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/* arcfour.c - the arc four algorithm.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifdef FREEBL_NO_DEPEND
#include "stubs.h"
#endif
#include "prerr.h"
#include "secerr.h"
#include "prtypes.h"
#include "blapi.h"
/* Architecture-dependent defines */
#if defined(SOLARIS) || defined(HPUX) || defined(NSS_X86) || \
defined(_WIN64)
/* Convert the byte-stream to a word-stream */
#define CONVERT_TO_WORDS
#endif
#if defined(AIX) || defined(OSF1) || defined(NSS_BEVAND_ARCFOUR)
/* Treat array variables as words, not bytes, on CPUs that take
* much longer to write bytes than to write words, or when using
* assembler code that required it.
*/
#define USE_WORD
#endif
#if defined(IS_64) || defined(NSS_BEVAND_ARCFOUR)
typedef PRUint64 WORD;
#else
typedef PRUint32 WORD;
#endif
#define WORDSIZE sizeof(WORD)
#if defined(USE_WORD)
typedef WORD Stype;
#else
typedef PRUint8 Stype;
#endif
#define ARCFOUR_STATE_SIZE 256
#define MASK1BYTE (WORD)(0xff)
#define SWAP(a, b) \
tmp = a; \
a = b; \
b = tmp;
/*
* State information for stream cipher.
*/
struct RC4ContextStr {
#if defined(NSS_ARCFOUR_IJ_B4_S) || defined(NSS_BEVAND_ARCFOUR)
Stype i;
Stype j;
Stype S[ARCFOUR_STATE_SIZE];
#else
Stype S[ARCFOUR_STATE_SIZE];
Stype i;
Stype j;
#endif
};
/*
* array indices [0..255] to initialize cx->S array (faster than loop).
*/
static const Stype Kinit[256] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
};
RC4Context *
RC4_AllocateContext(void)
{
return PORT_ZNew(RC4Context);
}
SECStatus
RC4_InitContext(RC4Context *cx, const unsigned char *key, unsigned int len,
const unsigned char *unused1, int unused2,
unsigned int unused3, unsigned int unused4)
{
unsigned int i;
PRUint8 j, tmp;
PRUint8 K[256];
PRUint8 *L;
/* verify the key length. */
PORT_Assert(len > 0 && len < ARCFOUR_STATE_SIZE);
if (len == 0 || len >= ARCFOUR_STATE_SIZE) {
PORT_SetError(SEC_ERROR_BAD_KEY);
return SECFailure;
}
if (cx == NULL) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
/* Initialize the state using array indices. */
memcpy(cx->S, Kinit, sizeof cx->S);
/* Fill in K repeatedly with values from key. */
L = K;
for (i = sizeof K; i > len; i -= len) {
memcpy(L, key, len);
L += len;
}
memcpy(L, key, i);
/* Stir the state of the generator. At this point it is assumed
* that the key is the size of the state buffer. If this is not
* the case, the key bytes are repeated to fill the buffer.
*/
j = 0;
#define ARCFOUR_STATE_STIR(ii) \
j = j + cx->S[ii] + K[ii]; \
SWAP(cx->S[ii], cx->S[j]);
for (i = 0; i < ARCFOUR_STATE_SIZE; i++) {
ARCFOUR_STATE_STIR(i);
}
cx->i = 0;
cx->j = 0;
return SECSuccess;
}
/*
* Initialize a new generator.
*/
RC4Context *
RC4_CreateContext(const unsigned char *key, int len)
{
RC4Context *cx = RC4_AllocateContext();
if (cx) {
SECStatus rv = RC4_InitContext(cx, key, len, NULL, 0, 0, 0);
if (rv != SECSuccess) {
PORT_ZFree(cx, sizeof(*cx));
cx = NULL;
}
}
return cx;
}
void
RC4_DestroyContext(RC4Context *cx, PRBool freeit)
{
if (freeit)
PORT_ZFree(cx, sizeof(*cx));
}
#if defined(NSS_BEVAND_ARCFOUR)
extern void ARCFOUR(RC4Context *cx, WORD inputLen,
const unsigned char *input, unsigned char *output);
#else
/*
* Generate the next byte in the stream.
*/
#define ARCFOUR_NEXT_BYTE() \
tmpSi = cx->S[++tmpi]; \
tmpj += tmpSi; \
tmpSj = cx->S[tmpj]; \
cx->S[tmpi] = tmpSj; \
cx->S[tmpj] = tmpSi; \
t = tmpSi + tmpSj;
#ifdef CONVERT_TO_WORDS
/*
* Straight ARCFOUR op. No optimization.
*/
static SECStatus
rc4_no_opt(RC4Context *cx, unsigned char *output,
unsigned int *outputLen, unsigned int maxOutputLen,
const unsigned char *input, unsigned int inputLen)
{
PRUint8 t;
Stype tmpSi, tmpSj;
register PRUint8 tmpi = cx->i;
register PRUint8 tmpj = cx->j;
unsigned int index;
PORT_Assert(maxOutputLen >= inputLen);
if (maxOutputLen < inputLen) {
PORT_SetError(SEC_ERROR_OUTPUT_LEN);
return SECFailure;
}
for (index = 0; index < inputLen; index++) {
/* Generate next byte from stream. */
ARCFOUR_NEXT_BYTE();
/* output = next stream byte XOR next input byte */
output[index] = cx->S[t] ^ input[index];
}
*outputLen = inputLen;
cx->i = tmpi;
cx->j = tmpj;
return SECSuccess;
}
#else
/* !CONVERT_TO_WORDS */
/*
* Byte-at-a-time ARCFOUR, unrolling the loop into 8 pieces.
*/
static SECStatus
rc4_unrolled(RC4Context *cx, unsigned char *output,
unsigned int *outputLen, unsigned int maxOutputLen,
const unsigned char *input, unsigned int inputLen)
{
PRUint8 t;
Stype tmpSi, tmpSj;
register PRUint8 tmpi = cx->i;
register PRUint8 tmpj = cx->j;
int index;
PORT_Assert(maxOutputLen >= inputLen);
if (maxOutputLen < inputLen) {
PORT_SetError(SEC_ERROR_OUTPUT_LEN);
return SECFailure;
}
for (index = inputLen / 8; index-- > 0; input += 8, output += 8) {
ARCFOUR_NEXT_BYTE();
output[0] = cx->S[t] ^ input[0];
ARCFOUR_NEXT_BYTE();
output[1] = cx->S[t] ^ input[1];
ARCFOUR_NEXT_BYTE();
output[2] = cx->S[t] ^ input[2];
ARCFOUR_NEXT_BYTE();
output[3] = cx->S[t] ^ input[3];
ARCFOUR_NEXT_BYTE();
output[4] = cx->S[t] ^ input[4];
ARCFOUR_NEXT_BYTE();
output[5] = cx->S[t] ^ input[5];
ARCFOUR_NEXT_BYTE();
output[6] = cx->S[t] ^ input[6];
ARCFOUR_NEXT_BYTE();
output[7] = cx->S[t] ^ input[7];
}
index = inputLen % 8;
if (index) {
input += index;
output += index;
switch (index) {
case 7:
ARCFOUR_NEXT_BYTE();
output[-7] = cx->S[t] ^ input[-7]; /* FALLTHRU */
case 6:
ARCFOUR_NEXT_BYTE();
output[-6] = cx->S[t] ^ input[-6]; /* FALLTHRU */
case 5:
ARCFOUR_NEXT_BYTE();
output[-5] = cx->S[t] ^ input[-5]; /* FALLTHRU */
case 4:
ARCFOUR_NEXT_BYTE();
output[-4] = cx->S[t] ^ input[-4]; /* FALLTHRU */
case 3:
ARCFOUR_NEXT_BYTE();
output[-3] = cx->S[t] ^ input[-3]; /* FALLTHRU */
case 2:
ARCFOUR_NEXT_BYTE();
output[-2] = cx->S[t] ^ input[-2]; /* FALLTHRU */
case 1:
ARCFOUR_NEXT_BYTE();
output[-1] = cx->S[t] ^ input[-1]; /* FALLTHRU */
default:
/* FALLTHRU */
; /* hp-ux build breaks without this */
}
}
cx->i = tmpi;
cx->j = tmpj;
*outputLen = inputLen;
return SECSuccess;
}
#endif
#ifdef IS_LITTLE_ENDIAN
#define ARCFOUR_NEXT4BYTES_L(n) \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n); \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n + 8); \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n + 16); \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n + 24);
#else
#define ARCFOUR_NEXT4BYTES_B(n) \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n + 24); \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n + 16); \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n + 8); \
ARCFOUR_NEXT_BYTE(); \
streamWord |= (WORD)cx->S[t] << (n);
#endif
#if (defined(IS_64) && !defined(__sparc)) || defined(NSS_USE_64)
/* 64-bit wordsize */
#ifdef IS_LITTLE_ENDIAN
#define ARCFOUR_NEXT_WORD() \
{ \
streamWord = 0; \
ARCFOUR_NEXT4BYTES_L(0); \
ARCFOUR_NEXT4BYTES_L(32); \
}
#else
#define ARCFOUR_NEXT_WORD() \
{ \
streamWord = 0; \
ARCFOUR_NEXT4BYTES_B(32); \
ARCFOUR_NEXT4BYTES_B(0); \
}
#endif
#else
/* 32-bit wordsize */
#ifdef IS_LITTLE_ENDIAN
#define ARCFOUR_NEXT_WORD() \
{ \
streamWord = 0; \
ARCFOUR_NEXT4BYTES_L(0); \
}
#else
#define ARCFOUR_NEXT_WORD() \
{ \
streamWord = 0; \
ARCFOUR_NEXT4BYTES_B(0); \
}
#endif
#endif
#ifdef IS_LITTLE_ENDIAN
#define RSH <<
#define LSH >>
#else
#define RSH >>
#define LSH <<
#endif
#ifdef IS_LITTLE_ENDIAN
#define LEFTMOST_BYTE_SHIFT 0
#define NEXT_BYTE_SHIFT(shift) shift + 8
#else
#define LEFTMOST_BYTE_SHIFT 8 * (WORDSIZE - 1)
#define NEXT_BYTE_SHIFT(shift) shift - 8
#endif
#ifdef CONVERT_TO_WORDS
static SECStatus
rc4_wordconv(RC4Context *cx, unsigned char *output,
unsigned int *outputLen, unsigned int maxOutputLen,
const unsigned char *input, unsigned int inputLen)
{
PR_STATIC_ASSERT(sizeof(PRUword) == sizeof(ptrdiff_t));
unsigned int inOffset = (PRUword)input % WORDSIZE;
unsigned int outOffset = (PRUword)output % WORDSIZE;
register WORD streamWord;
register const WORD *pInWord;
register WORD *pOutWord;
register WORD inWord, nextInWord;
PRUint8 t;
register Stype tmpSi, tmpSj;
register PRUint8 tmpi = cx->i;
register PRUint8 tmpj = cx->j;
unsigned int bufShift, invBufShift;
unsigned int i;
const unsigned char *finalIn;
unsigned char *finalOut;
PORT_Assert(maxOutputLen >= inputLen);
if (maxOutputLen < inputLen) {
PORT_SetError(SEC_ERROR_OUTPUT_LEN);
return SECFailure;
}
if (inputLen < 2 * WORDSIZE) {
/* Ignore word conversion, do byte-at-a-time */
return rc4_no_opt(cx, output, outputLen, maxOutputLen, input, inputLen);
}
*outputLen = inputLen;
pInWord = (const WORD *)(input - inOffset);
pOutWord = (WORD *)(output - outOffset);
if (inOffset <= outOffset) {
bufShift = 8 * (outOffset - inOffset);
invBufShift = 8 * WORDSIZE - bufShift;
} else {
invBufShift = 8 * (inOffset - outOffset);
bufShift = 8 * WORDSIZE - invBufShift;
}
/*****************************************************************/
/* Step 1: */
/* If the first output word is partial, consume the bytes in the */
/* first partial output word by loading one or two words of */
/* input and shifting them accordingly. Otherwise, just load */
/* in the first word of input. At the end of this block, at */
/* least one partial word of input should ALWAYS be loaded. */
/*****************************************************************/
if (outOffset) {
unsigned int byteCount = WORDSIZE - outOffset;
for (i = 0; i < byteCount; i++) {
ARCFOUR_NEXT_BYTE();
output[i] = cx->S[t] ^ input[i];
}
/* Consumed byteCount bytes of input */
inputLen -= byteCount;
pInWord++;
/* move to next word of output */
pOutWord++;
/* If buffers are relatively misaligned, shift the bytes in inWord
* to be aligned to the output buffer.
*/
if (inOffset < outOffset) {
/* The first input word (which may be partial) has more bytes
* than needed. Copy the remainder to inWord.
*/
unsigned int shift = LEFTMOST_BYTE_SHIFT;
inWord = 0;
for (i = 0; i < outOffset - inOffset; i++) {
inWord |= (WORD)input[byteCount + i] << shift;
shift = NEXT_BYTE_SHIFT(shift);
}
} else if (inOffset > outOffset) {
/* Consumed some bytes in the second input word. Copy the
* remainder to inWord.
*/
inWord = *pInWord++;
inWord = inWord LSH invBufShift;
} else {
inWord = 0;
}
} else {
/* output is word-aligned */
if (inOffset) {
/* Input is not word-aligned. The first word load of input
* will not produce a full word of input bytes, so one word
* must be pre-loaded. The main loop below will load in the
* next input word and shift some of its bytes into inWord
* in order to create a full input word. Note that the main
* loop must execute at least once because the input must
* be at least two words.
*/
unsigned int shift = LEFTMOST_BYTE_SHIFT;
inWord = 0;
for (i = 0; i < WORDSIZE - inOffset; i++) {
inWord |= (WORD)input[i] << shift;
shift = NEXT_BYTE_SHIFT(shift);
}
pInWord++;
} else {
/* Input is word-aligned. The first word load of input
* will produce a full word of input bytes, so nothing
* needs to be loaded here.
*/
inWord = 0;
}
}
/*****************************************************************/
/* Step 2: main loop */
/* At this point the output buffer is word-aligned. Any unused */
/* bytes from above will be in inWord (shifted correctly). If */
/* the input buffer is unaligned relative to the output buffer, */
/* shifting has to be done. */
/*****************************************************************/
if (bufShift) {
/* preloadedByteCount is the number of input bytes pre-loaded
* in inWord.
*/
unsigned int preloadedByteCount = bufShift / 8;
for (; inputLen >= preloadedByteCount + WORDSIZE;
inputLen -= WORDSIZE) {
nextInWord = *pInWord++;
inWord |= nextInWord RSH bufShift;
nextInWord = nextInWord LSH invBufShift;
ARCFOUR_NEXT_WORD();
*pOutWord++ = inWord ^ streamWord;
inWord = nextInWord;
}
if (inputLen == 0) {
/* Nothing left to do. */
cx->i = tmpi;
cx->j = tmpj;
return SECSuccess;
}
finalIn = (const unsigned char *)pInWord - preloadedByteCount;
} else {
for (; inputLen >= WORDSIZE; inputLen -= WORDSIZE) {
inWord = *pInWord++;
ARCFOUR_NEXT_WORD();
*pOutWord++ = inWord ^ streamWord;
}
if (inputLen == 0) {
/* Nothing left to do. */
cx->i = tmpi;
cx->j = tmpj;
return SECSuccess;
}
finalIn = (const unsigned char *)pInWord;
}
/*****************************************************************/
/* Step 3: */
/* Do the remaining partial word of input one byte at a time. */
/*****************************************************************/
finalOut = (unsigned char *)pOutWord;
for (i = 0; i < inputLen; i++) {
ARCFOUR_NEXT_BYTE();
finalOut[i] = cx->S[t] ^ finalIn[i];
}
cx->i = tmpi;
cx->j = tmpj;
return SECSuccess;
}
#endif
#endif /* NSS_BEVAND_ARCFOUR */
SECStatus
RC4_Encrypt(RC4Context *cx, unsigned char *output,
unsigned int *outputLen, unsigned int maxOutputLen,
const unsigned char *input, unsigned int inputLen)
{
PORT_Assert(maxOutputLen >= inputLen);
if (maxOutputLen < inputLen) {
PORT_SetError(SEC_ERROR_OUTPUT_LEN);
return SECFailure;
}
#if defined(NSS_BEVAND_ARCFOUR)
ARCFOUR(cx, inputLen, input, output);
*outputLen = inputLen;
return SECSuccess;
#elif defined(CONVERT_TO_WORDS)
/* Convert the byte-stream to a word-stream */
return rc4_wordconv(cx, output, outputLen, maxOutputLen, input, inputLen);
#else
/* Operate on bytes, but unroll the main loop */
return rc4_unrolled(cx, output, outputLen, maxOutputLen, input, inputLen);
#endif
}
SECStatus
RC4_Decrypt(RC4Context *cx, unsigned char *output,
unsigned int *outputLen, unsigned int maxOutputLen,
const unsigned char *input, unsigned int inputLen)
{
PORT_Assert(maxOutputLen >= inputLen);
if (maxOutputLen < inputLen) {
PORT_SetError(SEC_ERROR_OUTPUT_LEN);
return SECFailure;
}
/* decrypt and encrypt are same operation. */
#if defined(NSS_BEVAND_ARCFOUR)
ARCFOUR(cx, inputLen, input, output);
*outputLen = inputLen;
return SECSuccess;
#elif defined(CONVERT_TO_WORDS)
/* Convert the byte-stream to a word-stream */
return rc4_wordconv(cx, output, outputLen, maxOutputLen, input, inputLen);
#else
/* Operate on bytes, but unroll the main loop */
return rc4_unrolled(cx, output, outputLen, maxOutputLen, input, inputLen);
#endif
}
#undef CONVERT_TO_WORDS
#undef USE_WORD