From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.1 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 19770 invoked from network); 10 Apr 2022 11:07:23 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 10 Apr 2022 11:07:23 -0000 Received: (qmail 21570 invoked by uid 550); 10 Apr 2022 11:07:10 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 21569 invoked from network); 9 Apr 2022 22:59:16 -0000 Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="P/+miRDm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1649545142; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FLBM90BgVi5rBwzbgCpwAH+OkrBiyW7xwYZfYYZOHpc=; b=P/+miRDmqSqk+8MLUS+8DAjvp77h0wTON54LdjYpO/XaLDR4ucMfSaRcbP791UvMSyh8fB WVVDcOWXSCYzfeCbzq6rYKAMCgfRnlB54sh/gdPrYyQ6kEix7t0xVBqoxz7Laj4gDnbV32 wGKIYwkdIOl3tSLd6mCZ4sJqPt/+G7g= From: "Jason A. Donenfeld" To: Rich Felker , musl@lists.openwall.com Cc: "Jason A. Donenfeld" Date: Sun, 10 Apr 2022 00:58:50 +0200 Message-Id: <20220409225851.715796-2-Jason@zx2c4.com> In-Reply-To: <20220409225851.715796-1-Jason@zx2c4.com> References: <20220409225851.715796-1-Jason@zx2c4.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [musl] [PATCH v3] getentropy: fail if buffer not completely filled The man page for getentropy says that it either completely succeeds or completely fails for values < 256, so we can simplify this scenario by omitting the loop. As a safeguard, we still return EIO if it returns short, but otherwise we pass the error on through to the caller. --- Changes v2->v3: - v3 gets rid of the loop entirely. src/misc/getentropy.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/src/misc/getentropy.c b/src/misc/getentropy.c index 651ea95f..e8cb4d02 100644 --- a/src/misc/getentropy.c +++ b/src/misc/getentropy.c @@ -6,8 +6,8 @@ int getentropy(void *buffer, size_t len) { - int cs, ret = 0; - char *pos = buffer; + ssize_t ret; + int cs; if (len > 256) { errno = EIO; @@ -15,19 +15,13 @@ int getentropy(void *buffer, size_t len) } pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); - - while (len) { - ret = getrandom(pos, len, 0); - if (ret < 0) { - if (errno == EINTR) continue; - else break; - } - pos += ret; - len -= ret; - ret = 0; - } - + ret = getrandom(buffer, len, 0); pthread_setcancelstate(cs, 0); - return ret; + if (ret != len) { + if (ret >= 0) + errno = EIO; + return -1; + } + return 0; } -- 2.35.1