sasl_sspi: Tidy up of the existing digest code

Following the addition of SSPI support for HTTP digest, synchronised
elements of the email digest code with that of the new HTTP code.

lib/curl_sasl_sspi.c

@@ -124,11 +124,11 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
   CURLcode result = CURLE_OK;
   TCHAR *spn = NULL;
   size_t chlglen = 0;
-  size_t resp_max = 0;
-  unsigned char *chlg = NULL;
-  unsigned char *resp = NULL;
-  CredHandle handle;
-  CtxtHandle ctx;
+  size_t token_max = 0;
+  unsigned char *input_token = NULL;
+  unsigned char *output_token = NULL;
+  CredHandle credentials;
+  CtxtHandle context;
   PSecPkgInfo SecurityPackage;
   SEC_WINNT_AUTH_IDENTITY identity;
   SEC_WINNT_AUTH_IDENTITY *p_identity;
@@ -142,33 +142,33 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
 
   /* Decode the base-64 encoded challenge message */
   if(strlen(chlg64) && *chlg64 != '=') {
-    result = Curl_base64_decode(chlg64, &chlg, &chlglen);
+    result = Curl_base64_decode(chlg64, &input_token, &chlglen);
     if(result)
       return result;
   }
 
   /* Ensure we have a valid challenge message */
-  if(!chlg)
+  if(!input_token)
     return CURLE_BAD_CONTENT_ENCODING;
 
   /* Query the security package for DigestSSP */
   status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT(SP_NAME_DIGEST),
                                               &SecurityPackage);
   if(status != SEC_E_OK) {
-    Curl_safefree(chlg);
+    Curl_safefree(input_token);
 
     return CURLE_NOT_BUILT_IN;
   }
 
-  resp_max = SecurityPackage->cbMaxToken;
+  token_max = SecurityPackage->cbMaxToken;
 
   /* Release the package buffer as it is not required anymore */
   s_pSecFn->FreeContextBuffer(SecurityPackage);
 
   /* Allocate our response buffer */
-  resp = malloc(resp_max);
-  if(!resp) {
-    Curl_safefree(chlg);
+  output_token = malloc(token_max);
+  if(!output_token) {
+    Curl_safefree(input_token);
 
     return CURLE_OUT_OF_MEMORY;
   }
@@ -176,8 +176,8 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
   /* Generate our SPN */
   spn = Curl_sasl_build_spn(service, data->easy_conn->host.name);
   if(!spn) {
-    Curl_safefree(resp);
-    Curl_safefree(chlg);
+    Curl_safefree(output_token);
+    Curl_safefree(input_token);
 
     return CURLE_OUT_OF_MEMORY;
   }
@@ -187,8 +187,8 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
     result = Curl_create_sspi_identity(userp, passwdp, &identity);
     if(result) {
       Curl_safefree(spn);
-      Curl_safefree(resp);
-      Curl_safefree(chlg);
+      Curl_safefree(output_token);
+      Curl_safefree(input_token);
 
       return result;
     }
@@ -205,13 +205,13 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
                                               (TCHAR *) TEXT(SP_NAME_DIGEST),
                                               SECPKG_CRED_OUTBOUND, NULL,
                                               p_identity, NULL, NULL,
-                                              &handle, &expiry);
+                                              &credentials, &expiry);
 
   if(status != SEC_E_OK) {
     Curl_sspi_free_identity(p_identity);
     Curl_safefree(spn);
-    Curl_safefree(resp);
-    Curl_safefree(chlg);
+    Curl_safefree(output_token);
+    Curl_safefree(input_token);
 
     return CURLE_LOGIN_DENIED;
   }
@@ -221,7 +221,7 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
   chlg_desc.cBuffers  = 1;
   chlg_desc.pBuffers  = &chlg_buf;
   chlg_buf.BufferType = SECBUFFER_TOKEN;
-  chlg_buf.pvBuffer   = chlg;
+  chlg_buf.pvBuffer   = input_token;
   chlg_buf.cbBuffer   = curlx_uztoul(chlglen);
 
   /* Setup the response "output" security buffer */
@@ -229,34 +229,35 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
   resp_desc.cBuffers  = 1;
   resp_desc.pBuffers  = &resp_buf;
   resp_buf.BufferType = SECBUFFER_TOKEN;
-  resp_buf.pvBuffer   = resp;
-  resp_buf.cbBuffer   = curlx_uztoul(resp_max);
+  resp_buf.pvBuffer   = output_token;
+  resp_buf.cbBuffer   = curlx_uztoul(token_max);
 
-  /* Generate our challenge-response message */
-  status = s_pSecFn->InitializeSecurityContext(&handle, NULL, spn, 0, 0, 0,
-                                               &chlg_desc, 0, &ctx,
-                                               &resp_desc, &attrs, &expiry);
+  /* Generate our response message */
+  status = s_pSecFn->InitializeSecurityContext(&credentials, NULL, spn,
+                                               0, 0, 0, &chlg_desc, 0,
+                                               &context, &resp_desc, &attrs,
+                                               &expiry);
 
   if(status == SEC_I_COMPLETE_NEEDED ||
      status == SEC_I_COMPLETE_AND_CONTINUE)
-    s_pSecFn->CompleteAuthToken(&handle, &resp_desc);
+    s_pSecFn->CompleteAuthToken(&credentials, &resp_desc);
   else if(status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED) {
-    s_pSecFn->FreeCredentialsHandle(&handle);
+    s_pSecFn->FreeCredentialsHandle(&credentials);
     Curl_sspi_free_identity(p_identity);
     Curl_safefree(spn);
-    Curl_safefree(resp);
-    Curl_safefree(chlg);
+    Curl_safefree(output_token);
+    Curl_safefree(input_token);
 
     return CURLE_RECV_ERROR;
   }
 
   /* Base64 encode the response */
-  result = Curl_base64_encode(data, (char *)resp, resp_buf.cbBuffer, outptr,
-                              outlen);
+  result = Curl_base64_encode(data, (char *) output_token, resp_buf.cbBuffer,
+                              outptr, outlen);
 
   /* Free our handles */
-  s_pSecFn->DeleteSecurityContext(&ctx);
-  s_pSecFn->FreeCredentialsHandle(&handle);
+  s_pSecFn->DeleteSecurityContext(&context);
+  s_pSecFn->FreeCredentialsHandle(&credentials);
 
   /* Free the identity structure */
   Curl_sspi_free_identity(p_identity);
@@ -265,10 +266,10 @@ CURLcode Curl_sasl_create_digest_md5_message(struct SessionHandle *data,
   Curl_safefree(spn);
 
   /* Free the response buffer */
-  Curl_safefree(resp);
+  Curl_safefree(output_token);
 
   /* Free the decoded challenge message */
-  Curl_safefree(chlg);
+  Curl_safefree(input_token);
 
   return result;
 }