Revert changes relative to lib/*.[ch] recent renaming

This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:

  f871de0... build: make use of 76 lib/*.h renamed files
  ffd8e12... build: rename 76 lib/*.h files

This also reverts removal of redundant include guard (redundant thanks
to changes in above commits) done 2-12-2013, reverting 1 commit:

  c087374... curl_setup.h: remove redundant include guard

This also reverts renaming and usage of lib/*.c source files done
3-12-2013, reverting 3 commits:

  13606bb... build: make use of 93 lib/*.c renamed files
  5b6e792... build: rename 93 lib/*.c files
  7d83dff... build: commit 13606bbfde follow-up 1

Start of related discussion thread:

  http://curl.haxx.se/mail/lib-2013-01/0012.html

Asking for confirmation on pushing this revertion commit:

  http://curl.haxx.se/mail/lib-2013-01/0048.html

Confirmation summary:

  http://curl.haxx.se/mail/lib-2013-01/0079.html

NOTICE: The list of 2 files that have been modified by other
intermixed commits, while renamed, and also by at least one
of the 6 commits this one reverts follows below. These 2 files
will exhibit a hole in history unless git's '--follow' option
is used when viewing logs.

  lib/curl_imap.h
  lib/curl_smtp.h

1 files changed, 133 insertions, 0 deletions

diff --git a/lib/hmac.c b/lib/hmac.c
new file mode 100644
index 000000000..4df6f79ad
--- /dev/null
+++ b/lib/hmac.c
@@ -0,0 +1,133 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * RFC2104 Keyed-Hashing for Message Authentication
+ *
+ ***************************************************************************/
+
+#include "setup.h"
+
+#ifndef CURL_DISABLE_CRYPTO_AUTH
+
+#include "curl_hmac.h"
+
+#define _MPRINTF_REPLACE /* use our functions only */
+#include <curl/mprintf.h>
+
+#include "curl_memory.h"
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/*
+ * Generic HMAC algorithm.
+ *
+ *   This module computes HMAC digests based on any hash function. Parameters
+ * and computing procedures are set-up dynamically at HMAC computation
+ * context initialisation.
+ */
+
+static const unsigned char hmac_ipad = 0x36;
+static const unsigned char hmac_opad = 0x5C;
+
+
+
+HMAC_context *
+Curl_HMAC_init(const HMAC_params * hashparams,
+               const unsigned char * key,
+               unsigned int keylen)
+{
+  size_t i;
+  HMAC_context * ctxt;
+  unsigned char * hkey;
+  unsigned char b;
+
+  /* Create HMAC context. */
+  i = sizeof *ctxt + 2 * hashparams->hmac_ctxtsize +
+    hashparams->hmac_resultlen;
+  ctxt = malloc(i);
+
+  if(!ctxt)
+    return ctxt;
+
+  ctxt->hmac_hash = hashparams;
+  ctxt->hmac_hashctxt1 = (void *) (ctxt + 1);
+  ctxt->hmac_hashctxt2 = (void *) ((char *) ctxt->hmac_hashctxt1 +
+      hashparams->hmac_ctxtsize);
+
+  /* If the key is too long, replace it by its hash digest. */
+  if(keylen > hashparams->hmac_maxkeylen) {
+    (*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
+    (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, key, keylen);
+    hkey = (unsigned char *) ctxt->hmac_hashctxt2 + hashparams->hmac_ctxtsize;
+    (*hashparams->hmac_hfinal)(hkey, ctxt->hmac_hashctxt1);
+    key = hkey;
+    keylen = hashparams->hmac_resultlen;
+  }
+
+  /* Prime the two hash contexts with the modified key. */
+  (*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
+  (*hashparams->hmac_hinit)(ctxt->hmac_hashctxt2);
+
+  for(i = 0; i < keylen; i++) {
+    b = (unsigned char)(*key ^ hmac_ipad);
+    (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &b, 1);
+    b = (unsigned char)(*key++ ^ hmac_opad);
+    (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &b, 1);
+  }
+
+  for(; i < hashparams->hmac_maxkeylen; i++) {
+    (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &hmac_ipad, 1);
+    (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &hmac_opad, 1);
+  }
+
+  /* Done, return pointer to HMAC context. */
+  return ctxt;
+}
+
+int Curl_HMAC_update(HMAC_context * ctxt,
+                     const unsigned char * data,
+                     unsigned int len)
+{
+  /* Update first hash calculation. */
+  (*ctxt->hmac_hash->hmac_hupdate)(ctxt->hmac_hashctxt1, data, len);
+  return 0;
+}
+
+
+int Curl_HMAC_final(HMAC_context * ctxt, unsigned char * result)
+{
+  const HMAC_params * hashparams = ctxt->hmac_hash;
+
+  /* Do not get result if called with a null parameter: only release
+     storage. */
+
+  if(!result)
+    result = (unsigned char *) ctxt->hmac_hashctxt2 +
+     ctxt->hmac_hash->hmac_ctxtsize;
+
+  (*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt1);
+  (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2,
+   result, hashparams->hmac_resultlen);
+  (*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt2);
+  free((char *) ctxt);
+  return 0;
+}
+
+#endif /* CURL_DISABLE_CRYPTO_AUTH */