libcurl basic-auth soap example

basicauthsoap.c

/*
 * HTTP POST with authentiction using "basic" method.
 * Hybrid of anyauthput.c and postinmemory.c
 * Specifically adapted for SOAP use.
 *
 * Usage:
 * cc basicauthsoap.c -lcurl -o basicauthsoap
 * ./basicauthsoap
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>

struct MemoryStruct {
  char *memory;
  size_t size;
};

static size_t WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *context) {
  size_t bytec = size * nmemb;
  struct MemoryStruct *mem = (struct MemoryStruct *)context;
  mem->memory = realloc(mem->memory, mem->size + bytec + 1);
  if(mem->memory == NULL) {
    printf("not enough memory (realloc returned NULL)\n");
    return 0;
  }
  memcpy(&(mem->memory[mem->size]), ptr, bytec);
  mem->size += bytec;
  mem->memory[mem->size] = 0;
  return nmemb;
}

static size_t xmlEscape(char *out, char *in) {
  int i, j = 0;
  for(i = 0; in[i] != 0; i++) {
    // encoding non-ASCII characters is beyond the scope of this example...
    if((unsigned char)in[i] > 127) abort();
    switch(in[i]) {
      case '"':
        if(out) sprintf(out+j, "&quot;"); j += 6; break;
      case '\'':
        if(out) sprintf(out+j, "&apos;"); j += 6; break;
      case '<':
        if(out) sprintf(out+j, "&lt;"); j += 4; break;
      case '>':
        if(out) sprintf(out+j, "&gt;"); j += 4; break;
      case '&':
        if(out) sprintf(out+j, "&amp;"); j += 5; break;
      default:
        if(out) out[j] = in[i]; j++;
    }
  }
  if(out) out[j] = 0;
  return j;
}

static size_t compose_soap_frobnicate(char *buf, size_t size, char *foo, char *bar, char *baz) {
  char fooEsc[xmlEscape(NULL, foo) + 1]; xmlEscape(fooEsc, foo);
  char barEsc[xmlEscape(NULL, bar) + 1]; xmlEscape(barEsc, bar);
  char bazEsc[xmlEscape(NULL, baz) + 1]; xmlEscape(bazEsc, baz);
  return snprintf(buf, size, "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
    "<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
    " xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\""
    " xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">"
    "<soap:Body>"
    "<frobnicate xmlns=\"http://example.com/frobnicate\">"
    "<foo>%s</foo>"
    "<bar>%s</bar>"
    "<baz>%s</baz>"
    "</frobnicate>"
    "</soap:Body>"
    "</soap:Envelope>",
    fooEsc, barEsc, bazEsc);
}

int main(void) {
  CURL *curl;
  CURLcode res;
  struct MemoryStruct chunk;
  chunk.memory = malloc(1);
  chunk.size = 0;
  chunk.memory[chunk.size] = 0;
  curl_global_init(CURL_GLOBAL_ALL);
  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://ameriwether.com/cgi-bin/info.pl");
    size_t soap_size = compose_soap_frobnicate(NULL, 0, "'Ein'", ">Zwei<", "\"Drei\"") + 1;
    char soap[soap_size];
    compose_soap_frobnicate(soap, soap_size, "'Ein'", ">Zwei<", "\"Drei\"");
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, soap);
    curl_easy_setopt(curl, CURLOPT_HTTPAUTH, (long)CURLAUTH_BASIC);
    curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
    curl_easy_setopt(curl, CURLOPT_PASSWORD, "password");
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&chunk);
    struct curl_slist *headers = NULL;
    headers = curl_slist_append(headers, "Content-Type: text/xml; charset=utf-8");
    headers = curl_slist_append(headers, "SOAPAction: \"https://ameriwether.com/cgi-bin/info.pl/frobnicate\"");
    headers = curl_slist_append(headers, "Accept: text/plain"); // Example output easier to read as plain text.
    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
    // Make the example URL work even if your CA bundle is missing.
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
    res = curl_easy_perform(curl);
    if(res != CURLE_OK) {
      fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
    } else {
      printf("%s\n",chunk.memory);
    }
    // Remember to call the appropriate "free" functions.
    curl_slist_free_all(headers);
    curl_easy_cleanup(curl);
    free(chunk.memory);
    curl_global_cleanup();
  }
  return 0;
}

This is what it looks like when run:

$ ./basicauthsoap
TCP Connection:
 50.116.0.76:38556 > 50.116.0.76:443
SSL Layer (TLSv1.2):
 CIPHER=DHE-RSA-AES128-SHA
 CIPHER_ALGKEYSIZE=128
 CIPHER_EXPORT=false
 CIPHER_USEKEYSIZE=128
 CLIENT_VERIFY=NONE
 COMPRESS_METHOD=NULL
 SECURE_RENEG=true
 SESSION_ID=07E407495294F4FC38ED49CD8F7F0BDDB6AD59847298C2B0D306ECF30941AA4B
 TLS_SNI=ameriwether.com
HTTP Request:
 POST /cgi-bin/info.pl HTTP/1.1
HTTP Basic Auth:
 Username: user
 Password: password
HTTP Headers:
 Accept: text/plain
 ContentLength: 385
 ContentType: text/xml; charset=utf-8
 Host: ameriwether.com
 Soapaction: "https://ameriwether.com/cgi-bin/info.pl/frobnicate"
CGI Params:
 POSTDATA=<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><frobnicate xmlns="http://example.com/frobnicate'><foo>&apos;Ein&apos;</foo><bar>&gt;Zwei&lt;</bar><baz>&quot;Drei&quot;</baz></frobnicate></soap:Body></soap:Envelope>

The source for the CGI that is generating this response can be found here: https://gist.github.com/p120ph37/3bf6c500e0f00ab635da