Add support for random.org as a CSPRNG

.travis.yml

@@ -21,7 +21,7 @@ script:
  - make distclean > /dev/null
  - ./configure --disable-dependency-tracking --enable-minimal
  - make distcheck
- - ( echo '#include <sodium.h>' ; echo 'int main(void) { return sodium_init(); }' ) > /tmp/main.c && gcc -Isrc/libsodium/include -Isrc/libsodium/include/sodium $(find src -name '*.c' -o -name '*.S') /tmp/main.c
+ - ( echo '#include <sodium.h>' ; echo 'int main(void) { return sodium_init(); }' ) > /tmp/main.c && gcc -Isrc/libsodium/include -Isrc/libsodium/include/sodium $(find src -name '*.c' -o -name '*.S') /tmp/main.c -lcurl
 
 env:
   global:

configure.ac

@@ -700,6 +700,9 @@ AM_CONDITIONAL([EMSCRIPTEN], [test "x$EMSCRIPTEN" != "x"])
 
 AM_CONDITIONAL([NATIVECLIENT], [test "x$NATIVECLIENT" != "x"])
 
+LIBCURL_CHECK_CONFIG([yes], [], [],
+  [AC_MSG_ERROR([[Libcurl header files not found, install libcurl-dev]])])
+
 AC_DEFINE([CONFIGURED], [1], [the build system was properly configured])
 
 dnl Libtool.

src/libsodium/Makefile.am

@@ -99,7 +99,8 @@ libsodium_la_SOURCES = \
 
 if !EMSCRIPTEN
 libsodium_la_SOURCES += \
-	randombytes/salsa20/randombytes_salsa20_random.c
+	randombytes/salsa20/randombytes_salsa20_random.c \
+	randombytes/randomorg/randombytes_randomorg.c
 
 if NATIVECLIENT
 libsodium_la_SOURCES += \
@@ -183,12 +184,14 @@ endif
 
 libsodium_la_LDFLAGS = \
 	$(AM_LDFLAGS) \
+	@LIBCURL@ \
 	-export-dynamic \
 	-no-undefined \
 	$(LIBTOOL_EXTRA_FLAGS)
 
 libsodium_la_CPPFLAGS = \
 	$(LTDLINCL) \
+	@LIBCURL_CPPFLAGS@ \
 	-I$(srcdir)/include/sodium \
 	-I$(builddir)/include/sodium
 

src/libsodium/include/Makefile.am

@@ -53,6 +53,7 @@ SODIUM_EXPORT = \
 	sodium/crypto_verify_64.h \
 	sodium/export.h \
 	sodium/randombytes.h \
+	sodium/randombytes_randomorg.h \
 	sodium/randombytes_salsa20_random.h \
 	sodium/randombytes_sysrandom.h \
 	sodium/runtime.h \

src/libsodium/include/sodium.h

@@ -51,6 +51,7 @@
 #ifdef __native_client__
 # include "sodium/randombytes_nativeclient.h"
 #endif
+#include "sodium/randombytes_randomorg.h"
 #include "sodium/randombytes_salsa20_random.h"
 #include "sodium/randombytes_sysrandom.h"
 #include "sodium/runtime.h"

src/libsodium/include/sodium/randombytes_randomorg.h

@@ -0,0 +1,19 @@
+
+#ifndef randombytes_randomorg_H
+#define randombytes_randomorg_H
+
+#include "export.h"
+#include "randombytes.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+SODIUM_EXPORT
+extern struct randombytes_implementation randombytes_randomorg_implementation;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/libsodium/randombytes/randomorg/randombytes_randomorg.c

@@ -0,0 +1,103 @@
+
+#include <curl/curl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "randombytes.h"
+#include "randombytes_randomorg.h"
+#include "utils.h"
+
+typedef struct dynbuf {
+    char   *ptr;
+    size_t  len;
+} dynbuf;
+
+static size_t
+writefunc(void *ptr, size_t size, size_t nmemb, dynbuf *db)
+{
+    size_t new_len;
+
+    new_len = db->len + size * nmemb;
+    if (new_len < db->len) { /* might work */
+        abort();
+    }
+    db->ptr = (char *) realloc(db->ptr, new_len + 1);
+    if (db->ptr == NULL) {
+        abort();
+    }
+    memcpy(db->ptr + db->len, ptr, size * nmemb);
+    db->ptr[new_len] = 0;
+    db->len = new_len;
+
+    return size * nmemb;
+}
+
+static void
+randombytes_randomorg_buf(void * const buf, const size_t size)
+{
+    char      url[512];
+    dynbuf    db;
+    CURL     *curl;
+    CURLcode  res;
+
+    db.len = 0;
+    if ((db.ptr = (char *) malloc(1)) == NULL) {
+        abort();
+    }
+    curl_global_init(CURL_GLOBAL_DEFAULT);
+    curl = curl_easy_init();
+    if (curl == NULL) {
+        memset(buf, 0, size); /* Be robust to network failures */
+        return;
+    }
+    snprintf(url, sizeof url,
+             "https://www.random.org/integers/?num=%llu&min=0&max=255&col=1&base=10&format=plain&rnd=new",
+             (unsigned long long) size);
+    curl_easy_setopt(curl, CURLOPT_URL, url);
+    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
+    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
+    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+    curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &db);
+    res = curl_easy_perform(curl);
+    if (res == CURLE_OK) {
+        char   *p = db.ptr;
+        char   *q;
+        size_t  i = 0;
+
+        while (i < size && (q = strchr(p, '\n')) != NULL) {
+            *q = 0;
+            ((unsigned char *) buf)[i++] = (unsigned char) atoi(p);
+            p = q + 1;
+        }
+    }
+    free(db.ptr);
+    curl_easy_cleanup(curl);
+    curl_global_cleanup();
+}
+
+static uint32_t
+randombytes_randomorg(void)
+{
+    uint32_t r;
+
+    randombytes_randomorg_buf(&r, sizeof r);
+
+    return r;
+}
+static const char *
+randombytes_randomorg_implementation_name(void)
+{
+    return "random.org";
+}
+
+struct randombytes_implementation randombytes_randomorg_implementation = {
+    SODIUM_C99(.implementation_name =) randombytes_randomorg_implementation_name,
+    SODIUM_C99(.random =) randombytes_randomorg,
+    SODIUM_C99(.stir =) NULL,
+    SODIUM_C99(.uniform =) NULL,
+    SODIUM_C99(.buf =) randombytes_randomorg_buf,
+    SODIUM_C99(.close =) NULL
+};