Add built-in (Mozilla) SHA1 routines

Paul agreed to the GCC-exception license by email:
|
| From: Paul Kocher <paul@cryptography.com>
| Date: Sun, 15 Mar 2009 11:37:23 -0700
| Subject: Re: Adding Mozilla SHA1 implementation to libgit2
|
| Yes - that's fine.
|
| At 01:56 AM 3/5/2009, Andreas Ericsson wrote:
| > Hi Paul. We spoke earlier about this, if you remember?
| > We'd like to add the GCC-exception to the GPL license
| > for these files.

Signed-off-by: Paul Kocher <paul@cryptography.com>
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Makefile

@@ -2,6 +2,11 @@ all::
 
 # Define NO_VISIBILITY if your compiler does not support symbol
 # visibility in general (and the -fvisibility switch in particular).
+#
+# Define NO_OPENSSL if you do not have OpenSSL, or if you simply want
+# to use the bundled (Mozilla) SHA1 routines. (The bundled SHA1
+# routines are reported to be faster than OpenSSL on some platforms)
+#
 
 DOXYGEN = doxygen
 INSTALL = install
@@ -13,20 +18,19 @@ libdir=$(prefix)/lib
 uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo no')
 
 CFLAGS = -g -O2 -Wall
+LIBS   = -L. -lgit2 -lz
 OS     = unix
 
+EXTRA_LIBS =
+EXTRA_SRC =
+EXTRA_OBJ =
+
 # Platform specific tweaks
 
 ifneq (,$(findstring CYGWIN,$(uname_S)))
 	NO_VISIBILITY=YesPlease
 endif
 
-BASIC_CFLAGS := -Isrc
-ifndef NO_VISIBILITY
-BASIC_CFLAGS += -fvisibility=hidden
-endif
-ALL_CFLAGS = $(CFLAGS) $(BASIC_CFLAGS)
-
 SRC_C = $(wildcard src/*.c)
 OBJS = $(patsubst %.c,%.o,$(SRC_C))
 HDRS = $(wildcard src/*.h)
@@ -40,12 +44,32 @@ TEST_OBJ = $(patsubst %.c,%.o,\
 TEST_EXE = $(patsubst %.o,%.exe,$(TEST_OBJ))
 TEST_RUN = $(patsubst %.exe,%.run,$(TEST_EXE))
 
+ifndef NO_OPENSSL
+	SHA1_HEADER = <openssl/sha.h>
+	EXTRA_LIBS += -lcrypto
+else
+	SHA1_HEADER = "sha1/sha1.h"
+	EXTRA_SRC += src/sha1/sha1.c
+	EXTRA_OBJ += src/sha1/sha1.o
+endif
+
+BASIC_CFLAGS := -Isrc -DSHA1_HEADER='$(SHA1_HEADER)'
+ifndef NO_VISIBILITY
+BASIC_CFLAGS += -fvisibility=hidden
+endif
+
+ALL_CFLAGS = $(CFLAGS) $(BASIC_CFLAGS)
+SRC_C += $(EXTRA_SRC)
+OBJ += $(EXTRA_OBJ)
+LIBS += $(EXTRA_LIBS)
+
 all:: $(GIT_LIB)
 
 clean:
 	rm -f $(GIT_LIB)
 	rm -f libgit2.pc
 	rm -f src/*.o
+	rm -f src/sha1/*.o
 	rm -f tests/*.o tests/*.exe tests/*.toc
 	rm -rf trash-*.exe
 	rm -rf apidocs
@@ -86,7 +110,7 @@ uninstall:
 
 $(OBJS): $(HDRS)
 $(GIT_LIB): $(OBJS)
-	rm -f $(LIB)
+	rm -f $(GIT_LIB)
 	$(AR) cr $(GIT_LIB) $(OBJS)
 	$(RANLIB) $(GIT_LIB)
 
@@ -116,7 +140,7 @@ $(TEST_EXE): tests/%.exe: tests/%.o tests/%_main.o
 	$(CC) -o $@ \
 		$(patsubst %.exe,%_main.o,$@) \
 		$(patsubst %.exe,%.o,$@) \
-		$(T_LIB) -L. -lgit2 -lz -lcrypto
+		$(T_LIB) $(LIBS)
 
 $(TEST_RUN): tests/%.run: tests/%.exe
 	@t=trash-$(<F) && \

src/hash.c

@@ -25,7 +25,7 @@
 
 #include "common.h"
 #include "hash.h"
-#include <openssl/sha.h>
+#include SHA1_HEADER
 
 struct git_hash_ctx {
 	SHA_CTX c;

src/sha1/sha1.c

@@ -0,0 +1,170 @@
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is SHA 180-1 Reference Implementation (Compact version)
+ *
+ * The Initial Developer of the Original Code is Paul Kocher of
+ * Cryptography Research.  Portions created by Paul Kocher are
+ * Copyright (C) 1995-9 by Cryptography Research, Inc.  All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ *     Paul Kocher
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License, version 2, (the "GPL")
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ * If you wish to allow use of your version of this file only under
+ * the terms of the GPL and not to allow others to use your version
+ * of this file under the MPL, indicate your decision by deleting
+ * the provisions above and replace them with the notice and other
+ * provisions required by the GPL.  If you do not delete the
+ * provisions above, a recipient may use your version of this file
+ * under either the MPL or the GPL.
+ */
+
+#include "sha1.h"
+
+static void shaHashBlock(SHA_CTX *ctx);
+
+void SHA1_Init(SHA_CTX *ctx) {
+  int i;
+
+  ctx->lenW = 0;
+  ctx->sizeHi = ctx->sizeLo = 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;
+
+  for (i = 0; i < 80; i++)
+    ctx->W[i] = 0;
+}
+
+
+void SHA1_Update(SHA_CTX *ctx, const void *_dataIn, int len) {
+  const unsigned char *dataIn = _dataIn;
+  int i;
+
+  /* Read the data into W and process blocks as they get full
+   */
+  for (i = 0; i < len; i++) {
+    ctx->W[ctx->lenW / 4] <<= 8;
+    ctx->W[ctx->lenW / 4] |= (unsigned int)dataIn[i];
+    if ((++ctx->lenW) % 64 == 0) {
+      shaHashBlock(ctx);
+      ctx->lenW = 0;
+    }
+    ctx->sizeLo += 8;
+    ctx->sizeHi += (ctx->sizeLo < 8);
+  }
+}
+
+
+void SHA1_Final(unsigned char hashout[20], SHA_CTX *ctx) {
+  unsigned char pad0x80 = 0x80;
+  unsigned char pad0x00 = 0x00;
+  unsigned char padlen[8];
+  int i;
+
+  /* Pad with a binary 1 (e.g. 0x80), then zeroes, then length
+   */
+  padlen[0] = (unsigned char)((ctx->sizeHi >> 24) & 255);
+  padlen[1] = (unsigned char)((ctx->sizeHi >> 16) & 255);
+  padlen[2] = (unsigned char)((ctx->sizeHi >> 8) & 255);
+  padlen[3] = (unsigned char)((ctx->sizeHi >> 0) & 255);
+  padlen[4] = (unsigned char)((ctx->sizeLo >> 24) & 255);
+  padlen[5] = (unsigned char)((ctx->sizeLo >> 16) & 255);
+  padlen[6] = (unsigned char)((ctx->sizeLo >> 8) & 255);
+  padlen[7] = (unsigned char)((ctx->sizeLo >> 0) & 255);
+  SHA1_Update(ctx, &pad0x80, 1);
+  while (ctx->lenW != 56)
+    SHA1_Update(ctx, &pad0x00, 1);
+  SHA1_Update(ctx, padlen, 8);
+
+  /* Output hash
+   */
+  for (i = 0; i < 20; i++) {
+    hashout[i] = (unsigned char)(ctx->H[i / 4] >> 24);
+    ctx->H[i / 4] <<= 8;
+  }
+
+  /*
+   *  Re-initialize the context (also zeroizes contents)
+   */
+  SHA1_Init(ctx);
+}
+
+
+#define SHA_ROT(X,n) (((X) << (n)) | ((X) >> (32-(n))))
+
+static void shaHashBlock(SHA_CTX *ctx) {
+  int t;
+  unsigned int A,B,C,D,E,TEMP;
+
+  for (t = 16; t <= 79; t++)
+    ctx->W[t] =
+      SHA_ROT(ctx->W[t-3] ^ ctx->W[t-8] ^ ctx->W[t-14] ^ ctx->W[t-16], 1);
+
+  A = ctx->H[0];
+  B = ctx->H[1];
+  C = ctx->H[2];
+  D = ctx->H[3];
+  E = ctx->H[4];
+
+  for (t = 0; t <= 19; t++) {
+    TEMP = SHA_ROT(A,5) + (((C^D)&B)^D)     + E + ctx->W[t] + 0x5a827999;
+    E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
+  }
+  for (t = 20; t <= 39; t++) {
+    TEMP = SHA_ROT(A,5) + (B^C^D)           + E + ctx->W[t] + 0x6ed9eba1;
+    E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
+  }
+  for (t = 40; t <= 59; t++) {
+    TEMP = SHA_ROT(A,5) + ((B&C)|(D&(B|C))) + E + ctx->W[t] + 0x8f1bbcdc;
+    E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
+  }
+  for (t = 60; t <= 79; t++) {
+    TEMP = SHA_ROT(A,5) + (B^C^D)           + E + ctx->W[t] + 0xca62c1d6;
+    E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
+  }
+
+  ctx->H[0] += A;
+  ctx->H[1] += B;
+  ctx->H[2] += C;
+  ctx->H[3] += D;
+  ctx->H[4] += E;
+}

src/sha1/sha1.h

@@ -0,0 +1,64 @@
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is SHA 180-1 Header File
+ *
+ * The Initial Developer of the Original Code is Paul Kocher of
+ * Cryptography Research.  Portions created by Paul Kocher are
+ * Copyright (C) 1995-9 by Cryptography Research, Inc.  All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ *     Paul Kocher
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License, version 2, (the "GPL")
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ * If you wish to allow use of your version of this file only under
+ * the terms of the GPL and not to allow others to use your version
+ * of this file under the MPL, indicate your decision by deleting
+ * the provisions above and replace them with the notice and other
+ * provisions required by the GPL.  If you do not delete the
+ * provisions above, a recipient may use your version of this file
+ * under either the MPL or the GPL.
+ */
+
+typedef struct {
+  unsigned int H[5];
+  unsigned int W[80];
+  int lenW;
+  unsigned int sizeHi,sizeLo;
+} SHA_CTX;
+
+void SHA1_Init(SHA_CTX *ctx);
+void SHA1_Update(SHA_CTX *ctx, const void *dataIn, int len);
+void SHA1_Final(unsigned char hashout[20], SHA_CTX *ctx);