From 60596973b503637c742b597aeb862eecae9f9c91 Mon Sep 17 00:00:00 2001

From: Jakub Hrozek <jhrozek@redhat.com>

Date: Mon, 8 Aug 2016 14:07:04 +0200

Subject: [PATCH 109/111] UTIL: Use sss_atomic_read_s in generate_csprng_buffer

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There was a bug in generate_csprng_buffer() where if we read the exact

amount of bytes from /dev/urandom, we would always return EIO. Instead,

let's reuse the existing code from sss_atomic_read_s() which fixes this

bug and reduces code duplication.

Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

Reviewed-by: Fabiano Fidêncio <fabiano@fidencio.org>

---

 Makefile.am                  |  2 ++

 src/util/crypto/sss_crypto.c | 29 +++++------------------------

 2 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/Makefile.am b/Makefile.am

index 4d90c7a46e2ee0fe652aa392cf647d056e06c7fc..a32a1e37c85e2370fa006ee73b730145f03c3fc1 100644

--- a/Makefile.am

+++ b/Makefile.am

@@ -815,6 +815,7 @@ if HAVE_NSS

                         src/util/crypto/nss/nss_nite.c \

                         src/util/crypto/nss/nss_util.c \

 			src/util/crypto/sss_crypto.c \

+			src/util/atomic_io.c \

 			$(NULL)

     SSS_CRYPT_CFLAGS = $(NSS_CFLAGS)

     SSS_CRYPT_LIBS = $(NSS_LIBS)

@@ -836,6 +837,7 @@ else

                         src/util/crypto/libcrypto/crypto_obfuscate.c \

                         src/util/crypto/libcrypto/crypto_nite.c \

 			src/util/crypto/sss_crypto.c \

+			src/util/atomic_io.c \

 			$(NULL)

     SSS_CRYPT_CFLAGS = $(CRYPTO_CFLAGS)

     SSS_CRYPT_LIBS = $(CRYPTO_LIBS)

diff --git a/src/util/crypto/sss_crypto.c b/src/util/crypto/sss_crypto.c

index 4c775f3d926ae32f3cb72b1329c0a025a0550ed5..ac90bac07c7006a2950331b86bcc412207a3e401 100644

--- a/src/util/crypto/sss_crypto.c

+++ b/src/util/crypto/sss_crypto.c

@@ -25,41 +25,22 @@

 int generate_csprng_buffer(uint8_t *buf, size_t size)

 {

     ssize_t rsize;

-    ssize_t pos;

     int ret;

     int fd;

     fd = open("/dev/urandom", O_RDONLY);

     if (fd == -1) return errno;

-    rsize = 0;

-    pos = 0;

-    while (rsize < size) {

-        rsize = read(fd, buf + pos, size - pos);

-        switch (rsize) {

-        case -1:

-            if (errno == EINTR) continue;

-            ret = EIO;

-            goto done;

-        case 0:

-            ret = EIO;

-            goto done;

-        default:

-            if (rsize + pos < size - pos) {

-                pos += rsize;

-                continue;

-            }

-            ret = EIO;

-            goto done;

-        }

-    }

-    if (rsize != size) {

+    rsize = sss_atomic_read_s(fd, buf, size);

+    if (rsize == -1) {

+        ret = errno;

+        goto done;

+    } else if (rsize != size) {

         ret = EFAULT;

         goto done;

     }

     ret = EOK;

-

 done:

     close(fd);

     return ret;

-- 

2.4.11