usr/klibc/sha1hash.c

/*
SHA-1 in C
By Steve Reid <sreid@sea-to-sky.net>
100% Public Domain

-----------------
Modified 7/98
By James H. Brown <jbrown@burgoyne.com>
Still 100% Public Domain

Corrected a problem which generated improper hash values on 16 bit machines
Routine SHA1Update changed from
	void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int
len)
to
	void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned
long len)

The 'len' parameter was declared an int which works fine on 32 bit machines.
However, on 16 bit machines an int is too small for the shifts being done
against
it.  This caused the hash function to generate incorrect values if len was
greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update().

Since the file IO in main() reads 16K at a time, any file 8K or larger would
be guaranteed to generate the wrong hash (e.g. Test Vector #3, a million
"a"s).

I also changed the declaration of variables i & j in SHA1Update to
unsigned long from unsigned int for the same reason.

These changes should make no difference to any 32 bit implementations since
an
int and a long are the same size in those environments.

--
I also corrected a few compiler warnings generated by Borland C.
1. Added #include <process.h> for exit() prototype
2. Removed unused variable 'j' in SHA1Final
3. Changed exit(0) to return(0) at end of main.

ALL changes I made can be located by searching for comments containing 'JHB'
-----------------
Modified 8/98
By Steve Reid <sreid@sea-to-sky.net>
Still 100% public domain

1- Removed #include <process.h> and used return() instead of exit()
2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)
3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net

-----------------
Modified 4/01
By Saul Kravitz <Saul.Kravitz@celera.com>
Still 100% PD
Modified to run on Compaq Alpha hardware.

-----------------
Modified 2/03
By H. Peter Anvin <hpa@zytor.com>
Still 100% PD
Modified to run on any hardware with <inttypes.h> and <netinet/in.h>
Changed the driver program

*/

/*
Test Vectors (from FIPS PUB 180-1)
"abc"
  A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
  84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
A million repetitions of "a"
  34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
*/

/* #define SHA1HANDSOFF  */

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <netinet/in.h>		/* For htonl/ntohl/htons/ntohs */

/* #include <process.h> */	/* prototype for exit() - JHB */
/* Using return() instead of exit() - SWR */

typedef struct {
    uint32_t state[5];
    uint32_t count[2];
    unsigned char buffer[64];
} SHA1_CTX;

void SHA1Transform(uint32_t state[5], unsigned char buffer[64]);
void SHA1Init(SHA1_CTX* context);
void SHA1Update(SHA1_CTX* context, unsigned char* data, uint32_t len);	/*
JHB */
void SHA1Final(unsigned char digest[20], SHA1_CTX* context);

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

/* blk0() and blk() perform the initial expand. */
/* I got the idea of expanding during the round function from SSLeay */
#define blk0(i) (block->l[i] = ntohl(block->l[i]))
#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
    ^block->l[(i+2)&15]^block->l[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);


#ifdef VERBOSE  /* SAK */
void SHAPrintContext(SHA1_CTX *context, char *msg){
  printf("%s (%d,%d) %x %x %x %x %x\n",
	 msg,
	 context->count[0], context->count[1],
	 context->state[0],
	 context->state[1],
	 context->state[2],
	 context->state[3],
	 context->state[4]);
}
#endif

/* Hash a single 512-bit block. This is the core of the algorithm. */

void SHA1Transform(uint32_t state[5], unsigned char buffer[64])
{
uint32_t a, b, c, d, e;
typedef union {
    unsigned char c[64];
    uint32_t l[16];
} CHAR64LONG16;
CHAR64LONG16* block;
#ifdef SHA1HANDSOFF
static unsigned char workspace[64];
    block = (CHAR64LONG16*)workspace;
    memcpy(block, buffer, 64);
#else
    block = (CHAR64LONG16*)buffer;
#endif
    /* Copy context->state[] to working vars */
    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    /* 4 rounds of 20 operations each. Loop unrolled. */
    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
    /* Add the working vars back into context.state[] */
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    /* Wipe variables */
    a = b = c = d = e = 0;
}


/* SHA1Init - Initialize new context */

void SHA1Init(SHA1_CTX* context)
{
    /* SHA1 initialization constants */
    context->state[0] = 0x67452301;
    context->state[1] = 0xEFCDAB89;
    context->state[2] = 0x98BADCFE;
    context->state[3] = 0x10325476;
    context->state[4] = 0xC3D2E1F0;
    context->count[0] = context->count[1] = 0;
}


/* Run your data through this. */

void SHA1Update(SHA1_CTX* context, unsigned char* data, uint32_t len)	/*
JHB */
{
uint32_t i, j;	/* JHB */

#ifdef VERBOSE
    SHAPrintContext(context, "before");
#endif
    j = (context->count[0] >> 3) & 63;
    if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;
    context->count[1] += (len >> 29);
    if ((j + len) > 63) {
        memcpy(&context->buffer[j], data, (i = 64-j));
        SHA1Transform(context->state, context->buffer);
        for ( ; i + 63 < len; i += 64) {
            SHA1Transform(context->state, &data[i]);
        }
        j = 0;
    }
    else i = 0;
    memcpy(&context->buffer[j], &data[i], len - i);
#ifdef VERBOSE
    SHAPrintContext(context, "after ");
#endif
}


/* Add padding and return the message digest. */

void SHA1Final(unsigned char digest[20], SHA1_CTX* context)
{
uint32_t i;	/* JHB */
unsigned char finalcount[8];

    for (i = 0; i < 8; i++) {
        finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
         >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
    }
    SHA1Update(context, (unsigned char *)"\200", 1);
    while ((context->count[0] & 504) != 448) {
        SHA1Update(context, (unsigned char *)"\0", 1);
    }
    SHA1Update(context, finalcount, 8);  /* Should cause a SHA1Transform()
*/
    for (i = 0; i < 20; i++) {
        digest[i] = (unsigned char)
         ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
    }
    /* Wipe variables */
    i = 0;	/* JHB */
    memset(context->buffer, 0, 64);
    memset(context->state, 0, 20);
    memset(context->count, 0, 8);
    memset(finalcount, 0, 8);	/* SWR */
#ifdef SHA1HANDSOFF  /* make SHA1Transform overwrite it's own static vars */
    SHA1Transform(context->state, context->buffer);
#endif
}

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

/* This is not quite the MIME base64 algorithm: it uses _ instead of /,
   and instead of padding the output with = characters we just make the
   output shorter. */
char *mybase64(uint8_t digest[20])
{
  static const char charz[] =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
  uint8_t input[21];
  static char output[28];
  int i, j;
  uint8_t *p;
  char *q;
  uint32_t bv;

  memcpy(input, digest, 20);
  input[20] = 0;		/* Pad to multiple of 3 bytes */

  p = input;  q = output;
  for ( i = 0 ; i < 7 ; i++ ) {
    bv = (p[0] << 16) | (p[1] << 8) | p[2];
    p += 3;
    for ( j = 0 ; j < 4 ; j++ ) {
      *q++ = charz[(bv >> 18) & 0x3f];
      bv <<= 6;
    }
  }
  *--q = '\0';			/* The last character is not significant */
  return output;
}

int main(int argc, char** argv)
{
  int i;
  SHA1_CTX context;
  uint8_t digest[20], buffer[16384];
  FILE* file;

  if (argc < 2) {
    file = stdin;
  }
  else {
    if (!(file = fopen(argv[1], "rb"))) {
      fputs("Unable to open file.", stderr);
      return(-1);
    }
  }
  SHA1Init(&context);
  while (!feof(file)) {  /* note: what if ferror(file) */
    i = fread(buffer, 1, 16384, file);
    SHA1Update(&context, buffer, i);
  }
  SHA1Final(digest, &context);
  fclose(file);

  puts(mybase64(digest));

  return 0;
}
1	/*
2	SHA-1 in C
3	By Steve Reid <sreid@sea-to-sky.net>
4	100% Public Domain
5
6	-----------------
7	Modified 7/98
8	By James H. Brown <jbrown@burgoyne.com>
9	Still 100% Public Domain
10
11	Corrected a problem which generated improper hash values on 16 bit machines
12	Routine SHA1Update changed from
13	void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int
14	len)
15	to
16	void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned
17	long len)
18
19	The 'len' parameter was declared an int which works fine on 32 bit machines.
20	However, on 16 bit machines an int is too small for the shifts being done
21	against
22	it. This caused the hash function to generate incorrect values if len was
23	greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update().
24
25	Since the file IO in main() reads 16K at a time, any file 8K or larger would
26	be guaranteed to generate the wrong hash (e.g. Test Vector #3, a million
27	"a"s).
28
29	I also changed the declaration of variables i & j in SHA1Update to
30	unsigned long from unsigned int for the same reason.
31
32	These changes should make no difference to any 32 bit implementations since
33	an
34	int and a long are the same size in those environments.
35
36	--
37	I also corrected a few compiler warnings generated by Borland C.
38	1. Added #include <process.h> for exit() prototype
39	2. Removed unused variable 'j' in SHA1Final
40	3. Changed exit(0) to return(0) at end of main.
41
42	ALL changes I made can be located by searching for comments containing 'JHB'
43	-----------------
44	Modified 8/98
45	By Steve Reid <sreid@sea-to-sky.net>
46	Still 100% public domain
47
48	1- Removed #include <process.h> and used return() instead of exit()
49	2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)
50	3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net
51
52	-----------------
53	Modified 4/01
54	By Saul Kravitz <Saul.Kravitz@celera.com>
55	Still 100% PD
56	Modified to run on Compaq Alpha hardware.
57
58	-----------------
59	Modified 2/03
60	By H. Peter Anvin <hpa@zytor.com>
61	Still 100% PD
62	Modified to run on any hardware with <inttypes.h> and <netinet/in.h>
63	Changed the driver program
64
65	*/
66
67	/*
68	Test Vectors (from FIPS PUB 180-1)
69	"abc"
70	A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
71	"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
72	84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
73	A million repetitions of "a"
74	34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
75	*/
76
77	/* #define SHA1HANDSOFF */
78
79	#include <stdio.h>
80	#include <string.h>
81	#include <inttypes.h>
82	#include <netinet/in.h> /* For htonl/ntohl/htons/ntohs */
83
84	/* #include <process.h> / / prototype for exit() - JHB */
85	/* Using return() instead of exit() - SWR */
86
87	typedef struct {
88	uint32_t state[5];
89	uint32_t count[2];
90	unsigned char buffer[64];
91	} SHA1_CTX;
92
93	void SHA1Transform(uint32_t state[5], unsigned char buffer[64]);
94	void SHA1Init(SHA1_CTX* context);
95	void SHA1Update(SHA1_CTX* context, unsigned char* data, uint32_t len); /*
96	JHB */
97	void SHA1Final(unsigned char digest[20], SHA1_CTX* context);
98
99	#define rol(value, bits) (((value) << (bits)) \| ((value) >> (32 - (bits))))
100
101	/* blk0() and blk() perform the initial expand. */
102	/* I got the idea of expanding during the round function from SSLeay */
103	#define blk0(i) (block->l[i] = ntohl(block->l[i]))
104	#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
105	^block->l[(i+2)&15]^block->l[i&15],1))
106
107	/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
108	#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
109	#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
110	#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
111	#define R3(v,w,x,y,z,i) z+=(((w\|x)&y)\|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
112	#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
113
114
115	#ifdef VERBOSE /* SAK */
116	void SHAPrintContext(SHA1_CTX context, char msg){
117	printf("%s (%d,%d) %x %x %x %x %x\n",
118	msg,
119	context->count[0], context->count[1],
120	context->state[0],
121	context->state[1],
122	context->state[2],
123	context->state[3],
124	context->state[4]);
125	}
126	#endif
127
128	/* Hash a single 512-bit block. This is the core of the algorithm. */
129
130	void SHA1Transform(uint32_t state[5], unsigned char buffer[64])
131	{
132	uint32_t a, b, c, d, e;
133	typedef union {
134	unsigned char c[64];
135	uint32_t l[16];
136	} CHAR64LONG16;
137	CHAR64LONG16* block;
138	#ifdef SHA1HANDSOFF
139	static unsigned char workspace[64];
140	block = (CHAR64LONG16*)workspace;
141	memcpy(block, buffer, 64);
142	#else
143	block = (CHAR64LONG16*)buffer;
144	#endif
145	/* Copy context->state[] to working vars */
146	a = state[0];
147	b = state[1];
148	c = state[2];
149	d = state[3];
150	e = state[4];
151	/* 4 rounds of 20 operations each. Loop unrolled. */
152	R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
153	R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
154	R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
155	R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
156	R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
157	R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
158	R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
159	R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
160	R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
161	R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
162	R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
163	R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
164	R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
165	R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
166	R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
167	R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
168	R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
169	R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
170	R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
171	R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
172	/* Add the working vars back into context.state[] */
173	state[0] += a;
174	state[1] += b;
175	state[2] += c;
176	state[3] += d;
177	state[4] += e;
178	/* Wipe variables */
179	a = b = c = d = e = 0;
180	}
181
182
183	/* SHA1Init - Initialize new context */
184
185	void SHA1Init(SHA1_CTX* context)
186	{
187	/* SHA1 initialization constants */
188	context->state[0] = 0x67452301;
189	context->state[1] = 0xEFCDAB89;
190	context->state[2] = 0x98BADCFE;
191	context->state[3] = 0x10325476;
192	context->state[4] = 0xC3D2E1F0;
193	context->count[0] = context->count[1] = 0;
194	}
195
196
197	/* Run your data through this. */
198
199	void SHA1Update(SHA1_CTX* context, unsigned char* data, uint32_t len) /*
200	JHB */
201	{
202	uint32_t i, j; /* JHB */
203
204	#ifdef VERBOSE
205	SHAPrintContext(context, "before");
206	#endif
207	j = (context->count[0] >> 3) & 63;
208	if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;
209	context->count[1] += (len >> 29);
210	if ((j + len) > 63) {
211	memcpy(&context->buffer[j], data, (i = 64-j));
212	SHA1Transform(context->state, context->buffer);
213	for ( ; i + 63 < len; i += 64) {
214	SHA1Transform(context->state, &data[i]);
215	}
216	j = 0;
217	}
218	else i = 0;
219	memcpy(&context->buffer[j], &data[i], len - i);
220	#ifdef VERBOSE
221	SHAPrintContext(context, "after ");
222	#endif
223	}
224
225
226	/* Add padding and return the message digest. */
227
228	void SHA1Final(unsigned char digest[20], SHA1_CTX* context)
229	{
230	uint32_t i; /* JHB */
231	unsigned char finalcount[8];
232
233	for (i = 0; i < 8; i++) {
234	finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
235	>> ((3-(i & 3)) * 8) ) & 255); /* Endian independent */
236	}
237	SHA1Update(context, (unsigned char *)"\200", 1);
238	while ((context->count[0] & 504) != 448) {
239	SHA1Update(context, (unsigned char *)"\0", 1);
240	}
241	SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform()
242	*/
243	for (i = 0; i < 20; i++) {
244	digest[i] = (unsigned char)
245	((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
246	}
247	/* Wipe variables */
248	i = 0; /* JHB */
249	memset(context->buffer, 0, 64);
250	memset(context->state, 0, 20);
251	memset(context->count, 0, 8);
252	memset(finalcount, 0, 8); /* SWR */
253	#ifdef SHA1HANDSOFF /* make SHA1Transform overwrite it's own static vars */
254	SHA1Transform(context->state, context->buffer);
255	#endif
256	}
257
258	/*************************************************************/
259
260	/* This is not quite the MIME base64 algorithm: it uses _ instead of /,
261	and instead of padding the output with = characters we just make the
262	output shorter. */
263	char *mybase64(uint8_t digest[20])
264	{
265	static const char charz[] =
266	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
267	uint8_t input[21];
268	static char output[28];
269	int i, j;
270	uint8_t *p;
271	char *q;
272	uint32_t bv;
273
274	memcpy(input, digest, 20);
275	input[20] = 0; /* Pad to multiple of 3 bytes */
276
277	p = input; q = output;
278	for ( i = 0 ; i < 7 ; i++ ) {
279	bv = (p[0] << 16) \| (p[1] << 8) \| p[2];
280	p += 3;
281	for ( j = 0 ; j < 4 ; j++ ) {
282	*q++ = charz[(bv >> 18) & 0x3f];
283	bv <<= 6;
284	}
285	}
286	--q = '\0'; / The last character is not significant */
287	return output;
288	}
289
290	int main(int argc, char** argv)
291	{
292	int i;
293	SHA1_CTX context;
294	uint8_t digest[20], buffer[16384];
295	FILE* file;
296
297	if (argc < 2) {
298	file = stdin;
299	}
300	else {
301	if (!(file = fopen(argv[1], "rb"))) {
302	fputs("Unable to open file.", stderr);
303	return(-1);
304	}
305	}
306	SHA1Init(&context);
307	while (!feof(file)) { /* note: what if ferror(file) */
308	i = fread(buffer, 1, 16384, file);
309	SHA1Update(&context, buffer, i);
310	}
311	SHA1Final(digest, &context);
312	fclose(file);
313
314	puts(mybase64(digest));
315
316	return 0;
317	}