staging: crypto: skein: import code from Skein3Fish.git

This is a byte-for-byte copy of the skein implementation found at:

  https://github.com/wernerd/Skein3Fish.git

Specifically, from the master branch at commit:

  00e925444c2c Merge pull request #4 from csm/master

The next commit will do the minimum necessary to build this code as a
module.

I've generated the sha256 sums of the files by:

$ (cd drivers/staging/skein; find . -type f | sort | xargs sha256sum)
bcd73168e5805b1b157dbf08863e6a8c217a7b270b6be1a361540591b00624e3  ./CMakeLists.txt
e1adb97dd9e87bc7c05892ed7863a66d1d9fde6728a97a8b7b092709da664d29  ./include/brg_endian.h
240329b4ca4d829ac4d1490e96e83118e161e719e448c7e8dbf15735ab8a8e87  ./include/brg_types.h
0d8f16438f641fa365844a5991220eb04969f0a19c60dff08e10f521e74db5c3  ./include/skein.h
8f7362796e9e43f7619d51020d6faeedce786492b65bebd2ff6a833b621051cb  ./include/skeinApi.h
90510d8a9f686c3bfbf6cf7737237e3fa263c1ed5046b0f19727ba55b9bffeb9  ./include/skein_iv.h
42c6c8eff8f364ee2f0de3177d468dbceba9c6a73222fea473fe6d603213806a  ./include/skein_port.h
0154a4b8d54f5aa424b39a7ee668b31f2522b907bf3a8536fe46440b584531a1  ./include/threefishApi.h
ac0fc0f95a48a716d30cf02e5adad77af17725a938f939cf94f6dfba42badeca  ./skein.c
7af70b177bc63690f68eebceca2dbfef8a4473dcc847ae3525508c65c7d7bcc1  ./skeinApi.c
d7ef7330be8253f7f061de3c36880dbc83b0f5d90c8f2b72d3478766f54fbff0  ./skeinBlockNo3F.c
8bb3d7864afc9eab5569949fb2799cb6f14e583ba00641313cf877a5aea1c763  ./skein_block.c
438e6cb59a0090166e8f1e39418c0a2d0036737a32c5e2822c2ed8b803e2132f  ./threefish1024Block.c
e812ec6f2881300e90c803cfd9d044e954f1ca64faa2fc17a709f56a2f122ff8  ./threefish256Block.c
926f680057e128cdd1feba4a8544c177a74420137af480267b949ae79f3d02b8  ./threefish512Block.c
19357f5d47e7183bc8558a8d0949a3f5a80a931848917d26f36eebb7d205f003  ./threefishApi.c

Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 742 insertions, 0 deletions

diff --git a/drivers/staging/skein/skein.c b/drivers/staging/skein/skein.c
new file mode 100644
index 0000000..7693337
--- /dev/null
+++ b/drivers/staging/skein/skein.c
@@ -0,0 +1,742 @@
+/***********************************************************************
+**
+** Implementation of the Skein hash function.
+**
+** Source code author: Doug Whiting, 2008.
+**
+** This algorithm and source code is released to the public domain.
+**
+************************************************************************/
+
+#define  SKEIN_PORT_CODE /* instantiate any code in skein_port.h */
+
+#include <string.h>       /* get the memcpy/memset functions */
+#include <skein.h> /* get the Skein API definitions   */
+#include <skein_iv.h>    /* get precomputed IVs */
+
+/*****************************************************************/
+/* External function to process blkCnt (nonzero) full block(s) of data. */
+void    Skein_256_Process_Block(Skein_256_Ctxt_t *ctx,const u08b_t *blkPtr,size_t blkCnt,size_t byteCntAdd);
+void    Skein_512_Process_Block(Skein_512_Ctxt_t *ctx,const u08b_t *blkPtr,size_t blkCnt,size_t byteCntAdd);
+void    Skein1024_Process_Block(Skein1024_Ctxt_t *ctx,const u08b_t *blkPtr,size_t blkCnt,size_t byteCntAdd);
+
+/*****************************************************************/
+/*     256-bit Skein                                             */
+/*****************************************************************/
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* init the context for a straight hashing operation  */
+int Skein_256_Init(Skein_256_Ctxt_t *ctx, size_t hashBitLen)
+{
+    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);
+    ctx->h.hashBitLen = hashBitLen;         /* output hash bit count */
+
+    switch (hashBitLen)
+    {             /* use pre-computed values, where available */
+    case  256:
+        memcpy(ctx->X,SKEIN_256_IV_256,sizeof(ctx->X));
+        break;
+    case  224:
+        memcpy(ctx->X,SKEIN_256_IV_224,sizeof(ctx->X));
+        break;
+    case  160:
+        memcpy(ctx->X,SKEIN_256_IV_160,sizeof(ctx->X));
+        break;
+    case  128:
+        memcpy(ctx->X,SKEIN_256_IV_128,sizeof(ctx->X));
+        break;
+    default:
+        /* here if there is no precomputed IV value available */
+        /* build/process the config block, type == CONFIG (could be precomputed) */
+        Skein_Start_New_Type(ctx,CFG_FINAL);        /* set tweaks: T0=0; T1=CFG | FINAL */
+
+        cfg.w[0] = Skein_Swap64(SKEIN_SCHEMA_VER);  /* set the schema, version */
+        cfg.w[1] = Skein_Swap64(hashBitLen);        /* hash result length in bits */
+        cfg.w[2] = Skein_Swap64(SKEIN_CFG_TREE_INFO_SEQUENTIAL);
+        memset(&cfg.w[3],0,sizeof(cfg) - 3*sizeof(cfg.w[0])); /* zero pad config block */
+
+        /* compute the initial chaining values from config block */
+        memset(ctx->X,0,sizeof(ctx->X));            /* zero the chaining variables */
+        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;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* init the context for a MAC and/or tree hash operation */
+/* [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) */
+    Skein_Start_New_Type(ctx,MSG);
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* process the input bytes */
+int Skein_256_Update(Skein_256_Ctxt_t *ctx, const u08b_t *msg, size_t msgByteCnt)
+{
+    size_t n;
+
+    Skein_Assert(ctx->h.bCnt <= SKEIN_256_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    /* process full blocks, if any */
+    if (msgByteCnt + ctx->h.bCnt > SKEIN_256_BLOCK_BYTES)
+    {
+        if (ctx->h.bCnt)                              /* finish up any buffered message data */
+        {
+            n = SKEIN_256_BLOCK_BYTES - ctx->h.bCnt;  /* # bytes free in buffer b[] */
+            if (n)
+            {
+                Skein_assert(n < msgByteCnt);         /* check on our logic here */
+                memcpy(&ctx->b[ctx->h.bCnt],msg,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)
+        {
+            n = (msgByteCnt-1) / SKEIN_256_BLOCK_BYTES;   /* number of full blocks to process */
+            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);
+        memcpy(&ctx->b[ctx->h.bCnt],msg,msgByteCnt);
+        ctx->h.bCnt += msgByteCnt;
+    }
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* 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;
+}
+
+/*****************************************************************/
+/*     512-bit Skein                                             */
+/*****************************************************************/
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* init the context for a straight hashing operation  */
+int Skein_512_Init(Skein_512_Ctxt_t *ctx, size_t hashBitLen)
+{
+    union
+    {
+        u08b_t  b[SKEIN_512_STATE_BYTES];
+        u64b_t  w[SKEIN_512_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 */
+    case  512:
+        memcpy(ctx->X,SKEIN_512_IV_512,sizeof(ctx->X));
+        break;
+    case  384:
+        memcpy(ctx->X,SKEIN_512_IV_384,sizeof(ctx->X));
+        break;
+    case  256:
+        memcpy(ctx->X,SKEIN_512_IV_256,sizeof(ctx->X));
+        break;
+    case  224:
+        memcpy(ctx->X,SKEIN_512_IV_224,sizeof(ctx->X));
+        break;
+    default:
+        /* here if there is no precomputed IV value available */
+        /* build/process the config block, type == CONFIG (could be precomputed) */
+        Skein_Start_New_Type(ctx,CFG_FINAL);        /* set tweaks: T0=0; T1=CFG | FINAL */
+
+        cfg.w[0] = Skein_Swap64(SKEIN_SCHEMA_VER);  /* set the schema, version */
+        cfg.w[1] = Skein_Swap64(hashBitLen);        /* hash result length in bits */
+        cfg.w[2] = Skein_Swap64(SKEIN_CFG_TREE_INFO_SEQUENTIAL);
+        memset(&cfg.w[3],0,sizeof(cfg) - 3*sizeof(cfg.w[0])); /* zero pad config block */
+
+        /* compute the initial chaining values from config block */
+        memset(ctx->X,0,sizeof(ctx->X));            /* zero the chaining variables */
+        Skein_512_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;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* init the context for a MAC and/or tree hash operation */
+/* [identical to Skein_512_Init() when keyBytes == 0 && treeInfo == SKEIN_CFG_TREE_INFO_SEQUENTIAL] */
+int Skein_512_InitExt(Skein_512_Ctxt_t *ctx,size_t hashBitLen,u64b_t treeInfo, const u08b_t *key, size_t keyBytes)
+{
+    union
+    {
+        u08b_t  b[SKEIN_512_STATE_BYTES];
+        u64b_t  w[SKEIN_512_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_512_Update(ctx,key,keyBytes);     /* hash the key */
+        Skein_512_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_512_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(512,&ctx->h,key,keyBytes);
+
+    /* compute the initial chaining values from config block */
+    Skein_512_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) */
+    Skein_Start_New_Type(ctx,MSG);
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* process the input bytes */
+int Skein_512_Update(Skein_512_Ctxt_t *ctx, const u08b_t *msg, size_t msgByteCnt)
+{
+    size_t n;
+
+    Skein_Assert(ctx->h.bCnt <= SKEIN_512_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    /* process full blocks, if any */
+    if (msgByteCnt + ctx->h.bCnt > SKEIN_512_BLOCK_BYTES)
+    {
+        if (ctx->h.bCnt)                              /* finish up any buffered message data */
+        {
+            n = SKEIN_512_BLOCK_BYTES - ctx->h.bCnt;  /* # bytes free in buffer b[] */
+            if (n)
+            {
+                Skein_assert(n < msgByteCnt);         /* check on our logic here */
+                memcpy(&ctx->b[ctx->h.bCnt],msg,n);
+                msgByteCnt  -= n;
+                msg         += n;
+                ctx->h.bCnt += n;
+            }
+            Skein_assert(ctx->h.bCnt == SKEIN_512_BLOCK_BYTES);
+            Skein_512_Process_Block(ctx,ctx->b,1,SKEIN_512_BLOCK_BYTES);
+            ctx->h.bCnt = 0;
+        }
+        /* now process any remaining full blocks, directly from input message data */
+        if (msgByteCnt > SKEIN_512_BLOCK_BYTES)
+        {
+            n = (msgByteCnt-1) / SKEIN_512_BLOCK_BYTES;   /* number of full blocks to process */
+            Skein_512_Process_Block(ctx,msg,n,SKEIN_512_BLOCK_BYTES);
+            msgByteCnt -= n * SKEIN_512_BLOCK_BYTES;
+            msg        += n * SKEIN_512_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_512_BLOCK_BYTES);
+        memcpy(&ctx->b[ctx->h.bCnt],msg,msgByteCnt);
+        ctx->h.bCnt += msgByteCnt;
+    }
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* finalize the hash computation and output the result */
+int Skein_512_Final(Skein_512_Ctxt_t *ctx, u08b_t *hashVal)
+{
+    size_t i,n,byteCnt;
+    u64b_t X[SKEIN_512_STATE_WORDS];
+    Skein_Assert(ctx->h.bCnt <= SKEIN_512_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_512_BLOCK_BYTES)            /* zero pad b[] if necessary */
+        memset(&ctx->b[ctx->h.bCnt],0,SKEIN_512_BLOCK_BYTES - ctx->h.bCnt);
+
+    Skein_512_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_512_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_512_Process_Block(ctx,ctx->b,1,sizeof(u64b_t)); /* run "counter mode" */
+        n = byteCnt - i*SKEIN_512_BLOCK_BYTES;   /* number of output bytes left to go */
+        if (n >= SKEIN_512_BLOCK_BYTES)
+            n  = SKEIN_512_BLOCK_BYTES;
+        Skein_Put64_LSB_First(hashVal+i*SKEIN_512_BLOCK_BYTES,ctx->X,n);   /* "output" the ctr mode bytes */
+        Skein_Show_Final(512,&ctx->h,n,hashVal+i*SKEIN_512_BLOCK_BYTES);
+        memcpy(ctx->X,X,sizeof(X));   /* restore the counter mode key for next time */
+    }
+    return SKEIN_SUCCESS;
+}
+
+/*****************************************************************/
+/*    1024-bit Skein                                             */
+/*****************************************************************/
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* init the context for a straight hashing operation  */
+int Skein1024_Init(Skein1024_Ctxt_t *ctx, size_t hashBitLen)
+{
+    union
+    {
+        u08b_t  b[SKEIN1024_STATE_BYTES];
+        u64b_t  w[SKEIN1024_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 */
+    case  512:
+        memcpy(ctx->X,SKEIN1024_IV_512 ,sizeof(ctx->X));
+        break;
+    case  384:
+        memcpy(ctx->X,SKEIN1024_IV_384 ,sizeof(ctx->X));
+        break;
+    case 1024:
+        memcpy(ctx->X,SKEIN1024_IV_1024,sizeof(ctx->X));
+        break;
+    default:
+        /* here if there is no precomputed IV value available */
+        /* build/process the config block, type == CONFIG (could be precomputed) */
+        Skein_Start_New_Type(ctx,CFG_FINAL);        /* set tweaks: T0=0; T1=CFG | FINAL */
+
+        cfg.w[0] = Skein_Swap64(SKEIN_SCHEMA_VER);  /* set the schema, version */
+        cfg.w[1] = Skein_Swap64(hashBitLen);        /* hash result length in bits */
+        cfg.w[2] = Skein_Swap64(SKEIN_CFG_TREE_INFO_SEQUENTIAL);
+        memset(&cfg.w[3],0,sizeof(cfg) - 3*sizeof(cfg.w[0])); /* zero pad config block */
+
+        /* compute the initial chaining values from config block */
+        memset(ctx->X,0,sizeof(ctx->X));            /* zero the chaining variables */
+        Skein1024_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;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* init the context for a MAC and/or tree hash operation */
+/* [identical to Skein1024_Init() when keyBytes == 0 && treeInfo == SKEIN_CFG_TREE_INFO_SEQUENTIAL] */
+int Skein1024_InitExt(Skein1024_Ctxt_t *ctx,size_t hashBitLen,u64b_t treeInfo, const u08b_t *key, size_t keyBytes)
+{
+    union
+    {
+        u08b_t  b[SKEIN1024_STATE_BYTES];
+        u64b_t  w[SKEIN1024_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 */
+        Skein1024_Update(ctx,key,keyBytes);     /* hash the key */
+        Skein1024_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<SKEIN1024_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(1024,&ctx->h,key,keyBytes);
+
+    /* compute the initial chaining values from config block */
+    Skein1024_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) */
+    Skein_Start_New_Type(ctx,MSG);
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* process the input bytes */
+int Skein1024_Update(Skein1024_Ctxt_t *ctx, const u08b_t *msg, size_t msgByteCnt)
+{
+    size_t n;
+
+    Skein_Assert(ctx->h.bCnt <= SKEIN1024_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    /* process full blocks, if any */
+    if (msgByteCnt + ctx->h.bCnt > SKEIN1024_BLOCK_BYTES)
+    {
+        if (ctx->h.bCnt)                              /* finish up any buffered message data */
+        {
+            n = SKEIN1024_BLOCK_BYTES - ctx->h.bCnt;  /* # bytes free in buffer b[] */
+            if (n)
+            {
+                Skein_assert(n < msgByteCnt);         /* check on our logic here */
+                memcpy(&ctx->b[ctx->h.bCnt],msg,n);
+                msgByteCnt  -= n;
+                msg         += n;
+                ctx->h.bCnt += n;
+            }
+            Skein_assert(ctx->h.bCnt == SKEIN1024_BLOCK_BYTES);
+            Skein1024_Process_Block(ctx,ctx->b,1,SKEIN1024_BLOCK_BYTES);
+            ctx->h.bCnt = 0;
+        }
+        /* now process any remaining full blocks, directly from input message data */
+        if (msgByteCnt > SKEIN1024_BLOCK_BYTES)
+        {
+            n = (msgByteCnt-1) / SKEIN1024_BLOCK_BYTES;   /* number of full blocks to process */
+            Skein1024_Process_Block(ctx,msg,n,SKEIN1024_BLOCK_BYTES);
+            msgByteCnt -= n * SKEIN1024_BLOCK_BYTES;
+            msg        += n * SKEIN1024_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 <= SKEIN1024_BLOCK_BYTES);
+        memcpy(&ctx->b[ctx->h.bCnt],msg,msgByteCnt);
+        ctx->h.bCnt += msgByteCnt;
+    }
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* finalize the hash computation and output the result */
+int Skein1024_Final(Skein1024_Ctxt_t *ctx, u08b_t *hashVal)
+{
+    size_t i,n,byteCnt;
+    u64b_t X[SKEIN1024_STATE_WORDS];
+    Skein_Assert(ctx->h.bCnt <= SKEIN1024_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    ctx->h.T[1] |= SKEIN_T1_FLAG_FINAL;                 /* tag as the final block */
+    if (ctx->h.bCnt < SKEIN1024_BLOCK_BYTES)            /* zero pad b[] if necessary */
+        memset(&ctx->b[ctx->h.bCnt],0,SKEIN1024_BLOCK_BYTES - ctx->h.bCnt);
+
+    Skein1024_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*SKEIN1024_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);
+        Skein1024_Process_Block(ctx,ctx->b,1,sizeof(u64b_t)); /* run "counter mode" */
+        n = byteCnt - i*SKEIN1024_BLOCK_BYTES;   /* number of output bytes left to go */
+        if (n >= SKEIN1024_BLOCK_BYTES)
+            n  = SKEIN1024_BLOCK_BYTES;
+        Skein_Put64_LSB_First(hashVal+i*SKEIN1024_BLOCK_BYTES,ctx->X,n);   /* "output" the ctr mode bytes */
+        Skein_Show_Final(1024,&ctx->h,n,hashVal+i*SKEIN1024_BLOCK_BYTES);
+        memcpy(ctx->X,X,sizeof(X));   /* restore the counter mode key for next time */
+    }
+    return SKEIN_SUCCESS;
+}
+
+/**************** Functions to support MAC/tree hashing ***************/
+/*   (this code is identical for Optimized and Reference versions)    */
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* 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;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* finalize the hash computation and output the block, no OUTPUT stage */
+int Skein_512_Final_Pad(Skein_512_Ctxt_t *ctx, u08b_t *hashVal)
+{
+    Skein_Assert(ctx->h.bCnt <= SKEIN_512_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_512_BLOCK_BYTES)   /* zero pad b[] if necessary */
+        memset(&ctx->b[ctx->h.bCnt],0,SKEIN_512_BLOCK_BYTES - ctx->h.bCnt);
+    Skein_512_Process_Block(ctx,ctx->b,1,ctx->h.bCnt);    /* process the final block */
+
+    Skein_Put64_LSB_First(hashVal,ctx->X,SKEIN_512_BLOCK_BYTES);   /* "output" the state bytes */
+
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* finalize the hash computation and output the block, no OUTPUT stage */
+int Skein1024_Final_Pad(Skein1024_Ctxt_t *ctx, u08b_t *hashVal)
+{
+    Skein_Assert(ctx->h.bCnt <= SKEIN1024_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    ctx->h.T[1] |= SKEIN_T1_FLAG_FINAL;        /* tag as the final block */
+    if (ctx->h.bCnt < SKEIN1024_BLOCK_BYTES)   /* zero pad b[] if necessary */
+        memset(&ctx->b[ctx->h.bCnt],0,SKEIN1024_BLOCK_BYTES - ctx->h.bCnt);
+    Skein1024_Process_Block(ctx,ctx->b,1,ctx->h.bCnt);    /* process the final block */
+
+    Skein_Put64_LSB_First(hashVal,ctx->X,SKEIN1024_BLOCK_BYTES);   /* "output" the state bytes */
+
+    return SKEIN_SUCCESS;
+}
+
+#if SKEIN_TREE_HASH
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* just do the OUTPUT stage                                       */
+int Skein_256_Output(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 */
+
+    /* 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;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* just do the OUTPUT stage                                       */
+int Skein_512_Output(Skein_512_Ctxt_t *ctx, u08b_t *hashVal)
+{
+    size_t i,n,byteCnt;
+    u64b_t X[SKEIN_512_STATE_WORDS];
+    Skein_Assert(ctx->h.bCnt <= SKEIN_512_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    /* 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_512_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_512_Process_Block(ctx,ctx->b,1,sizeof(u64b_t)); /* run "counter mode" */
+        n = byteCnt - i*SKEIN_512_BLOCK_BYTES;   /* number of output bytes left to go */
+        if (n >= SKEIN_512_BLOCK_BYTES)
+            n  = SKEIN_512_BLOCK_BYTES;
+        Skein_Put64_LSB_First(hashVal+i*SKEIN_512_BLOCK_BYTES,ctx->X,n);   /* "output" the ctr mode bytes */
+        Skein_Show_Final(256,&ctx->h,n,hashVal+i*SKEIN_512_BLOCK_BYTES);
+        memcpy(ctx->X,X,sizeof(X));   /* restore the counter mode key for next time */
+    }
+    return SKEIN_SUCCESS;
+}
+
+/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+/* just do the OUTPUT stage                                       */
+int Skein1024_Output(Skein1024_Ctxt_t *ctx, u08b_t *hashVal)
+{
+    size_t i,n,byteCnt;
+    u64b_t X[SKEIN1024_STATE_WORDS];
+    Skein_Assert(ctx->h.bCnt <= SKEIN1024_BLOCK_BYTES,SKEIN_FAIL);    /* catch uninitialized context */
+
+    /* 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*SKEIN1024_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);
+        Skein1024_Process_Block(ctx,ctx->b,1,sizeof(u64b_t)); /* run "counter mode" */
+        n = byteCnt - i*SKEIN1024_BLOCK_BYTES;   /* number of output bytes left to go */
+        if (n >= SKEIN1024_BLOCK_BYTES)
+            n  = SKEIN1024_BLOCK_BYTES;
+        Skein_Put64_LSB_First(hashVal+i*SKEIN1024_BLOCK_BYTES,ctx->X,n);   /* "output" the ctr mode bytes */
+        Skein_Show_Final(256,&ctx->h,n,hashVal+i*SKEIN1024_BLOCK_BYTES);
+        memcpy(ctx->X,X,sizeof(X));   /* restore the counter mode key for next time */
+    }
+    return SKEIN_SUCCESS;
+}
+#endif