Exemplo n.º 1
0
/* finalize the hash computation and output the result */
int Skein_256_Final(Skein_256_Ctxt_t *ctx, u08b_t *hashVal)
{
    size_t i,n,byteCnt;
    u64b_t X[SKEIN_256_STATE_WORDS];
    Skein_Assert(ctx->h.bCnt <= SKEIN_256_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */

    ctx->h.T[1] |= SKEIN_T1_FLAG_FINAL;                 /* tag as the final block */
    if (ctx->h.bCnt < SKEIN_256_BLOCK_BYTES)            /* zero pad b[] if necessary */
        memset(&ctx->b[ctx->h.bCnt],0,SKEIN_256_BLOCK_BYTES - ctx->h.bCnt);

    Skein_256_Process_Block(ctx,ctx->b,1,ctx->h.bCnt);  /* process the final block */

    /* now output the result */
    byteCnt = (ctx->h.hashBitLen + 7) >> 3;             /* total number of output bytes */

    /* run Threefish in "counter mode" to generate output */
    memset(ctx->b,0,sizeof(ctx->b));  /* zero out b[], so it can hold the counter */
    memcpy(X,ctx->X,sizeof(X));       /* keep a local copy of counter mode "key" */
    for (i=0;i*SKEIN_256_BLOCK_BYTES < byteCnt;i++)
    {
        ((u64b_t *)ctx->b)[0]= Skein_Swap64((u64b_t) i); /* build the counter block */
        Skein_Start_New_Type(ctx,OUT_FINAL);
        Skein_256_Process_Block(ctx,ctx->b,1,sizeof(u64b_t)); /* run "counter mode" */
        n = byteCnt - i*SKEIN_256_BLOCK_BYTES;   /* number of output bytes left to go */
        if (n >= SKEIN_256_BLOCK_BYTES)
            n  = SKEIN_256_BLOCK_BYTES;
        Skein_Put64_LSB_First(hashVal+i*SKEIN_256_BLOCK_BYTES,ctx->X,n);   /* "output" the ctr mode bytes */
        Skein_Show_Final(256,&ctx->h,n,hashVal+i*SKEIN_256_BLOCK_BYTES);
        memcpy(ctx->X,X,sizeof(X));   /* restore the counter mode key for next time */
    }
    return SKEIN_SUCCESS;
}
Exemplo n.º 2
0
/* process the input bytes */
int
Skein_256_Update(Skein_256_Ctxt_t *ctx, const uint8_t *msg, size_t msgByteCnt)
{
	size_t n;

	/* catch uninitialized context */
	Skein_Assert(ctx->h.bCnt <= SKEIN_256_BLOCK_BYTES, SKEIN_FAIL);

	/* process full blocks, if any */
	if (msgByteCnt + ctx->h.bCnt > SKEIN_256_BLOCK_BYTES) {
		/* finish up any buffered message data */
		if (ctx->h.bCnt) {
			/* # bytes free in buffer b[] */
			n = SKEIN_256_BLOCK_BYTES - ctx->h.bCnt;
			if (n) {
				/* check on our logic here */
				Skein_assert(n < msgByteCnt);
				bcopy(msg, &ctx->b[ctx->h.bCnt], n);
				msgByteCnt -= n;
				msg += n;
				ctx->h.bCnt += n;
			}
			Skein_assert(ctx->h.bCnt == SKEIN_256_BLOCK_BYTES);
			Skein_256_Process_Block(ctx, ctx->b, 1,
			    SKEIN_256_BLOCK_BYTES);
			ctx->h.bCnt = 0;
		}
		/*
		 * now process any remaining full blocks, directly from input
		 * message data
		 */
		if (msgByteCnt > SKEIN_256_BLOCK_BYTES) {
			/* number of full blocks to process */
			n = (msgByteCnt - 1) / SKEIN_256_BLOCK_BYTES;
			Skein_256_Process_Block(ctx, msg, n,
			    SKEIN_256_BLOCK_BYTES);
			msgByteCnt -= n * SKEIN_256_BLOCK_BYTES;
			msg += n * SKEIN_256_BLOCK_BYTES;
		}
		Skein_assert(ctx->h.bCnt == 0);
	}

	/* copy any remaining source message data bytes into b[] */
	if (msgByteCnt) {
		Skein_assert(msgByteCnt + ctx->h.bCnt <= SKEIN_256_BLOCK_BYTES);
		bcopy(msg, &ctx->b[ctx->h.bCnt], msgByteCnt);
		ctx->h.bCnt += msgByteCnt;
	}

	return (SKEIN_SUCCESS);
}
Exemplo n.º 3
0
/* init the context for a straight hashing operation  */
int
Skein_256_Init(Skein_256_Ctxt_t *ctx, size_t hashBitLen)
{
	union {
		uint8_t b[SKEIN_256_STATE_BYTES];
		uint64_t w[SKEIN_256_STATE_WORDS];
	} cfg;			/* config block */

	Skein_Assert(hashBitLen > 0, SKEIN_BAD_HASHLEN);
	ctx->h.hashBitLen = hashBitLen;	/* output hash bit count */

	switch (hashBitLen) {	/* use pre-computed values, where available */
#ifndef	SKEIN_NO_PRECOMP
	case 256:
		bcopy(SKEIN_256_IV_256, ctx->X, sizeof (ctx->X));
		break;
	case 224:
		bcopy(SKEIN_256_IV_224, ctx->X, sizeof (ctx->X));
		break;
	case 160:
		bcopy(SKEIN_256_IV_160, ctx->X, sizeof (ctx->X));
		break;
	case 128:
		bcopy(SKEIN_256_IV_128, ctx->X, sizeof (ctx->X));
		break;
#endif
	default:
		/* here if there is no precomputed IV value available */
		/*
		 * build/process the config block, type == CONFIG (could be
		 * precomputed)
		 */
		/* set tweaks: T0=0; T1=CFG | FINAL */
		Skein_Start_New_Type(ctx, CFG_FINAL);

		/* set the schema, version */
		cfg.w[0] = Skein_Swap64(SKEIN_SCHEMA_VER);
		/* hash result length in bits */
		cfg.w[1] = Skein_Swap64(hashBitLen);
		cfg.w[2] = Skein_Swap64(SKEIN_CFG_TREE_INFO_SEQUENTIAL);
		/* zero pad config block */
		bzero(&cfg.w[3], sizeof (cfg) - 3 * sizeof (cfg.w[0]));

		/* compute the initial chaining values from config block */
		/* zero the chaining variables */
		bzero(ctx->X, sizeof (ctx->X));
		Skein_256_Process_Block(ctx, cfg.b, 1, SKEIN_CFG_STR_LEN);
		break;
	}
	/*
	 * The chaining vars ctx->X are now initialized for the given
	 * hashBitLen.
	 * Set up to process the data message portion of the hash (default)
	 */
	Skein_Start_New_Type(ctx, MSG);	/* T0=0, T1= MSG type */

	return (SKEIN_SUCCESS);
}
Exemplo n.º 4
0
/* [identical to Skein_256_Init() when keyBytes == 0 && treeInfo == SKEIN_CFG_TREE_INFO_SEQUENTIAL] */
int Skein_256_InitExt(Skein_256_Ctxt_t *ctx,size_t hashBitLen,u64b_t treeInfo, const u08b_t *key, size_t keyBytes)
    {
    union
        {
        u08b_t  b[SKEIN_256_STATE_BYTES];
        u64b_t  w[SKEIN_256_STATE_WORDS];
        } cfg;                              /* config block */
        
    Skein_Assert(hashBitLen > 0,SKEIN_BAD_HASHLEN);
    Skein_Assert(keyBytes == 0 || key != NULL,SKEIN_FAIL);

    /* compute the initial chaining values ctx->X[], based on key */
    if (keyBytes == 0)                          /* is there a key? */
        {                                   
        memset(ctx->X,0,sizeof(ctx->X));        /* no key: use all zeroes as key for config block */
        }
    else                                        /* here to pre-process a key */
        {
        Skein_assert(sizeof(cfg.b) >= sizeof(ctx->X));
        /* do a mini-Init right here */
        ctx->h.hashBitLen=8*sizeof(ctx->X);     /* set output hash bit count = state size */
        Skein_Start_New_Type(ctx,KEY);          /* set tweaks: T0 = 0; T1 = KEY type */
        memset(ctx->X,0,sizeof(ctx->X));        /* zero the initial chaining variables */
        Skein_256_Update(ctx,key,keyBytes);     /* hash the key */
        Skein_256_Final_Pad(ctx,cfg.b);         /* put result into cfg.b[] */
        memcpy(ctx->X,cfg.b,sizeof(cfg.b));     /* copy over into ctx->X[] */
#if SKEIN_NEED_SWAP
        {
        uint_t i;
        for (i=0;i<SKEIN_256_STATE_WORDS;i++)   /* convert key bytes to context words */
            ctx->X[i] = Skein_Swap64(ctx->X[i]);
        }
#endif
        }
    /* build/process the config block, type == CONFIG (could be precomputed for each key) */
    ctx->h.hashBitLen = hashBitLen;             /* output hash bit count */
    Skein_Start_New_Type(ctx,CFG_FINAL);

    memset(&cfg.w,0,sizeof(cfg.w));             /* pre-pad cfg.w[] with zeroes */
    cfg.w[0] = Skein_Swap64(SKEIN_SCHEMA_VER);
    cfg.w[1] = Skein_Swap64(hashBitLen);        /* hash result length in bits */
    cfg.w[2] = Skein_Swap64(treeInfo);          /* tree hash config info (or SKEIN_CFG_TREE_INFO_SEQUENTIAL) */

    Skein_Show_Key(256,&ctx->h,key,keyBytes);

    /* compute the initial chaining values from config block */
    Skein_256_Process_Block(ctx,cfg.b,1,SKEIN_CFG_STR_LEN);

    /* The chaining vars ctx->X are now initialized */
    /* Set up to process the data message portion of the hash (default) */
    ctx->h.bCnt = 0;                            /* buffer b[] starts out empty */
    Skein_Start_New_Type(ctx,MSG);
    
    return SKEIN_SUCCESS;
    }
Exemplo n.º 5
0
/* finalize the hash computation and output the block, no OUTPUT stage */
int Skein_256_Final_Pad(Skein_256_Ctxt_t *ctx, u08b_t *hashVal)
{
    Skein_Assert(ctx->h.bCnt <= SKEIN_256_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */

    ctx->h.T[1] |= SKEIN_T1_FLAG_FINAL;        /* tag as the final block */
    if (ctx->h.bCnt < SKEIN_256_BLOCK_BYTES)   /* zero pad b[] if necessary */
        memset(&ctx->b[ctx->h.bCnt],0,SKEIN_256_BLOCK_BYTES - ctx->h.bCnt);
    Skein_256_Process_Block(ctx,ctx->b,1,ctx->h.bCnt);    /* process the final block */

    Skein_Put64_LSB_First(hashVal,ctx->X,SKEIN_256_BLOCK_BYTES);   /* "output" the state bytes */

    return SKEIN_SUCCESS;
}
Exemplo n.º 6
0
/* just do the OUTPUT stage */
int
Skein_256_Output(Skein_256_Ctxt_t *ctx, uint8_t *hashVal)
{
	size_t i, n, byteCnt;
	uint64_t X[SKEIN_256_STATE_WORDS];

	/* catch uninitialized context */
	Skein_Assert(ctx->h.bCnt <= SKEIN_256_BLOCK_BYTES, SKEIN_FAIL);

	/* now output the result */
	/* total number of output bytes */
	byteCnt = (ctx->h.hashBitLen + 7) >> 3;

	/* run Threefish in "counter mode" to generate output */
	/* zero out b[], so it can hold the counter */
	bzero(ctx->b, sizeof (ctx->b));
	/* keep a local copy of counter mode "key" */
	bcopy(ctx->X, X, sizeof (X));
	for (i = 0; i * SKEIN_256_BLOCK_BYTES < byteCnt; i++) {
		/* build the counter block */
		uint64_t tmp = Skein_Swap64((uint64_t)i);
		bcopy(&tmp, ctx->b, sizeof (tmp));
		Skein_Start_New_Type(ctx, OUT_FINAL);
		/* run "counter mode" */
		Skein_256_Process_Block(ctx, ctx->b, 1, sizeof (uint64_t));
		/* number of output bytes left to go */
		n = byteCnt - i * SKEIN_256_BLOCK_BYTES;
		if (n >= SKEIN_256_BLOCK_BYTES)
			n = SKEIN_256_BLOCK_BYTES;
		Skein_Put64_LSB_First(hashVal + i * SKEIN_256_BLOCK_BYTES,
		    ctx->X, n);	/* "output" the ctr mode bytes */
		Skein_Show_Final(256, &ctx->h, n,
		    hashVal + i * SKEIN_256_BLOCK_BYTES);
		/* restore the counter mode key for next time */
		bcopy(X, ctx->X, sizeof (X));
	}
	return (SKEIN_SUCCESS);
}