/*
* Digest Command and Stacked Transform Channel
*
* Copyright (C) 2023 Brian O'Hagan
*
*/
#include "tlsInt.h"
#include "tclOpts.h"
#include <tcl.h>
#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
/* Constants */
const char *hex = "0123456789ABCDEF";
#define REASON() ERR_reason_error_string(ERR_get_error())
/*
* This structure describes the per-instance state of an SSL channel.
*
* The SSL processing context is maintained here, in the ClientData
*/
typedef struct DigestState {
Tcl_Channel self; /* This socket channel */
Tcl_TimerToken timer; /* Timer for read events */
int flags; /* Chan config flags */
int watchMask; /* Current WatchProc mask */
int mode; /* Current mode of parent channel */
int format; /* Output format */
Tcl_Interp *interp; /* Current interpreter */
EVP_MD_CTX *ctx; /* MD Context */
} DigestState;
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* DigestFile --
*
* Return message digest for file using user specified hash function.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Result is message digest or error message
*
*-------------------------------------------------------------------
*/
int DigestFile(Tcl_Interp *interp, Tcl_Obj *filename, const EVP_MD *md, int format) {
EVP_MD_CTX *ctx;
Tcl_Channel chan;
char buf[32768];
unsigned char md_buf[EVP_MAX_MD_SIZE];
unsigned int md_len;
/* Open file channel */
chan = Tcl_FSOpenFileChannel(interp, filename, "rb", 0444);
if (chan == NULL) {
return TCL_ERROR;
}
/* Configure channel */
if (Tcl_SetChannelOption(interp, chan, "-translation", "binary") == TCL_ERROR ||
Tcl_SetChannelOption(interp, chan, "-buffersize", "32768") == TCL_ERROR) {
Tcl_Close(interp, chan);
return TCL_ERROR;
}
/* Create message digest context */
ctx = EVP_MD_CTX_new();
if (ctx == NULL) {
Tcl_AppendResult(interp, "Create digest context failed: ", REASON(), NULL);
Tcl_Close(interp, chan);
return TCL_ERROR;
}
/* Initialize hash function */
#if OPENSSL_VERSION_NUMBER < 0x30000000L
if (!EVP_DigestInit_ex(ctx, md, NULL))
#else
if (!EVP_DigestInit_ex2(ctx, md, NULL))
#endif
{
Tcl_AppendResult(interp, "Initialize digest failed: ", REASON(), NULL);
Tcl_Close(interp, chan);
EVP_MD_CTX_free(ctx);
return TCL_ERROR;
}
/* Read file data and update hash function */
while (!Tcl_Eof(chan)) {
int len = Tcl_ReadRaw(chan, buf, 32768);
if (len > 0 && !EVP_DigestUpdate(ctx, &buf, (size_t) len)) {
Tcl_AppendResult(interp, "Update digest failed: ", REASON(), NULL);
Tcl_Close(interp, chan);
EVP_MD_CTX_free(ctx);
return TCL_ERROR;
}
}
/* Close channel */
if (Tcl_Close(interp, chan) == TCL_ERROR) {
EVP_MD_CTX_free(ctx);
return TCL_ERROR;
}
/* Finalize hash function and calculate message digest */
if (!EVP_DigestFinal_ex(ctx, md_buf, &md_len)) {
Tcl_AppendResult(interp, "Finalize digest failed: ", REASON(), NULL);
EVP_MD_CTX_free(ctx);
return TCL_ERROR;
}
EVP_MD_CTX_free(ctx);
/* Return message digest as either a binary or hex string */
if (format == 0) {
Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(md_buf, md_len));
} else {
Tcl_Obj *resultObj = Tcl_NewObj();
unsigned char *ptr = Tcl_SetByteArrayLength(resultObj, md_len*2);
for (unsigned int i = 0; i < md_len; i++) {
*ptr++ = hex[(md_buf[i] >> 4) & 0x0F];
*ptr++ = hex[md_buf[i] & 0x0F];
}
Tcl_SetObjResult(interp, resultObj);
}
return TCL_OK;
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* DigestBlockModeProc --
*
* This procedure is invoked by the generic IO level
* to set blocking and nonblocking modes.
*
* Returns:
* 0 if successful or POSIX error code if failed.
*
* Side effects:
* Sets the device into blocking or nonblocking mode.
* Can call Tcl_SetChannelError.
*
*-------------------------------------------------------------------
*/
static int DigestBlockModeProc(ClientData clientData, int mode) {
DigestState *statePtr = (DigestState *) clientData;
if (mode == TCL_MODE_NONBLOCKING) {
statePtr->flags |= TLS_TCL_ASYNC;
} else {
statePtr->flags &= ~(TLS_TCL_ASYNC);
}
return 0;
}
/*
*-------------------------------------------------------------------
*
* DigestFree --
*
* This procedure removes a digest state structure
*
* Returns:
* Nothing
*
* Side effects:
* Removes structure
*
*-------------------------------------------------------------------
*/
void DigestFree (DigestState *statePtr) {
if (statePtr == (DigestState *) NULL) return;
if (statePtr->ctx != NULL) {
EVP_MD_CTX_free(statePtr->ctx);
}
ckfree(statePtr);
}
/*
*-------------------------------------------------------------------
*
* DigestCloseProc --
*
* This procedure is invoked by the generic IO level to perform
* channel-type-specific cleanup when digest channel is closed.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Writes digest to output and closes the channel.
*
*-------------------------------------------------------------------
*/
int DigestCloseProc(ClientData clientData, Tcl_Interp *interp) {
DigestState *statePtr = (DigestState *) clientData;
int result = 0;
/* Cancel active timer, if any */
if (statePtr->timer != (Tcl_TimerToken) NULL) {
Tcl_DeleteTimerHandler(statePtr->timer);
statePtr->timer = (Tcl_TimerToken) NULL;
}
/* Clean-up */
DigestFree(statePtr);
return result;
}
/*
* Same as DigestCloseProc but with individual read and write close control
*/
static int DigestClose2Proc(ClientData instanceData, Tcl_Interp *interp, int flags) {
if ((flags & (TCL_CLOSE_READ | TCL_CLOSE_WRITE)) == 0) {
return DigestCloseProc(instanceData, interp);
}
return EINVAL;
}
/*
*----------------------------------------------------------------------
*
* DigestInputProc --
*
* Called by the generic IO system to read data from transform.
*
* Returns:
* Total bytes read
*
* Side effects:
* Read data from transform and write to buf
*
*----------------------------------------------------------------------
*/
int DigestInputProc(ClientData clientData, char *buf, int toRead, int *errorCodePtr) {
DigestState *statePtr = (DigestState *) clientData;
Tcl_Channel parent;
int read;
*errorCodePtr = 0;
if (toRead <= 0 || statePtr->self == (Tcl_Channel) NULL) {
return 0;
}
/* Get bytes from underlying channel */
parent = Tcl_GetStackedChannel(statePtr->self);
read = Tcl_ReadRaw(parent, buf, toRead);
/* Add to message digest */
if (read > 0) {
/* OK */
if (!EVP_DigestUpdate(statePtr->ctx, buf, read)) {
Tcl_SetChannelError(statePtr->self, Tcl_ObjPrintf("Digest update failed: %s", REASON()));
*errorCodePtr = EINVAL;
return -1;
}
*errorCodePtr = EAGAIN;
read = -1;
} else if (read < 0) {
/* Error */
*errorCodePtr = Tcl_GetErrno();
} else if (!(statePtr->flags & 0x10)) {
/* EOF */
*errorCodePtr = 0;
unsigned char md_buf[EVP_MAX_MD_SIZE];
unsigned int md_len = 0;
/* Get message digest */
if (!EVP_DigestFinal_ex(statePtr->ctx, md_buf, &md_len)) {
*errorCodePtr = EINVAL;
/* Write message digest to output channel as byte array or hex string */
} else if (md_len > 0) {
if (statePtr->format == 0) {
read = md_len;
memcpy(buf, md_buf, read);
} else {
unsigned char hex_buf[EVP_MAX_MD_SIZE*2];
unsigned char *ptr = hex_buf;
for (unsigned int i = 0; i < md_len; i++) {
*ptr++ = hex[(md_buf[i] >> 4) & 0x0F];
*ptr++ = hex[md_buf[i] & 0x0F];
}
read = md_len*2;
memcpy(buf, hex_buf, read);
}
}
statePtr->flags |= 0x10;
}
return read;
}
/*
*----------------------------------------------------------------------
*
* DigestOutputProc --
*
* Called by the generic IO system to write data to transform.
*
* Returns:
* Total bytes written
*
* Side effects:
* Get data from buf and update digest
*
*----------------------------------------------------------------------
*/
int DigestOutputProc(ClientData clientData, const char *buf, int toWrite, int *errorCodePtr) {
DigestState *statePtr = (DigestState *) clientData;
*errorCodePtr = 0;
if (toWrite <= 0 || statePtr->self == (Tcl_Channel) NULL) {
return 0;
}
return toWrite;
}
/*
*----------------------------------------------------------------------
*
* DigestSetOptionProc --
*
* Called by the generic IO system to set channel option to value.
*
* Returns:
* TCL_OK if successful or TCL_ERROR if failed.
*
* Side effects:
* Updates channel option to new value.
*
*----------------------------------------------------------------------
*/
static int DigestSetOptionProc(ClientData clientData, Tcl_Interp *interp, const char *optionName,
const char *optionValue) {
DigestState *statePtr = (DigestState *) clientData;
Tcl_Channel parent;
Tcl_DriverSetOptionProc *setOptionProc;
if (statePtr->self == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
/* Delegate options downstream */
parent = Tcl_GetStackedChannel(statePtr->self);
setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(parent));
if (setOptionProc != NULL) {
return (*setOptionProc)(Tcl_GetChannelInstanceData(parent), interp, optionName, optionValue);
} else {
return TCL_ERROR;
}
}
/*
*----------------------------------------------------------------------
*
* DigestGetOptionProc --
*
* Called by the generic IO system to get channel option's value.
*
* Returns:
* TCL_OK if successful or TCL_ERROR if failed.
*
* Side effects:
* Sets result to option's value
*
*----------------------------------------------------------------------
*/
static int DigestGetOptionProc(ClientData clientData, Tcl_Interp *interp, const char *optionName,
Tcl_DString *optionValue) {
DigestState *statePtr = (DigestState *) clientData;
Tcl_Channel parent;
Tcl_DriverGetOptionProc *getOptionProc;
if (statePtr->self == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
/* Delegate options downstream */
parent = Tcl_GetStackedChannel(statePtr->self);
getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(parent));
if (getOptionProc != NULL) {
return (*getOptionProc)(Tcl_GetChannelInstanceData(parent), interp, optionName, optionValue);
} else if (optionName == (char*) NULL) {
/* Request is query for all options, this is ok. */
return TCL_OK;
}
/* Request for a specific option has to fail, we don't have any. */
return Tcl_BadChannelOption(interp, optionName, "");
}
/*
*----------------------------------------------------------------------
*
* DigestTimerHandler --
*
* Called by the notifier via timer to flush out pending input data.
*
* Returns:
* Nothing
*
* Side effects:
* May call Tcl_NotifyChannel
*
*----------------------------------------------------------------------
*/
static void DigestTimerHandler(ClientData clientData) {
DigestState *statePtr = (DigestState *) clientData;
if (statePtr->self == (Tcl_Channel) NULL) {
return;
}
/* Clear timer token */
statePtr->timer = (Tcl_TimerToken) NULL;
/* Fire event if there is pending data, skip otherwise */
if ((statePtr->watchMask & TCL_READABLE) && (Tcl_InputBuffered(statePtr->self) > 0)) {
Tcl_NotifyChannel(statePtr->self, TCL_READABLE);
}
}
/*
*----------------------------------------------------------------------
*
* DigestWatchProc --
*
* Initialize the notifier to watch for events from this channel.
*
* Returns:
* Nothing
*
* Side effects:
* Configure notifier so future events on the channel will be seen by Tcl.
*
*----------------------------------------------------------------------
*/
#define READ_DELAY 5
void DigestWatchProc(ClientData clientData, int mask) {
DigestState *statePtr = (DigestState *) clientData;
Tcl_Channel parent;
Tcl_DriverWatchProc *watchProc;
if (statePtr->self == (Tcl_Channel) NULL) {
return;
}
/* Store OR-ed combination of TCL_READABLE, TCL_WRITABLE and TCL_EXCEPTION */
statePtr->watchMask = mask;
/* Propagate mask info to parent channel */
parent = Tcl_GetStackedChannel(statePtr->self);
watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(parent));
watchProc(Tcl_GetChannelInstanceData(parent), mask);
/* Remove pending timer */
if (statePtr->timer != (Tcl_TimerToken) NULL) {
Tcl_DeleteTimerHandler(statePtr->timer);
statePtr->timer = (Tcl_TimerToken) NULL;
}
/* If there is data pending, set new timer to call Tcl_NotifyChannel */
if ((mask & TCL_READABLE) && (Tcl_InputBuffered(statePtr->self) > 0)) {
statePtr->timer = Tcl_CreateTimerHandler(READ_DELAY, DigestTimerHandler, (ClientData) statePtr);
}
}
/*
*----------------------------------------------------------------------
*
* DigestGetHandleProc --
*
* Called from Tcl_GetChannelHandle to retrieve OS specific file handle
* from inside this channel. Not used for transformations?
*
* Returns:
* If direction is TCL_READABLE return the handle used for input, or if
* TCL_WRITABLE return the handle used for output.
*
* Side effects:
* None
*
*----------------------------------------------------------------------
*/
int DigestGetHandleProc(ClientData clientData, int direction, ClientData *handlePtr) {
DigestState *statePtr = (DigestState *) clientData;
if (statePtr->self == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
return Tcl_GetChannelHandle(Tcl_GetStackedChannel(statePtr->self), direction, handlePtr);
}
/*
*----------------------------------------------------------------------
*
* DigestNotifyProc --
*
* Called by Tcl to inform us of activity on the underlying channel.
*
* Returns:
* Unchanged interestMask which is an OR-ed combination of TCL_READABLE or TCL_WRITABLE
*
* Side effects:
* Cancels any pending timer.
*
*----------------------------------------------------------------------
*/
int DigestNotifyProc(ClientData clientData, int interestMask) {
DigestState *statePtr = (DigestState *) clientData;
/* Skip timer event as redundant */
if (statePtr->timer != (Tcl_TimerToken) NULL) {
Tcl_DeleteTimerHandler(statePtr->timer);
statePtr->timer = (Tcl_TimerToken) NULL;
}
return interestMask;
}
/*
*
* Channel type structure definition for digest transformations.
*
*/
static const Tcl_ChannelType digestChannelType = {
"digest", /* Type name */
TCL_CHANNEL_VERSION_5, /* v5 channel */
DigestCloseProc, /* Close proc */
DigestInputProc, /* Input proc */
DigestOutputProc, /* Output proc */
NULL, /* Seek proc */
DigestSetOptionProc, /* Set option proc */
DigestGetOptionProc, /* Get option proc */
DigestWatchProc, /* Initialize notifier */
DigestGetHandleProc, /* Get OS handles out of channel */
DigestClose2Proc, /* close2proc */
DigestBlockModeProc, /* Set blocking/nonblocking mode*/
NULL, /* Flush proc */
DigestNotifyProc, /* Handling of events bubbling up */
NULL, /* Wide seek proc */
NULL, /* Thread action */
NULL /* Truncate */
};
/*
*----------------------------------------------------------------------
*
* DigestChannel --
*
* Create a stacked channel for a message digest transformation.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Adds transform to channel and sets result to channel name or error message.
*
*----------------------------------------------------------------------
*/
static int
DigestChannel(Tcl_Interp *interp, const char *channel, const EVP_MD *md, int format) {
int mode; /* OR-ed combination of TCL_READABLE and TCL_WRITABLE */
Tcl_Channel chan;
EVP_MD_CTX *ctx;
DigestState *statePtr;
/* Validate args */
if (channel == (const char *) NULL || md == (const EVP_MD *) NULL) {
return TCL_ERROR;
}
chan = Tcl_GetChannel(interp, channel, &mode);
if (chan == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
/* Make sure to operate on the topmost channel */
chan = Tcl_GetTopChannel(chan);
/* Create internal storage structures */
ctx = EVP_MD_CTX_new();
statePtr = (DigestState *) ckalloc((unsigned) sizeof(DigestState));
if (ctx != NULL && statePtr != NULL) {
memset(statePtr, 0, sizeof(DigestState));
statePtr->self = chan; /* This socket channel */
statePtr->timer = (Tcl_TimerToken) NULL; /* Timer to flush data */
statePtr->flags = 0; /* Chan config flags */
statePtr->watchMask = 0; /* Current WatchProc mask */
statePtr->mode = mode; /* Current mode of parent channel */
statePtr->format = format; /* Output format */
statePtr->interp = interp; /* Current interpreter */
statePtr->ctx = ctx; /* SSL Context */
} else {
Tcl_AppendResult(interp, "Initialize digest error: memory allocation failure", (char *) NULL);
EVP_MD_CTX_free(ctx);
DigestFree(statePtr);
return TCL_ERROR;
}
/* Initialize digest */
#if OPENSSL_VERSION_NUMBER < 0x30000000L
if (!EVP_DigestInit_ex(ctx, md, NULL))
#else
if (!EVP_DigestInit_ex2(ctx, md, NULL))
#endif
{
Tcl_AppendResult(interp, "Initialize digest error: ", REASON(), (char *) NULL);
EVP_MD_CTX_free(ctx);
DigestFree(statePtr);
return TCL_ERROR;
}
/* Configure channel */
Tcl_SetChannelOption(interp, chan, "-translation", "binary");
if (Tcl_GetChannelBufferSize(chan) < EVP_MAX_MD_SIZE * 2) {
Tcl_SetChannelBufferSize(chan, EVP_MAX_MD_SIZE * 2);
}
/* Stack channel */
statePtr->self = Tcl_StackChannel(interp, &digestChannelType, (ClientData) statePtr, mode, chan);
if (statePtr->self == (Tcl_Channel) NULL) {
EVP_MD_CTX_free(ctx);
DigestFree(statePtr);
return TCL_ERROR;
}
Tcl_SetResult(interp, (char *) Tcl_GetChannelName(chan), TCL_VOLATILE);
return TCL_OK;
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* DigestHashFunction --
*
* Calculate message digest using hash function.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Sets result to message digest or error message
*
*-------------------------------------------------------------------
*/
int
DigestHashFunction(Tcl_Interp *interp, int objc, Tcl_Obj *const objv[], const EVP_MD *md, int format) {
char *data;
int len;
unsigned int md_len;
unsigned char md_buf[EVP_MAX_MD_SIZE];
if (objc != 2) {
Tcl_WrongNumArgs(interp, 1, objv, "data");
return TCL_ERROR;
}
/* Get data */
data = Tcl_GetByteArrayFromObj(objv[1], &len);
if (data == NULL || len == 0) {
Tcl_SetResult(interp, "No data", NULL);
return TCL_ERROR;
}
/* Calculate hash value, create bin/hex representation, and write to result */
if (EVP_Digest(data, (size_t) len, md_buf, &md_len, md, NULL)) {
if (format == 0) {
Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(md_buf, md_len));
} else {
Tcl_Obj *resultObj = Tcl_NewObj();
unsigned char *ptr = Tcl_SetByteArrayLength(resultObj, md_len*2);
for (unsigned int i = 0; i < md_len; i++) {
*ptr++ = hex[(md_buf[i] >> 4) & 0x0F];
*ptr++ = hex[md_buf[i] & 0x0F];
}
Tcl_SetObjResult(interp, resultObj);
}
} else {
Tcl_AppendResult(interp, "Hash calculation error:", REASON(), (char *) NULL);
return TCL_ERROR;
}
return TCL_OK;
}
/*
*-------------------------------------------------------------------
*
* DigestObjCmd --
*
* Return message digest using user specified hash function.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Sets result to message digest or error message
*
*-------------------------------------------------------------------
*/
static int
DigestObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
int idx, len, format = 1, key_len = 0, data_len = 0;
const char *digestname, *channel = NULL;
Tcl_Obj *dataObj = NULL, *fileObj = NULL;
unsigned char *key = NULL;
const EVP_MD *md;
Tcl_ResetResult(interp);
if (objc < 3 || objc > 5) {
Tcl_WrongNumArgs(interp, 1, objv, "type ?-bin|-hex? [-channel chan | -file filename | ?-data? data]");
return TCL_ERROR;
}
/* Get digest */
digestname = Tcl_GetStringFromObj(objv[1], &len);
if (digestname == NULL || (md = EVP_get_digestbyname(digestname)) == NULL) {
Tcl_AppendResult(interp, "Invalid digest type \"", digestname, "\"", NULL);
return TCL_ERROR;
}
/* Optimal case for blob of data */
if (objc == 3) {
return DigestHashFunction(interp, --objc, ++objv, md, format);
}
/* Get options */
for (idx = 2; idx < objc-1; idx++) {
char *opt = Tcl_GetStringFromObj(objv[idx], NULL);
if (opt[0] != '-')
break;
OPTFLAG("-bin", format, 0);
OPTFLAG("-binary", format, 0);
OPTFLAG("-hex", format, 1);
OPTFLAG("-hexadecimal", format, 1);
OPTOBJ("-data", dataObj);
OPTSTR("-chan", channel);
OPTSTR("-channel", channel);
OPTOBJ("-file", fileObj);
OPTOBJ("-filename", fileObj);
OPTBAD("option", "-bin, -data, -file, -filename, -key, or -hex");
return TCL_ERROR;
}
/* If no option for last arg, then its the data */
if (idx < objc) {
dataObj = objv[idx];
}
/* Calc digest on file, stacked channel, or data blob */
if (fileObj != NULL) {
return DigestFile(interp, fileObj, md, format);
} else if (channel != NULL) {
return DigestChannel(interp, channel, md, format);
} else if (dataObj != NULL) {
Tcl_Obj *objs[2];
objs[0] = NULL;
objs[1] = dataObj;
return DigestHashFunction(interp, 2, objs, md, format);
}
Tcl_AppendResult(interp, "No data specified.", NULL);
return TCL_ERROR;
}
/*
*-------------------------------------------------------------------
*
* Message Digest Convenience Commands --
*
* Convenience commands for message digests.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Sets result to message digest or error message
*
*-------------------------------------------------------------------
*/
int DigestMD4Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
return DigestHashFunction(interp, objc, objv, EVP_md4(), 1);
}
int DigestMD5Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
return DigestHashFunction(interp, objc, objv, EVP_md5(), 1);
}
int DigestSHA1Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
return DigestHashFunction(interp, objc, objv, EVP_sha1(), 1);
}
int DigestSHA256Cmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
return DigestHashFunction(interp, objc, objv, EVP_sha256(), 1);
}
/*
*-------------------------------------------------------------------
*
* Tls_DigestCommands --
*
* Create digest commands
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Creates commands
*
*-------------------------------------------------------------------
*/
int Tls_DigestCommands(Tcl_Interp *interp) {
Tcl_CreateObjCommand(interp, "tls::digest", DigestObjCmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
Tcl_CreateObjCommand(interp, "tls::md4", DigestMD4Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
Tcl_CreateObjCommand(interp, "tls::md5", DigestMD5Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
Tcl_CreateObjCommand(interp, "tls::sha1", DigestSHA1Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
Tcl_CreateObjCommand(interp, "tls::sha256", DigestSHA256Cmd, (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
return TCL_OK;
}