add fork of libsam3

add funtion to get i2p certificate crypto algo names

supportlibs/libsam3/examples/sam3/dgrams.c

@@ -0,0 +1,113 @@
+/* This program is free software. It comes without any warranty, to
+ * the extent permitted by applicable law. You can redistribute it
+ * and/or modify it under the terms of the Do What The Fuck You Want
+ * To Public License, Version 2, as published by Sam Hocevar. See
+ * http://sam.zoy.org/wtfpl/COPYING for more details.
+ *
+ * I2P-Bote:
+ * 5m77dFKGEq6~7jgtrfw56q3t~SmfwZubmGdyOLQOPoPp8MYwsZ~pfUCwud6LB1EmFxkm4C3CGlzq-hVs9WnhUV
+ * we are the Borg. */
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../libsam3/libsam3.h"
+
+#define KEYFILE "dgrams.key"
+
+int main(int argc, char *argv[]) {
+  Sam3Session ses;
+  char privkey[1024], pubkey[1024], buf[33 * 1024];
+
+  /** quit command */
+  const char *quitstr = "quit";
+  const size_t quitlen = strlen(quitstr);
+
+  /** reply response */
+  const char *replystr = "reply: ";
+  const size_t replylen = strlen(replystr);
+
+  FILE *fl;
+  //
+  libsam3_debug = 1;
+  //
+
+  /** generate new destination keypair */
+  printf("generating keys...\n");
+  if (sam3GenerateKeys(&ses, SAM3_HOST_DEFAULT, SAM3_PORT_DEFAULT, 4) < 0) {
+    fprintf(stderr, "FATAL: can't generate keys\n");
+    return 1;
+  }
+  /** copy keypair into local buffer */
+  strncpy(pubkey, ses.pubkey, sizeof(pubkey));
+  strncpy(privkey, ses.privkey, sizeof(privkey));
+  /** create sam session */
+  printf("creating session...\n");
+  if (sam3CreateSession(&ses, SAM3_HOST_DEFAULT, SAM3_PORT_DEFAULT, privkey,
+                        SAM3_SESSION_DGRAM, 5, NULL) < 0) {
+    fprintf(stderr, "FATAL: can't create session\n");
+    return 1;
+  }
+  /** make sure we have the right destination */
+  // FIXME: probably not needed
+  if (strcmp(pubkey, ses.pubkey) != 0) {
+    fprintf(stderr, "FATAL: destination keys don't match\n");
+    sam3CloseSession(&ses);
+    return 1;
+  }
+  /** print destination to stdout */
+  printf("PUB KEY\n=======\n%s\n=======\n", ses.pubkey);
+  if ((fl = fopen(KEYFILE, "wb")) != NULL) {
+    /** write public key to keyfile */
+    fwrite(pubkey, strlen(pubkey), 1, fl);
+    fclose(fl);
+  }
+
+  /* now listen for UDP packets */
+  printf("starting main loop...\n");
+  for (;;) {
+    /** save replylen bytes for out reply at begining */
+    char *datagramBuf = buf + replylen;
+    const size_t datagramMaxLen = sizeof(buf) - replylen;
+    int sz, isquit;
+    printf("waiting for datagram...\n");
+    /** blocks until we get a UDP packet */
+    if ((sz = sam3DatagramReceive(&ses, datagramBuf, datagramMaxLen) < 0)) {
+      fprintf(stderr, "ERROR: %s\n", ses.error);
+      goto error;
+    }
+    /** ensure null terminated string */
+    datagramBuf[sz] = 0;
+    /** print out datagram payload to user */
+    printf("FROM\n====\n%s\n====\n", ses.destkey);
+    printf("SIZE=%d\n", sz);
+    printf("data: [%s]\n", datagramBuf);
+    /** check for "quit" */
+    isquit = (sz == quitlen && memcmp(datagramBuf, quitstr, quitlen) == 0);
+    /** echo datagram back to sender with "reply: " at the beginning */
+    memcpy(buf, replystr, replylen);
+
+    if (sam3DatagramSend(&ses, ses.destkey, buf, sz + replylen) < 0) {
+      fprintf(stderr, "ERROR: %s\n", ses.error);
+      goto error;
+    }
+    /** if we got a quit command wait for 10 seconds and break out of the
+     * mainloop */
+    if (isquit) {
+      printf("shutting down...\n");
+      sleep(10); /* let dgram reach it's destination */
+      break;
+    }
+  }
+  /** close session and delete keyfile */
+  sam3CloseSession(&ses);
+  unlink(KEYFILE);
+  return 0;
+error:
+  /** error case, close session, delete keyfile and return exit code 1 */
+  sam3CloseSession(&ses);
+  unlink(KEYFILE);
+  return 1;
+}