diff options
Diffstat (limited to 'tcllib/modules/rc4/rc4c.tcl')
| -rw-r--r-- | tcllib/modules/rc4/rc4c.tcl | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/tcllib/modules/rc4/rc4c.tcl b/tcllib/modules/rc4/rc4c.tcl new file mode 100644 index 0000000..fd717df --- /dev/null +++ b/tcllib/modules/rc4/rc4c.tcl @@ -0,0 +1,168 @@ +# rc4c.tcl - Copyright (C) 2004 Pat Thoyts <patthoyts@users.sourceforge.net> +# +# This provides a critcl C implementation of RC4 +# +# INSTALLATION +# ------------ +# This package uses critcl (http://wiki.tcl.tk/critcl). To build do: +# critcl -libdir <your-tcl-lib-dir> -pkg rc4c rc4c +# +# To build this for tcllib use sak.tcl: +# tclsh sak.tcl critcl +# generates a tcllibc module. +# +# $Id: rc4c.tcl,v 1.4 2009/05/07 00:14:02 patthoyts Exp $ + +package require critcl +# @sak notprovided rc4c +package provide rc4c 1.1.0 + +namespace eval ::rc4 { + + critcl::ccode { + #include <string.h> + + typedef struct RC4_CTX { + unsigned char x; + unsigned char y; + unsigned char s[256]; + } RC4_CTX; + + /* #define TRACE trace */ + #define TRACE 1 ? ((void)0) : trace + + static void trace(const char *format, ...) + { + va_list args; + va_start(args, format); + vfprintf(stderr, format, args); + va_end(args); + } + static Tcl_ObjType rc4_type; + + static void rc4_free_rep(Tcl_Obj *obj) + { + RC4_CTX *ctx = (RC4_CTX *)obj->internalRep.otherValuePtr; + TRACE("rc4_free_rep(%08x)\n", (long)obj); + Tcl_Free((char *)ctx); + } + + static void rc4_dup_rep(Tcl_Obj *obj, Tcl_Obj *dup) + { + RC4_CTX *ctx = (RC4_CTX *)obj->internalRep.otherValuePtr; + TRACE("rc4_dup_rep(%08x,%08x)\n", (long)obj, (long)dup); + dup->internalRep.otherValuePtr = (RC4_CTX *)Tcl_Alloc(sizeof(RC4_CTX)); + memcpy(dup->internalRep.otherValuePtr, ctx, sizeof(RC4_CTX)); + dup->typePtr = &rc4_type; + } + + static void rc4_string_rep(Tcl_Obj* obj) + { + RC4_CTX *ctx = (RC4_CTX *)obj->internalRep.otherValuePtr; + Tcl_Obj* tmpObj; + char* str; + TRACE("rc4_string_rep(%08x)\n", (long)obj); + /* convert via a byte array to properly handle null bytes */ + tmpObj = Tcl_NewByteArrayObj((unsigned char *)ctx, sizeof(RC4_CTX)); + Tcl_IncrRefCount(tmpObj); + + str = Tcl_GetStringFromObj(tmpObj, &obj->length); + obj->bytes = Tcl_Alloc(obj->length + 1); + memcpy(obj->bytes, str, obj->length + 1); + + Tcl_DecrRefCount(tmpObj); + } + + static int rc4_from_any(Tcl_Interp* interp, Tcl_Obj* obj) + { + TRACE("rc4_from_any %08x\n", (long)obj); + return TCL_ERROR; + } + + static Tcl_ObjType rc4_type = { + "rc4c", rc4_free_rep, rc4_dup_rep, rc4_string_rep, rc4_from_any + }; +#ifdef __GNUC__ + inline +#elif defined(_MSC_VER) + __inline +#endif + void swap (unsigned char *lhs, unsigned char *rhs) { + unsigned char t = *lhs; + *lhs = *rhs; + *rhs = t; + } + } + + critcl::ccommand rc4c_init {dummy interp objc objv} { + RC4_CTX *ctx; + Tcl_Obj *obj; + const unsigned char *k; + int n = 0, i = 0, j = 0, keylen; + + if (objc != 2) { + Tcl_WrongNumArgs(interp, 1, objv, "keystring"); + return TCL_ERROR; + } + + k = Tcl_GetByteArrayFromObj(objv[1], &keylen); + + obj = Tcl_NewObj(); + ctx = (RC4_CTX *)Tcl_Alloc(sizeof(RC4_CTX)); + ctx->x = 0; + ctx->y = 0; + for (n = 0; n < 256; n++) + ctx->s[n] = n; + for (n = 0; n < 256; n++) { + j = (k[i] + ctx->s[n] + j) % 256; + swap(&ctx->s[n], &ctx->s[j]); + i = (i + 1) % keylen; + } + + if (obj->typePtr != NULL && obj->typePtr->freeIntRepProc != NULL) + obj->typePtr->freeIntRepProc(obj); + obj->internalRep.otherValuePtr = ctx; + obj->typePtr = &rc4_type; + Tcl_InvalidateStringRep(obj); + Tcl_SetObjResult(interp, obj); + return TCL_OK; + } + + critcl::ccommand rc4c {dummy interp objc objv} { + Tcl_Obj *resObj = NULL; + RC4_CTX *ctx = NULL; + unsigned char *data, *res, x, y; + int size, n, i; + + if (objc != 3) { + Tcl_WrongNumArgs(interp, 1, objv, "key data"); + return TCL_ERROR; + } + + if (objv[1]->typePtr != &rc4_type + && rc4_from_any(interp, objv[1]) != TCL_OK) { + return TCL_ERROR; + } + + ctx = objv[1]->internalRep.otherValuePtr; + data = Tcl_GetByteArrayFromObj(objv[2], &size); + res = (unsigned char *)Tcl_Alloc(size); + + x = ctx->x; + y = ctx->y; + for (n = 0; n < size; n++) { + x = (x + 1) % 256; + y = (ctx->s[x] + y) % 256; + swap(&ctx->s[x], &ctx->s[y]); + i = (ctx->s[x] + ctx->s[y]) % 256; + res[n] = data[n] ^ ctx->s[i]; + } + ctx->x = x; + ctx->y = y; + + resObj = Tcl_NewByteArrayObj(res, size); + Tcl_SetObjResult(interp, resObj); + Tcl_Free((char*)res); + return TCL_OK; + } +} |