/*
 * Copyright (C) 1997-2000 Matt Newman <[email protected]>
 *
 * TLS (aka SSL) Channel - can be layered on any bi-directional
 * Tcl_Channel (Note: Requires Trf Core Patch)
 *
 * This was built from scratch based upon observation of OpenSSL 0.9.2B
 *
 * Addition credit is due for Andreas Kupries ([email protected]), for
 * providing the Tcl_ReplaceChannel mechanism and working closely with me
 * to enhance it to support full fileevent semantics.
 *
 * Also work done by the follow people provided the impetus to do this "right":-
 *	tclSSL (Colin McCormack, Shared Technology)
 *	SSLtcl (Peter Antman)
 *
 */
#ifndef _TLSINT_H
#define _TLSINT_H

#include "tls.h"
#include <errno.h>
#include <string.h>
#include <stdint.h>

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <wincrypt.h> /* OpenSSL needs this on Windows */
#endif

#ifdef NO_PATENTS
#  define NO_IDEA
#  define NO_RC2
#  define NO_RC4
#  define NO_RC5
#  define NO_RSA
#endif

#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/opensslv.h>

/*
 * Determine if we should use the pre-OpenSSL 1.1.0 API
 */
#undef TCLTLS_OPENSSL_PRE_1_1
#if defined(LIBRESSL_VERSION_NUMBER)
#  define TCLTLS_OPENSSL_PRE_1_1_API 1
#endif

#ifndef ECONNABORTED
#define ECONNABORTED	130	/* Software caused connection abort */
#endif
#ifndef ECONNRESET
#define ECONNRESET	131	/* Connection reset by peer */
#endif

#ifdef TCLEXT_TCLTLS_DEBUG
#include <ctype.h>
#define dprintf(...) { \
	char dprintfBuffer[8192], *dprintfBuffer_p; \
	dprintfBuffer_p = &dprintfBuffer[0]; \
	dprintfBuffer_p += sprintf(dprintfBuffer_p, "%s:%i:%s():", __FILE__, __LINE__, __func__); \
	dprintfBuffer_p += sprintf(dprintfBuffer_p, __VA_ARGS__); \
	fprintf(stderr, "%s\n", dprintfBuffer); \
}
#define dprintBuffer(bufferName, bufferLength) { \
	int dprintBufferIdx; \
	unsigned char dprintBufferChar; \
	fprintf(stderr, "%s:%i:%s():%s[%llu]={", __FILE__, __LINE__, __func__, #bufferName, (unsigned long long) bufferLength); \
	for (dprintBufferIdx = 0; dprintBufferIdx < bufferLength; dprintBufferIdx++) { \
		dprintBufferChar = bufferName[dprintBufferIdx]; \
		if (isalpha(dprintBufferChar) || isdigit(dprintBufferChar)) { \
			fprintf(stderr, "'%c' ", dprintBufferChar); \
		} else { \
			fprintf(stderr, "%02x ", (unsigned int) dprintBufferChar); \
		}; \
	}; \
	fprintf(stderr, "}\n"); \
}
#define dprintFlags(statePtr) { \
	char dprintfBuffer[8192], *dprintfBuffer_p; \
	dprintfBuffer_p = &dprintfBuffer[0]; \
	dprintfBuffer_p += sprintf(dprintfBuffer_p, "%s:%i:%s():%s->flags=0", __FILE__, __LINE__, __func__, #statePtr); \
	if (((statePtr)->flags & TLS_TCL_ASYNC) == TLS_TCL_ASYNC) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_ASYNC"); }; \
	if (((statePtr)->flags & TLS_TCL_SERVER) == TLS_TCL_SERVER) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_SERVER"); }; \
	if (((statePtr)->flags & TLS_TCL_INIT) == TLS_TCL_INIT) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_INIT"); }; \
	if (((statePtr)->flags & TLS_TCL_DEBUG) == TLS_TCL_DEBUG) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_DEBUG"); }; \
	if (((statePtr)->flags & TLS_TCL_CALLBACK) == TLS_TCL_CALLBACK) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_CALLBACK"); }; \
	if (((statePtr)->flags & TLS_TCL_HANDSHAKE_FAILED) == TLS_TCL_HANDSHAKE_FAILED) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_HANDSHAKE_FAILED"); }; \
	if (((statePtr)->flags & TLS_TCL_FASTPATH) == TLS_TCL_FASTPATH) { dprintfBuffer_p += sprintf(dprintfBuffer_p, "|TLS_TCL_FASTPATH"); }; \
	fprintf(stderr, "%s\n", dprintfBuffer); \
}
#else
#define dprintf(...) if (0) { fprintf(stderr, __VA_ARGS__); }
#define dprintBuffer(bufferName, bufferLength) /**/
#define dprintFlags(statePtr) /**/
#endif

#define TCLTLS_SSL_ERROR(ssl,err) ((char*)ERR_reason_error_string((unsigned long)SSL_get_error((ssl),(err))))
/*
 * OpenSSL BIO Routines
 */
#define BIO_TYPE_TCL	(19|0x0400)

/*
 * Defines for State.flags
 */
#define TLS_TCL_ASYNC		(1<<0)	/* non-blocking mode */
#define TLS_TCL_SERVER		(1<<1)	/* Server-Side */
#define TLS_TCL_INIT		(1<<2)	/* Initializing connection */
#define TLS_TCL_DEBUG		(1<<3)	/* Show debug tracing */
#define TLS_TCL_CALLBACK	(1<<4)	/* In a callback, prevent update
					 * looping problem. [Bug 1652380] */
#define TLS_TCL_HANDSHAKE_FAILED (1<<5) /* Set on handshake failures and once set, all
                                         * further I/O will result in ECONNABORTED errors. */
#define TLS_TCL_FASTPATH 	(1<<6)	/* The parent channel is being used directly by the SSL library */
#define TLS_TCL_DELAY (5)

/*
 * This structure describes the per-instance state of an SSL channel.
 *
 * The SSL processing context is maintained here, in the ClientData
 */
typedef struct State {
	Tcl_Channel self;	/* this socket channel */
	Tcl_TimerToken timer;

	int flags;		/* see State.flags above  */
	int watchMask;		/* current WatchProc mask */
	int mode;		/* current mode of parent channel */

	Tcl_Interp *interp;	/* interpreter in which this resides */
	Tcl_Obj *callback;	/* script called for tracing, info, and errors */
	Tcl_Obj *password;	/* script called for certificate password */

	int vflags;		/* verify flags */
	SSL *ssl;		/* Struct for SSL processing */
	SSL_CTX *ctx;		/* SSL Context */
	BIO *bio;		/* Struct for SSL processing */
	BIO *p_bio;		/* Parent BIO (that is layered on Tcl_Channel) */

	const char *err;
} State;

#ifdef USE_TCL_STUBS
#ifndef Tcl_StackChannel
#error "Unable to compile on this version of Tcl"
#endif /* Tcl_GetStackedChannel */
#endif /* USE_TCL_STUBS */

#ifndef JOIN
#  define JOIN(a,b) JOIN1(a,b)
#  define JOIN1(a,b) a##b
#endif

#ifndef TCL_UNUSED
# if defined(__cplusplus)
#   define TCL_UNUSED(T) T
# elif defined(__GNUC__) && (__GNUC__ > 2)
#   define TCL_UNUSED(T) T JOIN(dummy, __LINE__) __attribute__((unused))
# else
#   define TCL_UNUSED(T) T JOIN(dummy, __LINE__)
# endif
#endif

#if (TCL_MAJOR_VERSION < 9) && defined(TCL_MINOR_VERSION) && (TCL_MINOR_VERSION < 7) && !defined(Tcl_Size)
#   define Tcl_Size int
#   define TCL_SIZE_MODIFIER ""
#endif

/*
 * Forward declarations
 */
const Tcl_ChannelType *Tls_ChannelType(void);
Tcl_Channel     Tls_GetParent(State *statePtr, int maskFlags);

Tcl_Obj        *Tls_NewX509Obj(Tcl_Interp *interp, X509 *cert);
void            Tls_Error(State *statePtr, char *msg);
#if TCL_MAJOR_VERSION > 8
void            Tls_Free(void *blockPtr);
#else
void            Tls_Free(char *blockPtr);
#endif
void            Tls_Clean(State *statePtr);
int             Tls_WaitForConnect(State *statePtr, int *errorCodePtr, int handshakeFailureIsPermanent);

BIO            *BIO_new_tcl(State* statePtr, int flags);

#define PTR2INT(x) ((int) ((intptr_t) (x)))

#endif /* _TLSINT_H */