/**
* Sign the parameters
*
* @param sdb the SimpleDB handle
* @param params the parameter array
* @param buffer the buffer to write the signature to (must be at least EVP_MAX_MD_SIZE * 2 bytes)
* @param plen the pointer to the place to store the length of the signature (can be NULL)
* @return SDB_OK if no errors occurred
*/
int sdb_params_sign(struct SDB* sdb, struct sdb_params* params, char* buffer, size_t* plen)
{
assert(params->size >= 2);
// Signature version 0
if (sdb->sdb_signature_ver == 0) {
assert(strcmp(params->params[0].key, "Action") == 0);
assert(strcmp(params->params[1].key, "Timestamp") == 0);
size_t l = strlen(params->params[0].value) + strlen(params->params[1].value) + 4;
char* b = (char*) alloca(l);
strcpy(b, params->params[0].value);
strcat(b, params->params[1].value);
return sdb_sign(sdb, b, buffer, plen);
}
// Signature version 1
if (sdb->sdb_signature_ver == 1) {
SDB_SAFE(sdb_params_sort(params));
size_t i, l = 0;
for (i = 0; i < params->size; i++) {
l += strlen(params->params[i].key);
l += strlen(params->params[i].value);
}
char* b = (char*) alloca(l);
*b = '\0';
for (i = 0; i < params->size; i++) {
strcat(b, params->params[i].key);
strcat(b, params->params[i].value);
}
return sdb_sign(sdb, b, buffer, plen);
}
return SDB_E_INVALID_SIGNATURE_VER;
}
/**
* Create the URL-encoded parameters string with SignatureVersion 2 sig.
*
* @param sdb the SimpleDB handle
* @param params the parameter array
* @param pbuffer the variable for the output buffer (will be allocated by the routine, but has to be freed by caller)
* @return SDB_OK if no errors occurred
*/
int sdb_params_export(struct SDB* sdb, struct sdb_params* params, char** pbuffer)
{
assert(params->size >= 2);
// Sign the parameters
char signature[EVP_MAX_MD_SIZE * 2];
// Determine the appropriate size
size_t i, l = 0;
for (i = 0; i < params->size; i++) {
l += strlen(params->params[i].key) + 1;
l += strlen(params->params[i].value) * 3 + 1;
}
// Allocate buffer
*pbuffer = (char*) malloc(l + 4);
char* b = *pbuffer;
*b = '\0';
// Build the string
SDB_SAFE(sdb_params_sort(params));
for (i = 0; i < params->size; i++) {
if (i > 0) strcat(b, "&");
strcat(b, params->params[i].key);
strcat(b, "=");
char* e = sdb_escape(sdb, params->params[i].value, strlen(params->params[i].value));
if (e == NULL) {
free(b);
*pbuffer = NULL;
return SDB_E_URL_ENCODE_FAILED;
}
strcat(b, e);
curl_free(e);
}
// string is built, now build complete string to sign
l = strlen(b) + 25;
char* s = (char*) alloca(l);
*s = '\0';
strcat(s, "POST\n");
strcat(s, "sdb.amazonaws.com\n");
strcat(s, "/\n");
strcat(s, b);
// Create the signature and add it to the URL-encoded param string
SDB_SAFE(sdb_sign(sdb, s, signature, NULL));
strcat(b, "&Signature=");
char* e = sdb_escape(sdb->curl_handle, signature, strlen(signature));
if (e == NULL) {
free(b);
*pbuffer = NULL;
return SDB_E_URL_ENCODE_FAILED;
}
strcat(b, e);
free(e);
return SDB_OK;
}