From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58206) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d38kT-0007s9-QU for qemu-devel@nongnu.org; Tue, 25 Apr 2017 18:15:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d38kP-0001St-Lr for qemu-devel@nongnu.org; Tue, 25 Apr 2017 18:15:53 -0400 Received: from mout.web.de ([212.227.15.14]:65437) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1d38kP-0001Rw-AP for qemu-devel@nongnu.org; Tue, 25 Apr 2017 18:15:49 -0400 From: Geert Martin Ijewski Date: Wed, 26 Apr 2017 00:15:01 +0200 Message-Id: <1493158501-22284-1-git-send-email-gm.ijewski@web.de> Subject: [Qemu-devel] [PATCH v5] crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Geert Martin Ijewski , "Daniel P. Berrange" If no crypto library is included in the build, QEMU uses qcrypto_random_bytes() to generate random data. That function tried to open /dev/urandom or /dev/random and if opening both files failed it errored out. Those files obviously do not exist on windows, so there the code uses CryptGenRandom(). Furthermore there was some refactoring and a new function qcrypto_random_init() was introduced. If a proper crypto library (gnutls or libgcrypt) is included in the build, this function does nothing. If neither is included it initializes the (platform specific) handles that are used by qcrypto_random_bytes(). Either: * a handle to /dev/urandom | /dev/random on unix like systems * a handle to a cryptographic service provider on windows Signed-off-by: Geert Martin Ijewski --- crypto/init.c | 6 ++++++ crypto/random-gcrypt.c | 2 ++ crypto/random-gnutls.c | 3 +++ crypto/random-platform.c | 45 +++++++++++++++++++++++++++++++++++++-------- include/crypto/random.h | 9 +++++++++ 5 files changed, 57 insertions(+), 8 deletions(-) diff --git a/crypto/init.c b/crypto/init.c index f65207e..f131c42 100644 --- a/crypto/init.c +++ b/crypto/init.c @@ -32,6 +32,8 @@ #include #endif +#include "crypto/random.h" + /* #define DEBUG_GNUTLS */ /* @@ -146,5 +148,9 @@ int qcrypto_init(Error **errp) gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0); #endif + if (qcrypto_random_init(errp) < 0) { + return -1; + } + return 0; } diff --git a/crypto/random-gcrypt.c b/crypto/random-gcrypt.c index 0de9a09..9f1c9ee 100644 --- a/crypto/random-gcrypt.c +++ b/crypto/random-gcrypt.c @@ -31,3 +31,5 @@ int qcrypto_random_bytes(uint8_t *buf, gcry_randomize(buf, buflen, GCRY_STRONG_RANDOM); return 0; } + +int qcrypto_random_init(Error **errp G_GNUC_UNUSED) { return 0; } diff --git a/crypto/random-gnutls.c b/crypto/random-gnutls.c index 04b45a8..5350003 100644 --- a/crypto/random-gnutls.c +++ b/crypto/random-gnutls.c @@ -41,3 +41,6 @@ int qcrypto_random_bytes(uint8_t *buf, return 0; } + + +int qcrypto_random_init(Error **errp G_GNUC_UNUSED) { return 0; } diff --git a/crypto/random-platform.c b/crypto/random-platform.c index 82b755a..0eddb91 100644 --- a/crypto/random-platform.c +++ b/crypto/random-platform.c @@ -22,14 +22,16 @@ #include "crypto/random.h" -int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, - size_t buflen G_GNUC_UNUSED, - Error **errp) -{ - int fd; - int ret = -1; - int got; +#ifdef _WIN32 +#include +static HCRYPTPROV hCryptProv; +#else +static int fd; /* a file handle to either /dev/urandom or /dev/random */ +#endif +int qcrypto_random_init(Error **errp) +{ +#ifndef _WIN32 /* TBD perhaps also add support for BSD getentropy / Linux * getrandom syscalls directly */ fd = open("/dev/urandom", O_RDONLY); @@ -41,6 +43,25 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, error_setg(errp, "No /dev/urandom or /dev/random found"); return -1; } +#else + if (!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, + CRYPT_SILENT | CRYPT_VERIFYCONTEXT)) { + error_setg_win32(errp, GetLastError(), + "Unable to create cryptographic provider"); + return -1; + } +#endif + + return 0; +} + +int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, + size_t buflen G_GNUC_UNUSED, + Error **errp) +{ +#ifndef _WIN32 + int ret = -1; + int got; while (buflen > 0) { got = read(fd, buf, buflen); @@ -59,6 +80,14 @@ int qcrypto_random_bytes(uint8_t *buf G_GNUC_UNUSED, ret = 0; cleanup: - close(fd); return ret; +#else + if (!CryptGenRandom(hCryptProv, buflen, buf)) { + error_setg_win32(errp, GetLastError(), + "Unable to read random bytes"); + return -1; + } + + return 0; +#endif } diff --git a/include/crypto/random.h b/include/crypto/random.h index a101353..a07229c 100644 --- a/include/crypto/random.h +++ b/include/crypto/random.h @@ -40,5 +40,14 @@ int qcrypto_random_bytes(uint8_t *buf, size_t buflen, Error **errp); +/** + * qcrypto_random_init: + * @errp: pointer to a NULL-initialized error object + * + * Initializes the handles used by qcrypto_random_bytes + * + * Returns 0 on success, -1 on error + */ +int qcrypto_random_init(Error **errp); #endif /* QCRYPTO_RANDOM_H */ -- 2.10.1.windows.1