bignums: detach bignum-related functions from dh.c.

Reviewed-by: Andreas Schneider <asn@samba.org>

include/libssh/bignum.h

@@ -0,0 +1,32 @@
+/*
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2014 by Aris Adamantiadis <aris@badcode.be>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef BIGNUM_H_
+#define BIGNUM_H_
+
+#include "libssh/libcrypto.h"
+#include "libssh/libgcrypt.h"
+
+bignum make_string_bn(ssh_string string);
+ssh_string make_bignum_string(bignum num);
+void ssh_print_bignum(const char *which,bignum num);
+
+
+#endif /* BIGNUM_H_ */

include/libssh/dh.h

@@ -25,7 +25,6 @@
 
 #include "libssh/crypto.h"
 
-void ssh_print_bignum(const char *which,bignum num);
 int dh_generate_e(ssh_session session);
 int dh_generate_f(ssh_session session);
 int dh_generate_x(ssh_session session);
@@ -48,8 +47,5 @@ int make_sessionid(ssh_session session);
 int hashbufin_add_cookie(ssh_session session, unsigned char *cookie);
 int hashbufout_add_cookie(ssh_session session);
 int generate_session_keys(ssh_session session);
-bignum make_string_bn(ssh_string string);
-ssh_string make_bignum_string(bignum num);
-
 
 #endif /* DH_H_ */

src/CMakeLists.txt

@@ -109,6 +109,7 @@ set(libssh_SRCS
   agent.c
   auth.c
   base64.c
+  bignum.c
   buffer.c
   callbacks.c
   channels.c

src/bignum.c

@@ -0,0 +1,94 @@
+/*
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2014 by Aris Adamantiadis <aris@badcode.be>
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ *
+ * The SSH Library 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 Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "libssh/priv.h"
+#include "libssh/bignum.h"
+#include "libssh/string.h"
+
+ssh_string make_bignum_string(bignum num) {
+  ssh_string ptr = NULL;
+  int pad = 0;
+  unsigned int len = bignum_num_bytes(num);
+  unsigned int bits = bignum_num_bits(num);
+
+  if (len == 0) {
+      return NULL;
+  }
+
+  /* If the first bit is set we have a negative number */
+  if (!(bits % 8) && bignum_is_bit_set(num, bits - 1)) {
+    pad++;
+  }
+
+#ifdef DEBUG_CRYPTO
+  fprintf(stderr, "%d bits, %d bytes, %d padding\n", bits, len, pad);
+#endif /* DEBUG_CRYPTO */
+
+  ptr = ssh_string_new(len + pad);
+  if (ptr == NULL) {
+    return NULL;
+  }
+
+  /* We have a negative number so we need a leading zero */
+  if (pad) {
+    ptr->data[0] = 0;
+  }
+
+#ifdef HAVE_LIBGCRYPT
+  bignum_bn2bin(num, len, ptr->data + pad);
+#elif HAVE_LIBCRYPTO
+  bignum_bn2bin(num, ptr->data + pad);
+#endif
+
+  return ptr;
+}
+
+bignum make_string_bn(ssh_string string){
+  bignum bn = NULL;
+  unsigned int len = ssh_string_len(string);
+
+#ifdef DEBUG_CRYPTO
+  fprintf(stderr, "Importing a %d bits, %d bytes object ...\n",
+      len * 8, len);
+#endif /* DEBUG_CRYPTO */
+
+#ifdef HAVE_LIBGCRYPT
+  bignum_bin2bn(string->data, len, &bn);
+#elif defined HAVE_LIBCRYPTO
+  bn = bignum_bin2bn(string->data, len, NULL);
+#endif
+
+  return bn;
+}
+
+/* prints the bignum on stderr */
+void ssh_print_bignum(const char *which, bignum num) {
+#ifdef HAVE_LIBGCRYPT
+  unsigned char *hex = NULL;
+  bignum_bn2hex(num, &hex);
+#elif defined HAVE_LIBCRYPTO
+  char *hex = NULL;
+  hex = bignum_bn2hex(num);
+#endif
+  fprintf(stderr, "%s value: ", which);
+  fprintf(stderr, "%s\n", (hex == NULL) ? "(null)" : (char *) hex);
+  SAFE_FREE(hex);
+}

src/buffer.c

@@ -34,7 +34,7 @@
 #include "libssh/priv.h"
 #include "libssh/buffer.h"
 #include "libssh/misc.h"
-#include "libssh/dh.h"
+#include "libssh/bignum.h"
 
 /**
  * @defgroup libssh_buffer The SSH buffer functions.

src/dh.c

@@ -60,6 +60,7 @@
 #include "libssh/dh.h"
 #include "libssh/ssh2.h"
 #include "libssh/pki.h"
+#include "libssh/bignum.h"
 
 /* todo: remove it */
 #include "libssh/string.h"
@@ -225,20 +226,6 @@ void ssh_crypto_finalize(void) {
   }
 }
 
-/* prints the bignum on stderr */
-void ssh_print_bignum(const char *which, bignum num) {
-#ifdef HAVE_LIBGCRYPT
-  unsigned char *hex = NULL;
-  bignum_bn2hex(num, &hex);
-#elif defined HAVE_LIBCRYPTO
-  char *hex = NULL;
-  hex = bignum_bn2hex(num);
-#endif
-  fprintf(stderr, "%s value: ", which);
-  fprintf(stderr, "%s\n", (hex == NULL) ? "(null)" : (char *) hex);
-  SAFE_FREE(hex);
-}
-
 int dh_generate_x(ssh_session session) {
   session->next_crypto->x = bignum_new();
   if (session->next_crypto->x == NULL) {
@@ -351,62 +338,6 @@ int dh_generate_f(ssh_session session) {
   return 0;
 }
 
-ssh_string make_bignum_string(bignum num) {
-  ssh_string ptr = NULL;
-  int pad = 0;
-  unsigned int len = bignum_num_bytes(num);
-  unsigned int bits = bignum_num_bits(num);
-
-  if (len == 0) {
-      return NULL;
-  }
-
-  /* If the first bit is set we have a negative number */
-  if (!(bits % 8) && bignum_is_bit_set(num, bits - 1)) {
-    pad++;
-  }
-
-#ifdef DEBUG_CRYPTO
-  fprintf(stderr, "%d bits, %d bytes, %d padding\n", bits, len, pad);
-#endif /* DEBUG_CRYPTO */
-
-  ptr = ssh_string_new(len + pad);
-  if (ptr == NULL) {
-    return NULL;
-  }
-
-  /* We have a negative number so we need a leading zero */
-  if (pad) {
-    ptr->data[0] = 0;
-  }
-
-#ifdef HAVE_LIBGCRYPT
-  bignum_bn2bin(num, len, ptr->data + pad);
-#elif HAVE_LIBCRYPTO
-  bignum_bn2bin(num, ptr->data + pad);
-#endif
-
-  return ptr;
-}
-
-bignum make_string_bn(ssh_string string){
-  bignum bn = NULL;
-  unsigned int len = ssh_string_len(string);
-
-#ifdef DEBUG_CRYPTO
-  fprintf(stderr, "Importing a %d bits, %d bytes object ...\n",
-      len * 8, len);
-#endif /* DEBUG_CRYPTO */
-
-#ifdef HAVE_LIBGCRYPT
-  bignum_bin2bn(string->data, len, &bn);
-#elif defined HAVE_LIBCRYPTO
-  bn = bignum_bin2bn(string->data, len, NULL);
-#endif
-
-  return bn;
-}
-
 ssh_string dh_get_e(ssh_session session) {
   return make_bignum_string(session->next_crypto->e);
 }

src/pki_crypto.c

@@ -44,7 +44,7 @@
 #include "libssh/session.h"
 #include "libssh/pki.h"
 #include "libssh/pki_priv.h"
-#include "libssh/dh.h"
+#include "libssh/bignum.h"
 
 struct pem_get_password_struct {
     ssh_auth_callback fn;