Replaced usage of random() with xs_rnd_buf().

6 files changed, 102 insertions, 23 deletions

diff --git a/Makefile b/Makefile
index 01dab0d..4570785 100644
--- a/Makefile
+++ b/Makefile
@@ -37,19 +37,20 @@ activitypub.o: activitypub.c xs.h xs_json.h xs_curl.h xs_mime.h \
  xs_openssl.h xs_regex.h xs_time.h xs_set.h snac.h
 data.o: data.c xs.h xs_io.h xs_json.h xs_openssl.h xs_glob.h xs_set.h \
  xs_time.h snac.h
-format.o: format.c xs.h xs_regex.h snac.h
+format.o: format.c xs.h xs_regex.h xs_mime.h snac.h
 html.o: html.c xs.h xs_io.h xs_json.h xs_regex.h xs_set.h xs_openssl.h \
  xs_time.h xs_mime.h snac.h
 http.o: http.c xs.h xs_io.h xs_openssl.h xs_curl.h xs_time.h xs_json.h \
  snac.h
 httpd.o: httpd.c xs.h xs_io.h xs_json.h xs_socket.h xs_httpd.h xs_mime.h \
- xs_time.h snac.h
+ xs_time.h xs_openssl.h snac.h
 main.o: main.c xs.h xs_io.h xs_json.h snac.h
 mastoapi.o: mastoapi.c xs.h xs_openssl.h xs_json.h xs_io.h xs_time.h \
- xs_glob.h xs_set.h snac.h
+ xs_glob.h xs_set.h xs_random.h snac.h
 snac.o: snac.c xs.h xs_io.h xs_unicode.h xs_json.h xs_curl.h xs_openssl.h \
  xs_socket.h xs_httpd.h xs_mime.h xs_regex.h xs_set.h xs_time.h xs_glob.h \
- snac.h
+ xs_random.h snac.h
 upgrade.o: upgrade.c xs.h xs_io.h xs_json.h xs_glob.h snac.h
-utils.o: utils.c xs.h xs_io.h xs_json.h xs_time.h xs_openssl.h snac.h
+utils.o: utils.c xs.h xs_io.h xs_json.h xs_time.h xs_openssl.h \
+ xs_random.h snac.h
 webfinger.o: webfinger.c xs.h xs_json.h xs_curl.h snac.h
diff --git a/mastoapi.c b/mastoapi.c
index f30971e..a76a6ab 100644
--- a/mastoapi.c
+++ b/mastoapi.c
@@ -10,6 +10,7 @@
 #include "xs_time.h"
 #include "xs_glob.h"
 #include "xs_set.h"
+#include "xs_random.h"
 
 #include "snac.h"
 
@@ -17,19 +18,8 @@ static xs_str *random_str(void)
 /* just what is says in the tin */
 {
     unsigned int data[4] = {0};
-    FILE *f;
-
-    if ((f = fopen("/dev/random", "r")) != NULL) {
-        fread(data, sizeof(data), 1, f);
-        fclose(f);
-    }
-    else {
-        data[0] = random() % 0xffffffff;
-        data[1] = random() % 0xffffffff;
-        data[2] = random() % 0xffffffff;
-        data[3] = random() % 0xffffffff;
-    }
 
+    xs_rnd_buf(data, sizeof(data));
     return xs_hex_enc((char *)data, sizeof(data));
 }
 
diff --git a/snac.c b/snac.c
index 722af62..691c2e2 100644
--- a/snac.c
+++ b/snac.c
@@ -16,6 +16,7 @@
 #include "xs_set.h"
 #include "xs_time.h"
 #include "xs_glob.h"
+#include "xs_random.h"
 
 #include "snac.h"
 
@@ -122,7 +123,9 @@ xs_str *hash_password(const char *uid, const char *passwd, const char *nonce)
     xs *hash;
 
     if (nonce == NULL) {
-        d_nonce = xs_fmt("%08x", random());
+        unsigned int r;
+        xs_rnd_buf(&r, sizeof(r));
+        d_nonce = xs_fmt("%08x", r);
         nonce = d_nonce;
     }
 
diff --git a/utils.c b/utils.c
index 1c03fee..f5b02ae 100644
--- a/utils.c
+++ b/utils.c
@@ -6,6 +6,7 @@
 #include "xs_json.h"
 #include "xs_time.h"
 #include "xs_openssl.h"
+#include "xs_random.h"
 
 #include "snac.h"
 
@@ -204,10 +205,7 @@ void new_password(const char *uid, d_char **clear_pwd, d_char **hashed_pwd)
 {
     int rndbuf[3];
 
-    srandom(time(NULL) ^ getpid());
-    rndbuf[0] = random() & 0xffffffff;
-    rndbuf[1] = random() & 0xffffffff;
-    rndbuf[2] = random() & 0xffffffff;
+    xs_rnd_buf(rndbuf, sizeof(rndbuf));
 
     *clear_pwd  = xs_base64_enc((char *)rndbuf, sizeof(rndbuf));
     *hashed_pwd = hash_password(uid, *clear_pwd, NULL);
diff --git a/xs_random.h b/xs_random.h
new file mode 100644
index 0000000..3566827
--- /dev/null
+++ b/xs_random.h
@@ -0,0 +1,87 @@
+/* copyright (c) 2022 - 2023 grunfink / MIT license */
+
+#ifndef _XS_RANDOM_H
+
+#define _XS_RANDOM_H
+
+unsigned int xs_rnd_int32_d(unsigned int *seed);
+void *xs_rnd_buf(void *buf, int size);
+
+#ifdef XS_IMPLEMENTATION
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+unsigned int xs_rnd_int32_d(unsigned int *seed)
+/* returns a deterministic random integer. If seed is NULL, uses a static one */
+{
+    static unsigned int s = 0;
+
+    if (seed == NULL)
+        seed = &s;
+
+    if (*seed == 0) {
+        struct timeval tv;
+
+        gettimeofday(&tv, NULL);
+        *seed = tv.tv_sec ^ tv.tv_usec ^ getpid();
+    }
+
+    /* Linear congruential generator by Numerical Recipes */
+    *seed = (*seed * 1664525) + 1013904223;
+
+    return *seed;
+}
+
+
+void *xs_rnd_buf(void *buf, int size)
+/* fills buf with random data */
+{
+#ifdef __OpenBSD__
+
+    /* available since OpenBSD 2.2 */
+    arc4random_buf(buf, size);
+
+#else
+
+    FILE *f;
+    int done = 0;
+
+    if ((f = fopen("/dev/urandom", "r")) != NULL) {
+        /* fill with great random data from the system */
+        if (fread(buf, size, 1, f) == 1)
+            done = 1;
+
+        fclose(f);
+    }
+
+    if (!done) {
+        /* fill the buffer with poor quality, deterministic data */
+        unsigned int s   = 0;
+        unsigned char *p = (unsigned char *)buf;
+        int n            = size / sizeof(s);
+
+        /* fill with full integers */
+        while (n--) {
+            xs_rnd_int32_d(&s);
+            p = memcpy(p, &s, sizeof(s)) + sizeof(s);
+        }
+
+        if ((n = size % sizeof(s))) {
+            /* fill the remaining */
+            xs_rnd_int32_d(&s);
+            memcpy(p, &s, n);
+        }
+    }
+
+#endif /* __OpenBSD__ */
+
+    return buf;
+}
+
+
+#endif /* XS_IMPLEMENTATION */
+
+#endif /* XS_RANDOM_H */
diff --git a/xs_version.h b/xs_version.h
index 7a793d1..b589fed 100644
--- a/xs_version.h
+++ b/xs_version.h
@@ -1 +1 @@
-/* 3588cbb7859917f1c5965254f8a53c3349c773ea */
+/* 5c255b45c8cd5d6c01c983b03e635936db12da03 */