/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) 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 https://curl.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.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

#include "curl_setup.h"

#ifdef HAVE_STRERROR_R

#  if (!defined(HAVE_POSIX_STRERROR_R) && \

       !defined(HAVE_GLIBC_STRERROR_R)) || \

      (defined(HAVE_POSIX_STRERROR_R) && defined(HAVE_GLIBC_STRERROR_R))

#    error "strerror_r MUST be either POSIX, glibc style"

#  endif

#endif

#include <curl/curl.h>

#ifdef USE_LIBIDN2

#include <idn2.h>

#endif

#ifdef USE_WINDOWS_SSPI

#include "curl_sspi.h"

#endif

#include "curlx/winapi.h"

#include "strerror.h"

/* The last 3 #include files should be in this order */

#include "curl_printf.h"

#include "curl_memory.h"

#include "memdebug.h"

const char *

curl_easy_strerror(CURLcode error)

{

#ifndef CURL_DISABLE_VERBOSE_STRINGS

  switch(error) {

  case CURLE_OK:

    return "No error";

  case CURLE_UNSUPPORTED_PROTOCOL:

    return "Unsupported protocol";

  case CURLE_FAILED_INIT:

    return "Failed initialization";

  case CURLE_URL_MALFORMAT:

    return "URL using bad/illegal format or missing URL";

  case CURLE_NOT_BUILT_IN:

    return "A requested feature, protocol or option was not found built-in in"

      " this libcurl due to a build-time decision.";

  case CURLE_COULDNT_RESOLVE_PROXY:

    return "Could not resolve proxy name";

  case CURLE_COULDNT_RESOLVE_HOST:

    return "Could not resolve hostname";

  case CURLE_COULDNT_CONNECT:

    return "Could not connect to server";

  case CURLE_WEIRD_SERVER_REPLY:

    return "Weird server reply";

  case CURLE_REMOTE_ACCESS_DENIED:

    return "Access denied to remote resource";

  case CURLE_FTP_ACCEPT_FAILED:

    return "FTP: The server failed to connect to data port";

  case CURLE_FTP_ACCEPT_TIMEOUT:

    return "FTP: Accepting server connect has timed out";

  case CURLE_FTP_PRET_FAILED:

    return "FTP: The server did not accept the PRET command.";

  case CURLE_FTP_WEIRD_PASS_REPLY:

    return "FTP: unknown PASS reply";

  case CURLE_FTP_WEIRD_PASV_REPLY:

    return "FTP: unknown PASV reply";

  case CURLE_FTP_WEIRD_227_FORMAT:

    return "FTP: unknown 227 response format";

  case CURLE_FTP_CANT_GET_HOST:

    return "FTP: cannot figure out the host in the PASV response";

  case CURLE_HTTP2:

    return "Error in the HTTP2 framing layer";

  case CURLE_FTP_COULDNT_SET_TYPE:

    return "FTP: could not set file type";

  case CURLE_PARTIAL_FILE:

    return "Transferred a partial file";

  case CURLE_FTP_COULDNT_RETR_FILE:

    return "FTP: could not retrieve (RETR failed) the specified file";

  case CURLE_QUOTE_ERROR:

    return "Quote command returned error";

  case CURLE_HTTP_RETURNED_ERROR:

    return "HTTP response code said error";

  case CURLE_WRITE_ERROR:

    return "Failed writing received data to disk/application";

  case CURLE_UPLOAD_FAILED:

    return "Upload failed (at start/before it took off)";

  case CURLE_READ_ERROR:

    return "Failed to open/read local data from file/application";

  case CURLE_OUT_OF_MEMORY:

    return "Out of memory";

  case CURLE_OPERATION_TIMEDOUT:

    return "Timeout was reached";

  case CURLE_FTP_PORT_FAILED:

    return "FTP: command PORT failed";

  case CURLE_FTP_COULDNT_USE_REST:

    return "FTP: command REST failed";

  case CURLE_RANGE_ERROR:

    return "Requested range was not delivered by the server";

  case CURLE_SSL_CONNECT_ERROR:

    return "SSL connect error";

  case CURLE_BAD_DOWNLOAD_RESUME:

    return "Could not resume download";

  case CURLE_FILE_COULDNT_READ_FILE:

    return "Could not read a file:// file";

  case CURLE_LDAP_CANNOT_BIND:

    return "LDAP: cannot bind";

  case CURLE_LDAP_SEARCH_FAILED:

    return "LDAP: search failed";

  case CURLE_ABORTED_BY_CALLBACK:

    return "Operation was aborted by an application callback";

  case CURLE_BAD_FUNCTION_ARGUMENT:

    return "A libcurl function was given a bad argument";

  case CURLE_INTERFACE_FAILED:

    return "Failed binding local connection end";

  case CURLE_TOO_MANY_REDIRECTS:

    return "Number of redirects hit maximum amount";

  case CURLE_UNKNOWN_OPTION:

    return "An unknown option was passed in to libcurl";

  case CURLE_SETOPT_OPTION_SYNTAX:

    return "Malformed option provided in a setopt";

  case CURLE_GOT_NOTHING:

    return "Server returned nothing (no headers, no data)";

  case CURLE_SSL_ENGINE_NOTFOUND:

    return "SSL crypto engine not found";

  case CURLE_SSL_ENGINE_SETFAILED:

    return "Can not set SSL crypto engine as default";

  case CURLE_SSL_ENGINE_INITFAILED:

    return "Failed to initialise SSL crypto engine";

  case CURLE_SEND_ERROR:

    return "Failed sending data to the peer";

  case CURLE_RECV_ERROR:

    return "Failure when receiving data from the peer";

  case CURLE_SSL_CERTPROBLEM:

    return "Problem with the local SSL certificate";

  case CURLE_SSL_CIPHER:

    return "Could not use specified SSL cipher";

  case CURLE_PEER_FAILED_VERIFICATION:

    return "SSL peer certificate or SSH remote key was not OK";

  case CURLE_SSL_CACERT_BADFILE:

    return "Problem with the SSL CA cert (path? access rights?)";

  case CURLE_BAD_CONTENT_ENCODING:

    return "Unrecognized or bad HTTP Content or Transfer-Encoding";

  case CURLE_FILESIZE_EXCEEDED:

    return "Maximum file size exceeded";

  case CURLE_USE_SSL_FAILED:

    return "Requested SSL level failed";

  case CURLE_SSL_SHUTDOWN_FAILED:

    return "Failed to shut down the SSL connection";

  case CURLE_SSL_CRL_BADFILE:

    return "Failed to load CRL file (path? access rights?, format?)";

  case CURLE_SSL_ISSUER_ERROR:

    return "Issuer check against peer certificate failed";

  case CURLE_SEND_FAIL_REWIND:

    return "Send failed since rewinding of the data stream failed";

  case CURLE_LOGIN_DENIED:

    return "Login denied";

  case CURLE_TFTP_NOTFOUND:

    return "TFTP: File Not Found";

  case CURLE_TFTP_PERM:

    return "TFTP: Access Violation";

  case CURLE_REMOTE_DISK_FULL:

    return "Disk full or allocation exceeded";

  case CURLE_TFTP_ILLEGAL:

    return "TFTP: Illegal operation";

  case CURLE_TFTP_UNKNOWNID:

    return "TFTP: Unknown transfer ID";

  case CURLE_REMOTE_FILE_EXISTS:

    return "Remote file already exists";

  case CURLE_TFTP_NOSUCHUSER:

    return "TFTP: No such user";

  case CURLE_REMOTE_FILE_NOT_FOUND:

    return "Remote file not found";

  case CURLE_SSH:

    return "Error in the SSH layer";

  case CURLE_AGAIN:

    return "Socket not ready for send/recv";

  case CURLE_RTSP_CSEQ_ERROR:

    return "RTSP CSeq mismatch or invalid CSeq";

  case CURLE_RTSP_SESSION_ERROR:

    return "RTSP session error";

  case CURLE_FTP_BAD_FILE_LIST:

    return "Unable to parse FTP file list";

  case CURLE_CHUNK_FAILED:

    return "Chunk callback failed";

  case CURLE_NO_CONNECTION_AVAILABLE:

    return "The max connection limit is reached";

  case CURLE_SSL_PINNEDPUBKEYNOTMATCH:

    return "SSL public key does not match pinned public key";

  case CURLE_SSL_INVALIDCERTSTATUS:

    return "SSL server certificate status verification FAILED";

  case CURLE_HTTP2_STREAM:

    return "Stream error in the HTTP/2 framing layer";

  case CURLE_RECURSIVE_API_CALL:

    return "API function called from within callback";

  case CURLE_AUTH_ERROR:

    return "An authentication function returned an error";

  case CURLE_HTTP3:

    return "HTTP/3 error";

  case CURLE_QUIC_CONNECT_ERROR:

    return "QUIC connection error";

  case CURLE_PROXY:

    return "proxy handshake error";

  case CURLE_SSL_CLIENTCERT:

    return "SSL Client Certificate required";

  case CURLE_UNRECOVERABLE_POLL:

    return "Unrecoverable error in select/poll";

  case CURLE_TOO_LARGE:

    return "A value or data field grew larger than allowed";

  case CURLE_ECH_REQUIRED:

    return "ECH attempted but failed";

    /* error codes not used by current libcurl */

  case CURLE_OBSOLETE20:

  case CURLE_OBSOLETE24:

  case CURLE_OBSOLETE29:

  case CURLE_OBSOLETE32:

  case CURLE_OBSOLETE34:

  case CURLE_OBSOLETE40:

  case CURLE_OBSOLETE41:

  case CURLE_OBSOLETE44:

  case CURLE_OBSOLETE46:

  case CURLE_OBSOLETE50:

  case CURLE_OBSOLETE51:

  case CURLE_OBSOLETE57:

  case CURLE_OBSOLETE62:

  case CURLE_OBSOLETE75:

  case CURLE_OBSOLETE76:

    /* error codes used by curl tests */

  case CURLE_RESERVED115:

  case CURLE_RESERVED116:

  case CURLE_RESERVED117:

  case CURLE_RESERVED118:

  case CURLE_RESERVED119:

  case CURLE_RESERVED120:

  case CURLE_RESERVED121:

  case CURLE_RESERVED122:

  case CURLE_RESERVED123:

  case CURLE_RESERVED124:

  case CURLE_RESERVED125:

  case CURLE_RESERVED126:

  case CURL_LAST:

    break;

  }

  /*

   * By using a switch, gcc -Wall will complain about enum values

   * which do not appear, helping keep this function up-to-date.

   * By using gcc -Wall -Werror, you cannot forget.

   *

   * A table would not have the same benefit. Most compilers will generate

   * code similar to a table in any case, so there is little performance gain

   * from a table. Something is broken for the user's application, anyways, so

   * does it matter how fast it _does not_ work?

   *

   * The line number for the error will be near this comment, which is why it

   * is here, and not at the start of the switch.

   */

  return "Unknown error";

#else

  if(!error)

    return "No error";

  else

    return "Error";

#endif

}

const char *

curl_multi_strerror(CURLMcode error)

{

#ifndef CURL_DISABLE_VERBOSE_STRINGS

  switch(error) {

  case CURLM_CALL_MULTI_PERFORM:

    return "Please call curl_multi_perform() soon";

  case CURLM_OK:

    return "No error";

  case CURLM_BAD_HANDLE:

    return "Invalid multi handle";

  case CURLM_BAD_EASY_HANDLE:

    return "Invalid easy handle";

  case CURLM_OUT_OF_MEMORY:

    return "Out of memory";

  case CURLM_INTERNAL_ERROR:

    return "Internal error";

  case CURLM_BAD_SOCKET:

    return "Invalid socket argument";

  case CURLM_UNKNOWN_OPTION:

    return "Unknown option";

  case CURLM_ADDED_ALREADY:

    return "The easy handle is already added to a multi handle";

  case CURLM_RECURSIVE_API_CALL:

    return "API function called from within callback";

  case CURLM_WAKEUP_FAILURE:

    return "Wakeup is unavailable or failed";

  case CURLM_BAD_FUNCTION_ARGUMENT:

    return "A libcurl function was given a bad argument";

  case CURLM_ABORTED_BY_CALLBACK:

    return "Operation was aborted by an application callback";

  case CURLM_UNRECOVERABLE_POLL:

    return "Unrecoverable error in select/poll";

  case CURLM_LAST:

    break;

  }

  return "Unknown error";

#else

  if(error == CURLM_OK)

    return "No error";

  else

    return "Error";

#endif

}

const char *

curl_share_strerror(CURLSHcode error)

{

#ifndef CURL_DISABLE_VERBOSE_STRINGS

  switch(error) {

  case CURLSHE_OK:

    return "No error";

  case CURLSHE_BAD_OPTION:

    return "Unknown share option";

  case CURLSHE_IN_USE:

    return "Share currently in use";

  case CURLSHE_INVALID:

    return "Invalid share handle";

  case CURLSHE_NOMEM:

    return "Out of memory";

  case CURLSHE_NOT_BUILT_IN:

    return "Feature not enabled in this library";

  case CURLSHE_LAST:

    break;

  }

  return "CURLSHcode unknown";

#else

  if(error == CURLSHE_OK)

    return "No error";

  else

    return "Error";

#endif

}

const char *

curl_url_strerror(CURLUcode error)

{

#ifndef CURL_DISABLE_VERBOSE_STRINGS

  switch(error) {

  case CURLUE_OK:

    return "No error";

  case CURLUE_BAD_HANDLE:

    return "An invalid CURLU pointer was passed as argument";

  case CURLUE_BAD_PARTPOINTER:

    return "An invalid 'part' argument was passed as argument";

  case CURLUE_MALFORMED_INPUT:

    return "Malformed input to a URL function";

  case CURLUE_BAD_PORT_NUMBER:

    return "Port number was not a decimal number between 0 and 65535";

  case CURLUE_UNSUPPORTED_SCHEME:

    return "Unsupported URL scheme";

  case CURLUE_URLDECODE:

    return "URL decode error, most likely because of rubbish in the input";

  case CURLUE_OUT_OF_MEMORY:

    return "A memory function failed";

  case CURLUE_USER_NOT_ALLOWED:

    return "Credentials was passed in the URL when prohibited";

  case CURLUE_UNKNOWN_PART:

    return "An unknown part ID was passed to a URL API function";

  case CURLUE_NO_SCHEME:

    return "No scheme part in the URL";

  case CURLUE_NO_USER:

    return "No user part in the URL";

  case CURLUE_NO_PASSWORD:

    return "No password part in the URL";

  case CURLUE_NO_OPTIONS:

    return "No options part in the URL";

  case CURLUE_NO_HOST:

    return "No host part in the URL";

  case CURLUE_NO_PORT:

    return "No port part in the URL";

  case CURLUE_NO_QUERY:

    return "No query part in the URL";

  case CURLUE_NO_FRAGMENT:

    return "No fragment part in the URL";

  case CURLUE_NO_ZONEID:

    return "No zoneid part in the URL";

  case CURLUE_BAD_LOGIN:

    return "Bad login part";

  case CURLUE_BAD_IPV6:

    return "Bad IPv6 address";

  case CURLUE_BAD_HOSTNAME:

    return "Bad hostname";

  case CURLUE_BAD_FILE_URL:

    return "Bad file:// URL";

  case CURLUE_BAD_SLASHES:

    return "Unsupported number of slashes following scheme";

  case CURLUE_BAD_SCHEME:

    return "Bad scheme";

  case CURLUE_BAD_PATH:

    return "Bad path";

  case CURLUE_BAD_FRAGMENT:

    return "Bad fragment";

  case CURLUE_BAD_QUERY:

    return "Bad query";

  case CURLUE_BAD_PASSWORD:

    return "Bad password";

  case CURLUE_BAD_USER:

    return "Bad user";

  case CURLUE_LACKS_IDN:

    return "libcurl lacks IDN support";

  case CURLUE_TOO_LARGE:

    return "A value or data field is larger than allowed";

  case CURLUE_LAST:

    break;

  }

  return "CURLUcode unknown";

#else

  if(error == CURLUE_OK)

    return "No error";

  else

    return "Error";

#endif

}

#ifdef USE_WINSOCK

/* This is a helper function for Curl_strerror that converts Winsock error

 * codes (WSAGetLastError) to error messages.

 * Returns NULL if no error message was found for error code.

 */

static const char *

get_winsock_error(int err, char *buf, size_t len)

{

#ifndef CURL_DISABLE_VERBOSE_STRINGS

  const char *p;

  size_t alen;

#endif

  if(!len)

    return NULL;

  *buf = '\0';

#ifdef CURL_DISABLE_VERBOSE_STRINGS

  (void)err;

  return NULL;

#else

  switch(err) {

  case WSAEINTR:

    p = "Call interrupted";

    break;

  case WSAEBADF:

    p = "Bad file";

    break;

  case WSAEACCES:

    p = "Bad access";

    break;

  case WSAEFAULT:

    p = "Bad argument";

    break;

  case WSAEINVAL:

    p = "Invalid arguments";

    break;

  case WSAEMFILE:

    p = "Out of file descriptors";

    break;

  case WSAEWOULDBLOCK:

    p = "Call would block";

    break;

  case WSAEINPROGRESS:

  case WSAEALREADY:

    p = "Blocking call in progress";

    break;

  case WSAENOTSOCK:

    p = "Descriptor is not a socket";

    break;

  case WSAEDESTADDRREQ:

    p = "Need destination address";

    break;

  case WSAEMSGSIZE:

    p = "Bad message size";

    break;

  case WSAEPROTOTYPE:

    p = "Bad protocol";

    break;

  case WSAENOPROTOOPT:

    p = "Protocol option is unsupported";

    break;

  case WSAEPROTONOSUPPORT:

    p = "Protocol is unsupported";

    break;

  case WSAESOCKTNOSUPPORT:

    p = "Socket is unsupported";

    break;

  case WSAEOPNOTSUPP:

    p = "Operation not supported";

    break;

  case WSAEAFNOSUPPORT:

    p = "Address family not supported";

    break;

  case WSAEPFNOSUPPORT:

    p = "Protocol family not supported";

    break;

  case WSAEADDRINUSE:

    p = "Address already in use";

    break;

  case WSAEADDRNOTAVAIL:

    p = "Address not available";

    break;

  case WSAENETDOWN:

    p = "Network down";

    break;

  case WSAENETUNREACH:

    p = "Network unreachable";

    break;

  case WSAENETRESET:

    p = "Network has been reset";

    break;

  case WSAECONNABORTED:

    p = "Connection was aborted";

    break;

  case WSAECONNRESET:

    p = "Connection was reset";

    break;

  case WSAENOBUFS:

    p = "No buffer space";

    break;

  case WSAEISCONN:

    p = "Socket is already connected";

    break;

  case WSAENOTCONN:

    p = "Socket is not connected";

    break;

  case WSAESHUTDOWN:

    p = "Socket has been shut down";

    break;

  case WSAETOOMANYREFS:

    p = "Too many references";

    break;

  case WSAETIMEDOUT:

    p = "Timed out";

    break;

  case WSAECONNREFUSED:

    p = "Connection refused";

    break;

  case WSAELOOP:

    p = "Loop??";

    break;

  case WSAENAMETOOLONG:

    p = "Name too long";

    break;

  case WSAEHOSTDOWN:

    p = "Host down";

    break;

  case WSAEHOSTUNREACH:

    p = "Host unreachable";

    break;

  case WSAENOTEMPTY:

    p = "Not empty";

    break;

  case WSAEPROCLIM:

    p = "Process limit reached";

    break;

  case WSAEUSERS:

    p = "Too many users";

    break;

  case WSAEDQUOT:

    p = "Bad quota";

    break;

  case WSAESTALE:

    p = "Something is stale";

    break;

  case WSAEREMOTE:

    p = "Remote error";

    break;

#ifdef WSAEDISCON  /* missing in SalfordC! */

  case WSAEDISCON:

    p = "Disconnected";

    break;

#endif

    /* Extended Winsock errors */

  case WSASYSNOTREADY:

    p = "Winsock library is not ready";

    break;

  case WSANOTINITIALISED:

    p = "Winsock library not initialised";

    break;

  case WSAVERNOTSUPPORTED:

    p = "Winsock version not supported";

    break;

    /* getXbyY() errors (already handled in herrmsg):

     * Authoritative Answer: Host not found */

  case WSAHOST_NOT_FOUND:

    p = "Host not found";

    break;

    /* Non-Authoritative: Host not found, or SERVERFAIL */

  case WSATRY_AGAIN:

    p = "Host not found, try again";

    break;

    /* Non recoverable errors, FORMERR, REFUSED, NOTIMP */

  case WSANO_RECOVERY:

    p = "Unrecoverable error in call to nameserver";

    break;

    /* Valid name, no data record of requested type */

  case WSANO_DATA:

    p = "No data record of requested type";

    break;

  default:

    return NULL;

  }

  alen = strlen(p);

  if(alen < len)

    strcpy(buf, p);

  return buf;

#endif

}

#endif   /* USE_WINSOCK */

/*

 * Our thread-safe and smart strerror() replacement.

 *

 * The 'err' argument passed in to this function MUST be a true errno number

 * as reported on this system. We do no range checking on the number before

 * we pass it to the "number-to-message" conversion function and there might

 * be systems that do not do proper range checking in there themselves.

 *

 * We do not do range checking (on systems other than Windows) since there is

 * no good reliable and portable way to do it.

 *

 * On Windows different types of error codes overlap. This function has an

 * order of preference when trying to match error codes:

 * CRT (errno), Winsock (WSAGetLastError), Windows API (GetLastError).

 *

 * It may be more correct to call one of the variant functions instead:

 * Call Curl_sspi_strerror if the error code is definitely Windows SSPI.

 * Call curlx_winapi_strerror if the error code is definitely Windows API.

 */

const char *Curl_strerror(int err, char *buf, size_t buflen)

{

#ifdef _WIN32

  DWORD old_win_err = GetLastError();

#endif

  int old_errno = errno;

  char *p;

  if(!buflen)

    return NULL;

#ifndef _WIN32

  DEBUGASSERT(err >= 0);

#endif

  *buf = '\0';

#ifdef _WIN32

#ifndef UNDER_CE

  /* 'sys_nerr' is the maximum errno number, it is not widely portable */

  if(err >= 0 && err < sys_nerr)

    curl_msnprintf(buf, buflen, "%s", sys_errlist[err]);

  else

#endif

  {

    if(

#ifdef USE_WINSOCK

      !get_winsock_error(err, buf, buflen) &&

#endif

      !curlx_get_winapi_error(err, buf, buflen))

      curl_msnprintf(buf, buflen, "Unknown error %d (%#x)", err, err);

  }

#else /* not Windows coming up */

#if defined(HAVE_STRERROR_R) && defined(HAVE_POSIX_STRERROR_R)

 /*

  * The POSIX-style strerror_r() may set errno to ERANGE if insufficient

  * storage is supplied via 'strerrbuf' and 'buflen' to hold the generated

  * message string, or EINVAL if 'errnum' is not a valid error number.

  */

  if(0 != strerror_r(err, buf, buflen)) {

    if('\0' == buf[0])

      curl_msnprintf(buf, buflen, "Unknown error %d", err);

  }

#elif defined(HAVE_STRERROR_R) && defined(HAVE_GLIBC_STRERROR_R)

 /*

  * The glibc-style strerror_r() only *might* use the buffer we pass to

  * the function, but it always returns the error message as a pointer,

  * so we must copy that string unconditionally (if non-NULL).

  */

  {

    char buffer[256];

    char *msg = strerror_r(err, buffer, sizeof(buffer));

    if(msg)

      curl_msnprintf(buf, buflen, "%s", msg);

    else

      curl_msnprintf(buf, buflen, "Unknown error %d", err);

  }

#else

  {

    /* !checksrc! disable BANNEDFUNC 1 */

    const char *msg = strerror(err);

    if(msg)

      curl_msnprintf(buf, buflen, "%s", msg);

    else

      curl_msnprintf(buf, buflen, "Unknown error %d", err);

  }

#endif

#endif /* end of not Windows */

  /* strip trailing '\r\n' or '\n'. */

  p = strrchr(buf, '\n');

  if(p && (p - buf) >= 2)

    *p = '\0';

  p = strrchr(buf, '\r');

  if(p && (p - buf) >= 1)

    *p = '\0';

  if(errno != old_errno)

    CURL_SETERRNO(old_errno);

#ifdef _WIN32

  if(old_win_err != GetLastError())

    SetLastError(old_win_err);

#endif

  return buf;

}

#ifdef USE_WINDOWS_SSPI

/*

 * Curl_sspi_strerror:

 * Variant of Curl_strerror if the error code is definitely Windows SSPI.

 */

const char *Curl_sspi_strerror(int err, char *buf, size_t buflen)

{

#ifdef _WIN32

  DWORD old_win_err = GetLastError();

#endif

  int old_errno = errno;

  const char *txt;

  if(!buflen)

    return NULL;

  *buf = '\0';

#ifndef CURL_DISABLE_VERBOSE_STRINGS

  switch(err) {

    case SEC_E_OK:

      txt = "No error";

      break;

#define SEC2TXT(sec) case sec: txt = #sec; break

    SEC2TXT(CRYPT_E_REVOKED);

    SEC2TXT(CRYPT_E_NO_REVOCATION_DLL);

    SEC2TXT(CRYPT_E_NO_REVOCATION_CHECK);

    SEC2TXT(CRYPT_E_REVOCATION_OFFLINE);

    SEC2TXT(CRYPT_E_NOT_IN_REVOCATION_DATABASE);

    SEC2TXT(SEC_E_ALGORITHM_MISMATCH);

    SEC2TXT(SEC_E_BAD_BINDINGS);

    SEC2TXT(SEC_E_BAD_PKGID);

    SEC2TXT(SEC_E_BUFFER_TOO_SMALL);

    SEC2TXT(SEC_E_CANNOT_INSTALL);

    SEC2TXT(SEC_E_CANNOT_PACK);

    SEC2TXT(SEC_E_CERT_EXPIRED);

    SEC2TXT(SEC_E_CERT_UNKNOWN);

    SEC2TXT(SEC_E_CERT_WRONG_USAGE);

    SEC2TXT(SEC_E_CONTEXT_EXPIRED);

    SEC2TXT(SEC_E_CROSSREALM_DELEGATION_FAILURE);

    SEC2TXT(SEC_E_CRYPTO_SYSTEM_INVALID);

    SEC2TXT(SEC_E_DECRYPT_FAILURE);

    SEC2TXT(SEC_E_DELEGATION_POLICY);

    SEC2TXT(SEC_E_DELEGATION_REQUIRED);

    SEC2TXT(SEC_E_DOWNGRADE_DETECTED);

    SEC2TXT(SEC_E_ENCRYPT_FAILURE);

    SEC2TXT(SEC_E_ILLEGAL_MESSAGE);

    SEC2TXT(SEC_E_INCOMPLETE_CREDENTIALS);

    SEC2TXT(SEC_E_INCOMPLETE_MESSAGE);

    SEC2TXT(SEC_E_INSUFFICIENT_MEMORY);

    SEC2TXT(SEC_E_INTERNAL_ERROR);

    SEC2TXT(SEC_E_INVALID_HANDLE);

    SEC2TXT(SEC_E_INVALID_PARAMETER);

    SEC2TXT(SEC_E_INVALID_TOKEN);

    SEC2TXT(SEC_E_ISSUING_CA_UNTRUSTED);

    SEC2TXT(SEC_E_ISSUING_CA_UNTRUSTED_KDC);

    SEC2TXT(SEC_E_KDC_CERT_EXPIRED);

    SEC2TXT(SEC_E_KDC_CERT_REVOKED);

    SEC2TXT(SEC_E_KDC_INVALID_REQUEST);

    SEC2TXT(SEC_E_KDC_UNABLE_TO_REFER);

    SEC2TXT(SEC_E_KDC_UNKNOWN_ETYPE);

    SEC2TXT(SEC_E_LOGON_DENIED);

    SEC2TXT(SEC_E_MAX_REFERRALS_EXCEEDED);

    SEC2TXT(SEC_E_MESSAGE_ALTERED);

    SEC2TXT(SEC_E_MULTIPLE_ACCOUNTS);

    SEC2TXT(SEC_E_MUST_BE_KDC);

    SEC2TXT(SEC_E_NOT_OWNER);

    SEC2TXT(SEC_E_NO_AUTHENTICATING_AUTHORITY);

    SEC2TXT(SEC_E_NO_CREDENTIALS);

    SEC2TXT(SEC_E_NO_IMPERSONATION);

    SEC2TXT(SEC_E_NO_IP_ADDRESSES);

    SEC2TXT(SEC_E_NO_KERB_KEY);

    SEC2TXT(SEC_E_NO_PA_DATA);

    SEC2TXT(SEC_E_NO_S4U_PROT_SUPPORT);

    SEC2TXT(SEC_E_NO_TGT_REPLY);

    SEC2TXT(SEC_E_OUT_OF_SEQUENCE);

    SEC2TXT(SEC_E_PKINIT_CLIENT_FAILURE);

    SEC2TXT(SEC_E_PKINIT_NAME_MISMATCH);

    SEC2TXT(SEC_E_POLICY_NLTM_ONLY);

    SEC2TXT(SEC_E_QOP_NOT_SUPPORTED);

    SEC2TXT(SEC_E_REVOCATION_OFFLINE_C);

    SEC2TXT(SEC_E_REVOCATION_OFFLINE_KDC);

    SEC2TXT(SEC_E_SECPKG_NOT_FOUND);

    SEC2TXT(SEC_E_SECURITY_QOS_FAILED);

    SEC2TXT(SEC_E_SHUTDOWN_IN_PROGRESS);

    SEC2TXT(SEC_E_SMARTCARD_CERT_EXPIRED);

    SEC2TXT(SEC_E_SMARTCARD_CERT_REVOKED);

    SEC2TXT(SEC_E_SMARTCARD_LOGON_REQUIRED);

    SEC2TXT(SEC_E_STRONG_CRYPTO_NOT_SUPPORTED);

    SEC2TXT(SEC_E_TARGET_UNKNOWN);

    SEC2TXT(SEC_E_TIME_SKEW);

    SEC2TXT(SEC_E_TOO_MANY_PRINCIPALS);

    SEC2TXT(SEC_E_UNFINISHED_CONTEXT_DELETED);

    SEC2TXT(SEC_E_UNKNOWN_CREDENTIALS);

    SEC2TXT(SEC_E_UNSUPPORTED_FUNCTION);

    SEC2TXT(SEC_E_UNSUPPORTED_PREAUTH);

    SEC2TXT(SEC_E_UNTRUSTED_ROOT);

    SEC2TXT(SEC_E_WRONG_CREDENTIAL_HANDLE);

    SEC2TXT(SEC_E_WRONG_PRINCIPAL);

    SEC2TXT(SEC_I_COMPLETE_AND_CONTINUE);

    SEC2TXT(SEC_I_COMPLETE_NEEDED);

    SEC2TXT(SEC_I_CONTEXT_EXPIRED);

    SEC2TXT(SEC_I_CONTINUE_NEEDED);

    SEC2TXT(SEC_I_INCOMPLETE_CREDENTIALS);

    SEC2TXT(SEC_I_LOCAL_LOGON);

    SEC2TXT(SEC_I_NO_LSA_CONTEXT);

    SEC2TXT(SEC_I_RENEGOTIATE);

    SEC2TXT(SEC_I_SIGNATURE_NEEDED);

    default:

      txt = "Unknown error";

  }

  if(err == SEC_E_ILLEGAL_MESSAGE) {

    curl_msnprintf(buf, buflen,

                   "SEC_E_ILLEGAL_MESSAGE (0x%08X) - This error usually "

                   "occurs when a fatal SSL/TLS alert is received (e.g. "

                   "handshake failed). More detail may be available in "

                   "the Windows System event log.", err);