vauth: Moved the CRAM-MD5 authentication code to the new vauth directory

2 files changed, 151 insertions, 0 deletions

diff --git a/lib/vauth/cram.c b/lib/vauth/cram.c
new file mode 100644
index 000000000..972b74c12
--- /dev/null
+++ b/lib/vauth/cram.c
@@ -0,0 +1,138 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2015, 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.
+ *
+ * RFC2195 CRAM-MD5 authentication
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if !defined(CURL_DISABLE_CRYPTO_AUTH)
+
+#include <curl/curl.h>
+#include "urldata.h"
+
+#include "vauth/vauth.h"
+#include "curl_base64.h"
+#include "curl_hmac.h"
+#include "curl_md5.h"
+#include "warnless.h"
+#include "curl_printf.h"
+
+/* The last #include files should be: */
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * sasl_decode_cram_md5_message()
+ *
+ * This is used to decode an already encoded CRAM-MD5 challenge message.
+ *
+ * Parameters:
+ *
+ * chlg64  [in]     - The base64 encoded challenge message.
+ * outptr  [in/out] - The address where a pointer to newly allocated memory
+ *                    holding the result will be stored upon completion.
+ * outlen  [out]    - The length of the output message.
+ *
+ * Returns CURLE_OK on success.
+ */
+CURLcode sasl_decode_cram_md5_message(const char *chlg64, char **outptr,
+                                      size_t *outlen)
+{
+  CURLcode result = CURLE_OK;
+  size_t chlg64len = strlen(chlg64);
+
+  *outptr = NULL;
+  *outlen = 0;
+
+  /* Decode the challenge if necessary */
+  if(chlg64len && *chlg64 != '=')
+    result = Curl_base64_decode(chlg64, (unsigned char **) outptr, outlen);
+
+  return result;
+}
+
+/*
+ * sasl_create_cram_md5_message()
+ *
+ * This is used to generate an already encoded CRAM-MD5 response message ready
+ * for sending to the recipient.
+ *
+ * Parameters:
+ *
+ * data    [in]     - The session handle.
+ * chlg    [in]     - The challenge.
+ * userp   [in]     - The user name.
+ * passdwp [in]     - The user's password.
+ * outptr  [in/out] - The address where a pointer to newly allocated memory
+ *                    holding the result will be stored upon completion.
+ * outlen  [out]    - The length of the output message.
+ *
+ * Returns CURLE_OK on success.
+ */
+CURLcode sasl_create_cram_md5_message(struct SessionHandle *data,
+                                      const char *chlg,
+                                      const char *userp,
+                                      const char *passwdp,
+                                      char **outptr, size_t *outlen)
+{
+  CURLcode result = CURLE_OK;
+  size_t chlglen = 0;
+  HMAC_context *ctxt;
+  unsigned char digest[MD5_DIGEST_LEN];
+  char *response;
+
+  if(chlg)
+    chlglen = strlen(chlg);
+
+  /* Compute the digest using the password as the key */
+  ctxt = Curl_HMAC_init(Curl_HMAC_MD5,
+                        (const unsigned char *) passwdp,
+                        curlx_uztoui(strlen(passwdp)));
+  if(!ctxt)
+    return CURLE_OUT_OF_MEMORY;
+
+  /* Update the digest with the given challenge */
+  if(chlglen > 0)
+    Curl_HMAC_update(ctxt, (const unsigned char *) chlg,
+                     curlx_uztoui(chlglen));
+
+  /* Finalise the digest */
+  Curl_HMAC_final(ctxt, digest);
+
+  /* Generate the response */
+  response = aprintf(
+    "%s %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
+    userp, digest[0], digest[1], digest[2], digest[3], digest[4],
+    digest[5], digest[6], digest[7], digest[8], digest[9], digest[10],
+    digest[11], digest[12], digest[13], digest[14], digest[15]);
+  if(!response)
+    return CURLE_OUT_OF_MEMORY;
+
+  /* Base64 encode the response */
+  result = Curl_base64_encode(data, response, 0, outptr, outlen);
+
+  free(response);
+
+  return result;
+}
+
+#endif /* !CURL_DISABLE_CRYPTO_AUTH */
diff --git a/lib/vauth/vauth.h b/lib/vauth/vauth.h
index 4e02a27c9..7469ccd8b 100644
--- a/lib/vauth/vauth.h
+++ b/lib/vauth/vauth.h
@@ -53,4 +53,17 @@ CURLcode sasl_create_external_message(struct SessionHandle *data,
                                       const char *user, char **outptr,
                                       size_t *outlen);
 
+#if !defined(CURL_DISABLE_CRYPTO_AUTH)
+/* This is used to decode a CRAM-MD5 challenge message */
+CURLcode sasl_decode_cram_md5_message(const char *chlg64, char **outptr,
+                                      size_t *outlen);
+
+/* This is used to generate a CRAM-MD5 response message */
+CURLcode sasl_create_cram_md5_message(struct SessionHandle *data,
+                                      const char *chlg,
+                                      const char *userp,
+                                      const char *passwdp,
+                                      char **outptr, size_t *outlen);
+#endif /* !CURL_DISABLE_CRYPTO_AUTH */
+
 #endif /* HEADER_CURL_VAUTH_H */