Fix a bunch of -Wmaybe-uninitialized

Reviewed-By: Aris Adamantiadis <aris@0xbadc0de.be>

src/libgcrypt.c

@@ -181,7 +181,7 @@ void ssh_mac_update(ssh_mac_ctx ctx, const void *data, unsigned long len) {
 }
 
 void ssh_mac_final(unsigned char *md, ssh_mac_ctx ctx) {
-  size_t len;
+  size_t len = 0;
   switch(ctx->mac_type){
     case SSH_MAC_SHA1:
       len=SHA_DIGEST_LEN;

src/pki.c

@@ -1753,7 +1753,7 @@ ssh_string ssh_srv_pki_do_sign_sessionid(ssh_session session,
                                          const ssh_key privkey)
 {
     struct ssh_crypto_struct *crypto;
-    ssh_signature sig;
+    ssh_signature sig = NULL;
     ssh_string sig_blob;
     int rc;
 

src/pki_gcrypt.c

@@ -737,7 +737,7 @@ int pki_pubkey_build_ecdsa(ssh_key key, int nid, ssh_string e)
 ssh_key pki_key_dup(const ssh_key key, int demote)
 {
     ssh_key new;
-    gcry_sexp_t sexp;
+    gcry_sexp_t sexp = NULL;
     gcry_error_t err;
     const char *tmp = NULL;
     size_t size;

tests/benchmarks/bench_sftp.c

@@ -45,7 +45,7 @@ int benchmarks_sync_sftp_up (ssh_session session, struct argument_s *args,
   float ms=0.0;
   unsigned long total=0;
   sftp_session sftp;
-  sftp_file file;
+  sftp_file file = NULL;
 
   bytes = args->datasize * 1024 * 1024;
   sftp = sftp_new(session);
@@ -101,7 +101,7 @@ int benchmarks_sync_sftp_down (ssh_session session, struct argument_s *args,
   float ms=0.0;
   unsigned long total=0;
   sftp_session sftp;
-  sftp_file file;
+  sftp_file file = NULL;
   int r;
 
   bytes = args->datasize * 1024 * 1024;
@@ -163,7 +163,7 @@ int benchmarks_async_sftp_down (ssh_session session, struct argument_s *args,
   float ms=0.0;
   unsigned long total=0;
   sftp_session sftp;
-  sftp_file file;
+  sftp_file file = NULL;
   int r,i;
   int warned = 0;
   unsigned long toread;