif |
| #ifndef FALSE |
| #define FALSE 0 |
| #endif |
| |
| typedef struct { |
| PyObject_HEAD |
| int seed[3]; |
| short key[5]; |
| int isinited; |
| int size; |
| int size_mask; |
| int rotors; |
| unsigned char *e_rotor; /* [num_rotors][size] */ |
| unsigned char *d_rotor; /* [num_rotors][size] */ |
| unsigned char *positions; /* [num_rotors] */ |
| unsigned char *advances; /* [num_rotors] */ |
| } Rotorobj; |
| |
| staticforward PyTypeObject Rotor_Type; |
| |
| #define is_rotor(v) ((v)->ob_type == &Rotor_Type) |
| |
| |
| /* This defines the necessary routines to manage rotor objects */ |
| |
| static void |
| set_seed(Rotorobj *r) |
| { |
| r->seed[0] = r->key[0]; |
| r->seed[1] = r->key[1]; |
| r->seed[2] = r->key[2]; |
| r->isinited = FALSE; |
| } |
| |
| /* Return the next random number in the range [0.0 .. 1.0) */ |
| static double |
| r_random(Rotorobj *r) |
| { |
| int x, y, z; |
| double val, term; |
| |
| x = r->seed[0]; |
| y = r->seed[1]; |
| z = r->seed[2]; |
| |
| x = 171 * (x % 177) - 2 * (x/177); |
| y = 172 * (y % 176) - 35 * (y/176); |
| z = 170 * (z % 178) - 63 * (z/178); |
| |
| if (x < 0) x = x + 30269; |
| if (y < 0) y = y + 30307; |
| if (z < 0) z = z + 30323; |
| |
| r->seed[0] = x; |
| r->seed[1] = y; |
| r->seed[2] = z; |
| |
| term = (double)( |
| (((double)x)/(double)30269.0) + |
| (((double)y)/(double)30307.0) + |
| (((double)z)/(double)30323.0) |
| ); |
| val = term - (double)floor((double)term); |
| |
| if (val >= 1.0) |
| val = 0.0; |
| |
| return val; |
| } |
| |
| static short |
| r_rand(Rotorobj *r, short s) |
| { |
| return (short)((short)(r_random(r) * (double)s) % s); |
| } |
| |
| static void |
| set_key(Rotorobj *r, char *key) |
| { |
| unsigned long k1=995, k2=576, k3=767, k4=671, k5=463; |
| size_t i; |
| size_t len = strlen(key); |
| |
| for (i = 0; i < len; i++) { |
| unsigned short ki = Py_CHARMASK(key[i]); |
| |
| k1 = (((k1<<3 | k1>>13) + ki) & 65535); |
| k2 = (((k2<<3 | k2>>13) ^ ki) & 65535); |
| k3 = (((k3<<3 | k3>>13) - ki) & 65535); |
| k4 = ((ki - (k4<<3 | k4>>13)) & 65535); |
| k5 = (((k5<<3 | k5>>13) ^ ~ki) & 65535); |
| } |
| r->key[0] = (short)k1; |
| r->key[1] = (short)(k2|1); |
| r->key[2] = (short)k3; |
| r->key[3] = (short)k4; |
| r->key[4] = (short)k5; |
| |
| set_seed(r); |
| } |
| |
| |
| |
| /* These define the interface to a rotor object */ |
| static Rotorobj * |
| rotorobj_new(int num_rotors, char *key) |
| { |
| Rotorobj *xp; |
| |
| xp = PyObject_New(Rotorobj, &Rotor_Type); |
| if (xp == NULL) |
| return NULL; |
| set_key(xp, key); |
| |
| xp->size = 256; |
| xp->size_mask = xp->size - 1; |
| xp->size_mask = 0; |
| xp->rotors = num_rotors; |
| xp->e_rotor = NULL; |
| xp->d_rotor = NULL; |
| xp->positions = NULL; |
| xp->advances = NULL; |
| |
| if (!(xp->e_rotor = PyMem_NEW(unsigned char, num_rotors * xp->size))) |
| goto finally; |
| if (!(xp->d_rotor = PyMem_NEW(unsigned char, num_rotors * xp->size))) |
| goto finally; |
| if (!(xp->positions = PyMem_NEW(unsigned char, num_rotors))) |
| goto finally; |
| if (!(xp->advances = PyMem_NEW(unsigned char, num_rotors))) |
| goto finally; |
| |
| return xp; |
| |
| finally: |
| if (xp->e_rotor) |
| PyMem_DEL(xp->e_rotor); |
| if (xp->d_rotor) |
| PyMem_DEL(xp->d_rotor); |
| if (xp->positions) |
| PyMem_DEL(xp->positions); |
| if (xp->advances) |
| PyMem_DEL(xp->advances); |
| Py_DECREF(xp); |
| return (Rotorobj*)PyErr_NoMemory(); |
| } |
| |
| |
| /* These routines implement the rotor itself */ |
| |
| /* Here is a fairly sophisticated {en,de}cryption system. It is based on |
| the idea of a "rotor" machine. A bunch of rotors, each with a |
| different permutation of the alphabet, rotate around a different amount |
| after encrypting one character. The current state of the rotors is |
| used to encrypt one character. |
| |
| The code is smart enough to tell if your alphabet has a number of |
| characters equal to a power of two. If it does, it uses logical |
| operations, if not it uses div and mod (both require a division). |
| |
| You will need to make two changes to the code 1) convert to c, and |
| customize for an alphabet of 255 chars 2) add a filter at the begining, |
| and end, which subtracts one on the way in, and adds one on the way |
| out. |
| |
| You might wish to do some timing studies. Another viable alternative |
| is to "byte stuff" the encrypted data of a normal (perhaps this one) |
| encryption routine. |
| |
| j' |
| |
| */ |
| |
| /* Note: the C code here is a fairly straightforward transliteration of a |
| * rotor implemented in lisp. The original lisp code has been removed from |
| * this file to for simplification, but I've kept the docstrings as |
| * comments in front of the functions. |
| */ |
| |
| |
| /* Set ROTOR to the identity permutation */ |
| static void |
| RTR_make_id_rotor(Rotorobj *r, unsigned char *rtr) |
| { |
| register int j; |
| register int size = r->size; |
| for (j = 0; j < size; j++) { |
| rtr[j] = (unsigned char)j; |
| } |
| } |
| |
| |
| /* The current set of encryption rotors */ |
| static void |
| RTR_e_rotors(Rotorobj *r) |
| { |
| int i; |
| for (i = 0; i < r->rotors; i++) { |
| RTR_make_id_rotor(r, &(r->e_rotor[(i*r->size)])); |
| } |
| } |
| |
| /* The current set of decryption rotors */ |
| static void |
| RTR_d_rotors(Rotorobj *r) |
| { |
| register int i, j; |
| for (i = 0; i < r->rotors; i++) { |
| for (j = 0; j < r->size; j++) { |
| r->d_rotor[((i*r->size)+j)] = (unsigned char)j; |
| } |
| } |
| } |
| |
| /* The positions of the rotors at this time */ |
| static void |
| RTR_positions(Rotorobj *r) |
| { |
| int i; |
| for (i = 0; i < r->rotors; i++) { |
| r->positions[i] = 1; |
| } |
| } |
| |
| /* The number of positions to advance the rotors at a time */ |
| static void |
| RTR_advances(Rotorobj *r) |
| { |
| int i; |
| for (i = 0; i < r->rotors; i++) { |
| r->advances[i] = 1; |
| } |
| } |
| |
| /* Permute the E rotor, and make the D rotor its inverse |
| * see Knuth for explanation of algorithm. |
| */ |
| static void |
| RTR_permute_rotor(Rotorobj *r, unsigned char *e, unsigned char *d) |
| { |
| short i = r->size; |
| short q; |
| unsigned char j; |
| RTR_make_id_rotor(r,e); |
| while (2 <= i) { |
| q = r_rand(r,i); |
| i--; |
| j = e[q]; |
| e[q] = (unsigned char)e[i]; |
| e[i] = (unsigned char)j; |
| d[j] = (unsigned char)i; |
| } |
| e[0] = (unsigned char)e[0]; |
| d[(e[0])] = (unsigned char)0; |
| } |
| |
| /* Given KEY (a list of 5 16 bit numbers), initialize the rotor machine. |
| * Set the advancement, position, and permutation of the rotors |
| */ |
| static void |
| RTR_init(Rotorobj *r) |
| { |
| int i; |
| set_seed(r); |
| RTR_positions(r); |
| RTR_advances(r); |
| RTR_e_rotors(r); |
| RTR_d_rotors(r); |
| for (i = 0; i < r->rotors; i++) { |
| r->positions[i] = (unsigned char) r_rand(r, (short)r->size); |
| r->advances[i] = (1+(2*(r_rand(r, (short)(r->size/2))))); |
| RTR_permute_rotor(r, |
| &(r->e_rotor[(i*r->size)]), |
| &(r->d_rotor[(i*r->size)])); |
| } |
| r->isinited = TRUE; |
| } |
| |
| /* Change the RTR-positions vector, using the RTR-advances vector */ |
| static void |
| RTR_advance(Rotorobj *r) |
| { |
| register int i=0, temp=0; |
| if (r->size_mask) { |
| while (i < r->rotors) { |
| temp = r->positions[i] + r->advances[i]; |
| r->positions[i] = temp & r->size_mask; |
| if ((temp >= r->size) && (i < (r->rotors - 1))) { |
| r->positions[(i+1)] = 1 + r->positions[(i+1)]; |
| } |
| i++; |
| } |
| } else { |
| while (i < r->rotors) { |
| temp = r->positions[i] + r->advances[i]; |
| r->positions[i] = temp%r->size; |
| if ((temp >= r->size) && (i < (r->rotors - 1))) { |
| r->positions[(i+1)] = 1 + r->positions[(i+1)]; |
| } |
| i++; |
| } |
| } |
| } |
| |
| /* Encrypt the character P with the current rotor machine */ |
| static unsigned char |
| RTR_e_char(Rotorobj *r, unsigned char p) |
| { |
| register int i=0; |
| register unsigned char tp=p; |
| if (r->size_mask) { |
| while (i < r->rotors) { |
| tp = r->e_rotor[(i*r->size) + |
| (((r->positions[i] ^ tp) & |
| r->size_mask))]; |
| i++; |
| } |
| } else { |
| while (i < r->rotors) { |
| tp = r->e_rotor[(i*r->size) + |
| (((r->positions[i] ^ tp) % |
| (unsigned int) r->size))]; |
| i++; |
| } |
| } |
| RTR_advance(r); |
| return ((unsigned char)tp); |
| } |
| |
| /* Decrypt the character C with the current rotor machine */ |
| static unsigned char |
| RTR_d_char(Rotorobj *r, unsigned char c) |
| { |
| register int i = r->rotors - 1; |
| register unsigned char tc = c; |
| |
| if (r->size_mask) { |
| while (0 <= i) { |
| tc = (r->positions[i] ^ |
| r->d_rotor[(i*r->size)+tc]) & r->size_mask; |
| i--; |
| } |
| } else { |
| while (0 <= i) { |
| tc = (r->positions[i] ^ |
| r->d_rotor[(i*r->size)+tc]) % |
| (unsigned int) r->size; |
| i--; |
| } |
| } |
| RTR_advance(r); |
| return(tc); |
| } |
| |
| /* Perform a rotor encryption of the region from BEG to END by KEY */ |
| static void |
| RTR_e_region(Rotorobj *r, unsigned char *beg, int len, int doinit) |
| { |
| register int i; |
| if (doinit || r->isinited == FALSE) |
| RTR_init(r); |
| for (i = 0; i < len; i++) { |
| beg[i] = RTR_e_char(r, beg[i]); |
| } |
| } |
| |
| /* Perform a rotor decryption of the region from BEG to END by KEY */ |
| static void |
| RTR_d_region(Rotorobj *r, unsigned char *beg, int len, int doinit) |
| { |
| register int i; |
| if (doinit || r->isinited == FALSE) |
| RTR_init(r); |
| for (i = 0; i < len; i++) { |
| beg[i] = RTR_d_char(r, beg[i]); |
| } |
| } |
| |
| |
| |
| /* Rotor methods */ |
| static void |
| rotor_dealloc(Rotorobj *xp) |
| { |
| if (xp->e_rotor) |
| PyMem_DEL(xp->e_rotor); |
| if (xp->d_rotor) |
| PyMem_DEL(xp->d_rotor); |
| if (xp->positions) |
| PyMem_DEL(xp->positions); |
| if (xp->advances) |
| PyMem_DEL(xp->advances); |
| PyObject_Del(xp); |
| } |
| |
| static PyObject * |
| rotorobj_encrypt(Rotorobj *self, PyObject *args) |
| { |
| char *string = NULL; |
| int len = 0; |
| PyObject *rtn = NULL; |
| char *tmp; |
| |
| if (!PyArg_Parse(args, "s#", &string, &len)) |
| return NULL; |
| if (!(tmp = PyMem_NEW(char, len+5))) { |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| memset(tmp, '\0', len+1); |
| memcpy(tmp, string, len); |
| RTR_e_region(self, (unsigned char *)tmp, len, TRUE); |
| rtn = PyString_FromStringAndSize(tmp, len); |
| PyMem_DEL(tmp); |
| return(rtn); |
| } |
| |
| static PyObject * |
| rotorobj_encrypt_more(Rotorobj *self, PyObject *args) |
| { |
| char *string = NULL; |
| int len = 0; |
| PyObject *rtn = NULL; |
| char *tmp; |
| |
| if (!PyArg_Parse(args, "s#", &string, &len)) |
| return NULL; |
| if (!(tmp = PyMem_NEW(char, len+5))) { |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| memset(tmp, '\0', len+1); |
| memcpy(tmp, string, len); |
| RTR_e_region(self, (unsigned char *)tmp, len, FALSE); |
| rtn = PyString_FromStringAndSize(tmp, len); |
| PyMem_DEL(tmp); |
| return(rtn); |
| } |
| |
| static PyObject * |
| rotorobj_decrypt(Rotorobj *self, PyObject *args) |
| { |
| char *string = NULL; |
| int len = 0; |
| PyObject *rtn = NULL; |
| char *tmp; |
| |
| if (!PyArg_Parse(args, "s#", &string, &len)) |
| return NULL; |
| if (!(tmp = PyMem_NEW(char, len+5))) { |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| memset(tmp, '\0', len+1); |
| memcpy(tmp, string, len); |
| RTR_d_region(self, (unsigned char *)tmp, len, TRUE); |
| rtn = PyString_FromStringAndSize(tmp, len); |
| PyMem_DEL(tmp); |
| return(rtn); |
| } |
| |
| static PyObject * |
| rotorobj_decrypt_more(Rotorobj *self, PyObject *args) |
| { |
| char *string = NULL; |
| int len = 0; |
| PyObject *rtn = NULL; |
| char *tmp; |
| |
| if (!PyArg_Parse(args, "s#", &string, &len)) |
| return NULL; |
| if (!(tmp = PyMem_NEW(char, len+5))) { |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| memset(tmp, '\0', len+1); |
| memcpy(tmp, string, len); |
| RTR_d_region(self, (unsigned char *)tmp, len, FALSE); |
| rtn = PyString_FromStringAndSize(tmp, len); |
| PyMem_DEL(tmp); |
| return(rtn); |
| } |
| |
| static PyObject * |
| rotorobj_setkey(Rotorobj *self, PyObject *args) |
| { |
| char *key; |
| |
| if (!PyArg_ParseTuple(args, "s:setkey", &key)) |
| return NULL; |
| |
| set_key(self, key); |
| Py_INCREF(Py_None); |
| return Py_None; |
| } |
| |
| static struct PyMethodDef |
| rotorobj_methods[] = { |
| {"encrypt", (PyCFunction)rotorobj_encrypt}, |
| {"encryptmore", (PyCFunction)rotorobj_encrypt_more}, |
| {"decrypt", (PyCFunction)rotorobj_decrypt}, |
| {"decryptmore", (PyCFunction)rotorobj_decrypt_more}, |
| {"setkey", (PyCFunction)rotorobj_setkey, 1}, |
| {NULL, NULL} /* sentinel */ |
| }; |
| |
| |
| /* Return a rotor object's named attribute. */ |
| static PyObject * |
| rotorobj_getattr(Rotorobj *s, char *name) |
| { |
| return Py_FindMethod(rotorobj_methods, (PyObject*)s, name); |
| } |
| |
| |
| statichere PyTypeObject Rotor_Type = { |
| PyObject_HEAD_INIT(&PyType_Type) |
| 0, /*ob_size*/ |
| "rotor", /*tp_name*/ |
| sizeof(Rotorobj), /*tp_size*/ |
| 0, /*tp_itemsize*/ |
| /* methods */ |
| (destructor)rotor_dealloc, /*tp_dealloc*/ |
| 0, /*tp_print*/ |
| (getattrfunc)rotorobj_getattr, /*tp_getattr*/ |
| 0, /*tp_setattr*/ |
| 0, /*tp_compare*/ |
| 0, /*tp_repr*/ |
| 0, /*tp_hash*/ |
| }; |
| |
| |
| static PyObject * |
| rotor_rotor(PyObject *self, PyObject *args) |
| { |
| Rotorobj *r; |
| char *string; |
| int len; |
| int num_rotors = 6; |
| |
| if (!PyArg_ParseTuple(args, "s#|i:newrotor", &string, &len, &num_rotors)) |
| return NULL; |
| |
| r = rotorobj_new(num_rotors, string); |
| return (PyObject *)r; |
| } |
| |
| |
| |
| static struct PyMethodDef |
| rotor_methods[] = { |
| {"newrotor", rotor_rotor, 1}, |
| {NULL, NULL} /* sentinel */ |
| }; |
| |
| |
| DL_EXPORT(void) |
| initrotor(void) |
| { |
| (void)Py_InitModule("rotor", rotor_methods); |
| } |