The Tor Browser: security/nss/lib/freebl/sha_fast.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/sha_fast.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/sha_fast.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifdef FREEBL_NO_DEPEND
 #include "stubs.h"
 #endif
 #include <memory.h>
 #include "blapi.h"
 #include "sha_fast.h"
 #include "prerror.h"
 #ifdef TRACING_SSL
 #include "ssl.h"
 #include "ssltrace.h"
 #endif
 static void shaCompress(volatile SHA_HW_t *X, const PRUint32 * datain);
 #define W u.w
 #define B u.b
 #define SHA_F1(X,Y,Z) ((((Y)^(Z))&(X))^(Z))
 #define SHA_F2(X,Y,Z) ((X)^(Y)^(Z))
 #define SHA_F3(X,Y,Z) (((X)&(Y))|((Z)&((X)|(Y))))
 #define SHA_F4(X,Y,Z) ((X)^(Y)^(Z))
 #define SHA_MIX(n,a,b,c)    XW(n) = SHA_ROTL(XW(a)^XW(b)^XW(c)^XW(n), 1)
 /*
  *  SHA: initialize context
  */
 void
 SHA1_Begin(SHA1Context *ctx)
 {
   ctx->size = 0;
   /*
    *  Initialize H with constants from FIPS180-1.
    */
   ctx->H[0] = 0x67452301L;
   ctx->H[1] = 0xefcdab89L;
   ctx->H[2] = 0x98badcfeL;
   ctx->H[3] = 0x10325476L;
   ctx->H[4] = 0xc3d2e1f0L;
 }
 /* Explanation of H array and index values:
  * The context's H array is actually the concatenation of two arrays
  * defined by SHA1, the H array of state variables (5 elements),
  * and the W array of intermediate values, of which there are 16 elements.
  * The W array starts at H[5], that is W[0] is H[5].
  * Although these values are defined as 32-bit values, we use 64-bit
  * variables to hold them because the AMD64 stores 64 bit values in
  * memory MUCH faster than it stores any smaller values.
  *
  * Rather than passing the context structure to shaCompress, we pass
  * this combined array of H and W values.  We do not pass the address
  * of the first element of this array, but rather pass the address of an
  * element in the middle of the array, element X.  Presently X[0] is H[11].
  * So we pass the address of H[11] as the address of array X to shaCompress.
  * Then shaCompress accesses the members of the array using positive AND
  * negative indexes.
  *
  * Pictorially: (each element is 8 bytes)
  * H | H0 H1 H2 H3 H4 W0 W1 W2 W3 W4 W5 W6 W7 W8 W9 Wa Wb Wc Wd We Wf |
  * X |-11-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 |
  *
  * The byte offset from X[0] to any member of H and W is always
  * representable in a signed 8-bit value, which will be encoded
  * as a single byte offset in the X86-64 instruction set.
  * If we didn't pass the address of H[11], and instead passed the
  * address of H[0], the offsets to elements H[16] and above would be
  * greater than 127, not representable in a signed 8-bit value, and the
  * x86-64 instruction set would encode every such offset as a 32-bit
  * signed number in each instruction that accessed element H[16] or
  * higher.  This results in much bigger and slower code.
  */
 #if !defined(SHA_PUT_W_IN_STACK)
 #define H2X 11 /* X[0] is H[11], and H[0] is X[-11] */
 #define W2X  6 /* X[0] is W[6],  and W[0] is X[-6]  */
 #else
 #define H2X 0
 #endif
 /*
  *  SHA: Add data to context.
  */
 void
 SHA1_Update(SHA1Context *ctx, const unsigned char *dataIn, unsigned int len)
 {
   register unsigned int lenB;
   register unsigned int togo;
   if (!len)
     return;
   /* accumulate the byte count. */
   lenB = (unsigned int)(ctx->size) & 63U;
   ctx->size += len;
   /*
    *  Read the data into W and process blocks as they get full
    */
   if (lenB > 0) {
     togo = 64U - lenB;
     if (len < togo)
       togo = len;
     memcpy(ctx->B + lenB, dataIn, togo);
     len    -= togo;
     dataIn += togo;
     lenB    = (lenB + togo) & 63U;
     if (!lenB) {
       shaCompress(&ctx->H[H2X], ctx->W);
     }
   }
 #if !defined(SHA_ALLOW_UNALIGNED_ACCESS)
   if ((ptrdiff_t)dataIn % sizeof(PRUint32)) {
     while (len >= 64U) {
       memcpy(ctx->B, dataIn, 64);
       len    -= 64U;
       shaCompress(&ctx->H[H2X], ctx->W);
       dataIn += 64U;
     }
   } else
 #endif
   {
     while (len >= 64U) {
       len    -= 64U;
       shaCompress(&ctx->H[H2X], (PRUint32 *)dataIn);
       dataIn += 64U;
     }
   }
   if (len) {
     memcpy(ctx->B, dataIn, len);
   }
 }
 /*
  *  SHA: Generate hash value from context
  */
 void
 SHA1_End(SHA1Context *ctx, unsigned char *hashout,
          unsigned int *pDigestLen, unsigned int maxDigestLen)
 {
   register PRUint64 size;
   register PRUint32 lenB;
   PRUint32 tmpbuf[5];
   static const unsigned char bulk_pad[64] = { 0x80,0,0,0,0,0,0,0,0,0,
 ,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  };
 #define tmp lenB
   PORT_Assert (maxDigestLen >= SHA1_LENGTH);
   /*
    *  Pad with a binary 1 (e.g. 0x80), then zeroes, then length in bits
    */
   size = ctx->size;
   lenB = (PRUint32)size & 63;
   SHA1_Update(ctx, bulk_pad, (((55+64) - lenB) & 63) + 1);
   PORT_Assert(((PRUint32)ctx->size & 63) == 56);
   /* Convert size from bytes to bits. */
   size <<= 3;
   ctx->W[14] = SHA_HTONL((PRUint32)(size >> 32));
   ctx->W[15] = SHA_HTONL((PRUint32)size);
   shaCompress(&ctx->H[H2X], ctx->W);
   /*
    *  Output hash
    */
   SHA_STORE_RESULT;
   if (pDigestLen) {
     *pDigestLen = SHA1_LENGTH;
   }
 #undef tmp
 }
 void
 SHA1_EndRaw(SHA1Context *ctx, unsigned char *hashout,
             unsigned int *pDigestLen, unsigned int maxDigestLen)
 {
 #if defined(SHA_NEED_TMP_VARIABLE)
   register PRUint32 tmp;
 #endif
   PRUint32 tmpbuf[5];
   PORT_Assert (maxDigestLen >= SHA1_LENGTH);
   SHA_STORE_RESULT;
   if (pDigestLen)
     *pDigestLen = SHA1_LENGTH;
 }
 #undef B
 /*
  *  SHA: Compression function, unrolled.
  *
  * Some operations in shaCompress are done as 5 groups of 16 operations.
  * Others are done as 4 groups of 20 operations.
  * The code below shows that structure.
  *
  * The functions that compute the new values of the 5 state variables
  * A-E are done in 4 groups of 20 operations (or you may also think
  * of them as being done in 16 groups of 5 operations).  They are
  * done by the SHA_RNDx macros below, in the right column.
  *
  * The functions that set the 16 values of the W array are done in
  * 5 groups of 16 operations.  The first group is done by the
  * LOAD macros below, the latter 4 groups are done by SHA_MIX below,
  * in the left column.
  *
  * gcc's optimizer observes that each member of the W array is assigned
  * a value 5 times in this code.  It reduces the number of store
  * operations done to the W array in the context (that is, in the X array)
  * by creating a W array on the stack, and storing the W values there for
  * the first 4 groups of operations on W, and storing the values in the
  * context's W array only in the fifth group.  This is undesirable.
  * It is MUCH bigger code than simply using the context's W array, because
  * all the offsets to the W array in the stack are 32-bit signed offsets,
  * and it is no faster than storing the values in the context's W array.
  *
  * The original code for sha_fast.c prevented this creation of a separate
  * W array in the stack by creating a W array of 80 members, each of
  * whose elements is assigned only once. It also separated the computations
  * of the W array values and the computations of the values for the 5
  * state variables into two separate passes, W's, then A-E's so that the
  * second pass could be done all in registers (except for accessing the W
  * array) on machines with fewer registers.  The method is suboptimal
  * for machines with enough registers to do it all in one pass, and it
  * necessitates using many instructions with 32-bit offsets.
  *
  * This code eliminates the separate W array on the stack by a completely
  * different means: by declaring the X array volatile.  This prevents
  * the optimizer from trying to reduce the use of the X array by the
  * creation of a MORE expensive W array on the stack. The result is
  * that all instructions use signed 8-bit offsets and not 32-bit offsets.
  *
  * The combination of this code and the -O3 optimizer flag on GCC 3.4.3
  * results in code that is 3 times faster than the previous NSS sha_fast
  * code on AMD64.
  */
 static void
 shaCompress(volatile SHA_HW_t *X, const PRUint32 *inbuf)
 {
   register SHA_HW_t A, B, C, D, E;
 #if defined(SHA_NEED_TMP_VARIABLE)
   register PRUint32 tmp;
 #endif
 #if !defined(SHA_PUT_W_IN_STACK)
 #define XH(n) X[n-H2X]
 #define XW(n) X[n-W2X]
 #else
   SHA_HW_t w_0, w_1, w_2, w_3, w_4, w_5, w_6, w_7,
            w_8, w_9, w_10, w_11, w_12, w_13, w_14, w_15;
 #define XW(n) w_ ## n
 #define XH(n) X[n]
 #endif
 #define K0 0x5a827999L
 #define K1 0x6ed9eba1L
 #define K2 0x8f1bbcdcL
 #define K3 0xca62c1d6L
 #define SHA_RND1(a,b,c,d,e,n) \
   a = SHA_ROTL(b,5)+SHA_F1(c,d,e)+a+XW(n)+K0; c=SHA_ROTL(c,30)
 #define SHA_RND2(a,b,c,d,e,n) \
   a = SHA_ROTL(b,5)+SHA_F2(c,d,e)+a+XW(n)+K1; c=SHA_ROTL(c,30)
 #define SHA_RND3(a,b,c,d,e,n) \
   a = SHA_ROTL(b,5)+SHA_F3(c,d,e)+a+XW(n)+K2; c=SHA_ROTL(c,30)
 #define SHA_RND4(a,b,c,d,e,n) \
   a = SHA_ROTL(b,5)+SHA_F4(c,d,e)+a+XW(n)+K3; c=SHA_ROTL(c,30)
 #define LOAD(n) XW(n) = SHA_HTONL(inbuf[n])
   A = XH(0);
   B = XH(1);
   C = XH(2);
   D = XH(3);
   E = XH(4);
   LOAD(0);		   SHA_RND1(E,A,B,C,D, 0);
   LOAD(1);		   SHA_RND1(D,E,A,B,C, 1);
   LOAD(2);		   SHA_RND1(C,D,E,A,B, 2);
   LOAD(3);		   SHA_RND1(B,C,D,E,A, 3);
   LOAD(4);		   SHA_RND1(A,B,C,D,E, 4);
   LOAD(5);		   SHA_RND1(E,A,B,C,D, 5);
   LOAD(6);		   SHA_RND1(D,E,A,B,C, 6);
   LOAD(7);		   SHA_RND1(C,D,E,A,B, 7);
   LOAD(8);		   SHA_RND1(B,C,D,E,A, 8);
   LOAD(9);		   SHA_RND1(A,B,C,D,E, 9);
   LOAD(10);		   SHA_RND1(E,A,B,C,D,10);
   LOAD(11);		   SHA_RND1(D,E,A,B,C,11);
   LOAD(12);		   SHA_RND1(C,D,E,A,B,12);
   LOAD(13);		   SHA_RND1(B,C,D,E,A,13);
   LOAD(14);		   SHA_RND1(A,B,C,D,E,14);
   LOAD(15);		   SHA_RND1(E,A,B,C,D,15);
   SHA_MIX( 0, 13,  8,  2); SHA_RND1(D,E,A,B,C, 0);
   SHA_MIX( 1, 14,  9,  3); SHA_RND1(C,D,E,A,B, 1);
   SHA_MIX( 2, 15, 10,  4); SHA_RND1(B,C,D,E,A, 2);
   SHA_MIX( 3,  0, 11,  5); SHA_RND1(A,B,C,D,E, 3);
   SHA_MIX( 4,  1, 12,  6); SHA_RND2(E,A,B,C,D, 4);
   SHA_MIX( 5,  2, 13,  7); SHA_RND2(D,E,A,B,C, 5);
   SHA_MIX( 6,  3, 14,  8); SHA_RND2(C,D,E,A,B, 6);
   SHA_MIX( 7,  4, 15,  9); SHA_RND2(B,C,D,E,A, 7);
   SHA_MIX( 8,  5,  0, 10); SHA_RND2(A,B,C,D,E, 8);
   SHA_MIX( 9,  6,  1, 11); SHA_RND2(E,A,B,C,D, 9);
   SHA_MIX(10,  7,  2, 12); SHA_RND2(D,E,A,B,C,10);
   SHA_MIX(11,  8,  3, 13); SHA_RND2(C,D,E,A,B,11);
   SHA_MIX(12,  9,  4, 14); SHA_RND2(B,C,D,E,A,12);
   SHA_MIX(13, 10,  5, 15); SHA_RND2(A,B,C,D,E,13);
   SHA_MIX(14, 11,  6,  0); SHA_RND2(E,A,B,C,D,14);
   SHA_MIX(15, 12,  7,  1); SHA_RND2(D,E,A,B,C,15);
   SHA_MIX( 0, 13,  8,  2); SHA_RND2(C,D,E,A,B, 0);
   SHA_MIX( 1, 14,  9,  3); SHA_RND2(B,C,D,E,A, 1);
   SHA_MIX( 2, 15, 10,  4); SHA_RND2(A,B,C,D,E, 2);
   SHA_MIX( 3,  0, 11,  5); SHA_RND2(E,A,B,C,D, 3);
   SHA_MIX( 4,  1, 12,  6); SHA_RND2(D,E,A,B,C, 4);
   SHA_MIX( 5,  2, 13,  7); SHA_RND2(C,D,E,A,B, 5);
   SHA_MIX( 6,  3, 14,  8); SHA_RND2(B,C,D,E,A, 6);
   SHA_MIX( 7,  4, 15,  9); SHA_RND2(A,B,C,D,E, 7);
   SHA_MIX( 8,  5,  0, 10); SHA_RND3(E,A,B,C,D, 8);
   SHA_MIX( 9,  6,  1, 11); SHA_RND3(D,E,A,B,C, 9);
   SHA_MIX(10,  7,  2, 12); SHA_RND3(C,D,E,A,B,10);
   SHA_MIX(11,  8,  3, 13); SHA_RND3(B,C,D,E,A,11);
   SHA_MIX(12,  9,  4, 14); SHA_RND3(A,B,C,D,E,12);
   SHA_MIX(13, 10,  5, 15); SHA_RND3(E,A,B,C,D,13);
   SHA_MIX(14, 11,  6,  0); SHA_RND3(D,E,A,B,C,14);
   SHA_MIX(15, 12,  7,  1); SHA_RND3(C,D,E,A,B,15);
   SHA_MIX( 0, 13,  8,  2); SHA_RND3(B,C,D,E,A, 0);
   SHA_MIX( 1, 14,  9,  3); SHA_RND3(A,B,C,D,E, 1);
   SHA_MIX( 2, 15, 10,  4); SHA_RND3(E,A,B,C,D, 2);
   SHA_MIX( 3,  0, 11,  5); SHA_RND3(D,E,A,B,C, 3);
   SHA_MIX( 4,  1, 12,  6); SHA_RND3(C,D,E,A,B, 4);
   SHA_MIX( 5,  2, 13,  7); SHA_RND3(B,C,D,E,A, 5);
   SHA_MIX( 6,  3, 14,  8); SHA_RND3(A,B,C,D,E, 6);
   SHA_MIX( 7,  4, 15,  9); SHA_RND3(E,A,B,C,D, 7);
   SHA_MIX( 8,  5,  0, 10); SHA_RND3(D,E,A,B,C, 8);
   SHA_MIX( 9,  6,  1, 11); SHA_RND3(C,D,E,A,B, 9);
   SHA_MIX(10,  7,  2, 12); SHA_RND3(B,C,D,E,A,10);
   SHA_MIX(11,  8,  3, 13); SHA_RND3(A,B,C,D,E,11);
   SHA_MIX(12,  9,  4, 14); SHA_RND4(E,A,B,C,D,12);
   SHA_MIX(13, 10,  5, 15); SHA_RND4(D,E,A,B,C,13);
   SHA_MIX(14, 11,  6,  0); SHA_RND4(C,D,E,A,B,14);
   SHA_MIX(15, 12,  7,  1); SHA_RND4(B,C,D,E,A,15);
   SHA_MIX( 0, 13,  8,  2); SHA_RND4(A,B,C,D,E, 0);
   SHA_MIX( 1, 14,  9,  3); SHA_RND4(E,A,B,C,D, 1);
   SHA_MIX( 2, 15, 10,  4); SHA_RND4(D,E,A,B,C, 2);
   SHA_MIX( 3,  0, 11,  5); SHA_RND4(C,D,E,A,B, 3);
   SHA_MIX( 4,  1, 12,  6); SHA_RND4(B,C,D,E,A, 4);
   SHA_MIX( 5,  2, 13,  7); SHA_RND4(A,B,C,D,E, 5);
   SHA_MIX( 6,  3, 14,  8); SHA_RND4(E,A,B,C,D, 6);
   SHA_MIX( 7,  4, 15,  9); SHA_RND4(D,E,A,B,C, 7);
   SHA_MIX( 8,  5,  0, 10); SHA_RND4(C,D,E,A,B, 8);
   SHA_MIX( 9,  6,  1, 11); SHA_RND4(B,C,D,E,A, 9);
   SHA_MIX(10,  7,  2, 12); SHA_RND4(A,B,C,D,E,10);
   SHA_MIX(11,  8,  3, 13); SHA_RND4(E,A,B,C,D,11);
   SHA_MIX(12,  9,  4, 14); SHA_RND4(D,E,A,B,C,12);
   SHA_MIX(13, 10,  5, 15); SHA_RND4(C,D,E,A,B,13);
   SHA_MIX(14, 11,  6,  0); SHA_RND4(B,C,D,E,A,14);
   SHA_MIX(15, 12,  7,  1); SHA_RND4(A,B,C,D,E,15);
   XH(0) += A;
   XH(1) += B;
   XH(2) += C;
   XH(3) += D;
   XH(4) += E;
 }
 /*************************************************************************
 ** Code below this line added to make SHA code support BLAPI interface
 */
 SHA1Context *
 SHA1_NewContext(void)
 {
     SHA1Context *cx;
     /* no need to ZNew, SHA1_Begin will init the context */
     cx = PORT_New(SHA1Context);
     return cx;
 }
 /* Zero and free the context */
 void
 SHA1_DestroyContext(SHA1Context *cx, PRBool freeit)
 {
     memset(cx, 0, sizeof *cx);
     if (freeit) {
         PORT_Free(cx);
     }
 }
 SECStatus
 SHA1_HashBuf(unsigned char *dest, const unsigned char *src, PRUint32 src_length)
 {
     SHA1Context ctx;
     unsigned int outLen;
     SHA1_Begin(&ctx);
     SHA1_Update(&ctx, src, src_length);
     SHA1_End(&ctx, dest, &outLen, SHA1_LENGTH);
     memset(&ctx, 0, sizeof ctx);
     return SECSuccess;
 }
 /* Hash a null-terminated character string. */
 SECStatus
 SHA1_Hash(unsigned char *dest, const char *src)
 {
     return SHA1_HashBuf(dest, (const unsigned char *)src, PORT_Strlen (src));
 }
 /*
  * need to support save/restore state in pkcs11. Stores all the info necessary
  * for a structure into just a stream of bytes.
  */
 unsigned int
 SHA1_FlattenSize(SHA1Context *cx)
 {
     return sizeof(SHA1Context);
 }
 SECStatus
 SHA1_Flatten(SHA1Context *cx,unsigned char *space)
 {
     PORT_Memcpy(space,cx, sizeof(SHA1Context));
     return SECSuccess;
 }
 SHA1Context *
 SHA1_Resurrect(unsigned char *space,void *arg)
 {
     SHA1Context *cx = SHA1_NewContext();
     if (cx == NULL) return NULL;
     PORT_Memcpy(cx,space, sizeof(SHA1Context));
     return cx;
 }
 void SHA1_Clone(SHA1Context *dest, SHA1Context *src)
 {
     memcpy(dest, src, sizeof *dest);
 }
 void
 SHA1_TraceState(SHA1Context *ctx)
 {
     PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
 }

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security/nss/lib/freebl/sha_fast.c@b8a032363ba2 (annotated)

security/nss/lib/freebl/sha_fast.c