Digest-Hashcash/Hashcash.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <time.h>
#include <stdlib.h>
#include <stdint.h>

/* NIST Secure Hash Algorithm */
/* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
/* from Peter C. Gutmann's implementation as found in */
/* Applied Cryptography by Bruce Schneier */
/* Further modifications to include the "UNRAVEL" stuff, below */

/* This code is in the public domain */

/* pcg: I was tempted to just rip this code off, after all, if you don't
 * demand anything I am inclined not to give anything. *Sigh* something
 * kept me from doing it, so here's the truth: I took this code from the
 * SHA1 perl module, since it looked reasonably well-crafted. I modified
 * it here and there, though.
 */

/*
 * we have lots of micro-optimizations here, this is just for toying
 * around...
 */

/* don't expect _too_ much from compilers for now. */
#if __GNUC__ > 2
#  define restrict __restrict__
#  define inline __inline__
#  ifdef __i386
#     define GCCX86ASM 1
#  endif
#elif __STDC_VERSION__ < 199900
#  define restrict
#  define inline
#endif

#if __GNUC__ < 2
#  define __attribute__(x)
#endif

#ifdef __i386
#  define a_regparm(n) __attribute__((__regparm__(n)))
#else
#  define a_regparm(n)
#endif

#define a_const __attribute__((__const__))

/* Useful defines & typedefs */

#if defined(U64TYPE) && (defined(USE_64_BIT_INT) || ((BYTEORDER != 0x1234) && (BYTEORDER != 0x4321)))
typedef U64TYPE ULONG;
#  if BYTEORDER == 0x1234
#    undef BYTEORDER
#    define BYTEORDER 0x12345678
#  elif BYTEORDER == 0x4321
#    undef BYTEORDER
#    define BYTEORDER 0x87654321   
#  endif
#else
typedef uint_fast32_t ULONG;     /* 32-or-more-bit quantity */
#endif

#if GCCX86ASM
#  define zprefix(n) ({ int _r; __asm__ ("bsrl %1, %0" : "=r" (_r) : "r" (n)); 31 - _r ; })
#elif __GNUC__ > 2 && __GNUC_MINOR__ > 3
#  define zprefix(n) (__extension__ ({ uint32_t n__ = (n); n ? __builtin_clz (n) : 32; }))
#else
static int a_const zprefix (ULONG n)
{
  static char zp[256] =
    {
      8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
      3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
      2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
      2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
      1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
      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, 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, 0, 0,
    };

  return
    n > 0xffffff ?      zp[n >> 24]
    : n > 0xffff ?  8 + zp[n >> 16]
    : n >   0xff ? 16 + zp[n >>  8]
    :              24 + zp[n];
}
#endif

#define SHA_BLOCKSIZE           64
#define SHA_DIGESTSIZE          20

typedef struct {
    ULONG digest[5];            /* message digest */
    ULONG count;                /* 32-bit bit count */
    int local;                  /* unprocessed amount in data */
    U8 data[SHA_BLOCKSIZE];     /* SHA data buffer */
} SHA_INFO;


/* SHA f()-functions */
#define f1(x,y,z)       ((x & y) | (~x & z))
#define f2(x,y,z)       (x ^ y ^ z)
#define f3(x,y,z)       ((x & y) | (x & z) | (y & z))
#define f4(x,y,z)       (x ^ y ^ z)

/* SHA constants */
#define CONST1          0x5a827999L
#define CONST2          0x6ed9eba1L
#define CONST3          0x8f1bbcdcL
#define CONST4          0xca62c1d6L

/* truncate to 32 bits -- should be a null op on 32-bit machines */
#define T32(x)  ((x) & 0xffffffffL)

/* 32-bit rotate */
#define R32(x,n)        T32(((x << n) | (x >> (32 - n))))

/* specific cases, for when the overall rotation is unraveled */
#define FA(n)   \
    T = T32(R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n); B = R32(B,30)

#define FB(n)   \
    E = T32(R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n); A = R32(A,30)

#define FC(n)   \
    D = T32(R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n); T = R32(T,30)

#define FD(n)   \
    C = T32(R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n); E = R32(E,30)

#define FE(n)   \
    B = T32(R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n); D = R32(D,30)

#define FT(n)   \
    A = T32(R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n); C = R32(C,30)

static void a_regparm(1) sha_transform(SHA_INFO *restrict sha_info)
{
    int i;
    U8 *restrict dp;
    ULONG T, A, B, C, D, E, W[80], *restrict WP;

    dp = sha_info->data;

#if BYTEORDER == 0x1234
    assert(sizeof(ULONG) == 4);
#  ifdef HAS_NTOHL
    for (i = 0; i < 16; ++i) {
        T = *((ULONG *) dp);
        dp += 4;
        W[i] = ntohl (T);
    }
#  else
    for (i = 0; i < 16; ++i) {
        T = *((ULONG *) dp);
        dp += 4;
        W[i] =  ((T << 24) & 0xff000000) | ((T <<  8) & 0x00ff0000) |
                ((T >>  8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
    }
#  endif
#elif BYTEORDER == 0x4321
    assert(sizeof(ULONG) == 4);
    for (i = 0; i < 16; ++i) {
        T = *((ULONG *) dp);
        dp += 4;
        W[i] = T32(T);
    }
#elif BYTEORDER == 0x12345678
    assert(sizeof(ULONG) == 8);
    for (i = 0; i < 16; i += 2) {
        T = *((ULONG *) dp);
        dp += 8;
        W[i] =  ((T << 24) & 0xff000000) | ((T <<  8) & 0x00ff0000) |
                ((T >>  8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
        T >>= 32;
        W[i+1] = ((T << 24) & 0xff000000) | ((T <<  8) & 0x00ff0000) |
                 ((T >>  8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
    }
#elif BYTEORDER == 0x87654321
    assert(sizeof(ULONG) == 8);
    for (i = 0; i < 16; i += 2) {
        T = *((ULONG *) dp);
        dp += 8;
        W[i] = T32(T >> 32);
        W[i+1] = T32(T);
    }
#else
#error Unknown byte order -- you need to add code here
#endif

    for (i = 16; i < 80; ++i)
      {
        T = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
        W[i] = R32(T,1);
      }

    A = sha_info->digest[0];
    B = sha_info->digest[1];
    C = sha_info->digest[2];
    D = sha_info->digest[3];
    E = sha_info->digest[4];

    WP = W;
    FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
    FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
    FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
    FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
    FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
    FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
    FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
    FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);

    sha_info->digest[0] = T32(sha_info->digest[0] + E);
    sha_info->digest[1] = T32(sha_info->digest[1] + T);
    sha_info->digest[2] = T32(sha_info->digest[2] + A);
    sha_info->digest[3] = T32(sha_info->digest[3] + B);
    sha_info->digest[4] = T32(sha_info->digest[4] + C);
}

/* initialize the SHA digest */

static void sha_init(SHA_INFO *restrict sha_info)
{
    sha_info->digest[0] = 0x67452301L;
    sha_info->digest[1] = 0xefcdab89L;
    sha_info->digest[2] = 0x98badcfeL;
    sha_info->digest[3] = 0x10325476L;
    sha_info->digest[4] = 0xc3d2e1f0L;
    sha_info->count = 0L;
    sha_info->local = 0;
}

/* update the SHA digest */

static void sha_update(SHA_INFO *restrict sha_info, U8 *restrict buffer, int count)
{
    int i;

    sha_info->count += count;
    if (sha_info->local) {
        i = SHA_BLOCKSIZE - sha_info->local;
        if (i > count) {
            i = count;
        }
        memcpy(((U8 *) sha_info->data) + sha_info->local, buffer, i);
        count -= i;
        buffer += i;
        sha_info->local += i;
        if (sha_info->local == SHA_BLOCKSIZE) {
            sha_transform(sha_info);
        } else {
            return;
        }
    }
    while (count >= SHA_BLOCKSIZE) {
        memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
        buffer += SHA_BLOCKSIZE;
        count -= SHA_BLOCKSIZE;
        sha_transform(sha_info);
    }
    memcpy(sha_info->data, buffer, count);
    sha_info->local = count;
}

/* finish computing the SHA digest */
static int sha_final(SHA_INFO *sha_info)
{
  int count = sha_info->count;
  int local = sha_info->local;

  sha_info->data[local] = 0x80;

  if (sha_info->local >= SHA_BLOCKSIZE - 8) {
    memset(sha_info->data + local + 1, 0, SHA_BLOCKSIZE - 1 - local);
    sha_transform(sha_info);
    memset(sha_info->data, 0, SHA_BLOCKSIZE - 2);
  } else {
    memset(sha_info->data + local + 1, 0, SHA_BLOCKSIZE - 3 - local);
  }

  sha_info->data[62] = count >> 5;
  sha_info->data[63] = count << 3;

  sha_transform (sha_info);

  return sha_info->digest[0]
           ? zprefix (sha_info->digest[0])
           : zprefix (sha_info->digest[1]) + 32;
}

#define TRIALCHAR "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!#$%&()*+,-./;<=>?@[]{}^_|"

static char       nextenc[256];

static char rand_char ()
{
  return TRIALCHAR[rand () % sizeof (TRIALCHAR)];
}

typedef double (*NVTime)(void);

static double simple_nvtime (void)
{
  return time (0);
}

static NVTime get_nvtime (void)
{
  SV **svp = hv_fetch (PL_modglobal, "Time::NVtime", 12, 0);

  if (svp && SvIOK(*svp))
    return INT2PTR(NVTime, SvIV(*svp));
  else
    return simple_nvtime;

}

MODULE = Digest::Hashcash               PACKAGE = Digest::Hashcash

BOOT:
{
   int i;

   for (i = 0; i < sizeof (TRIALCHAR); i++)
     nextenc[TRIALCHAR[i]] = TRIALCHAR[(i + 1) % sizeof (TRIALCHAR)];
}

PROTOTYPES: ENABLE

# could be improved quite a bit in accuracy
NV
_estimate_rounds ()
        CODE:
{
        char data[40];
        NVTime nvtime = get_nvtime ();
        NV t1, t2, t;
        int count = 0;
        SHA_INFO ctx;

        t = nvtime ();
        do {
          t1 = nvtime ();
        } while (t == t1);

        t = t2 = nvtime ();
        do {
          volatile int i;
          sha_init (&ctx);
          sha_update (&ctx, data, sizeof (data));
          i = sha_final (&ctx);

          if (!(++count & 1023))
            t2 = nvtime ();

        } while (t == t2);

        RETVAL = (NV)count / (t2 - t1);
}
        OUTPUT:
        RETVAL

SV *
_gentoken (int size, IV timestamp, char *resource, char *trial = "", int extrarand = 0)
        CODE:
{
        SHA_INFO ctx1, ctx;
        char *token, *seq, *s;
        int toklen, i;
        time_t tstamp = timestamp ? timestamp : time (0);
        struct tm *tm = gmtime (&tstamp);

        New (0, token,
            1 + 1                    // version
            + 12 + 1                 // time field sans century
            + strlen (resource) + 1  // ressource
            + strlen (trial) + extrarand + 8 + 1 // trial
            + 1,
            char);

        if (!token)
          croak ("out of memory");

        if (size > 64)
          croak ("size must be <= 64 in this implementation\n");

        toklen = sprintf (token, "%d:%02d%02d%02d%02d%02d%02d:%s:%s",
                          0, tm->tm_year % 100, tm->tm_mon + 1, tm->tm_mday,
                          tm->tm_hour, tm->tm_min, tm->tm_sec,
                          resource, trial);

        if (toklen > 8000)
          croak ("token length must be <= 8000 in this implementation\n");

        i = toklen + extrarand;
        while (toklen < i)
          token[toklen++] = rand_char ();

        sha_init (&ctx1);
        sha_update (&ctx1, token, toklen);

        seq = token + toklen;
        i +=  8;
        while (toklen < i)
          token[toklen++] = rand_char ();

        for (;;)
          {
            ctx = ctx1; // this "optimization" can help a lot for longer resource strings
            sha_update (&ctx, seq, 8);
            i = sha_final (&ctx);

            if (i >= size)
              break;

            s = seq;
            do {
              *s = nextenc [*s];
            } while (*s++ == 'a');
          }

        RETVAL = newSVpvn (token, toklen);
}
        OUTPUT:
        RETVAL

int
_prefixlen (SV *tok)
        CODE:
{
        STRLEN toklen;
        char *token = SvPV (tok, toklen);
        SHA_INFO ctx;

        sha_init (&ctx);
        sha_update (&ctx, token, toklen);
        RETVAL = sha_final (&ctx);
}
        OUTPUT:
        RETVAL


Revision:	1.5
Committed:	Mon Oct 20 04:31:25 2003 UTC (20 years, 7 months ago) by root
Branch:	MAIN
Changes since 1.4:	+20 -3 lines
Log Message:	* empty log message *
#	Content
1	#include "EXTERN.h"
2	#include "perl.h"
3	#include "XSUB.h"
4
5	#include <time.h>
6	#include <stdlib.h>
7	#include <stdint.h>
8
9	/* NIST Secure Hash Algorithm */
10	/* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
11	/* from Peter C. Gutmann's implementation as found in */
12	/* Applied Cryptography by Bruce Schneier */
13	/* Further modifications to include the "UNRAVEL" stuff, below */
14
15	/* This code is in the public domain */
16
17	/* pcg: I was tempted to just rip this code off, after all, if you don't
18	* demand anything I am inclined not to give anything. Sigh something
19	* kept me from doing it, so here's the truth: I took this code from the
20	* SHA1 perl module, since it looked reasonably well-crafted. I modified
21	* it here and there, though.
22	*/
23
24	/*
25	* we have lots of micro-optimizations here, this is just for toying
26	* around...
27	*/
28
29	/* don't expect _too_ much from compilers for now. */
30	#if __GNUC__ > 2
31	# define restrict __restrict__
32	# define inline __inline__
33	# ifdef __i386
34	# define GCCX86ASM 1
35	# endif
36	#elif __STDC_VERSION__ < 199900
37	# define restrict
38	# define inline
39	#endif
40
41	#if __GNUC__ < 2
42	# define __attribute__(x)
43	#endif
44
45	#ifdef __i386
46	# define a_regparm(n) __attribute__((__regparm__(n)))
47	#else
48	# define a_regparm(n)
49	#endif
50
51	#define a_const __attribute__((__const__))
52
53	/* Useful defines & typedefs */
54
55	#if defined(U64TYPE) && (defined(USE_64_BIT_INT) \|\| ((BYTEORDER != 0x1234) && (BYTEORDER != 0x4321)))
56	typedef U64TYPE ULONG;
57	# if BYTEORDER == 0x1234
58	# undef BYTEORDER
59	# define BYTEORDER 0x12345678
60	# elif BYTEORDER == 0x4321
61	# undef BYTEORDER
62	# define BYTEORDER 0x87654321
63	# endif
64	#else
65	typedef uint_fast32_t ULONG; /* 32-or-more-bit quantity */
66	#endif
67
68	#if GCCX86ASM
69	# define zprefix(n) ({ int _r; __asm__ ("bsrl %1, %0" : "=r" (_r) : "r" (n)); 31 - _r ; })
70	#elif __GNUC__ > 2 && __GNUC_MINOR__ > 3
71	# define zprefix(n) (__extension__ ({ uint32_t n__ = (n); n ? __builtin_clz (n) : 32; }))
72	#else
73	static int a_const zprefix (ULONG n)
74	{
75	static char zp[256] =
76	{
77	8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
78	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
79	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
80	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
81	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
82	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
83	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
84	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
85	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
86	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
87	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
88	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
89	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
90	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
91	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
92	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
93	};
94
95	return
96	n > 0xffffff ? zp[n >> 24]
97	: n > 0xffff ? 8 + zp[n >> 16]
98	: n > 0xff ? 16 + zp[n >> 8]
99	: 24 + zp[n];
100	}
101	#endif
102
103	#define SHA_BLOCKSIZE 64
104	#define SHA_DIGESTSIZE 20
105
106	typedef struct {
107	ULONG digest[5]; /* message digest */
108	ULONG count; /* 32-bit bit count */
109	int local; /* unprocessed amount in data */
110	U8 data[SHA_BLOCKSIZE]; /* SHA data buffer */
111	} SHA_INFO;
112
113
114	/* SHA f()-functions */
115	#define f1(x,y,z) ((x & y) \| (~x & z))
116	#define f2(x,y,z) (x ^ y ^ z)
117	#define f3(x,y,z) ((x & y) \| (x & z) \| (y & z))
118	#define f4(x,y,z) (x ^ y ^ z)
119
120	/* SHA constants */
121	#define CONST1 0x5a827999L
122	#define CONST2 0x6ed9eba1L
123	#define CONST3 0x8f1bbcdcL
124	#define CONST4 0xca62c1d6L
125
126	/* truncate to 32 bits -- should be a null op on 32-bit machines */
127	#define T32(x) ((x) & 0xffffffffL)
128
129	/* 32-bit rotate */
130	#define R32(x,n) T32(((x << n) \| (x >> (32 - n))))
131
132	/* specific cases, for when the overall rotation is unraveled */
133	#define FA(n) \
134	T = T32(R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n); B = R32(B,30)
135
136	#define FB(n) \
137	E = T32(R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n); A = R32(A,30)
138
139	#define FC(n) \
140	D = T32(R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n); T = R32(T,30)
141
142	#define FD(n) \
143	C = T32(R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n); E = R32(E,30)
144
145	#define FE(n) \
146	B = T32(R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n); D = R32(D,30)
147
148	#define FT(n) \
149	A = T32(R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n); C = R32(C,30)
150
151	static void a_regparm(1) sha_transform(SHA_INFO *restrict sha_info)
152	{
153	int i;
154	U8 *restrict dp;
155	ULONG T, A, B, C, D, E, W[80], *restrict WP;
156
157	dp = sha_info->data;
158
159	#if BYTEORDER == 0x1234
160	assert(sizeof(ULONG) == 4);
161	# ifdef HAS_NTOHL
162	for (i = 0; i < 16; ++i) {
163	T = ((ULONG ) dp);
164	dp += 4;
165	W[i] = ntohl (T);
166	}
167	# else
168	for (i = 0; i < 16; ++i) {
169	T = ((ULONG ) dp);
170	dp += 4;
171	W[i] = ((T << 24) & 0xff000000) \| ((T << 8) & 0x00ff0000) \|
172	((T >> 8) & 0x0000ff00) \| ((T >> 24) & 0x000000ff);
173	}
174	# endif
175	#elif BYTEORDER == 0x4321
176	assert(sizeof(ULONG) == 4);
177	for (i = 0; i < 16; ++i) {
178	T = ((ULONG ) dp);
179	dp += 4;
180	W[i] = T32(T);
181	}
182	#elif BYTEORDER == 0x12345678
183	assert(sizeof(ULONG) == 8);
184	for (i = 0; i < 16; i += 2) {
185	T = ((ULONG ) dp);
186	dp += 8;
187	W[i] = ((T << 24) & 0xff000000) \| ((T << 8) & 0x00ff0000) \|
188	((T >> 8) & 0x0000ff00) \| ((T >> 24) & 0x000000ff);
189	T >>= 32;
190	W[i+1] = ((T << 24) & 0xff000000) \| ((T << 8) & 0x00ff0000) \|
191	((T >> 8) & 0x0000ff00) \| ((T >> 24) & 0x000000ff);
192	}
193	#elif BYTEORDER == 0x87654321
194	assert(sizeof(ULONG) == 8);
195	for (i = 0; i < 16; i += 2) {
196	T = ((ULONG ) dp);
197	dp += 8;
198	W[i] = T32(T >> 32);
199	W[i+1] = T32(T);
200	}
201	#else
202	#error Unknown byte order -- you need to add code here
203	#endif
204
205	for (i = 16; i < 80; ++i)
206	{
207	T = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
208	W[i] = R32(T,1);
209	}
210
211	A = sha_info->digest[0];
212	B = sha_info->digest[1];
213	C = sha_info->digest[2];
214	D = sha_info->digest[3];
215	E = sha_info->digest[4];
216
217	WP = W;
218	FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
219	FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
220	FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
221	FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
222	FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
223	FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
224	FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
225	FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);
226
227	sha_info->digest[0] = T32(sha_info->digest[0] + E);
228	sha_info->digest[1] = T32(sha_info->digest[1] + T);
229	sha_info->digest[2] = T32(sha_info->digest[2] + A);
230	sha_info->digest[3] = T32(sha_info->digest[3] + B);
231	sha_info->digest[4] = T32(sha_info->digest[4] + C);
232	}
233
234	/* initialize the SHA digest */
235
236	static void sha_init(SHA_INFO *restrict sha_info)
237	{
238	sha_info->digest[0] = 0x67452301L;
239	sha_info->digest[1] = 0xefcdab89L;
240	sha_info->digest[2] = 0x98badcfeL;
241	sha_info->digest[3] = 0x10325476L;
242	sha_info->digest[4] = 0xc3d2e1f0L;
243	sha_info->count = 0L;
244	sha_info->local = 0;
245	}
246
247	/* update the SHA digest */
248
249	static void sha_update(SHA_INFO restrict sha_info, U8 restrict buffer, int count)
250	{
251	int i;
252
253	sha_info->count += count;
254	if (sha_info->local) {
255	i = SHA_BLOCKSIZE - sha_info->local;
256	if (i > count) {
257	i = count;
258	}
259	memcpy(((U8 *) sha_info->data) + sha_info->local, buffer, i);
260	count -= i;
261	buffer += i;
262	sha_info->local += i;
263	if (sha_info->local == SHA_BLOCKSIZE) {
264	sha_transform(sha_info);
265	} else {
266	return;
267	}
268	}
269	while (count >= SHA_BLOCKSIZE) {
270	memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
271	buffer += SHA_BLOCKSIZE;
272	count -= SHA_BLOCKSIZE;
273	sha_transform(sha_info);
274	}
275	memcpy(sha_info->data, buffer, count);
276	sha_info->local = count;
277	}
278
279	/* finish computing the SHA digest */
280	static int sha_final(SHA_INFO *sha_info)
281	{
282	int count = sha_info->count;
283	int local = sha_info->local;
284
285	sha_info->data[local] = 0x80;
286
287	if (sha_info->local >= SHA_BLOCKSIZE - 8) {
288	memset(sha_info->data + local + 1, 0, SHA_BLOCKSIZE - 1 - local);
289	sha_transform(sha_info);
290	memset(sha_info->data, 0, SHA_BLOCKSIZE - 2);
291	} else {
292	memset(sha_info->data + local + 1, 0, SHA_BLOCKSIZE - 3 - local);
293	}
294
295	sha_info->data[62] = count >> 5;
296	sha_info->data[63] = count << 3;
297
298	sha_transform (sha_info);
299
300	return sha_info->digest[0]
301	? zprefix (sha_info->digest[0])
302	: zprefix (sha_info->digest[1]) + 32;
303	}
304
305	#define TRIALCHAR "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!#$%&()*+,-./;<=>?@[]{}^_\|"
306
307	static char nextenc[256];
308
309	static char rand_char ()
310	{
311	return TRIALCHAR[rand () % sizeof (TRIALCHAR)];
312	}
313
314	typedef double (*NVTime)(void);
315
316	static double simple_nvtime (void)
317	{
318	return time (0);
319	}
320
321	static NVTime get_nvtime (void)
322	{
323	SV **svp = hv_fetch (PL_modglobal, "Time::NVtime", 12, 0);
324
325	if (svp && SvIOK(*svp))
326	return INT2PTR(NVTime, SvIV(*svp));
327	else
328	return simple_nvtime;
329
330	}
331
332	MODULE = Digest::Hashcash PACKAGE = Digest::Hashcash
333
334	BOOT:
335	{
336	int i;
337
338	for (i = 0; i < sizeof (TRIALCHAR); i++)
339	nextenc[TRIALCHAR[i]] = TRIALCHAR[(i + 1) % sizeof (TRIALCHAR)];
340	}
341
342	PROTOTYPES: ENABLE
343
344	# could be improved quite a bit in accuracy
345	NV
346	_estimate_rounds ()
347	CODE:
348	{
349	char data[40];
350	NVTime nvtime = get_nvtime ();
351	NV t1, t2, t;
352	int count = 0;
353	SHA_INFO ctx;
354
355	t = nvtime ();
356	do {
357	t1 = nvtime ();
358	} while (t == t1);
359
360	t = t2 = nvtime ();
361	do {
362	volatile int i;
363	sha_init (&ctx);
364	sha_update (&ctx, data, sizeof (data));
365	i = sha_final (&ctx);
366
367	if (!(++count & 1023))
368	t2 = nvtime ();
369
370	} while (t == t2);
371
372	RETVAL = (NV)count / (t2 - t1);
373	}
374	OUTPUT:
375	RETVAL
376
377	SV *
378	_gentoken (int size, IV timestamp, char resource, char trial = "", int extrarand = 0)
379	CODE:
380	{
381	SHA_INFO ctx1, ctx;
382	char token, seq, *s;
383	int toklen, i;
384	time_t tstamp = timestamp ? timestamp : time (0);
385	struct tm *tm = gmtime (&tstamp);
386
387	New (0, token,
388	1 + 1 // version
389	+ 12 + 1 // time field sans century
390	+ strlen (resource) + 1 // ressource
391	+ strlen (trial) + extrarand + 8 + 1 // trial
392	+ 1,
393	char);
394
395	if (!token)
396	croak ("out of memory");
397
398	if (size > 64)
399	croak ("size must be <= 64 in this implementation\n");
400
401	toklen = sprintf (token, "%d:%02d%02d%02d%02d%02d%02d:%s:%s",
402	0, tm->tm_year % 100, tm->tm_mon + 1, tm->tm_mday,
403	tm->tm_hour, tm->tm_min, tm->tm_sec,
404	resource, trial);
405
406	if (toklen > 8000)
407	croak ("token length must be <= 8000 in this implementation\n");
408
409	i = toklen + extrarand;
410	while (toklen < i)
411	token[toklen++] = rand_char ();
412
413	sha_init (&ctx1);
414	sha_update (&ctx1, token, toklen);
415
416	seq = token + toklen;
417	i += 8;
418	while (toklen < i)
419	token[toklen++] = rand_char ();
420
421	for (;;)
422	{
423	ctx = ctx1; // this "optimization" can help a lot for longer resource strings
424	sha_update (&ctx, seq, 8);
425	i = sha_final (&ctx);
426
427	if (i >= size)
428	break;
429
430	s = seq;
431	do {
432	s = nextenc [s];
433	} while (*s++ == 'a');
434	}
435
436	RETVAL = newSVpvn (token, toklen);
437	}
438	OUTPUT:
439	RETVAL
440
441	int
442	_prefixlen (SV *tok)
443	CODE:
444	{
445	STRLEN toklen;
446	char *token = SvPV (tok, toklen);
447	SHA_INFO ctx;
448
449	sha_init (&ctx);
450	sha_update (&ctx, token, toklen);
451	RETVAL = sha_final (&ctx);
452	}
453	OUTPUT:
454	RETVAL
455
456