nss-3.41/nss/lib/freebl/arcfour.c - manifest_repos/nss - Git at Google

 /* 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
	/* 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