Merge branch 'bug25120'

src/common/crypto.c

@@ -1891,6 +1891,12 @@ crypto_strongest_rand_syscall(uint8_t *out, size_t out_len)
 {
   tor_assert(out_len <= MAX_STRONGEST_RAND_SIZE);
 
+  /* We only log at notice-level here because in the case that this function
+   * fails the crypto_strongest_rand_raw() caller will log with a warning-level
+   * message and let crypto_strongest_rand() error out and finally terminating
+   * Tor with an assertion error.
+   */
+
 #ifdef TOR_UNIT_TESTS
   if (break_strongest_rng_syscall)
     return -1;
@@ -1903,13 +1909,13 @@ crypto_strongest_rand_syscall(uint8_t *out, size_t out_len)
   if (!provider_set) {
     if (!CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL,
                              CRYPT_VERIFYCONTEXT)) {
-      log_warn(LD_CRYPTO, "Can't get CryptoAPI provider [1]");
+      log_notice(LD_CRYPTO, "Unable to set Windows CryptoAPI provider [1].");
       return -1;
     }
     provider_set = 1;
   }
   if (!CryptGenRandom(provider, out_len, out)) {
-    log_warn(LD_CRYPTO, "Can't get entropy from CryptoAPI.");
+    log_notice(LD_CRYPTO, "Unable get entropy from the Windows CryptoAPI.");
     return -1;
   }
 
@@ -1951,12 +1957,14 @@ crypto_strongest_rand_syscall(uint8_t *out, size_t out_len)
 
       /* Useful log message for errno. */
       if (errno == ENOSYS) {
-        log_warn(LD_CRYPTO, "Can't get entropy from getrandom()."
-                 " You are running a version of Tor built to support"
-                 " getrandom(), but the kernel doesn't implement this"
-                 " function--probably because it is too old?");
+        log_notice(LD_CRYPTO, "Can't get entropy from getrandom()."
+                   " You are running a version of Tor built to support"
+                   " getrandom(), but the kernel doesn't implement this"
+                   " function--probably because it is too old?"
+                   " Trying fallback method instead.");
       } else {
-        log_warn(LD_CRYPTO, "Can't get entropy from getrandom(): %s.",
+        log_notice(LD_CRYPTO, "Can't get entropy from getrandom(): %s.",
+                              " Trying fallback method instead."
                  strerror(errno));
       }
 
@@ -2009,7 +2017,7 @@ crypto_strongest_rand_fallback(uint8_t *out, size_t out_len)
   size_t n;
 
   for (i = 0; filenames[i]; ++i) {
-    log_debug(LD_FS, "Considering %s for entropy", filenames[i]);
+    log_debug(LD_FS, "Considering %s as entropy source", filenames[i]);
     fd = open(sandbox_intern_string(filenames[i]), O_RDONLY, 0);
     if (fd<0) continue;
     log_info(LD_CRYPTO, "Reading entropy from \"%s\"", filenames[i]);
@@ -2018,9 +2026,10 @@ crypto_strongest_rand_fallback(uint8_t *out, size_t out_len)
     if (n != out_len) {
       /* LCOV_EXCL_START
        * We can't make /dev/foorandom actually fail. */
-      log_warn(LD_CRYPTO,
-               "Error reading from entropy source (read only %lu bytes).",
-               (unsigned long)n);
+      log_notice(LD_CRYPTO,
+                 "Error reading from entropy source %s (read only %lu bytes).",
+                 filenames[i],
+                 (unsigned long)n);
       return -1;
       /* LCOV_EXCL_STOP */
     }