strerror: make the strerror function use local buffers

Instead of using a fixed 256 byte buffer in the connectdata struct.

In my build, this reduces the size of the connectdata struct by 11.8%,
from 2160 to 1904 bytes with no functionality or performance loss.

This also fixes a bug in schannel's Curl_verify_certificate where it
called Curl_sspi_strerror when it should have called Curl_strerror for
string from GetLastError. the only effect would have been no text or the
wrong text being shown for the error.

Co-authored-by: Jay Satiro

Closes #3612

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/vauth/spnego_sspi.c b/lib/vauth/spnego_sspi.c
index 00d840465..98c471e58 100644
--- a/lib/vauth/spnego_sspi.c
+++ b/lib/vauth/spnego_sspi.c
@@ -248,8 +248,9 @@ CURLcode Curl_auth_decode_spnego_message(struct Curl_easy *data,
   free(chlg);
 
   if(GSS_ERROR(nego->status)) {
+    char buffer[STRERROR_LEN];
     failf(data, "InitializeSecurityContext failed: %s",
-          Curl_sspi_strerror(data->conn, nego->status));
+          Curl_sspi_strerror(nego->status, buffer, sizeof(buffer)));
     return CURLE_OUT_OF_MEMORY;
   }