Corrected a number of the error codes that can be returned from the
Curl_sasl_create_gssapi_security_message() function when things go
wrong.
It makes more sense to return CURLE_BAD_CONTENT_ENCODING when the
inbound security challenge can't be decoded correctly or doesn't
contain the KERB_WRAP_NO_ENCRYPT flag and CURLE_OUT_OF_MEMORY when
EncryptMessage() fails. Unfortunately the previous error code of
CURLE_RECV_ERROR was a copy and paste mistakes on my part and should
have been correct in commit 4b491c675f :(
Given the SSPI package info query indicates a token size of 4096 bytes,
updated to use a dynamic buffer for the response message generation
rather than a fixed buffer of 1024 bytes.
Curl_sasl_create_digest_md5_message() would simply cast the SPN variable
to a TCHAR when calling InitializeSecurityContext(). This meant that,
under Unicode builds, it would not be valid wide character string.
Updated to use the recently introduced Curl_sasl_build_spn() function
which performs the correct conversion for us.
Various parts of the libcurl source code build a SPN for inclusion in
authentication data. This information is either used by our own native
generation routines or passed to authentication functions in third-party
libraries such as SSPI. However, some of these instances use fixed
buffers rather than dynamically allocated ones and not all of those that
should, convert to wide character strings in Unicode builds.
Implemented a common function that generates a SPN and performs the
wide character conversion where necessary.
When CURL_DISABLE_CRYPTO_AUTH is defined the DIGEST-MD5 code should not
be included, regardless of whether USE__WINDOWS_SSPI is defined or not.
This is indicated by the definition of USE_HTTP_NEGOTIATE and USE_NTLM
in curl_setup.h.
