fixed libtools portability bug, fixed arc4random() portability,

fixed htobe32 and be32toh portability, fixed error handling in main(),
fixed invalid type parameter for randomart image in pcppubkey_printshortinfo(),
fixed configure search for libsodium.

libpcp/platform.h

@@ -9,5 +9,71 @@
 #error Need either CONFIG_H_FILE or HAVE_CONFIG_H defined.
 #endif
 
+#ifdef HAVE_ENDIAN_H
+#include <endian.h>
+#else
+#ifdef HAVE_SYS_ENDIAN_H
+#include <sys/endian.h>
+#else
+#ifdef HAVE_BETOH32
+// openbsd, use aliases
+#define be32toh betoh32
+#define htobe32 hto32be
+#else
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+// Copyright (c) 1999 Joseph Samuel Myers. bsd-games
+#define be32toh(x)	((void)0)
+#define htobe32(x)	((void)0)
+#else
+#define be32toh(x)	((u_int32_t)ntohl((u_int32_t)(x)))
+#define htobe32(x)	((u_int32_t)htonl((u_int32_t)(x)))
+#endif
+
+#endif // HAVE_BETOH32
+#endif // HAVE_SYS_ENDIAN_H
+#endif // HAVE_ENDIAN_H
+
+
+#ifndef HAVE_ARC4RANDOM_BUF
+// shitty OS. we've got to use other stuff
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdint.h>
+
+static inline FILE *__getranddev() {
+  FILE *R;
+  if((R = fopen("/dev/urandom", "rb")) == NULL) {
+    // not even this is here! what a shame
+    if((R = fopen("/dev/random", "rb")) == NULL) {
+      // not available or depleted. that's too bad
+      fprintf(stderr, "ERROR: /dev/urandom not available, /dev/random is depleted.\n");
+      fprintf(stderr, "That's horrible for you but a nightmare for me. I die. Bye.\n");
+      exit(2);
+    }
+  }
+  return R;
+}
+
+static inline u_int32_t arc4random() {
+  uint32_t x;
+  FILE *R = __getranddev();
+  fread(&x, sizeof(uint32_t), 1, R);
+  fclose(R);
+  return x;
+}
+
+static inline void arc4random_buf(void *buf, size_t nbytes) {
+  FILE *R = __getranddev();
+  fread(buf, nbytes, 1, R);
+  fclose(R);
+}
+
+
+#endif
+
+
 #endif /* !_HAVE_PCP_PLATFORM_H */