Add support for --with-crypto-lib from autoconf

The default configure script generated from autoconf will default to
using OpenSSL as the crypto library.  With the new --with-crypto-lib
flag, users can specify libtomcrypto as an alternative crypto library.

Makefile.in

@@ -142,8 +142,8 @@ CRYPTOSRC = \
   $(TOP)/src/crypto.c \
   $(TOP)/src/crypto_impl.h \
   $(TOP)/src/crypto_impl.c \
-	$(TOP)/src/crypto_libtomcrypt.c
-#  $(TOP)/src/crypto_openssl.c
+	$(TOP)/src/crypto_libtomcrypt.c \
+	$(TOP)/src/crypto_openssl.c
 
 # END CRYPTO
 

configure.ac

@@ -253,6 +253,23 @@ if test "$SQLITE_THREADSAFE" = "1"; then
   AC_SEARCH_LIBS(pthread_create, pthread)
 fi
 
+##########
+# Which crypto library do we use
+#
+AC_ARG_WITH([crypto-lib],
+AC_HELP_STRING([--with-crypto-lib],[Specify which crypto library to use]),
+crypto_lib=$withval)
+AC_MSG_CHECKING([for crypto library to use])
+if test "$crypto_lib" = "libtomcrypto"; then
+   CFLAGS+=" -DSQLCIPHER_CRYPTO_LIBTOMCRYPTO"
+   BUILD_CFLAGS+=" -DSQLCIPHER_CRYPTO_LIBTOMCRYPTO"
+   AC_MSG_RESULT([libtomcrypto])
+else
+  CFLAGS+=" -DSQLCIPHER_CRYPTO_OPENSSL"
+  BUILD_CFLAGS+=" -DSQLCIPHER_CRYPTO_OPENSSL"
+  AC_MSG_RESULT([openssl])
+fi
+
 ##########
 # Do we want to allow a connection created in one thread to be used
 # in another thread.  This does not work on many Linux systems (ex: RedHat 9)

src/crypto_libtomcrypt.c

@@ -1,3 +1,4 @@
+#ifdef SQLCIPHER_CRYPTO_LIBTOMCRYPTO
 #include <tomcrypt.h>
 
 void sqlcipher_activate(void *ctx) {
@@ -105,3 +106,4 @@ int sqlcipher_ctx_init(void **ctx) {
 int sqlcipher_ctx_free(void **ctx) {
   return SQLITE_OK;
 }
+#endif

src/crypto_openssl.c

@@ -1,3 +1,4 @@
+#ifdef SQLCIPHER_CRYPTO_OPENSSL
 #include <openssl/rand.h>
 #include <openssl/evp.h>
 #include <openssl/hmac.h>
@@ -138,5 +139,4 @@ int sqlcipher_ctx_free(void **ctx) {
   sqlcipher_free(*ctx, sizeof(openssl_ctx));
   return SQLITE_OK;
 }
-
-
+#endif

tool/mksqlite3c.tcl

@@ -222,12 +222,14 @@ proc copy_file {filename} {
 # used subroutines first in order to help the compiler find
 # inlining opportunities.
 #
+
 foreach file {
    sqliteInt.h
 
    crypto.c
    crypto_impl.c
    crypto_libtomcrypt.c
+   crypto_openssl.c
 
    global.c
    ctime.c