[thirdparty/git.git] / block-sha1 / sha1.c

/*
 * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.c),
 * optimized to do word accesses rather than byte accesses,
 * and to avoid unnecessary copies into the context array.
 */

#include <string.h>
#include <arpa/inet.h>

#include "sha1.h"

/* Hash one 64-byte block of data */
static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data);

void blk_SHA1_Init(blk_SHA_CTX *ctx)
{
	ctx->size = 0;

	/* Initialize H with the magic constants (see FIPS180 for constants)
	 */
	ctx->H[0] = 0x67452301;
	ctx->H[1] = 0xefcdab89;
	ctx->H[2] = 0x98badcfe;
	ctx->H[3] = 0x10325476;
	ctx->H[4] = 0xc3d2e1f0;
}


void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len)
{
	int lenW = ctx->size & 63;

	ctx->size += len;

	/* Read the data into W and process blocks as they get full
	 */
	if (lenW) {
		int left = 64 - lenW;
		if (len < left)
			left = len;
		memcpy(lenW + (char *)ctx->W, data, left);
		lenW = (lenW + left) & 63;
		len -= left;
		data += left;
		if (lenW)
			return;
		blk_SHA1Block(ctx, ctx->W);
	}
	while (len >= 64) {
		blk_SHA1Block(ctx, data);
		data += 64;
		len -= 64;
	}
	if (len)
		memcpy(ctx->W, data, len);
}


void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx)
{
	static const unsigned char pad[64] = { 0x80 };
	unsigned int padlen[2];
	int i;

	/* Pad with a binary 1 (ie 0x80), then zeroes, then length
	 */
	padlen[0] = htonl(ctx->size >> 29);
	padlen[1] = htonl(ctx->size << 3);

	i = ctx->size & 63;
	blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - i)));
	blk_SHA1_Update(ctx, padlen, 8);

	/* Output hash
	 */
	for (i = 0; i < 5; i++)
		((unsigned int *)hashout)[i] = htonl(ctx->H[i]);
}

#if defined(__i386__) || defined(__x86_64__)

#define SHA_ASM(op, x, n) ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; })
#define SHA_ROL(x,n)	SHA_ASM("rol", x, n)
#define SHA_ROR(x,n)	SHA_ASM("ror", x, n)

#else

#define SHA_ROT(X,l,r)	(((X) << (l)) | ((X) >> (r)))
#define SHA_ROL(X,n)	SHA_ROT(X,n,32-(n))
#define SHA_ROR(X,n)	SHA_ROT(X,32-(n),n)

#endif

/* This "rolls" over the 512-bit array */
#define W(x) (array[(x)&15])

/*
 * Where do we get the source from? The first 16 iterations get it from
 * the input data, the next mix it from the 512-bit array.
 */
#define SHA_SRC(t) htonl(data[t])
#define SHA_MIX(t) SHA_ROL(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1)

#define SHA_ROUND(t, input, fn, constant) \
	TEMP = input(t); W(t) = TEMP; \
	TEMP += SHA_ROL(A,5) + (fn) + E + (constant); \
	E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP

#define T_0_15(t)  SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999 )
#define T_16_19(t) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999 )
#define T_20_39(t) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1 )
#define T_40_59(t) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc )
#define T_60_79(t) SHA_ROUND(t, SHA_MIX, (B^C^D) ,  0xca62c1d6 )

static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data)
{
	unsigned int A,B,C,D,E,TEMP;
	unsigned int array[16];

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

	/* Round 1 - iterations 0-16 take their input from 'data' */
	T_0_15( 0); T_0_15( 1); T_0_15( 2); T_0_15( 3); T_0_15( 4);
	T_0_15( 5); T_0_15( 6); T_0_15( 7); T_0_15( 8); T_0_15( 9);
	T_0_15(10); T_0_15(11); T_0_15(12); T_0_15(13); T_0_15(14);
	T_0_15(15);

	/* Round 1 - tail. Input from 512-bit mixing array */
	T_16_19(16); T_16_19(17); T_16_19(18); T_16_19(19);

	/* Round 2 */
	T_20_39(20); T_20_39(21); T_20_39(22); T_20_39(23); T_20_39(24);
	T_20_39(25); T_20_39(26); T_20_39(27); T_20_39(28); T_20_39(29);
	T_20_39(30); T_20_39(31); T_20_39(32); T_20_39(33); T_20_39(34);
	T_20_39(35); T_20_39(36); T_20_39(37); T_20_39(38); T_20_39(39);

	/* Round 3 */
	T_40_59(40); T_40_59(41); T_40_59(42); T_40_59(43); T_40_59(44);
	T_40_59(45); T_40_59(46); T_40_59(47); T_40_59(48); T_40_59(49);
	T_40_59(50); T_40_59(51); T_40_59(52); T_40_59(53); T_40_59(54);
	T_40_59(55); T_40_59(56); T_40_59(57); T_40_59(58); T_40_59(59);

	/* Round 4 */
	T_60_79(60); T_60_79(61); T_60_79(62); T_60_79(63); T_60_79(64);
	T_60_79(65); T_60_79(66); T_60_79(67); T_60_79(68); T_60_79(69);
	T_60_79(70); T_60_79(71); T_60_79(72); T_60_79(73); T_60_79(74);
	T_60_79(75); T_60_79(76); T_60_79(77); T_60_79(78); T_60_79(79);

	ctx->H[0] += A;
	ctx->H[1] += B;
	ctx->H[2] += C;
	ctx->H[3] += D;
	ctx->H[4] += E;
}
Commit	Line	Data
d7c208a9 LT	1	/*
	2	* Based on the Mozilla SHA1 (see mozilla-sha1/sha1.c),
	3	* optimized to do word accesses rather than byte accesses,
	4	* and to avoid unnecessary copies into the context array.
	5	*/
	6
	7	#include <string.h>
	8	#include <arpa/inet.h>
	9
	10	#include "sha1.h"
	11
	12	/* Hash one 64-byte block of data */
	13	static void blk_SHA1Block(blk_SHA_CTX ctx, const unsigned int data);
	14
	15	void blk_SHA1_Init(blk_SHA_CTX *ctx)
	16	{
d7c208a9 LT	17	ctx->size = 0;
	18
	19	/* Initialize H with the magic constants (see FIPS180 for constants)
	20	*/
	21	ctx->H[0] = 0x67452301;
	22	ctx->H[1] = 0xefcdab89;
	23	ctx->H[2] = 0x98badcfe;
	24	ctx->H[3] = 0x10325476;
	25	ctx->H[4] = 0xc3d2e1f0;
	26	}
	27
	28
	29	void blk_SHA1_Update(blk_SHA_CTX ctx, const void data, unsigned long len)
	30	{
5d5210c3	31	int lenW = ctx->size & 63;
d7c208a9	32
5d5210c3	33	ctx->size += len;
d7c208a9 LT	34
	35	/* Read the data into W and process blocks as they get full
	36	*/
	37	if (lenW) {
	38	int left = 64 - lenW;
	39	if (len < left)
	40	left = len;
	41	memcpy(lenW + (char *)ctx->W, data, left);
	42	lenW = (lenW + left) & 63;
	43	len -= left;
	44	data += left;
d7c208a9 LT	45	if (lenW)
	46	return;
	47	blk_SHA1Block(ctx, ctx->W);
	48	}
	49	while (len >= 64) {
	50	blk_SHA1Block(ctx, data);
	51	data += 64;
	52	len -= 64;
	53	}
5d5210c3	54	if (len)
d7c208a9	55	memcpy(ctx->W, data, len);
d7c208a9 LT	56	}
	57
	58
	59	void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx)
	60	{
	61	static const unsigned char pad[64] = { 0x80 };
	62	unsigned int padlen[2];
	63	int i;
	64
	65	/* Pad with a binary 1 (ie 0x80), then zeroes, then length
	66	*/
5d5210c3 LT	67	padlen[0] = htonl(ctx->size >> 29);
5d5210c3 LT	68	padlen[1] = htonl(ctx->size << 3);
d7c208a9	69
5d5210c3 LT	70	i = ctx->size & 63;
5d5210c3 LT	71	blk_SHA1_Update(ctx, pad, 1+ (63 & (55 - i)));
d7c208a9 LT	72	blk_SHA1_Update(ctx, padlen, 8);
	73
	74	/* Output hash
	75	*/
	76	for (i = 0; i < 5; i++)
	77	((unsigned int *)hashout)[i] = htonl(ctx->H[i]);
	78	}
	79
b8e48a89 LT	80	#if defined(__i386__) \|\| defined(__x86_64__)
b8e48a89 LT	81
fd536d34	82	#define SHA_ASM(op, x, n) ({ unsigned int __res; __asm__(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; })
b8e48a89 LT	83	#define SHA_ROL(x,n) SHA_ASM("rol", x, n)
	84	#define SHA_ROR(x,n) SHA_ASM("ror", x, n)
	85
	86	#else
	87
fd536d34	88	#define SHA_ROT(X,l,r) (((X) << (l)) \| ((X) >> (r)))
b8e48a89 LT	89	#define SHA_ROL(X,n) SHA_ROT(X,n,32-(n))
	90	#define SHA_ROR(X,n) SHA_ROT(X,32-(n),n)
	91
	92	#endif
d7c208a9	93
ab14c823 LT	94	/* This "rolls" over the 512-bit array */
	95	#define W(x) (array[(x)&15])
	96
	97	/*
	98	* Where do we get the source from? The first 16 iterations get it from
	99	* the input data, the next mix it from the 512-bit array.
	100	*/
	101	#define SHA_SRC(t) htonl(data[t])
	102	#define SHA_MIX(t) SHA_ROL(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1)
	103
	104	#define SHA_ROUND(t, input, fn, constant) \
	105	TEMP = input(t); W(t) = TEMP; \
	106	TEMP += SHA_ROL(A,5) + (fn) + E + (constant); \
	107	E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP
	108
	109	#define T_0_15(t) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999 )
	110	#define T_16_19(t) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999 )
	111	#define T_20_39(t) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1 )
e869e113	112	#define T_40_59(t) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc )
ab14c823 LT	113	#define T_60_79(t) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6 )
ab14c823 LT	114
d7c208a9 LT	115	static void blk_SHA1Block(blk_SHA_CTX ctx, const unsigned int data)
d7c208a9 LT	116	{
d7c208a9	117	unsigned int A,B,C,D,E,TEMP;
7b5075fc	118	unsigned int array[16];
d7c208a9	119
d7c208a9 LT	120	A = ctx->H[0];
	121	B = ctx->H[1];
	122	C = ctx->H[2];
	123	D = ctx->H[3];
	124	E = ctx->H[4];
	125
ab14c823	126	/* Round 1 - iterations 0-16 take their input from 'data' */
139e3456 LT	127	T_0_15( 0); T_0_15( 1); T_0_15( 2); T_0_15( 3); T_0_15( 4);
	128	T_0_15( 5); T_0_15( 6); T_0_15( 7); T_0_15( 8); T_0_15( 9);
	129	T_0_15(10); T_0_15(11); T_0_15(12); T_0_15(13); T_0_15(14);
	130	T_0_15(15);
	131
ab14c823	132	/* Round 1 - tail. Input from 512-bit mixing array */
139e3456	133	T_16_19(16); T_16_19(17); T_16_19(18); T_16_19(19);
d7c208a9	134
ab14c823	135	/* Round 2 */
d7c208a9 LT	136	T_20_39(20); T_20_39(21); T_20_39(22); T_20_39(23); T_20_39(24);
	137	T_20_39(25); T_20_39(26); T_20_39(27); T_20_39(28); T_20_39(29);
	138	T_20_39(30); T_20_39(31); T_20_39(32); T_20_39(33); T_20_39(34);
	139	T_20_39(35); T_20_39(36); T_20_39(37); T_20_39(38); T_20_39(39);
	140
ab14c823	141	/* Round 3 */
d7c208a9 LT	142	T_40_59(40); T_40_59(41); T_40_59(42); T_40_59(43); T_40_59(44);
	143	T_40_59(45); T_40_59(46); T_40_59(47); T_40_59(48); T_40_59(49);
	144	T_40_59(50); T_40_59(51); T_40_59(52); T_40_59(53); T_40_59(54);
	145	T_40_59(55); T_40_59(56); T_40_59(57); T_40_59(58); T_40_59(59);
	146
ab14c823	147	/* Round 4 */
d7c208a9 LT	148	T_60_79(60); T_60_79(61); T_60_79(62); T_60_79(63); T_60_79(64);
	149	T_60_79(65); T_60_79(66); T_60_79(67); T_60_79(68); T_60_79(69);
	150	T_60_79(70); T_60_79(71); T_60_79(72); T_60_79(73); T_60_79(74);
	151	T_60_79(75); T_60_79(76); T_60_79(77); T_60_79(78); T_60_79(79);
	152
	153	ctx->H[0] += A;
	154	ctx->H[1] += B;
	155	ctx->H[2] += C;
	156	ctx->H[3] += D;
	157	ctx->H[4] += E;
	158	}