Re: [Qemu-devel] [PATCH v1 01/15] crypto: add cryptographic random byte source

[Fam Zheng <famz@redhat.com>]

On Tue, 01/12 18:56, Daniel P. Berrange wrote:
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  crypto/Makefile.objs    |  1 +
>  crypto/random.c         | 50 +++++++++++++++++++++++++++++++++++++++++++++++++
>  include/crypto/random.h | 43 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 94 insertions(+)
>  create mode 100644 crypto/random.c
>  create mode 100644 include/crypto/random.h
> 
> diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
> index a3135f1..5f38d2d 100644
> --- a/crypto/Makefile.objs
> +++ b/crypto/Makefile.objs
> @@ -8,6 +8,7 @@ crypto-obj-y += tlscredsanon.o
>  crypto-obj-y += tlscredsx509.o
>  crypto-obj-y += tlssession.o
>  crypto-obj-y += secret.o
> +crypto-obj-y += random.o
>  
>  # Let the userspace emulators avoid linking gnutls/etc
>  crypto-aes-obj-y = aes.o
> diff --git a/crypto/random.c b/crypto/random.c
> new file mode 100644
> index 0000000..8257d24
> --- /dev/null
> +++ b/crypto/random.c
> @@ -0,0 +1,50 @@
> +/*
> + * QEMU Crypto random number provider
> + *
> + * Copyright (c) 2015 Red Hat, Inc.

s/2015/2016/

> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +
> +#include <config-host.h>
> +
> +#include "crypto/random.h"
> +
> +int qcrypto_random_bytes(uint8_t *buf,
> +                         size_t buflen,
> +                         Error **errp)
> +{
> +    ssize_t ret;
> +    int fd = open("/dev/random", O_RDONLY);
> +    if (fd < 0) {
> +        error_setg_errno(errp, errno,
> +                         "Unable to open /dev/random");
> +        return -1;
> +    }
> +
> +    while (buflen) {
> +        ret = read(fd, buf, buflen);
> +        if (ret < 0) {
> +            error_setg_errno(errp, errno,
> +                             "Unable to read random bytes");
> +            close(fd);
> +            return -1;
> +        }
> +        buflen -= ret;
> +    }
> +
> +    close(fd);
> +    return 0;
> +}
> diff --git a/include/crypto/random.h b/include/crypto/random.h
> new file mode 100644
> index 0000000..ce1626b
> --- /dev/null
> +++ b/include/crypto/random.h
> @@ -0,0 +1,43 @@
> +/*
> + * QEMU Crypto random number provider
> + *
> + * Copyright (c) 2015 Red Hat, Inc.

s/2015/2016/

> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +
> +#ifndef QCRYPTO_RANDOM_H__
> +#define QCRYPTO_RANDOM_H__
> +
> +#include "qemu-common.h"
> +#include "qapi/error.h"
> +
> +
> +/**
> + * qcrypto_random_bytes:
> + * @buf: the buffer to fill
> + * @buflen: length of @buf in bytes
> + * @errp: pointer to uninitialized error objet

s/objet/object/, but more importantly @errp must be NULL, so it's not exact to
say it "uninitialized".

> + *
> + * Fill @buf with @buflen bytes of random data
> + *
> + * Returns 0 on sucess, -1 on error
> + */
> +int qcrypto_random_bytes(uint8_t *buf,
> +                         size_t buflen,
> +                         Error **errp);
> +
> +
> +#endif /* QCRYPTO_RANDOM_H__ */
> -- 
> 2.5.0
> 
>