/* 

 * This library is free software; you can redistribute it and/or

 * modify it under the same terms as Perl itself.

 * 

 *  Copyright 1998-2000 Gisle Aas.

 *  Copyright 1995-1996 Neil Winton.

 *  Copyright 1991-1992 RSA Data Security, Inc.

 *

 * This code is derived from Neil Winton's MD5-1.7 Perl module, which in

 * turn is derived from the reference implementation in RFC 1321 which

 * comes with this message:

 *

 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All

 * rights reserved.

 *

 * License to copy and use this software is granted provided that it

 * is identified as the "RSA Data Security, Inc. MD5 Message-Digest

 * Algorithm" in all material mentioning or referencing this software

 * or this function.

 *

 * License is also granted to make and use derivative works provided

 * that such works are identified as "derived from the RSA Data

 * Security, Inc. MD5 Message-Digest Algorithm" in all material

 * mentioning or referencing the derived work.

 *

 * RSA Data Security, Inc. makes no representations concerning either

 * the merchantability of this software or the suitability of this

 * software for any particular purpose. It is provided "as is"

 * without express or implied warranty of any kind.

 *

 * These notices must be retained in any copies of any part of this

 * documentation and/or software.

 */

#ifdef __cplusplus

extern "C" {

#endif

#define PERL_NO_GET_CONTEXT     /* we want efficiency */

#include "EXTERN.h"

#include "perl.h"

#include "XSUB.h"

#ifdef __cplusplus

}

#endif

#ifndef PERL_UNUSED_VAR

# define PERL_UNUSED_VAR(x) ((void)x)

#endif

#ifndef PERL_MAGIC_ext

# define PERL_MAGIC_ext '~'

#endif

#ifndef Newxz

# define Newxz(v,n,t) Newz(0,v,n,t)

#endif

#ifndef SvMAGIC_set

# define SvMAGIC_set(sv, mg) (SvMAGIC(sv) = (mg))

#endif

#ifndef sv_magicext

# define sv_magicext(sv, obj, type, vtbl, name, namlen) \

    THX_sv_magicext(aTHX_ sv, obj, type, vtbl, name, namlen)

static MAGIC *THX_sv_magicext(pTHX_ SV *sv, SV *obj, int type,

    MGVTBL const *vtbl, char const *name, I32 namlen)

{

    MAGIC *mg;

    if (obj || namlen)

	/* exceeded intended usage of this reserve implementation */

	return NULL;

    Newxz(mg, 1, MAGIC);

    mg->mg_virtual = (MGVTBL*)vtbl;

    mg->mg_type = type;

    mg->mg_ptr = (char *)name;

    mg->mg_len = -1;

    (void) SvUPGRADE(sv, SVt_PVMG);

    mg->mg_moremagic = SvMAGIC(sv);

    SvMAGIC_set(sv, mg);

    SvMAGICAL_off(sv);

    mg_magical(sv);

    return mg;

}

#endif

#if PERL_VERSION < 8

# undef SvPVbyte

# define SvPVbyte(sv, lp) (sv_utf8_downgrade((sv), 0), SvPV((sv), (lp)))

#endif

/* Perl does not guarantee that U32 is exactly 32 bits.  Some system

 * has no integral type with exactly 32 bits.  For instance, A Cray has

 * short, int and long all at 64 bits so we need to apply this macro

 * to reduce U32 values to 32 bits at appropriate places. If U32

 * really does have 32 bits then this is a no-op.

 */

#if BYTEORDER > 0x4321 || defined(TRUNCATE_U32)

  #define TO32(x)    ((x) &  0xFFFFffff)

  #define TRUNC32(x) ((x) &= 0xFFFFffff)

#else

  #define TO32(x)    (x)

  #define TRUNC32(x) /*nothing*/

#endif

/* The MD5 algorithm is defined in terms of little endian 32-bit

 * values.  The following macros (and functions) allow us to convert

 * between native integers and such values.

 */

#undef BYTESWAP

#ifndef U32_ALIGNMENT_REQUIRED

 #if BYTEORDER == 0x1234      /* 32-bit little endian */

  #define BYTESWAP(x) (x)     /* no-op */

 #elif BYTEORDER == 0x4321    /* 32-bit big endian */

  #define BYTESWAP(x) 	((((x)&0xFF)<<24)	\

			|(((x)>>24)&0xFF)	\

			|(((x)&0x0000FF00)<<8)	\

			|(((x)&0x00FF0000)>>8)	)

 #endif

#endif

#ifndef BYTESWAP

static void u2s(U32 u, U8* s)

{

    *s++ = (U8)(u         & 0xFF);

    *s++ = (U8)((u >>  8) & 0xFF);

    *s++ = (U8)((u >> 16) & 0xFF);

    *s   = (U8)((u >> 24) & 0xFF);

}

#define s2u(s,u) ((u) =  (U32)(*s)            |  \

                        ((U32)(*(s+1)) << 8)  |  \

                        ((U32)(*(s+2)) << 16) |  \

                        ((U32)(*(s+3)) << 24))

#endif

/* This structure keeps the current state of algorithm.

 */

typedef struct {

  U32 A, B, C, D;  /* current digest */

  U32 bytes_low;   /* counts bytes in message */

  U32 bytes_high;  /* turn it into a 64-bit counter */

  U8 buffer[128];  /* collect complete 64 byte blocks */

} MD5_CTX;

#if defined(USE_ITHREADS) && defined(MGf_DUP)

STATIC int dup_md5_ctx(pTHX_ MAGIC *mg, CLONE_PARAMS *params)

{

    MD5_CTX *new_ctx;

    PERL_UNUSED_VAR(params);

    New(55, new_ctx, 1, MD5_CTX);

    memcpy(new_ctx, mg->mg_ptr, sizeof(MD5_CTX));

    mg->mg_ptr = (char *)new_ctx;

    return 0;

}

#endif

#if defined(MGf_DUP) && defined(USE_ITHREADS)

STATIC const MGVTBL vtbl_md5 = {

    NULL, /* get */

    NULL, /* set */

    NULL, /* len */

    NULL, /* clear */

    NULL, /* free */

    NULL, /* copy */

    dup_md5_ctx, /* dup */

    NULL /* local */

};

#else

/* declare as 5 member, not normal 8 to save image space*/

STATIC const struct {

	int (*svt_get)(SV* sv, MAGIC* mg);

	int (*svt_set)(SV* sv, MAGIC* mg);

	U32 (*svt_len)(SV* sv, MAGIC* mg);

	int (*svt_clear)(SV* sv, MAGIC* mg);

	int (*svt_free)(SV* sv, MAGIC* mg);

} vtbl_md5 = {

	NULL, NULL, NULL, NULL, NULL

};

#endif

/* Padding is added at the end of the message in order to fill a

 * complete 64 byte block (- 8 bytes for the message length).  The

 * padding is also the reason the buffer in MD5_CTX have to be

 * 128 bytes.

 */

static const unsigned char PADDING[64] = {

  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

};

/* Constants for MD5Transform routine.

 */

#define S11 7

#define S12 12

#define S13 17

#define S14 22

#define S21 5

#define S22 9

#define S23 14

#define S24 20

#define S31 4

#define S32 11

#define S33 16

#define S34 23

#define S41 6

#define S42 10

#define S43 15

#define S44 21

/* F, G, H and I are basic MD5 functions.

 */

#define F(x, y, z) ((((x) & ((y) ^ (z))) ^ (z)))

#define G(x, y, z) F(z, x, y)

#define H(x, y, z) ((x) ^ (y) ^ (z))

#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits.

 */

#define ROTATE_LEFT(x, n) (((x) << (n) | ((x) >> (32-(n)))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.

 * Rotation is separate from addition to prevent recomputation.

 */

#define FF(a, b, c, d, s, ac)                    \

 (a) += F ((b), (c), (d)) + (NEXTx) + (U32)(ac); \

 TRUNC32((a));                                   \

 (a) = ROTATE_LEFT ((a), (s));                   \

 (a) += (b);                                     \

 TRUNC32((a));

#define GG(a, b, c, d, x, s, ac)                 \

 (a) += G ((b), (c), (d)) + X[x] + (U32)(ac);    \

 TRUNC32((a));                                   \

 (a) = ROTATE_LEFT ((a), (s));                   \

 (a) += (b);                                     \

 TRUNC32((a));

#define HH(a, b, c, d, x, s, ac)                 \

 (a) += H ((b), (c), (d)) + X[x] + (U32)(ac);    \

 TRUNC32((a));                                   \

 (a) = ROTATE_LEFT ((a), (s));                   \

 (a) += (b);                                     \

 TRUNC32((a));

#define II(a, b, c, d, x, s, ac)                 \

 (a) += I ((b), (c), (d)) + X[x] + (U32)(ac);    \

 TRUNC32((a));                                   \

 (a) = ROTATE_LEFT ((a), (s));                   \

 (a) += (b);                                     \

 TRUNC32((a));

static void

MD5Init(MD5_CTX *ctx)

{

  /* Start state */

  ctx->A = 0x67452301;

  ctx->B = 0xefcdab89;

  ctx->C = 0x98badcfe;

  ctx->D = 0x10325476;

  /* message length */

  ctx->bytes_low = ctx->bytes_high = 0;

}

static void

MD5Transform(MD5_CTX* ctx, const U8* buf, STRLEN blocks)

{

#ifdef MD5_DEBUG

    static int tcount = 0;

#endif

    U32 A = ctx->A;

    U32 B = ctx->B;

    U32 C = ctx->C;

    U32 D = ctx->D;

#ifndef U32_ALIGNMENT_REQUIRED

    const U32 *x = (U32*)buf;  /* really just type casting */

#endif

    do {

	U32 a = A;

	U32 b = B;

	U32 c = C;

	U32 d = D;

#if BYTEORDER == 0x1234 && !defined(U32_ALIGNMENT_REQUIRED)

	const U32 *X = x;

        #define NEXTx  (*x++)

#else

	U32 X[16];      /* converted values, used in round 2-4 */

	U32 *uptr = X;

	U32 tmp;

 #ifdef BYTESWAP

        #define NEXTx  (tmp=*x++, *uptr++ = BYTESWAP(tmp))

 #else

        #define NEXTx  (s2u(buf,tmp), buf += 4, *uptr++ = tmp)

 #endif

#endif

#ifdef MD5_DEBUG

	if (buf == ctx->buffer)

	    fprintf(stderr,"%5d: Transform ctx->buffer", ++tcount);

	else 

	    fprintf(stderr,"%5d: Transform %p (%d)", ++tcount, buf, blocks);

	{

	    int i;

	    fprintf(stderr,"[");

	    for (i = 0; i < 16; i++) {

		fprintf(stderr,"%x,", x[i]);

	    }

	    fprintf(stderr,"]\n");

	}

#endif

	/* Round 1 */

	FF (a, b, c, d, S11, 0xd76aa478); /* 1 */

	FF (d, a, b, c, S12, 0xe8c7b756); /* 2 */

	FF (c, d, a, b, S13, 0x242070db); /* 3 */

	FF (b, c, d, a, S14, 0xc1bdceee); /* 4 */

	FF (a, b, c, d, S11, 0xf57c0faf); /* 5 */

	FF (d, a, b, c, S12, 0x4787c62a); /* 6 */

	FF (c, d, a, b, S13, 0xa8304613); /* 7 */

	FF (b, c, d, a, S14, 0xfd469501); /* 8 */

	FF (a, b, c, d, S11, 0x698098d8); /* 9 */

	FF (d, a, b, c, S12, 0x8b44f7af); /* 10 */

	FF (c, d, a, b, S13, 0xffff5bb1); /* 11 */

	FF (b, c, d, a, S14, 0x895cd7be); /* 12 */

	FF (a, b, c, d, S11, 0x6b901122); /* 13 */

	FF (d, a, b, c, S12, 0xfd987193); /* 14 */

	FF (c, d, a, b, S13, 0xa679438e); /* 15 */

	FF (b, c, d, a, S14, 0x49b40821); /* 16 */

	/* Round 2 */

	GG (a, b, c, d,  1, S21, 0xf61e2562); /* 17 */

	GG (d, a, b, c,  6, S22, 0xc040b340); /* 18 */

	GG (c, d, a, b, 11, S23, 0x265e5a51); /* 19 */

	GG (b, c, d, a,  0, S24, 0xe9b6c7aa); /* 20 */

	GG (a, b, c, d,  5, S21, 0xd62f105d); /* 21 */

	GG (d, a, b, c, 10, S22,  0x2441453); /* 22 */

	GG (c, d, a, b, 15, S23, 0xd8a1e681); /* 23 */

	GG (b, c, d, a,  4, S24, 0xe7d3fbc8); /* 24 */

	GG (a, b, c, d,  9, S21, 0x21e1cde6); /* 25 */

	GG (d, a, b, c, 14, S22, 0xc33707d6); /* 26 */

	GG (c, d, a, b,  3, S23, 0xf4d50d87); /* 27 */

	GG (b, c, d, a,  8, S24, 0x455a14ed); /* 28 */

	GG (a, b, c, d, 13, S21, 0xa9e3e905); /* 29 */

	GG (d, a, b, c,  2, S22, 0xfcefa3f8); /* 30 */

	GG (c, d, a, b,  7, S23, 0x676f02d9); /* 31 */

	GG (b, c, d, a, 12, S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */

	HH (a, b, c, d,  5, S31, 0xfffa3942); /* 33 */

	HH (d, a, b, c,  8, S32, 0x8771f681); /* 34 */

	HH (c, d, a, b, 11, S33, 0x6d9d6122); /* 35 */

	HH (b, c, d, a, 14, S34, 0xfde5380c); /* 36 */

	HH (a, b, c, d,  1, S31, 0xa4beea44); /* 37 */

	HH (d, a, b, c,  4, S32, 0x4bdecfa9); /* 38 */

	HH (c, d, a, b,  7, S33, 0xf6bb4b60); /* 39 */

	HH (b, c, d, a, 10, S34, 0xbebfbc70); /* 40 */

	HH (a, b, c, d, 13, S31, 0x289b7ec6); /* 41 */

	HH (d, a, b, c,  0, S32, 0xeaa127fa); /* 42 */

	HH (c, d, a, b,  3, S33, 0xd4ef3085); /* 43 */

	HH (b, c, d, a,  6, S34,  0x4881d05); /* 44 */

	HH (a, b, c, d,  9, S31, 0xd9d4d039); /* 45 */

	HH (d, a, b, c, 12, S32, 0xe6db99e5); /* 46 */

	HH (c, d, a, b, 15, S33, 0x1fa27cf8); /* 47 */

	HH (b, c, d, a,  2, S34, 0xc4ac5665); /* 48 */

	/* Round 4 */

	II (a, b, c, d,  0, S41, 0xf4292244); /* 49 */

	II (d, a, b, c,  7, S42, 0x432aff97); /* 50 */

	II (c, d, a, b, 14, S43, 0xab9423a7); /* 51 */

	II (b, c, d, a,  5, S44, 0xfc93a039); /* 52 */

	II (a, b, c, d, 12, S41, 0x655b59c3); /* 53 */

	II (d, a, b, c,  3, S42, 0x8f0ccc92); /* 54 */

	II (c, d, a, b, 10, S43, 0xffeff47d); /* 55 */

	II (b, c, d, a,  1, S44, 0x85845dd1); /* 56 */

	II (a, b, c, d,  8, S41, 0x6fa87e4f); /* 57 */

	II (d, a, b, c, 15, S42, 0xfe2ce6e0); /* 58 */

	II (c, d, a, b,  6, S43, 0xa3014314); /* 59 */

	II (b, c, d, a, 13, S44, 0x4e0811a1); /* 60 */

	II (a, b, c, d,  4, S41, 0xf7537e82); /* 61 */

	II (d, a, b, c, 11, S42, 0xbd3af235); /* 62 */

	II (c, d, a, b,  2, S43, 0x2ad7d2bb); /* 63 */

	II (b, c, d, a,  9, S44, 0xeb86d391); /* 64 */

	A += a;  TRUNC32(A);

	B += b;  TRUNC32(B);

	C += c;  TRUNC32(C);

	D += d;  TRUNC32(D);

    } while (--blocks);

    ctx->A = A;

    ctx->B = B;

    ctx->C = C;

    ctx->D = D;

}

#ifdef MD5_DEBUG

static char*

ctx_dump(MD5_CTX* ctx)

{

    static char buf[1024];

    sprintf(buf, "{A=%x,B=%x,C=%x,D=%x,%d,%d(%d)}",

	    ctx->A, ctx->B, ctx->C, ctx->D,

	    ctx->bytes_low, ctx->bytes_high, (ctx->bytes_low&0x3F));

    return buf;

}

#endif

static void

MD5Update(MD5_CTX* ctx, const U8* buf, STRLEN len)

{

    STRLEN blocks;

    STRLEN fill = ctx->bytes_low & 0x3F;

#ifdef MD5_DEBUG  

    static int ucount = 0;

    fprintf(stderr,"%5i: Update(%s, %p, %d)\n", ++ucount, ctx_dump(ctx),

	                                        buf, len);

#endif

    ctx->bytes_low += len;

    if (ctx->bytes_low < len) /* wrap around */

	ctx->bytes_high++;

    if (fill) {

	STRLEN missing = 64 - fill;

	if (len < missing) {

	    Copy(buf, ctx->buffer + fill, len, U8);

	    return;

	}

	Copy(buf, ctx->buffer + fill, missing, U8);

	MD5Transform(ctx, ctx->buffer, 1);

	buf += missing;

	len -= missing;

    }

    blocks = len >> 6;

    if (blocks)

	MD5Transform(ctx, buf, blocks);

    if ( (len &= 0x3F)) {

	Copy(buf + (blocks << 6), ctx->buffer, len, U8);

    }

}

static void

MD5Final(U8* digest, MD5_CTX *ctx)

{

    STRLEN fill = ctx->bytes_low & 0x3F;

    STRLEN padlen = (fill < 56 ? 56 : 120) - fill;

    U32 bits_low, bits_high;

#ifdef MD5_DEBUG

    fprintf(stderr,"       Final:  %s\n", ctx_dump(ctx));

#endif

    Copy(PADDING, ctx->buffer + fill, padlen, U8);

    fill += padlen;

    bits_low = ctx->bytes_low << 3;

    bits_high = (ctx->bytes_high << 3) | (ctx->bytes_low  >> 29);

#ifdef BYTESWAP

    *(U32*)(ctx->buffer + fill) = BYTESWAP(bits_low);    fill += 4;

    *(U32*)(ctx->buffer + fill) = BYTESWAP(bits_high);   fill += 4;

#else

    u2s(bits_low,  ctx->buffer + fill);   fill += 4;

    u2s(bits_high, ctx->buffer + fill);   fill += 4;

#endif

    MD5Transform(ctx, ctx->buffer, fill >> 6);

#ifdef MD5_DEBUG

    fprintf(stderr,"       Result: %s\n", ctx_dump(ctx));

#endif

#ifdef BYTESWAP

    *(U32*)digest = BYTESWAP(ctx->A);  digest += 4;

    *(U32*)digest = BYTESWAP(ctx->B);  digest += 4;

    *(U32*)digest = BYTESWAP(ctx->C);  digest += 4;

    *(U32*)digest = BYTESWAP(ctx->D);

#else

    u2s(ctx->A, digest);

    u2s(ctx->B, digest+4);

    u2s(ctx->C, digest+8);

    u2s(ctx->D, digest+12);

#endif

}

#ifndef INT2PTR

#define INT2PTR(any,d)	(any)(d)

#endif

static MD5_CTX* get_md5_ctx(pTHX_ SV* sv)

{

    MAGIC *mg;

    if (!sv_derived_from(sv, "Digest::MD5"))

	croak("Not a reference to a Digest::MD5 object");

    for (mg = SvMAGIC(SvRV(sv)); mg; mg = mg->mg_moremagic) {

	if (mg->mg_type == PERL_MAGIC_ext

	    && mg->mg_virtual == (const MGVTBL * const)&vtbl_md5) {

	    return (MD5_CTX *)mg->mg_ptr;

	}

    }

    croak("Failed to get MD5_CTX pointer");

    return (MD5_CTX*)0; /* some compilers insist on a return value */

}

static SV * new_md5_ctx(pTHX_ MD5_CTX *context, const char *klass)

{

    SV *sv = newSV(0);

    SV *obj = newRV_noinc(sv);

#ifdef USE_ITHREADS

    MAGIC *mg;

#endif

    sv_bless(obj, gv_stashpv(klass, 0));

#ifdef USE_ITHREADS

    mg =

#endif

	sv_magicext(sv, NULL, PERL_MAGIC_ext, (const MGVTBL * const)&vtbl_md5, (const char *)context, 0);

#if defined(USE_ITHREADS) && defined(MGf_DUP)

    mg->mg_flags |= MGf_DUP;

#endif

    return obj;

}

static char* hex_16(const unsigned char* from, char* to)

{

    static const char hexdigits[] = "0123456789abcdef";

    const unsigned char *end = from + 16;

    char *d = to;

    while (from < end) {

	*d++ = hexdigits[(*from >> 4)];

	*d++ = hexdigits[(*from & 0x0F)];

	from++;

    }

    *d = '\0';

    return to;

}

static char* base64_16(const unsigned char* from, char* to)

{

    static const char base64[] =

	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    const unsigned char *end = from + 16;

    unsigned char c1, c2, c3;

    char *d = to;

    while (1) {

	c1 = *from++;

	*d++ = base64[c1>>2];

	if (from == end) {

	    *d++ = base64[(c1 & 0x3) << 4];

	    break;

	}

	c2 = *from++;

	c3 = *from++;

	*d++ = base64[((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)];

	*d++ = base64[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)];

	*d++ = base64[c3 & 0x3F];

    }

    *d = '\0';

    return to;

}

/* Formats */

#define F_BIN 0

#define F_HEX 1

#define F_B64 2

static SV* make_mortal_sv(pTHX_ const unsigned char *src, int type)

{

    STRLEN len;

    char result[33];

    char *ret;

    switch (type) {

    case F_BIN:

	ret = (char*)src;

	len = 16;

	break;

    case F_HEX:

	ret = hex_16(src, result);

	len = 32;

	break;

    case F_B64:

	ret = base64_16(src, result);

	len = 22;

	break;

    default:

	croak("Bad conversion type (%d)", type);

	break;

    }

    return sv_2mortal(newSVpv(ret,len));

}

/********************************************************************/

typedef PerlIO* InputStream;

MODULE = Digest::MD5		PACKAGE = Digest::MD5

PROTOTYPES: DISABLE

void

new(xclass)

	SV* xclass

    PREINIT:

	MD5_CTX* context;

    PPCODE:

	if (!SvROK(xclass)) {

	    STRLEN my_na;

	    const char *sclass = SvPV(xclass, my_na);

	    New(55, context, 1, MD5_CTX);

	    ST(0) = sv_2mortal(new_md5_ctx(aTHX_ context, sclass));

	} else {

	    context = get_md5_ctx(aTHX_ xclass);

	}

	MD5Init(context);

	XSRETURN(1);

void

clone(self)

	SV* self

    PREINIT:

	MD5_CTX* cont = get_md5_ctx(aTHX_ self);

	const char *myname = sv_reftype(SvRV(self),TRUE);

	MD5_CTX* context;

    PPCODE:

	New(55, context, 1, MD5_CTX);

	ST(0) = sv_2mortal(new_md5_ctx(aTHX_ context, myname));

	memcpy(context,cont,sizeof(MD5_CTX));

	XSRETURN(1);

void

DESTROY(context)

	MD5_CTX* context

    CODE:

        Safefree(context);

void

add(self, ...)

	SV* self

    PREINIT:

	MD5_CTX* context = get_md5_ctx(aTHX_ self);

	int i;

	unsigned char *data;

	STRLEN len;

    PPCODE:

	for (i = 1; i < items; i++) {

            U32 had_utf8 = SvUTF8(ST(i));

	    data = (unsigned char *)(SvPVbyte(ST(i), len));

	    MD5Update(context, data, len);

	    if (had_utf8) sv_utf8_upgrade(ST(i));

	}

	XSRETURN(1);  /* self */

void

addfile(self, fh)

	SV* self

	InputStream fh

    PREINIT:

	MD5_CTX* context = get_md5_ctx(aTHX_ self);

	STRLEN fill = context->bytes_low & 0x3F;

#ifdef USE_HEAP_INSTEAD_OF_STACK

	unsigned char* buffer;

#else

	unsigned char buffer[4096];

#endif

	int  n;

    CODE:

	if (fh) {

#ifdef USE_HEAP_INSTEAD_OF_STACK

	    New(0, buffer, 4096, unsigned char);

	    assert(buffer);

#endif

            if (fill) {

	        /* The MD5Update() function is faster if it can work with

	         * complete blocks.  This will fill up any buffered block

	         * first.

	         */

	        STRLEN missing = 64 - fill;

	        if ( (n = PerlIO_read(fh, buffer, missing)) > 0)

	 	    MD5Update(context, buffer, n);

	        else

		    XSRETURN(1);  /* self */

	    }

	    /* Process blocks until EOF or error */

            while ( (n = PerlIO_read(fh, buffer, sizeof(buffer))) > 0) {

	        MD5Update(context, buffer, n);

	    }

#ifdef USE_HEAP_INSTEAD_OF_STACK

	    Safefree(buffer);

#endif

	    if (PerlIO_error(fh)) {

		croak("Reading from filehandle failed");

	    }

	}

	else {

	    croak("No filehandle passed");

	}

	XSRETURN(1);  /* self */

void

digest(context)

	MD5_CTX* context

    ALIAS:

	Digest::MD5::digest    = F_BIN

	Digest::MD5::hexdigest = F_HEX

	Digest::MD5::b64digest = F_B64

    PREINIT:

	unsigned char digeststr[16];

    PPCODE:

        MD5Final(digeststr, context);

	MD5Init(context);  /* In case it is reused */

        ST(0) = make_mortal_sv(aTHX_ digeststr, ix);

        XSRETURN(1);

void

context(ctx, ...)

	MD5_CTX* ctx

    PREINIT:

	char out[16];

        U32 w;

    PPCODE:

	if (items > 2) {

	    STRLEN len;

	    unsigned long blocks = SvUV(ST(1));

	    unsigned char *buf = (unsigned char *)(SvPV(ST(2), len));

	    ctx->A = buf[ 0] | (buf[ 1]<<8) | (buf[ 2]<<16) | (buf[ 3]<<24);

	    ctx->B = buf[ 4] | (buf[ 5]<<8) | (buf[ 6]<<16) | (buf[ 7]<<24);

	    ctx->C = buf[ 8] | (buf[ 9]<<8) | (buf[10]<<16) | (buf[11]<<24);

	    ctx->D = buf[12] | (buf[13]<<8) | (buf[14]<<16) | (buf[15]<<24);

	    ctx->bytes_low = blocks << 6;

	    ctx->bytes_high = blocks >> 26;

	    if (items == 4) {

		buf = (unsigned char *)(SvPV(ST(3), len));

		MD5Update(ctx, buf, len);

	    }

	    XSRETURN(1); /* ctx */

	} else if (items != 1) {

	    XSRETURN(0);

	}

        w=ctx->A; out[ 0]=w; out[ 1]=(w>>8); out[ 2]=(w>>16); out[ 3]=(w>>24);

        w=ctx->B; out[ 4]=w; out[ 5]=(w>>8); out[ 6]=(w>>16); out[ 7]=(w>>24);

        w=ctx->C; out[ 8]=w; out[ 9]=(w>>8); out[10]=(w>>16); out[11]=(w>>24);

        w=ctx->D; out[12]=w; out[13]=(w>>8); out[14]=(w>>16); out[15]=(w>>24);

	EXTEND(SP, 3);

	ST(0) = sv_2mortal(newSVuv(ctx->bytes_high << 26 |

				   ctx->bytes_low >> 6));

	ST(1) = sv_2mortal(newSVpv(out, 16));

	ST(2) = sv_2mortal(newSVpv((char *)ctx->buffer,

				   ctx->bytes_low & 0x3F));

	XSRETURN(3);

void

md5(...)

    ALIAS:

	Digest::MD5::md5        = F_BIN

	Digest::MD5::md5_hex    = F_HEX

	Digest::MD5::md5_base64 = F_B64

    PREINIT:

	MD5_CTX ctx;

	int i;

	unsigned char *data;

        STRLEN len;

	unsigned char digeststr[16];

    PPCODE:

	MD5Init(&ctx;;

	if ((PL_dowarn & G_WARN_ON) || ckWARN(WARN_SYNTAX)) {

            const char *msg = 0;

	    if (items == 1) {

		if (SvROK(ST(0))) {

                    SV* sv = SvRV(ST(0));

                    char *name;

		    if (SvOBJECT(sv) && (name = HvNAME(SvSTASH(sv)))

                                     && strEQ(name, "Digest::MD5"))

		        msg = "probably called as method";

		    else

			msg = "called with reference argument";

		}

	    }

	    else if (items > 1) {

		data = (unsigned char *)SvPV(ST(0), len);

		if (len == 11 && memEQ("Digest::MD5", data, 11)) {

		    msg = "probably called as class method";

		}

		else if (SvROK(ST(0))) {

		    SV* sv = SvRV(ST(0));

                    char *name;

		    if (SvOBJECT(sv) && (name = HvNAME(SvSTASH(sv)))

                                     && strEQ(name, "Digest::MD5"))

		        msg = "probably called as method";

		}

	    }

	    if (msg) {

	        const char *f = (ix == F_BIN) ? "md5" :

		                (ix == F_HEX) ? "md5_hex" : "md5_base64";

	        warn("&Digest::MD5::%s function %s", f, msg);

	    }

	}

	for (i = 0; i < items; i++) {

            U32 had_utf8 = SvUTF8(ST(i));

	    data = (unsigned char *)(SvPVbyte(ST(i), len));

	    MD5Update(&ctx, data, len);

	    if (had_utf8) sv_utf8_upgrade(ST(i));

	}

	MD5Final(digeststr, &ctx;;

        ST(0) = make_mortal_sv(aTHX_ digeststr, ix);

        XSRETURN(1);