random_seed: on error, continue to next method

instead of exiting the process

diff --git a/random_seed.c b/random_seed.c
index b4c0afd3d443a446e659f83630982b0899c71e4d..ff5338f76300e50174c18481d7ba415c397c13bf 100644 (file)
--- a/random_seed.c
+++ b/random_seed.c
@@ -162,15 +162,14 @@ retry:
 #include <sys/random.h>
 #endif
 
-static int get_getrandom_seed(void)
+static int get_getrandom_seed(int *seed)
 {
        DEBUG_SEED("get_getrandom_seed");
 
-       int r;
        ssize_t ret;
 
        do {
-               ret = getrandom(&r, sizeof(r), GRND_NONBLOCK);
+               ret = getrandom(seed, sizeof(*seed), GRND_NONBLOCK);
        } while ((ret == -1) && (errno == EINTR));
 
        if (ret == -1)
@@ -181,17 +180,17 @@ static int get_getrandom_seed(void)
                        return -1;
 
                fprintf(stderr, "error from getrandom(): %s", strerror(errno));
-               exit(1);
+               return -1;
        }
 
-       if (ret != sizeof(r))
+       if (ret != sizeof(*seed))
                return -1;
 
-       return r;
+       return 0;
 }
 #endif /* defined HAVE_GETRANDOM */
 
-/* has_dev_urandom */
+/* get_dev_random_seed */
 
 #if defined(__APPLE__) || defined(__unix__) || defined(__linux__)
 
@@ -207,39 +206,32 @@ static int get_getrandom_seed(void)
 
 static const char *dev_random_file = "/dev/urandom";
 
-static int has_dev_urandom(void)
+static int get_dev_random_seed(int *seed)
 {
+       DEBUG_SEED("get_dev_random_seed");
+
        struct stat buf;
        if (stat(dev_random_file, &buf))
-       {
-               return 0;
-       }
-       return ((buf.st_mode & S_IFCHR) != 0);
-}
-
-/* get_dev_random_seed */
-
-static int get_dev_random_seed(void)
-{
-       DEBUG_SEED("get_dev_random_seed");
+               return -1;
+       if ((buf.st_mode & S_IFCHR) == 0)
+               return -1;
 
        int fd = open(dev_random_file, O_RDONLY);
        if (fd < 0)
        {
                fprintf(stderr, "error opening %s: %s", dev_random_file, strerror(errno));
-               exit(1);
+               return -1;
        }
 
-       int r;
-       ssize_t nread = read(fd, &r, sizeof(r));
-       if (nread != sizeof(r))
+       ssize_t nread = read(fd, seed, sizeof(*seed));
+       if (nread != sizeof(*seed))
        {
                fprintf(stderr, "error short read %s: %s", dev_random_file, strerror(errno));
-               exit(1);
+               return -1;
        }
 
        close(fd);
-       return r;
+       return 0;
 }
 
 #endif
@@ -262,9 +254,7 @@ static int get_dev_random_seed(void)
 #pragma comment(lib, "advapi32.lib")
 #endif
 
-static int get_time_seed(void);
-
-static int get_cryptgenrandom_seed(void)
+static int get_cryptgenrandom_seed(int *seed)
 {
        HCRYPTPROV hProvider = 0;
        DWORD dwFlags = CRYPT_VERIFYCONTEXT;
@@ -279,20 +269,20 @@ static int get_cryptgenrandom_seed(void)
        if (!CryptAcquireContextA(&hProvider, 0, 0, PROV_RSA_FULL, dwFlags))
        {
                fprintf(stderr, "error CryptAcquireContextA 0x%08lx", GetLastError());
-               r = get_time_seed();
+               return -1;
        }
        else
        {
-               BOOL ret = CryptGenRandom(hProvider, sizeof(r), (BYTE*)&r);
+               BOOL ret = CryptGenRandom(hProvider, sizeof(*seed), (BYTE*)seed);
                CryptReleaseContext(hProvider, 0);
                if (!ret)
                {
                        fprintf(stderr, "error CryptGenRandom 0x%08lx", GetLastError());
-                       r = get_time_seed();
+                       return -1;
                }
        }
 
-       return r;
+       return 0;
 }
 
 #endif
@@ -312,6 +302,7 @@ static int get_time_seed(void)
 
 int json_c_get_random_seed(void)
 {
+       int seed;
 #ifdef OVERRIDE_GET_RANDOM_SEED
        OVERRIDE_GET_RANDOM_SEED;
 #endif
@@ -320,18 +311,16 @@ int json_c_get_random_seed(void)
                return get_rdrand_seed();
 #endif
 #ifdef HAVE_GETRANDOM
-       {
-               int seed = get_getrandom_seed();
-               if (seed != -1)
-                       return seed;
-       }
+       if (get_getrandom_seed(&seed) == 0)
+               return seed;
 #endif
 #if defined HAVE_DEV_RANDOM && HAVE_DEV_RANDOM
-       if (has_dev_urandom())
-               return get_dev_random_seed();
+       if (get_dev_random_seed(&seed) == 0)
+               return seed;
 #endif
 #if defined HAVE_CRYPTGENRANDOM && HAVE_CRYPTGENRANDOM
-       return get_cryptgenrandom_seed();
+       if (get_cryptgenrandom_seed(&seed) == 0)
+               return seed;
 #endif
        return get_time_seed();
 }