aws4c.c

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/**

*/


/*!
  \mainpage

  This is a small library that provides Amazon Web Services binding
  for C programs.  
  
  The AWS4C leverages CURL and OPENSSL libraries for HTTP transfer and 
  cryptographic functions.

  The \ref todo list is here.

  The \ref bug list is here.

*/

/// \todo Document .awsAuth file
/// \todo Include license
/// \todo Include regression testing
/// \todo Run thing through valgrind

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <sys/stat.h>
#include <curl/curl.h>
#include <openssl/hmac.h>
#include <openssl/evp.h>
#include <openssl/bio.h>
#include <openssl/buffer.h>

#include "aws4c.h"


/*!
  \defgroup internal Internal Functions
  \{
*/

static int debug = 0;   /// <flag to control debugging options
static char * ID       = NULL;  /// <Current ID
static char * awsKeyID = NULL;  /// <AWS Key ID
static char * awsKey   = NULL;  /// <AWS Key Material
static char * S3Host     = "s3.amazonaws.com";     /// <AWS S3 host
static char * SQSHost  = "queue.amazonaws.com";  /// <AWS SQS host
static char * Bucket   = NULL;

static void __debug ( char *fmt, ... ) ;
static char * __aws_get_iso_date ();
static char * __aws_get_httpdate ();
static FILE * __aws_getcfg ();
static int s3_do_get ( IOBuf *b, char * const signature, 
                          char * const date, char * const resource );
static int s3_do_put ( IOBuf *b, char * const signature, 
                          char * const date, char * const resource );
static char* __aws_sign ( char * const str );
static void __chomp ( char  * str );


/// Decode base64 into binary
/// \param input base64 text
/// \param length length of the input text
/// \return decoded data in  newly allocated buffer
/// \internal
///
/// This function allocates a buffer of the same size as the input
/// buffer and then decodes the given base64 encoded text into 
/// binary.   The result is placed into the allocated buffer. It is
/// the caller's responsibility to free this buffer
static char *unbase64(unsigned char *input, int length)
{
  BIO *b64, *bmem;

  /// Allocate and zero the buffer
  char *buffer = (char *)malloc(length);
  memset(buffer, 0, length);

  /// Decode the input into the newly allocated buffer
  /// \todo Check for errors during decode
  b64 = BIO_new(BIO_f_base64());
  bmem = BIO_new_mem_buf(input, length);
  bmem = BIO_push(b64, bmem);

  BIO_read(bmem, buffer, length);

  BIO_free_all(bmem);

  /// Return the decoded text
  return buffer;
}

/// Encode a binary into base64 buffer
/// \param input binary data  text
/// \param length length of the input text
/// \internal
/// \return a newly allocated buffer with base64 encoded data 
static char *__b64_encode(const unsigned char *input, int length)
{
  BIO *bmem, *b64;
  BUF_MEM *bptr;

  b64 = BIO_new(BIO_f_base64());
  bmem = BIO_new(BIO_s_mem());
  b64 = BIO_push(b64, bmem);
  BIO_write(b64, input, length);
  BIO_flush(b64);
  BIO_get_mem_ptr(b64, &bptr);

  char *buff = (char *)malloc(bptr->length);
  memcpy(buff, bptr->data, bptr->length-1);
  buff[bptr->length-1] = 0;

  BIO_free_all(b64);

  return buff;
}

/// Chomp (remove the trailing '\n' from the string
/// \param str string
static void __chomp ( char  * str )
{
  if ( str[0] == 0 ) return;
  int ln = strlen(str);
  ln--;
  if ( str[ln] == '\n' ) str[ln] = 0;
  if ( ln == 0 ) return ;
  ln--;
  if ( str[ln] == '\r' ) str[ln] = 0;
}

/// Handles reception of the data
/// \param ptr pointer to the incoming data
/// \param size size of the data member
/// \param nmemb number of data memebers
/// \param stream pointer to I/O buffer
/// \return number of bytes processed
static size_t writefunc ( void * ptr, size_t size, size_t nmemb, void * stream )
{
  __debug ( "DATA RCVD %d items of size %d ",  nmemb, size );
  aws_iobuf_append ( stream, ptr, nmemb*size );
  return nmemb * size;
}

/// Handles sending of the data
/// \param ptr pointer to the incoming data
/// \param size size of the data member
/// \param nmemb number of data memebers
/// \param stream pointer to I/O buffer
/// \return number of bytes written
static size_t readfunc ( void * ptr, size_t size, size_t nmemb, void * stream )
{
  static int x = 101;

  char * Ln = ptr;
  int sz = aws_iobuf_getline ( stream, ptr, size*nmemb);
  __debug ( "Sent[%3d] %s", sz, Ln );
  return sz;
}

/// Process incming header
/// \param ptr pointer to the incoming data
/// \param size size of the data member
/// \param nmemb number of data memebers
/// \param stream pointer to I/O buffer
/// \return number of bytes processed
static size_t header ( void * ptr, size_t size, size_t nmemb, void * stream )
{
  IOBuf * b = stream;

  if (!strncmp ( ptr, "HTTP/1.1", 8 ))
    {
      b->result = strdup ( ptr + 9 );
      __chomp(b->result);
      b->code   = atoi ( ptr + 9 );
    }
  else if ( !strncmp ( ptr, "ETag: ", 6 ))
    {
      b->eTag = strdup ( ptr + 6 );
      __chomp(b->eTag);
    }
  else if ( !strncmp ( ptr, "Last-Modified: ", 14 ))
    {
      b->lastMod = strdup ( ptr + 15 );
      __chomp(b->lastMod);
    }
  else if ( !strncmp ( ptr, "Content-Length: ", 15 ))
    {
      b->len = atoi ( ptr + 16 );
    }

  return nmemb * size;
}


/// Get Data for authentication of SQS request
/// \return date in ISO format
static char * __aws_get_iso_date ()
{
  static char dTa[256];
  time_t t = time(NULL);
  struct tm * gTime = gmtime ( & t );

  memset ( dTa, 0 , sizeof(dTa));
  strftime ( dTa, sizeof(dTa), "%FT%H:%M:%SZ", gTime );
  __debug ( "Request Time: %s", dTa );
  return dTa;
}


/// Dump current state
/// \internal
static void Dump ()
{
  printf ( "----------------------------------------\n");
  printf ( "ID     : %-40s \n", ID );
  printf ( "KeyID  : %-40s \n", awsKeyID );
  printf ( "Key    : %-40s \n", awsKey );
  printf ( "S3  Host   : %-40s \n", S3Host );
  printf ( "SQS Host   : %-40s \n", SQSHost );
  printf ( "Bucket : %-40s \n", Bucket );
  printf ( "----------------------------------------\n");
}


/// Print debug output
/// \internal
/// \param fmt printf like formating string
static void __debug ( char *fmt, ... ) {
  /// If debug flag is not set we won't print anything
  if ( ! debug ) return ;
  /// Otherwise process the arguments and print the result
  va_list args;
  va_start( args, fmt );
  fprintf( stderr, "DBG: " );
  vfprintf( stderr, fmt, args );
  fprintf( stderr, "\n" );
  va_end( args );
}


/// Get Request Date
/// \internal
/// \return date in HTTP format
static char * __aws_get_httpdate ()
{
  static char dTa[256];
  time_t t = time(NULL);
  struct tm * gTime = gmtime ( & t );
  memset ( dTa, 0 , sizeof(dTa));
  strftime ( dTa, sizeof(dTa), "%a, %d %b %Y %H:%M:%S +0000", gTime );
  __debug ( "Request Time: %s", dTa );
  return dTa;
}

/// Internal function to get configuration file
static FILE * __aws_getcfg ()
{
  int rv;
  char ConfigFile[256] = "";
  /// Compose FileName and check
  snprintf ( ConfigFile, sizeof(ConfigFile) - 3, "%s/.awsAuth",
             getenv("HOME"));
  __debug ( "Config File %s", ConfigFile );

  struct stat sBuf;
  rv = stat ( ConfigFile, &sBuf );
  if ( rv == -1 ) return NULL;

  
  if ( sBuf.st_mode & 066   ||
       sBuf.st_uid != getuid () )
    {
      fprintf ( stderr, "I refuse to read your credentials from %s as this "
               "file is readable by, writable by or owned by someone else."
                "Try chmod 600 %s", ConfigFile, ConfigFile );
      return NULL;
    }

  return fopen ( ConfigFile, "r" );

}


/// Get S3 Request signature
/// \internal
/// \param resource -- URI of the object
/// \param resSize --  size of the resoruce buffer
/// \param date -- HTTP date
/// \param method -- HTTP method
/// \param bucket -- bucket 
/// \param file --  file
/// \return fills up resource and date parameters, also 
///         returns request signature to be used with Authorization header
static char * GetStringToSign ( char * resource,  int resSize, 
                             char ** date,
                             char * const method,
                             char * const bucket,
                             char * const file )
{
  char  reqToSign[2048];
  
  * date = __aws_get_httpdate();

  memset ( resource,0,resSize);
  if ( bucket != NULL )
    snprintf ( resource, resSize,"%s/%s", bucket, file );
  else
    snprintf ( resource, resSize,"%s", file );
    

  snprintf ( reqToSign, sizeof(reqToSign),"%s\n\n\n%s\n/%s",
             method, *date, resource );
  return __aws_sign(reqToSign);

}

static int __aws_urlencode ( char * src, char * dest, int nDest )
{
  int i;
  int n;
  memset ( dest, 0, nDest );
  __debug ( "Encoding: %s", src );
  const char * badChrs = " \n$&+,/:;=?@";
  const char * hexDigit = "0123456789ABCDEF";

  n = 0;
  for ( i = 0 ; src[i] ; i ++ )
    {
      if ( n + 5 > nDest ) 
        { puts ( "URLEncode:: Dest buffer to small.. can't continue \n" ); exit(0); }
      if ( strchr ( badChrs, src[i] ))
        {
          unsigned char c = src[i];
          dest[n++] = '%'; 
          dest[n++] = hexDigit [(c >> 4 ) & 0xF ];
          dest[n++] = hexDigit [c & 0xF ];
        }
      else dest[n++] = src[i];
    }
  __debug ( "Encoded To: %s", dest );
}

static int SQSRequest ( IOBuf *b, char * verb, char * const url )
{
  char Buf[1024];

  
  CURL* ch =  curl_easy_init( );
  struct curl_slist *slist=NULL;


  curl_easy_setopt ( ch, CURLOPT_URL, url );
  curl_easy_setopt ( ch, CURLOPT_HEADERDATA, b );
  curl_easy_setopt ( ch, CURLOPT_VERBOSE, debug );
  curl_easy_setopt ( ch, CURLOPT_INFILESIZE, b->len );
  curl_easy_setopt ( ch, CURLOPT_POST, 1 );
  curl_easy_setopt ( ch, CURLOPT_POST, CURLOPT_POSTFIELDSIZE , 0 );
  curl_easy_setopt ( ch, CURLOPT_HEADERFUNCTION, header );
  curl_easy_setopt ( ch, CURLOPT_WRITEFUNCTION, writefunc );
  curl_easy_setopt ( ch, CURLOPT_WRITEDATA, b );
  curl_easy_setopt ( ch, CURLOPT_READFUNCTION, readfunc );
  curl_easy_setopt ( ch, CURLOPT_READDATA, b );

  int  sc  = curl_easy_perform(ch);
  /** \todo check the return code  */
  __debug ( "Return Code: %d ", sc );
  
  curl_slist_free_all(slist);

  return sc;
}
static char * SQSSign ( char * str )
{
  char RealSign[1024];
  char * signature = __aws_sign(str);
  int c = 0;
  int n = strlen(signature);

  __aws_urlencode ( signature, RealSign, sizeof(RealSign));
    
  free ( signature );
  return strdup(RealSign);

}



/*!
  \}
*/


/*!
  \defgroup Conf Configuration Functions
  \{
*/

/// Initialize  the library 
void aws_init () { curl_global_init (CURL_GLOBAL_ALL); }

/// Set debuging output
/// \param d  when non-zero causes debugging output to be printed
void aws_set_debug (int d)
{
  debug = d;
}

/// \brief Set AWS account ID to be read from .awsAuth file
/// \param str account ID
void aws_set_id ( char * const str )     
{ ID = str == NULL ? NULL : strdup(str); }

/// Set AWS account access key
void aws_set_key ( char * const str )   
{ awsKey = str == NULL ? NULL : strdup(str); }

/// Set AWS account access key ID
void aws_set_keyid ( char * const str ) 
{ awsKeyID = str == NULL ? NULL :  strdup(str);}

/// Read AWS authentication records
/// \param id  user ID
int aws_read_config ( char * const id )
{
  aws_set_id ( id );
  aws_set_keyid ( NULL );
  aws_set_key   ( NULL   );

  /// Open File
  /// Make sure that file permissions are set right
  __debug ( "Reading Config File ID[%s]", ID );
  FILE * f = __aws_getcfg();
  if ( f == NULL ) { perror ("Error opening config file"); exit(1); }
  

  /// Read Lines
  char line[1024];
  int  ln = 0;
  while ( !feof(f))
    {
      ln++;
      memset (line,0,sizeof(line));
      fgets ( line, sizeof(line), f );

  /// Skip Comments
      if ( line[0] == '#' ) continue;
      if ( line[0] == 0 ) continue;

      __chomp ( line );
      

        /// Split the line on ':'
      char * keyID = strchr(line,':');
      if ( keyID == NULL )
        { printf ( "Syntax error in credentials file line %d, no keyid\n", ln );
          exit(1);
        }
      *keyID = 0; keyID ++;

      char * key = strchr(keyID,':');
      if ( key == NULL )
        { printf ( "Syntax error in credentials file line %d, no key\n", ln );
          exit(1);
        }
      *key = 0; key ++;
      
      
      /// If the line is correct Set the IDs
      if ( !strcmp(line,id))
        {
          aws_set_keyid ( keyID );
          aws_set_key   ( key   );
          break;
        }

    }
  /// Return error if not found
  if ( awsKeyID == NULL ) return -1;
  return 0;
}

/*!
  \}
*/




/*!
  \defgroup S3 S3 interface functions
  \{
*/


/// Select current S3 bucket
/// \param str bucket ID
void s3_set_bucket ( char * const str ) 
{ Bucket = str == NULL ? NULL : strdup(str); }

/// Set S3 host
void s3_set_host ( char * const str )  
{ S3Host = str == NULL ? NULL :  strdup(str); }



/// Upload the file into currently selected bucket
/// \param b I/O buffer
/// \param file filename
int s3_put ( IOBuf * b, char * const file )
{
  char * const method = "PUT";
  char  resource [1024];
  char * date = NULL;

  char * signature = GetStringToSign ( resource, sizeof(resource), 
                                       &date, method, Bucket, file ); 
  int sc = s3_do_put( b, signature, date, resource ); 
  free ( signature );
  return sc;

}


/// Download the file from the current bucket
/// \param b I/O buffer
/// \param file filename 
int s3_get ( IOBuf * b, char * const file )
{
  char * const method = "GET";
  
  char  resource [1024];
  char * date = NULL;

  
  char * signature = GetStringToSign ( resource, sizeof(resource), 
                                       &date, method, Bucket, file ); 
  int sc = s3_do_get( b, signature, date, resource ); 
  free ( signature );
  return sc;
}



static int s3_do_put ( IOBuf *b, char * const signature, 
                       char * const date, char * const resource )
{
  char Buf[1024];

  CURL* ch =  curl_easy_init( );
  struct curl_slist *slist=NULL;


  snprintf ( Buf, sizeof(Buf), "Date: %s", date );
  slist = curl_slist_append(slist, Buf );
  snprintf ( Buf, sizeof(Buf), "Authorization: AWS %s:%s", awsKeyID, signature );
  slist = curl_slist_append(slist, Buf );

  snprintf ( Buf, sizeof(Buf), "http://%s/%s", S3Host , resource );

  curl_easy_setopt ( ch, CURLOPT_HTTPHEADER, slist);
  curl_easy_setopt ( ch, CURLOPT_URL, Buf );
  curl_easy_setopt ( ch, CURLOPT_READDATA, b );
  curl_easy_setopt ( ch, CURLOPT_READFUNCTION, readfunc );
  curl_easy_setopt ( ch, CURLOPT_HEADERFUNCTION, header );
  curl_easy_setopt ( ch, CURLOPT_HEADERDATA, b );
  curl_easy_setopt ( ch, CURLOPT_VERBOSE, debug );
  curl_easy_setopt ( ch, CURLOPT_UPLOAD, 1 );
  curl_easy_setopt ( ch, CURLOPT_INFILESIZE, b->len );

  int  sc  = curl_easy_perform(ch);
  /** \todo check the return code  */
  __debug ( "Return Code: %d ", sc );
  
  curl_slist_free_all(slist);

  return sc;

}


static int s3_do_get ( IOBuf *b, char * const signature, 
                       char * const date, char * const resource )
{
  char Buf[1024];

  CURL* ch =  curl_easy_init( );
  struct curl_slist *slist=NULL;

  slist = curl_slist_append(slist, "If-Modified-Since: Tue, 26 May 2009 18:58:55 GMT" );
  slist = curl_slist_append(slist, "ETag: \"6ea58533db38eca2c2cc204b7550aab6\"");

  snprintf ( Buf, sizeof(Buf), "Date: %s", date );
  slist = curl_slist_append(slist, Buf );
  snprintf ( Buf, sizeof(Buf), "Authorization: AWS %s:%s", awsKeyID, signature );
  slist = curl_slist_append(slist, Buf );

  snprintf ( Buf, sizeof(Buf), "http://%s/%s", S3Host, resource );

  curl_easy_setopt ( ch, CURLOPT_HTTPHEADER, slist);
  curl_easy_setopt ( ch, CURLOPT_URL, Buf );
  curl_easy_setopt ( ch, CURLOPT_WRITEFUNCTION, writefunc );
  curl_easy_setopt ( ch, CURLOPT_WRITEDATA, b );
  curl_easy_setopt ( ch, CURLOPT_HEADERFUNCTION, header );
  curl_easy_setopt ( ch, CURLOPT_HEADERDATA, b );
  curl_easy_setopt ( ch, CURLOPT_VERBOSE, debug );

  int  sc  = curl_easy_perform(ch);
  /** \todo check the return code  */
  __debug ( "Return Code: %d ", sc );
  
  curl_slist_free_all(slist);

  return sc;

}






static char* __aws_sign ( char * const str )
{
  int result;
  HMAC_CTX ctx;
  unsigned char MD[256];
  unsigned len;

  __debug("StrToSign:%s", str );

  HMAC_CTX_init(&ctx);
  HMAC_Init(&ctx, awsKey, strlen(awsKey), EVP_sha1());
  HMAC_Update(&ctx,(unsigned char*)str, strlen(str));
  HMAC_Final(&ctx,(unsigned char*)MD,&len);
  HMAC_CTX_cleanup(&ctx);

  char * b64 = __b64_encode (MD,len);
  __debug("Signature:  %s", b64 );

  return b64;
}
/*!
  \}
*/



#define SQS_REQ_TAIL   "&Signature=%s" "&SignatureVersion=1" "&Timestamp=%s" "&Version=2009-02-01"
/*!
  \defgroup SQS SQS interface functions
  \{
*/


/// Create SQS queue
/// \param b I/O buffer
/// \param name queue name
/// \return on success return 0, otherwise error code
int sqs_create_queue ( IOBuf *b, char * const name )
{
  __debug ( "Creating Que: %s\n", name );


  const char * method = "POST";
  char  resource [1024];
  char  customSign [1024];
  char * date = NULL;
  char * signature = NULL;


  
  char * Req = 
    "http://queue.amazonaws.com/"
    "?Action=CreateQueue"
    "&QueueName=%s"
    "&AWSAccessKeyId=%s"
    SQS_REQ_TAIL ;

  char * Sign = "ActionCreateQueue"
                "AWSAccessKeyId%s"
                "QueueName%s"
                "SignatureVersion1"
                "Timestamp%sVersion2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, awsKeyID, name, date );
  signature =  SQSSign ( customSign );

  snprintf ( resource, sizeof(resource), Req , name, awsKeyID, signature, date );

  int sc = SQSRequest( b, "POST", resource ); 
  free ( signature );
  return sc;

}

/// Retrieve URL of the queue
/// \param b I/O buffer
/// \param prefix queue prefix. better use the whole name
/// \return on success return 0, otherwise error code
///
/// URL is placed into the I/O buffer. User get_line to retrieve it
int sqs_list_queues ( IOBuf *b, char * const prefix )
{
  __debug ( "Listing Queues PFX: %s\n", prefix );

  const char * method = "POST";
  char  resource [1024];
  char  customSign [1024];
  char * date = NULL;
  char * signature = NULL;


  
  char * Req = 
    "http://queue.amazonaws.com/"
    "?Action=ListQueues"
    "&QueueNamePrefix=%s"
    "&AWSAccessKeyId=%s"
      SQS_REQ_TAIL ;

  char * Sign = "ActionListQueues"
                "AWSAccessKeyId%s"
                "QueueNamePrefix%s"
                "SignatureVersion1"
                "Timestamp%sVersion2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, awsKeyID, prefix, date );
  signature =  SQSSign ( customSign );

  snprintf ( resource, sizeof(resource), Req , prefix, awsKeyID,
             signature, date );

  IOBuf *nb = aws_iobuf_new();
  int sc = SQSRequest( nb, "POST", resource ); 
  free ( signature );

  b-> result = strdup(nb->result);
  b-> code   = nb->code;

  /// \todo This only retrieves just one line in the string..
  ///       make that all URLs are returned

  if ( b->code == 200 )
    {
      /// Parse Out the List Of Queues
      while(-1)
        {
          char Ln[1024];
          int sz = aws_iobuf_getline ( nb, Ln, sizeof(Ln));
          if ( Ln[0] == 0 ) break;
          char *q = strstr ( Ln, "<QueueUrl>" );
          if ( q != 0 )
            {
              q += 10;
              char * end = NULL;
              end = strstr ( q, "</QueueUrl>" );
              if ( *end != 0 )
                {
                  * end = 0;
                  aws_iobuf_append ( b, q, strlen(q ));
                  aws_iobuf_append ( b, "\n", 1 );
                }
            }
        }      
    }
  aws_iobuf_free ( nb );

  return sc;
}


/// Retrieve queue attributes
/// \param b I/O buffer
/// \param url queue url. Use sqs_list_queues to retrieve
/// \param timeOut queue visibility timeout
/// \param nMesg   approximate number of messages in the queue
/// \return on success return 0, otherwise error code
int sqs_get_queueattributes ( IOBuf *b, char * url, int *timeOut, int *nMesg )
{
  __debug ( "Getting Que Attributes\n" );

  const char * method = "POST";
  char  resource [1024];
  char  customSign [1024];
  char * date = NULL;
  char * signature = NULL;

  char * Req = 
    "%s/"
    "?Action=GetQueueAttributes"
    "&AttributeName.1=VisibilityTimeout"
    "&AttributeName.2=ApproximateNumberOfMessages"
    "&AWSAccessKeyId=%s"
    SQS_REQ_TAIL ;

  char * Sign = 
    "ActionGetQueueAttributes"
    "AttributeName.1VisibilityTimeout"
    "AttributeName.2ApproximateNumberOfMessages"
    "AWSAccessKeyId%s"
    "SignatureVersion1"
    "Timestamp%s"
    "Version2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, awsKeyID, date );
  signature =  SQSSign ( customSign );

  snprintf ( resource, sizeof(resource), Req , url, awsKeyID, signature, date );

  const char *pfxVisTO = "<Name>VisibilityTimeout</Name><Value>";
  const char *pfxQLen  = "<Name>ApproximateNumberOfMessages</Name><Value>";


  int sc = SQSRequest( b, "POST", resource ); 
  while(-1) 
    {
      char Ln[1024];
      int sz = aws_iobuf_getline ( b, Ln, sizeof(Ln));
      if ( Ln[0] == 0 ) break;
      
      char *q;
      q = strstr ( Ln, pfxVisTO );
      if ( q != 0 ) { *timeOut = atoi(q+strlen(pfxVisTO));  }
      q = strstr ( Ln, pfxQLen );
      if ( q != 0 ) { *nMesg = atoi(q+strlen(pfxQLen));  }
    }

  free ( signature );
  return sc;
}

/// Set queue visibility timeout
/// \param b I/O buffer
/// \param url queue url. Use sqs_list_queues to retrieve
/// \param sec queue visibility timeout
/// \return on success return 0, otherwise error code
int sqs_set_queuevisibilitytimeout ( IOBuf *b, char * url, int sec )
{
  __debug ( "Setting Visibility Timeout : %d\n", sec );

  const char * method = "POST";
  char  resource [1024];
  char  customSign [1024];
  char * date = NULL;
  char * signature = NULL;

  char * Req = 
    "%s/"
    "?Action=SetQueueAttributes"
    "&Attribute.1.Name=VisibilityTimeout"
    "&Attribute.1.Value=%d"
    "&AWSAccessKeyId=%s"
    SQS_REQ_TAIL ;

  char * Sign = 
    "ActionSetQueueAttributes"
    "Attribute.1.NameVisibilityTimeout"
    "Attribute.1.Value%d"
    "AWSAccessKeyId%s"
    "SignatureVersion1"
    "Timestamp%s"
    "Version2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, sec, awsKeyID, date );
  signature =  SQSSign ( customSign );

  snprintf ( resource, sizeof(resource), Req , 
             url, sec, awsKeyID, signature, date );

  int sc = SQSRequest( b, "POST", resource ); 
  free ( signature );
  return sc;
}

/// Send a message to the queue
/// \param b I/O buffer
/// \param url queue url. Use sqs_list_queues to retrieve
/// \param msg a message to send
/// \return on success return 0, otherwise error code
int sqs_send_message ( IOBuf *b, char * const url, char * const msg )
{
  __debug ( "Sending Message to the queue %s\n[%s]",
          url, msg );

  const char * method = "POST";
  char  resource [10900];
  char  customSign [10900];
  char * date = NULL;
  char * signature = NULL;
  char  encodedMsg[8192];


  int i,n;
  n = 0;
  __aws_urlencode ( msg, encodedMsg, sizeof(encodedMsg));
  __debug ( "Encoded MSG %s", encodedMsg );

  char * Req = 
    "%s/"
    "?Action=SendMessage"
    "&MessageBody=%s"
    "&AWSAccessKeyId=%s"
    SQS_REQ_TAIL ;

  char * Sign = 
    "ActionSendMessage"
    "AWSAccessKeyId%s"
    "MessageBody%s"
    "SignatureVersion1"
    "Timestamp%s"
    "Version2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, awsKeyID, msg, date );
  signature =  SQSSign ( customSign );

  snprintf ( resource, sizeof(resource), Req , 
             url, encodedMsg, awsKeyID, signature, date );

  int sc = SQSRequest( b, "POST", resource ); 
  free ( signature );
  return sc;
}

/// Retrieve a message from the queue
/// \param b I/O buffer
/// \param url queue url. Use sqs_list_queues to retrieve
/// \param id Message receipt handle. 
/// \return on success return 0, otherwise error code
///
/// Message contents are placed into I/O buffer
/// Caller has to allocate enough memory for the receipt handle 
/// 1024 bytes should be enough
int sqs_get_message ( IOBuf * b, char * const url, char * id  )
{
  __debug ( "Retieving message from: %s", url );

  const char * method = "POST";
  char  resource [10900];
  char  customSign [10900];
  char * date = NULL;
  char * signature = NULL;
  char  encodedMsg[8192];



  char * Req = 
    "%s/"
    "?Action=ReceiveMessage"
    "&AWSAccessKeyId=%s"
    SQS_REQ_TAIL ;

  char * Sign = 
    "ActionReceiveMessage"
    "AWSAccessKeyId%s"
    "SignatureVersion1"
    "Timestamp%s"
    "Version2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, awsKeyID, date );
  signature =  SQSSign ( customSign );

  snprintf ( resource, sizeof(resource), Req , 
             url, awsKeyID, signature, date );
  free ( signature );

  IOBuf * bf = aws_iobuf_new();
  int sc = SQSRequest( bf, "POST", resource ); 

  b->code = bf->code;
  b->result = strdup(bf->result);
  
  if ( bf->code != 200 ) { aws_iobuf_free(bf);  return sc; }

      /// \todo This is really bad. Must get a real message parser
      int inBody = 0;
      while(-1) 
        {
          char Ln[1024];
          int sz = aws_iobuf_getline ( bf, Ln, sizeof(Ln));
          if ( Ln[0] == 0 ) break;

          __debug ( "%s|%s|", inBody ? ">>": "", Ln );
          
          char *q;
          char *e;

          /// Handle a body already being processed..
          if ( inBody )
            {
              e = strstr ( Ln, "</Body>" );
              if ( e ) { *e = 0; inBody = 0; }
              aws_iobuf_append (b,Ln,strlen(Ln));
              if ( ! inBody ) break;
              continue;     
            }

          q = strstr ( Ln, "<ReceiptHandle>" );
          if ( q != 0 ) 
            {
              q += 15;
              e = strstr ( Ln, "</ReceiptHandle>" );
              *e = 0;
              strcpy ( id, q );
              q = e+1;
              q = strstr ( q, "<Body>" );
              if ( q != 0 ) 
                {
                  q += 6;
                  e = strstr ( q, "</Body>" );
                  if ( e ) *e = 0; else inBody = 1;
                  aws_iobuf_append (b,q,strlen(q));
                }
            }
        }
     

  return sc;
}

/// Delete processed message from the queue
/// \param bf I/O buffer
/// \param url queue url. Use sqs_list_queues to retrieve
/// \param receipt Message receipt handle. 
/// \return on success return 0, otherwise error code
///
int sqs_delete_message ( IOBuf * bf, char * const url, char * receipt )
{
  const char * method = "POST";
  char  resource [10900];
  char  customSign [10900];
  char * date = NULL;
  char * signature = NULL;
  char  encodedMsg[8192];



  char * Req = 
    "%s/"
    "?Action=DeleteMessage"
    "&ReceiptHandle=%s"
    "&AWSAccessKeyId=%s"
      SQS_REQ_TAIL ;

  char * Sign = 
    "ActionDeleteMessage"
    "AWSAccessKeyId%s"
    "ReceiptHandle%s"
    "SignatureVersion1"
    "Timestamp%s"
    "Version2009-02-01";

  date = __aws_get_iso_date  ();
  snprintf ( customSign, sizeof(customSign), Sign, awsKeyID, receipt, date );
  signature =  SQSSign ( customSign );

  char encReceipt[1024];
  __aws_urlencode ( receipt, encReceipt, sizeof(encReceipt));

  snprintf ( resource, sizeof(resource), Req , url, encReceipt, awsKeyID, signature, date );
  free ( signature );

  int sc = SQSRequest( bf, "POST", resource ); 
  return sc;
}

/*!
  \}
*/



/*!
  \defgroup IOBuf I/O Buffer functions
  \{
*/

/// \todo Place sentinels at the begining of the buffer

/// Create a new I/O buffer
/// \return a newly allocated I/O buffer
IOBuf * aws_iobuf_new ()
{
  IOBuf * bf = malloc(sizeof(IOBuf));

  bf->first   = NULL;
  bf->current = NULL;
  bf->pos     = NULL;

  bf->result  = NULL;
  bf->lastMod = NULL;
  bf->eTag    = NULL;
  bf->len     = 0;
  bf->code    = 0;

  return bf;
}


/// Append data to I/O buffer
/// \param B  I/O buffer
/// \param d  pointer to the data to be appended
/// \param len length of the data to be appended
void   aws_iobuf_append ( IOBuf *B, char * d, int len )
{

  IOBufNode * N = malloc(sizeof(IOBufNode));
  N->next = NULL;
  N->buf  = malloc(len+1);
  memcpy(N->buf,d,len);
  N->buf[len] = 0;
  B->len += len;

  if ( B->first == NULL )
    {
      B->first   = N;
      B->current = N;
      B->pos     = N->buf;
    }
  else
    {
      // Find the last block
      IOBufNode * D = B->first;
      while(D->next != NULL ) D = D->next;
      D->next = N;
    }
}

/// Read the next line from the buffer
///  \param B I/O buffer
///  \param Line  character array to store the read line in
///  \param size  size of the character array Line
///  \return  number of characters read or 0 
int    aws_iobuf_getline   ( IOBuf * B, char * Line, int size )
{
  int ln = 0;
  memset ( Line, 0, size );

  if ( B->current == NULL ) return 0;

  while ( size - ln > 1 )
    {
      if (* B->pos == '\n' ) { B->pos++; Line[ln] = '\n'; ln++; break; }
      if ( *B->pos == 0 ) 
      {
        B->current = B->current->next;
        if ( B->current == NULL ) break;
        B->pos = B->current->buf;
        continue;
      }
      Line[ln] = * B->pos;
      ln++;
      
      B->pos++;
      // At the end of the block switch again
    }
  B->len -= ln;
  return ln;
}

/// Release IO Buffer
/// \param  bf I/O buffer to be deleted
void   aws_iobuf_free ( IOBuf * bf )
{ 
  /// Release Things
  IOBufNode * N = bf->first;
  if ( bf->result  != NULL ) free ( bf->result  );
  if ( bf->lastMod != NULL ) free ( bf->lastMod );
  if ( bf->eTag    != NULL ) free ( bf->eTag    );
  free (bf);

  if ( N == NULL ) return;

  /// Walk down the list and release blocks
  while ( N->next != NULL )
    {
      IOBufNode * NN = N->next;
      free(N);
      N = NN;
    }
  if ( N != NULL ) free ( N );
}

/*!
  \}
*/

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