/*
* Encryption Functions Module
*
* This module provides commands that can be used to encrypt or decrypt data.
*
* 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>
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
#include <openssl/params.h>
#endif
/* Macros */
#define BUFFER_SIZE 32768
#define CHAN_EOF 0x10
#define READ_DELAY 5
/* Encryption functions */
#define TYPE_MD 0x010
#define TYPE_HMAC 0x020
#define TYPE_CMAC 0x040
#define TYPE_MAC 0x080
#define TYPE_ENCRYPT 0x100
#define TYPE_DECRYPT 0x200
#define TYPE_SIGN 0x400
#define TYPE_VERIFY 0x800
/*******************************************************************/
/*
* This structure defines the per-instance state of a encrypt operation.
*/
typedef struct EncryptState {
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 type; /* Operation type */
Tcl_Interp *interp; /* Current interpreter */
EVP_CIPHER_CTX *ctx; /* Cipher Context */
Tcl_Command token; /* Command token */
} EncryptState;
/*
*-------------------------------------------------------------------
*
* EncryptStateNew --
*
* This function creates a per-instance state data structure
*
* Returns:
* State structure pointer
*
* Side effects:
* Creates structure
*
*-------------------------------------------------------------------
*/
EncryptState *EncryptStateNew(Tcl_Interp *interp, int type) {
EncryptState *statePtr = (EncryptState *) ckalloc((unsigned) sizeof(EncryptState));
if (statePtr != NULL) {
memset(statePtr, 0, sizeof(EncryptState));
statePtr->self = NULL; /* This socket channel */
statePtr->timer = NULL; /* Timer to flush data */
statePtr->flags = 0; /* Chan config flags */
statePtr->watchMask = 0; /* Current WatchProc mask */
statePtr->mode = 0; /* Current mode of parent channel */
statePtr->type = type; /* Operation type */
statePtr->interp = interp; /* Current interpreter */
statePtr->ctx = NULL; /* Cipher Context */
statePtr->token = NULL; /* Command token */
}
return statePtr;
}
/*
*-------------------------------------------------------------------
*
* EncryptStateFree --
*
* This function deletes a state data structure
*
* Returns:
* Nothing
*
* Side effects:
* Removes structure
*
*-------------------------------------------------------------------
*/
void EncryptStateFree(EncryptState *statePtr) {
if (statePtr == (EncryptState *) NULL) {
return;
}
/* Remove pending timer */
if (statePtr->timer != (Tcl_TimerToken) NULL) {
Tcl_DeleteTimerHandler(statePtr->timer);
}
/* Free context structures */
if (statePtr->ctx != (EVP_CIPHER_CTX *) NULL) {
EVP_CIPHER_CTX_free(statePtr->ctx);
}
ckfree(statePtr);
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* EncryptInitialize --
*
* Initialize an encryption function
*
* Returns:
* TCL_OK if successful or TCL_ERROR for failure with result set
* to error message.
*
* Side effects:
* No result or error message
*
*-------------------------------------------------------------------
*/
int EncryptInitialize(Tcl_Interp *interp, int type, EVP_CIPHER_CTX **ctx,
Tcl_Obj *cipherObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
const EVP_CIPHER *cipher;
char *keyString = NULL, *ivString = NULL;
int cipher_len = 0, key_len = 0, iv_len = 0, res, max;
unsigned char key[EVP_MAX_KEY_LENGTH], iv[EVP_MAX_IV_LENGTH];
dprintf("Called");
/* Init buffers */
memset(key, 0, EVP_MAX_KEY_LENGTH);
memset(iv, 0, EVP_MAX_IV_LENGTH);
/* Get cipher */
cipher = Util_GetCipher(interp, cipherObj, 1);
if (cipher == NULL) {
return TCL_ERROR;
}
/* Get key - Only support internally defined cipher lengths.
Custom ciphers can be up to size_t bytes. */
max = EVP_CIPHER_key_length(cipher);
keyString = (const void *) Util_GetKey(interp, keyObj, &key_len, "key", max, FALSE);
if (keyString != NULL) {
memcpy((void *) key, (const void *) keyString, (size_t) key_len);
} else if (keyObj != NULL) {
return TCL_ERROR;
}
/* Get IV */
max = EVP_CIPHER_iv_length(cipher);
ivString = (const void *) Util_GetIV(interp, ivObj, &iv_len, max, FALSE);
if (ivString != NULL) {
memcpy((void *) iv, (const void *) ivString, (size_t) iv_len);
} else if (ivObj != NULL) {
return TCL_ERROR;
}
/* Create context */
if((*ctx = EVP_CIPHER_CTX_new()) == NULL) {
Tcl_AppendResult(interp, "Memory allocation error", (char *) NULL);
return TCL_ERROR;
}
/* Initialize the operation. Need appropriate key and iv size. */
if (type == TYPE_ENCRYPT) {
res = EVP_EncryptInit_ex(*ctx, cipher, NULL, key, iv);
} else {
res = EVP_DecryptInit_ex(*ctx, cipher, NULL, key, iv);
}
if(!res) {
Tcl_AppendResult(interp, "Initialize failed: ", REASON(), NULL);
return TCL_ERROR;
}
/* Erase buffers */
memset(key, 0, EVP_MAX_KEY_LENGTH);
memset(iv, 0, EVP_MAX_IV_LENGTH);
return TCL_OK;
}
/*
*-------------------------------------------------------------------
*
* EncryptUpdate --
*
* Update an encryption function with data
*
* Returns:
* 1 if successful or 0 for failure
*
* Side effects:
* Adds encrypted data to buffer or sets result to error message
*
*-------------------------------------------------------------------
*/
int EncryptUpdate(Tcl_Interp *interp, int type, EVP_CIPHER_CTX *ctx, unsigned char *out_buf,
int *out_len, unsigned char *data, int data_len) {
int res;
dprintf("Called");
/* Encrypt/decrypt data */
if (type == TYPE_ENCRYPT) {
res = EVP_EncryptUpdate(ctx, out_buf, out_len, data, data_len);
} else {
res = EVP_DecryptUpdate(ctx, out_buf, out_len, data, data_len);
}
if (res) {
return TCL_OK;
} else {
Tcl_AppendResult(interp, "Update failed: ", REASON(), NULL);
return TCL_ERROR;
}
}
/*
*-------------------------------------------------------------------
*
* EncryptFinalize --
*
* Finalize an encryption function
*
* Returns:
* TCL_OK if successful or TCL_ERROR for failure with result set
* to error message.
*
* Side effects:
* Adds encrypted data to buffer or sets result to error message
*
*-------------------------------------------------------------------
*/
int EncryptFinalize(Tcl_Interp *interp, int type, EVP_CIPHER_CTX *ctx, unsigned char *out_buf,
int *out_len) {
int res;
dprintf("Called");
/* Finalize data */
if (type == TYPE_ENCRYPT) {
res = EVP_EncryptFinal_ex(ctx, out_buf, out_len);
} else {
res = EVP_DecryptFinal_ex(ctx, out_buf, out_len);
}
if (res) {
return TCL_OK;
} else {
Tcl_AppendResult(interp, "Finalize failed: ", REASON(), NULL);
return TCL_ERROR;
}
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* EncryptBlockModeProc --
*
* This function 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 EncryptBlockModeProc(ClientData clientData, int mode) {
EncryptState *statePtr = (EncryptState *) clientData;
if (mode == TCL_MODE_NONBLOCKING) {
statePtr->flags |= TLS_TCL_ASYNC;
} else {
statePtr->flags &= ~(TLS_TCL_ASYNC);
}
return 0;
}
/*
*-------------------------------------------------------------------
*
* EncryptCloseProc --
*
* This function is invoked by the generic IO level to perform
* channel-type specific cleanup when the channel is closed. All
* queued output is flushed prior to calling this function.
*
* Returns:
* 0 if successful or POSIX error code if failed.
*
* Side effects:
* Deletes stored state data.
*
*-------------------------------------------------------------------
*/
int EncryptCloseProc(ClientData clientData, Tcl_Interp *interp) {
EncryptState *statePtr = (EncryptState *) clientData;
/* Cancel active timer, if any */
if (statePtr->timer != (Tcl_TimerToken) NULL) {
Tcl_DeleteTimerHandler(statePtr->timer);
statePtr->timer = (Tcl_TimerToken) NULL;
}
/* Output remaining data, if any */
if (!(statePtr->flags & CHAN_EOF)) {
Tcl_Channel parent = Tcl_GetStackedChannel(statePtr->self);
int out_len;
unsigned char out_buf[EVP_MAX_BLOCK_LENGTH];
/* Finalize function */
if (EncryptFinalize(interp, statePtr->type, statePtr->ctx, out_buf, &out_len) == TCL_OK) {
if (out_len > 0) {
int len = Tcl_WriteRaw(parent, (const char *) out_buf, out_len);
if (len < 0) {
return Tcl_GetErrno();
}
}
} else {
/* Error */
}
statePtr->flags |= CHAN_EOF;
}
/* Clean-up */
EncryptStateFree(statePtr);
return 0;
}
/*
* Same as EncryptCloseProc but with individual read and write close control
*/
static int EncryptClose2Proc(ClientData instanceData, Tcl_Interp *interp, int flags) {
if ((flags & (TCL_CLOSE_READ | TCL_CLOSE_WRITE)) == 0) {
return EncryptCloseProc(instanceData, interp);
}
return EINVAL;
}
/*
*----------------------------------------------------------------------
*
* EncryptInputProc --
*
* Called by the generic IO system to read data from transform and
* place in buf. Transform gets data from the underlying channel.
*
* Returns:
* Total bytes read or -1 for an error along with a POSIX error
* code in errorCodePtr. Use EAGAIN for nonblocking and no data.
*
* Side effects:
* Read data from transform and write to buf
*
*----------------------------------------------------------------------
*/
int EncryptInputProc(ClientData clientData, char *buf, int toRead, int *errorCodePtr) {
EncryptState *statePtr = (EncryptState *) clientData;
Tcl_Channel parent;
int read, out_len;
*errorCodePtr = 0;
char *in_buf;
/* Abort if nothing to process */
if (toRead <= 0 || statePtr->self == (Tcl_Channel) NULL) {
return 0;
}
/* Get bytes from underlying channel */
in_buf = Tcl_Alloc(toRead);
parent = Tcl_GetStackedChannel(statePtr->self);
read = Tcl_ReadRaw(parent, in_buf, toRead);
/* Update function */
if (read > 0) {
/* Have data - Update function */
if (EncryptUpdate(statePtr->interp, statePtr->type, statePtr->ctx, buf, &out_len, in_buf, read) == TCL_OK) {
/* If have data, put in buf, otherwise tell TCL to try again */
if (out_len > 0) {
read = out_len;
} else {
*errorCodePtr = EAGAIN;
read = -1;
}
} else {
Tcl_SetChannelError(statePtr->self, Tcl_ObjPrintf("Update failed: %s", REASON()));
*errorCodePtr = EINVAL;
read = 0;
}
} else if (read < 0) {
/* Error */
*errorCodePtr = Tcl_GetErrno();
} else if (!(statePtr->flags & CHAN_EOF)) {
/* EOF - Finalize function and put any remaining data in buf */
if (EncryptFinalize(statePtr->interp, statePtr->type, statePtr->ctx, buf, &out_len) == TCL_OK) {
read = out_len;
} else {
Tcl_SetChannelError(statePtr->self, Tcl_ObjPrintf("Finalize failed: %s", REASON()));
*errorCodePtr = EINVAL;
read = 0;
}
statePtr->flags |= CHAN_EOF;
}
Tcl_Free(in_buf);
return read;
}
/*
*----------------------------------------------------------------------
*
* EncryptOutputProc --
*
* Called by the generic IO system to write data in buf to transform.
* The transform writes the result to the underlying channel.
*
* Returns:
* Total bytes written or -1 for an error along with a POSIX error
* code in errorCodePtr. Use EAGAIN for nonblocking and can't write data.
*
* Side effects:
* Get data from buf and update encryption
*
*----------------------------------------------------------------------
*/
int EncryptOutputProc(ClientData clientData, const char *buf, int toWrite, int *errorCodePtr) {
EncryptState *statePtr = (EncryptState *) clientData;
int write = 0, out_len;
*errorCodePtr = 0;
char *out_buf;
/* Abort if nothing to process */
if (toWrite <= 0 || statePtr->self == (Tcl_Channel) NULL) {
return 0;
}
out_buf = Tcl_Alloc(toWrite+EVP_MAX_BLOCK_LENGTH);
/* Update function */
if (EncryptUpdate(statePtr->interp, statePtr->type, statePtr->ctx, out_buf, &out_len, buf, toWrite) == TCL_OK) {
/* If have data, output it, otherwise tell TCL to try again */
if (out_len > 0) {
Tcl_Channel parent = Tcl_GetStackedChannel(statePtr->self);
write = Tcl_WriteRaw(parent, (const char *) out_buf, out_len);
write = toWrite;
} else {
*errorCodePtr = EAGAIN;
write = -1;
}
} else {
Tcl_SetChannelError(statePtr->self, Tcl_ObjPrintf("Update failed: %s", REASON()));
*errorCodePtr = EINVAL;
write = 0;
}
Tcl_Free(out_buf);
return write;
}
/*
*----------------------------------------------------------------------
*
* EncryptSetOptionProc --
*
* Called by the generic IO system to set channel option name to value.
*
* Returns:
* TCL_OK if successful or TCL_ERROR if failed along with an error
* message in interp and Tcl_SetErrno.
*
* Side effects:
* Updates channel option to new value.
*
*----------------------------------------------------------------------
*/
static int EncryptSetOptionProc(ClientData clientData, Tcl_Interp *interp, const char *optionName,
const char *optionValue) {
EncryptState *statePtr = (EncryptState *) clientData;
Tcl_Channel parent;
Tcl_DriverSetOptionProc *setOptionProc;
/* Abort if no channel */
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 {
Tcl_SetErrno(EINVAL);
return Tcl_BadChannelOption(interp, optionName, NULL);
}
}
/*
*----------------------------------------------------------------------
*
* EncryptGetOptionProc --
*
* Called by the generic IO system to get channel option name's value.
*
* Returns:
* TCL_OK if successful or TCL_ERROR if failed along with an error
* message in interp and Tcl_SetErrno.
*
* Side effects:
* Sets result to option's value
*
*----------------------------------------------------------------------
*/
static int EncryptGetOptionProc(ClientData clientData, Tcl_Interp *interp, const char *optionName,
Tcl_DString *optionValue) {
EncryptState *statePtr = (EncryptState *) clientData;
Tcl_Channel parent;
Tcl_DriverGetOptionProc *getOptionProc;
/* Abort if no channel */
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;
} else {
Tcl_SetErrno(EINVAL);
return Tcl_BadChannelOption(interp, optionName, NULL);
}
}
/*
*----------------------------------------------------------------------
*
* EncryptTimerHandler --
*
* Called by the notifier via timer to flush out pending input data.
*
* Returns:
* Nothing
*
* Side effects:
* May call Tcl_NotifyChannel
*
*----------------------------------------------------------------------
*/
static void EncryptTimerHandler(ClientData clientData) {
EncryptState *statePtr = (EncryptState *) clientData;
/* Abort if no channel */
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);
}
}
/*
*----------------------------------------------------------------------
*
* EncryptWatchProc --
*
* Initialize the notifier to watch for events from this channel.
*
* Returns:
* Nothing (can't return error messages)
*
* Side effects:
* Configure notifier so future events on the channel will be seen by Tcl.
*
*----------------------------------------------------------------------
*/
void EncryptWatchProc(ClientData clientData, int mask) {
EncryptState *statePtr = (EncryptState *) clientData;
Tcl_Channel parent;
Tcl_DriverWatchProc *watchProc;
/* Abort if no channel */
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, EncryptTimerHandler, (ClientData) statePtr);
}
}
/*
*----------------------------------------------------------------------
*
* EncryptGetHandleProc --
*
* Called from Tcl_GetChannelHandle to retrieve OS specific file handle
* from inside this channel. Not used for transformations?
*
* Returns:
* TCL_OK for success or TCL_ERROR for error or if not supported. If
* direction is TCL_READABLE, sets handlePtr to the handle used for
* input, or if TCL_WRITABLE sets to the handle used for output.
*
* Side effects:
* None
*
*----------------------------------------------------------------------
*/
int EncryptGetHandleProc(ClientData clientData, int direction, ClientData *handlePtr) {
EncryptState *statePtr = (EncryptState *) clientData;
Tcl_Channel parent;
/* Abort if no channel */
if (statePtr->self == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
parent = Tcl_GetStackedChannel(statePtr->self);
return Tcl_GetChannelHandle(parent, direction, handlePtr);
}
/*
*----------------------------------------------------------------------
*
* EncryptNotifyProc --
*
* 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 EncryptNotifyProc(ClientData clientData, int interestMask) {
EncryptState *statePtr = (EncryptState *) 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 encryption transformations.
*
*/
static const Tcl_ChannelType encryptChannelType = {
"encryption", /* Type name */
TCL_CHANNEL_VERSION_5, /* v5 channel */
EncryptCloseProc, /* Close proc */
EncryptInputProc, /* Input proc */
EncryptOutputProc, /* Output proc */
NULL, /* Seek proc */
EncryptSetOptionProc, /* Set option proc */
EncryptGetOptionProc, /* Get option proc */
EncryptWatchProc, /* Initialize notifier */
EncryptGetHandleProc, /* Get OS handles out of channel */
EncryptClose2Proc, /* close2proc */
EncryptBlockModeProc, /* Set blocking/nonblocking mode*/
NULL, /* Flush proc */
EncryptNotifyProc, /* Handling of events bubbling up */
NULL, /* Wide seek proc */
NULL, /* Thread action */
NULL /* Truncate */
};
/*
*----------------------------------------------------------------------
*
* EncryptChannelHandler --
*
* Create a stacked channel for a message encryption transformation.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Adds transform to channel and sets result to channel id or error message.
*
*----------------------------------------------------------------------
*/
static int EncryptChannelHandler(Tcl_Interp *interp, int type, const char *channel,
Tcl_Obj *cipherObj, Tcl_Obj *digestObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
int mode; /* OR-ed combination of TCL_READABLE and TCL_WRITABLE */
Tcl_Channel chan;
EncryptState *statePtr;
(void *) digestObj;
dprintf("Called");
/* Validate args */
if (channel == (const char *) NULL) {
Tcl_AppendResult(interp, "No channel", (char *) NULL);
return TCL_ERROR;
}
/* Get channel Id */
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);
/* Configure channel */
Tcl_SetChannelOption(interp, chan, "-translation", "binary");
/* Create state data structure */
if ((statePtr = EncryptStateNew(interp, type)) == NULL) {
Tcl_AppendResult(interp, "Memory allocation error", (char *) NULL);
return TCL_ERROR;
}
statePtr->self = chan;
statePtr->mode = mode;
/* Initialize function */
if (EncryptInitialize(interp, type, &statePtr->ctx, cipherObj, keyObj, ivObj) != TCL_OK) {
EncryptStateFree(statePtr);
return TCL_ERROR;
}
/* Stack channel */
statePtr->self = Tcl_StackChannel(interp, &encryptChannelType, (ClientData) statePtr, mode, chan);
if (statePtr->self == (Tcl_Channel) NULL) {
EncryptStateFree(statePtr);
return TCL_ERROR;
}
/* Set result to channel Id */
Tcl_SetResult(interp, (char *) Tcl_GetChannelName(chan), TCL_VOLATILE);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Unstack Channel --
*
* This function removes the stacked channel from the top of the
* channel stack if it is a encryption channel.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Removes transform from channel or sets result to error message.
*
*----------------------------------------------------------------------
*/
static int EncryptUnstackObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
Tcl_Channel chan;
int mode; /* OR-ed combination of TCL_READABLE and TCL_WRITABLE */
(void) clientData;
dprintf("Called");
/* Validate arg count */
if (objc != 2) {
Tcl_WrongNumArgs(interp, 1, objv, "channelId");
return TCL_ERROR;
}
/* Get channel */
chan = Tcl_GetChannel(interp, Tcl_GetStringFromObj(objv[1], NULL), &mode);
if (chan == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
/* Make sure to operate on the topmost channel */
chan = Tcl_GetTopChannel(chan);
/* Check if encryption channel */
if (Tcl_GetChannelType(chan) != &encryptChannelType) {
Tcl_AppendResult(interp, "bad channel \"", Tcl_GetChannelName(chan),
"\": not a encryption channel", NULL);
Tcl_SetErrorCode(interp, "TLS", "UNSTACK", "CHANNEL", "INVALID", (char *) NULL);
return TCL_ERROR;
}
/* Pop transform from channel */
return Tcl_UnstackChannel(interp, chan);
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* EncryptInstanceObjCmd --
*
* Handler for encrypt/decrypt command instances. Used to update
* and finalize data for encrypt/decrypt function.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Adds data to encrypt/decrypt function
*
*-------------------------------------------------------------------
*/
int EncryptInstanceObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
EncryptState *statePtr = (EncryptState *) clientData;
int fn, data_len = 0, out_len;
char *data = NULL;
Tcl_Obj *resultObj;
unsigned char *out_buf;
static const char *instance_fns [] = { "finalize", "update", NULL };
dprintf("Called");
/* Validate arg count */
if (objc < 2 || objc > 3) {
Tcl_WrongNumArgs(interp, 1, objv, "function ?data?");
return TCL_ERROR;
}
/* Get function */
if (Tcl_GetIndexFromObj(interp, objv[1], instance_fns, "function", 0, &fn) != TCL_OK) {
return TCL_ERROR;
}
/* Allocate storage for result. Size should be data size + block size. */
resultObj = Tcl_NewObj();
out_buf = Tcl_SetByteArrayLength(resultObj, data_len+EVP_MAX_BLOCK_LENGTH);
if (resultObj == NULL || out_buf == NULL) {
Tcl_AppendResult(interp, "Memory allocation error", (char *) NULL);
Tcl_DecrRefCount(resultObj);
return TCL_ERROR;
}
/* Do function */
if (fn) {
/* Get data or return error if none */
if (objc == 3) {
data = Tcl_GetByteArrayFromObj(objv[2], &data_len);
} else {
Tcl_WrongNumArgs(interp, 1, objv, "update data");
Tcl_DecrRefCount(resultObj);
return TCL_ERROR;
}
/* Update function */
if (EncryptUpdate(interp, statePtr->type, statePtr->ctx, out_buf, &out_len, data, data_len) == TCL_OK) {
out_buf = Tcl_SetByteArrayLength(resultObj, out_len);
Tcl_SetObjResult(interp, resultObj);
} else {
Tcl_DecrRefCount(resultObj);
return TCL_ERROR;
}
} else {
/* Finalize function */
if (EncryptFinalize(interp, statePtr->type, statePtr->ctx, out_buf, &out_len) == TCL_OK) {
out_buf = Tcl_SetByteArrayLength(resultObj, out_len);
Tcl_SetObjResult(interp, resultObj);
} else {
Tcl_DecrRefCount(resultObj);
return TCL_ERROR;
}
/* Clean-up */
Tcl_DeleteCommandFromToken(interp, statePtr->token);
}
return TCL_OK;
}
/*
*-------------------------------------------------------------------
*
* EncryptCommandDeleteHandler --
*
* Callback to clean-up when encrypt/decrypt command is deleted.
*
* Returns:
* Nothing
*
* Side effects:
* Destroys state info structure
*
*-------------------------------------------------------------------
*/
void EncryptCommandDeleteHandler(ClientData clientData) {
EncryptState *statePtr = (EncryptState *) clientData;
/* Clean-up */
EncryptStateFree(statePtr);
}
/*
*-------------------------------------------------------------------
*
* EncryptCommandHandler --
*
* Create command to add data to encrypt/decrypt function.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Creates command or error message
*
*-------------------------------------------------------------------
*/
int EncryptCommandHandler(Tcl_Interp *interp, int type, Tcl_Obj *cmdObj,
Tcl_Obj *cipherObj, Tcl_Obj *digestObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
EncryptState *statePtr;
char *cmdName = Tcl_GetStringFromObj(cmdObj, NULL);
(void *) digestObj;
dprintf("Called");
if ((statePtr = EncryptStateNew(interp, type)) == NULL) {
Tcl_AppendResult(interp, "Memory allocation error", (char *) NULL);
return TCL_ERROR;
}
/* Initialize function */
if (EncryptInitialize(interp, type, &statePtr->ctx, cipherObj, keyObj, ivObj) != TCL_OK) {
EncryptStateFree(statePtr);
return TCL_ERROR;
}
/* Create instance command */
statePtr->token = Tcl_CreateObjCommand(interp, cmdName, EncryptInstanceObjCmd,
(ClientData) statePtr, EncryptCommandDeleteHandler);
/* Return command name */
Tcl_SetObjResult(interp, cmdObj);
return TCL_OK;
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* EncryptDataHandler --
*
* Perform encryption function on a block of data and return result.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Sets result or error message
*
*-------------------------------------------------------------------
*/
int EncryptDataHandler(Tcl_Interp *interp, int type, Tcl_Obj *dataObj, Tcl_Obj *cipherObj,
Tcl_Obj *digestObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
EVP_CIPHER_CTX *ctx = NULL;
int data_len = 0, out_len = 0, len = 0, res = TCL_OK;
unsigned char *data, *out_buf;
Tcl_Obj *resultObj;
(void *) digestObj;
dprintf("Called");
/* Get data */
if (dataObj != NULL) {
data = Tcl_GetByteArrayFromObj(dataObj, &data_len);
} else {
Tcl_AppendResult(interp, "No data", NULL);
return TCL_ERROR;
}
/* Allocate storage for result. Size should be data size + block size. */
resultObj = Tcl_NewObj();
out_buf = Tcl_SetByteArrayLength(resultObj, data_len+EVP_MAX_BLOCK_LENGTH);
if (resultObj == NULL || out_buf == NULL) {
Tcl_AppendResult(interp, "Memory allocation error", (char *) NULL);
return TCL_ERROR;
}
/* Perform operation */
if (EncryptInitialize(interp, type, &ctx, cipherObj, keyObj, ivObj) != TCL_OK ||
EncryptUpdate(interp, type, ctx, out_buf, &out_len, data, data_len) != TCL_OK ||
EncryptFinalize(interp, type, ctx, out_buf+out_len, &len) != TCL_OK) {
res = TCL_ERROR;
goto done;
}
out_len += len;
done:
/* Set output result */
if (res == TCL_OK) {
out_buf = Tcl_SetByteArrayLength(resultObj, out_len);
Tcl_SetObjResult(interp, resultObj);
} else {
Tcl_DecrRefCount(resultObj);
/* Result is error message */
}
/* Clean up */
if (ctx != NULL) {
EVP_CIPHER_CTX_free(ctx);
}
return res;
}
/*******************************************************************/
/*
*-------------------------------------------------------------------
*
* EncryptFileHandler --
*
* Perform encryption function on a block of data and return result.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Encrypts or decrypts inFile data to outFile and sets result to
* size of outFile, or an error message.
*
*-------------------------------------------------------------------
*/
int EncryptFileHandler(Tcl_Interp *interp, int type, Tcl_Obj *inFileObj, Tcl_Obj *outFileObj,
Tcl_Obj *cipherObj, Tcl_Obj *digestObj, Tcl_Obj *keyObj, Tcl_Obj *ivObj) {
EVP_CIPHER_CTX *ctx = NULL;
int total = 0, res, out_len = 0, len;
Tcl_Channel in = NULL, out = NULL;
unsigned char in_buf[BUFFER_SIZE];
unsigned char out_buf[BUFFER_SIZE+EVP_MAX_BLOCK_LENGTH];
(void *) digestObj;
dprintf("Called");
/* Open input file */
if ((in = Tcl_FSOpenFileChannel(interp, inFileObj, "rb", 0444)) == (Tcl_Channel) NULL) {
return TCL_ERROR;
}
/* Open output file */
if ((out = Tcl_FSOpenFileChannel(interp, outFileObj, "wb", 0644)) == (Tcl_Channel) NULL) {
Tcl_Close(interp, in);
return TCL_ERROR;
}
/* Initialize operation */
if ((res = EncryptInitialize(interp, type, &ctx, cipherObj, keyObj, ivObj)) != TCL_OK) {
goto done;
}
/* Read file data from inFile, encrypt/decrypt it, then output to outFile */
while (!Tcl_Eof(in)) {
int read = Tcl_ReadRaw(in, (char *) in_buf, BUFFER_SIZE);
if (read > 0) {
if ((res = EncryptUpdate(interp, type, ctx, out_buf, &out_len, in_buf, read)) == TCL_OK) {
if (out_len > 0) {
len = Tcl_WriteRaw(out, (const char *) out_buf, out_len);
if (len >= 0) {
total += len;
} else {
Tcl_AppendResult(interp, "Write error: ", Tcl_ErrnoMsg(Tcl_GetErrno()), (char *) NULL);
res = TCL_ERROR;
goto done;
}
}
} else {
goto done;
}
} else if (read < 0) {
Tcl_AppendResult(interp, "Read error: ", Tcl_ErrnoMsg(Tcl_GetErrno()), (char *) NULL);
res = TCL_ERROR;
goto done;
}
}
/* Finalize data and write any remaining data in block */
if ((res = EncryptFinalize(interp, type, ctx, out_buf, &out_len)) == TCL_OK) {
if (out_len > 0) {
len = Tcl_WriteRaw(out, (const char *) out_buf, out_len);
if (len >= 0) {
total += len;
} else {
Tcl_AppendResult(interp, "Write error: ", Tcl_ErrnoMsg(Tcl_GetErrno()), (char *) NULL);
res = TCL_ERROR;
goto done;
}
}
Tcl_SetObjResult(interp, Tcl_NewIntObj(total));
} else {
goto done;
}
done:
/* Clean up */
if (in != NULL) {
Tcl_Close(interp, in);
}
if (out != NULL) {
Tcl_Close(interp, out);
}
if (ctx != NULL) {
EVP_CIPHER_CTX_free(ctx);
}
return res;
}
/*******************************************************************/
static const char *command_opts [] = {
"-chan", "-channel", "-cipher", "-command", "-data", "-digest", "-infile", "-filename",
"-outfile", "-hash", "-iv", "-key", "-mac", NULL};
enum _command_opts {
_opt_chan, _opt_channel, _opt_cipher, _opt_command, _opt_data, _opt_digest, _opt_infile,
_opt_filename, _opt_outfile, _opt_hash, _opt_iv, _opt_key, _opt_mac
};
/*
*-------------------------------------------------------------------
*
* EncryptMain --
*
* Perform encryption function and return result.
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Sets result or error message
*
*-------------------------------------------------------------------
*/
static int EncryptMain(int type, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
Tcl_Obj *cipherObj = NULL, *cmdObj = NULL, *dataObj = NULL, *digestObj = NULL;
Tcl_Obj *inFileObj = NULL, *outFileObj = NULL, *keyObj = NULL, *ivObj = NULL, *macObj = NULL;
const char *channel = NULL, *opt;
int res, start = 1, fn;
dprintf("Called");
/* Clear interp result */
Tcl_ResetResult(interp);
/* Validate arg count */
if (objc < 3 || objc > 12) {
Tcl_WrongNumArgs(interp, 1, objv, "?-cipher? name ?-digest name? -key key ?-iv string? ?-mac name? [-channel chan | -command cmdName | -infile filename -outfile filename | ?-data? data]");
return TCL_ERROR;
}
/* Special case of first arg is cipher */
opt = Tcl_GetStringFromObj(objv[start], NULL);
if (opt[0] != '-') {
switch(type) {
case TYPE_ENCRYPT:
case TYPE_DECRYPT:
cipherObj = objv[start++];
break;
}
}
/* Get options */
for (int idx = start; idx < objc; idx++) {
/* Special case for when last arg is data */
if (idx == objc - 1) {
opt = Tcl_GetStringFromObj(objv[idx], NULL);
if (opt[0] != '-' && dataObj == NULL) {
dataObj = objv[idx];
break;
}
}
/* Get option */
if (Tcl_GetIndexFromObj(interp, objv[idx], command_opts, "option", 0, &fn) != TCL_OK) {
return TCL_ERROR;
}
/* Validate arg has a value */
if (++idx >= objc) {
Tcl_AppendResult(interp, "No value for option \"", command_opts[fn], "\"", (char *) NULL);
return TCL_ERROR;
}
switch(fn) {
case _opt_chan:
case _opt_channel:
GET_OPT_STRING(objv[idx], channel, NULL);
break;
case _opt_cipher:
cipherObj = objv[idx];
break;
case _opt_command:
cmdObj = objv[idx];
break;
case _opt_data:
dataObj = objv[idx];
break;
case _opt_digest:
case _opt_hash:
digestObj = objv[idx];
break;
case _opt_infile:
case _opt_filename:
inFileObj = objv[idx];
break;
case _opt_outfile:
outFileObj = objv[idx];
break;
case _opt_iv:
ivObj = objv[idx];
break;
case _opt_key:
keyObj = objv[idx];
break;
case _opt_mac:
macObj = objv[idx];
break;
}
}
/* Check for required options */
if (cipherObj == NULL) {
Tcl_AppendResult(interp, "No cipher", NULL);
} else if (keyObj == NULL) {
Tcl_AppendResult(interp, "No key", NULL);
return TCL_ERROR;
}
/* Perform encryption function on file, stacked channel, using instance command, or data blob */
if (inFileObj != NULL && outFileObj != NULL) {
res = EncryptFileHandler(interp, type, inFileObj, outFileObj, cipherObj, digestObj, keyObj, ivObj);
} else if (channel != NULL) {
res = EncryptChannelHandler(interp, type, channel, cipherObj, digestObj, keyObj, ivObj);
} else if (cmdObj != NULL) {
res = EncryptCommandHandler(interp, type, cmdObj, cipherObj, digestObj, keyObj, ivObj);
} else if (dataObj != NULL) {
res = EncryptDataHandler(interp, type, dataObj, cipherObj, digestObj, keyObj, ivObj);
} else {
Tcl_AppendResult(interp, "No operation specified: Use -channel, -command, -data, or -infile option", NULL);
res = TCL_ERROR;
}
return res;
}
/*
*-------------------------------------------------------------------
*
* Encryption Commands --
*
* Perform encryption function and return results
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Command dependent
*
*-------------------------------------------------------------------
*/
static int EncryptObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
(void) clientData;
return EncryptMain(TYPE_ENCRYPT, interp, objc, objv);
}
static int DecryptObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]) {
(void) clientData;
return EncryptMain(TYPE_DECRYPT, interp, objc, objv);
}
/*
*-------------------------------------------------------------------
*
* Encrypt_Initialize --
*
* Create namespace, commands, and register package version
*
* Returns:
* TCL_OK or TCL_ERROR
*
* Side effects:
* Creates commands
*
*-------------------------------------------------------------------
*/
int Tls_EncryptCommands(Tcl_Interp *interp) {
Tcl_CreateObjCommand(interp, "tls::encrypt", EncryptObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
Tcl_CreateObjCommand(interp, "tls::decrypt", DecryptObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
Tcl_CreateObjCommand(interp, "tls::unstack2", EncryptUnstackObjCmd, (ClientData) NULL, (Tcl_CmdDeleteProc *) NULL);
return TCL_OK;
}
Documentation