openssl/crypto/rand/rand_egd.c
ganesh c2114afc16 RAND_egd_bytes: No need to check RAND_status on connection error.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1886)
2017-01-24 14:39:20 +01:00

249 lines
7 KiB
C

/*
* Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/opensslconf.h>
#ifdef OPENSSL_NO_EGD
NON_EMPTY_TRANSLATION_UNIT
#else
# include <openssl/crypto.h>
# include <openssl/e_os2.h>
# include <openssl/rand.h>
/*-
* Query the EGD <URL: http://www.lothar.com/tech/crypto/>.
*
* This module supplies three routines:
*
* RAND_query_egd_bytes(path, buf, bytes)
* will actually query "bytes" bytes of entropy form the egd-socket located
* at path and will write them to buf (if supplied) or will directly feed
* it to RAND_seed() if buf==NULL.
* The number of bytes is not limited by the maximum chunk size of EGD,
* which is 255 bytes. If more than 255 bytes are wanted, several chunks
* of entropy bytes are requested. The connection is left open until the
* query is competed.
* RAND_query_egd_bytes() returns with
* -1 if an error occurred during connection or communication.
* num the number of bytes read from the EGD socket. This number is either
* the number of bytes requested or smaller, if the EGD pool is
* drained and the daemon signals that the pool is empty.
* This routine does not touch any RAND_status(). This is necessary, since
* PRNG functions may call it during initialization.
*
* RAND_egd_bytes(path, bytes) will query "bytes" bytes and have them
* used to seed the PRNG.
* RAND_egd_bytes() is a wrapper for RAND_query_egd_bytes() with buf=NULL.
* Unlike RAND_query_egd_bytes(), RAND_status() is used to test the
* seed status so that the return value can reflect the seed state:
* -1 if an error occurred during connection or communication _or_
* if the PRNG has still not received the required seeding.
* num the number of bytes read from the EGD socket. This number is either
* the number of bytes requested or smaller, if the EGD pool is
* drained and the daemon signals that the pool is empty.
*
* RAND_egd(path) will query 255 bytes and use the bytes retrieved to seed
* the PRNG.
* RAND_egd() is a wrapper for RAND_egd_bytes() with numbytes=255.
*/
# if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_VOS) || defined(OPENSSL_SYS_UEFI)
int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
{
return (-1);
}
int RAND_egd(const char *path)
{
return (-1);
}
int RAND_egd_bytes(const char *path, int bytes)
{
return (-1);
}
# else
# include <openssl/opensslconf.h>
# include OPENSSL_UNISTD
# include <stddef.h>
# include <sys/types.h>
# include <sys/socket.h>
# ifndef NO_SYS_UN_H
# ifdef OPENSSL_SYS_VXWORKS
# include <streams/un.h>
# else
# include <sys/un.h>
# endif
# else
struct sockaddr_un {
short sun_family; /* AF_UNIX */
char sun_path[108]; /* path name (gag) */
};
# endif /* NO_SYS_UN_H */
# include <string.h>
# include <errno.h>
int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
{
int ret = 0;
struct sockaddr_un addr;
int len, num, numbytes;
int fd = -1;
int success;
unsigned char egdbuf[2], tempbuf[255], *retrievebuf;
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
if (strlen(path) >= sizeof(addr.sun_path))
return (-1);
OPENSSL_strlcpy(addr.sun_path, path, sizeof addr.sun_path);
len = offsetof(struct sockaddr_un, sun_path) + strlen(path);
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd == -1)
return (-1);
success = 0;
while (!success) {
if (connect(fd, (struct sockaddr *)&addr, len) == 0)
success = 1;
else {
switch (errno) {
# ifdef EINTR
case EINTR:
# endif
# ifdef EAGAIN
case EAGAIN:
# endif
# ifdef EINPROGRESS
case EINPROGRESS:
# endif
# ifdef EALREADY
case EALREADY:
# endif
/* No error, try again */
break;
# ifdef EISCONN
case EISCONN:
success = 1;
break;
# endif
default:
ret = -1;
goto err; /* failure */
}
}
}
while (bytes > 0) {
egdbuf[0] = 1;
egdbuf[1] = bytes < 255 ? bytes : 255;
numbytes = 0;
while (numbytes != 2) {
num = write(fd, egdbuf + numbytes, 2 - numbytes);
if (num >= 0)
numbytes += num;
else {
switch (errno) {
# ifdef EINTR
case EINTR:
# endif
# ifdef EAGAIN
case EAGAIN:
# endif
/* No error, try again */
break;
default:
ret = -1;
goto err; /* failure */
}
}
}
numbytes = 0;
while (numbytes != 1) {
num = read(fd, egdbuf, 1);
if (num == 0)
goto err; /* descriptor closed */
else if (num > 0)
numbytes += num;
else {
switch (errno) {
# ifdef EINTR
case EINTR:
# endif
# ifdef EAGAIN
case EAGAIN:
# endif
/* No error, try again */
break;
default:
ret = -1;
goto err; /* failure */
}
}
}
if (egdbuf[0] == 0)
goto err;
if (buf)
retrievebuf = buf + ret;
else
retrievebuf = tempbuf;
numbytes = 0;
while (numbytes != egdbuf[0]) {
num = read(fd, retrievebuf + numbytes, egdbuf[0] - numbytes);
if (num == 0)
goto err; /* descriptor closed */
else if (num > 0)
numbytes += num;
else {
switch (errno) {
# ifdef EINTR
case EINTR:
# endif
# ifdef EAGAIN
case EAGAIN:
# endif
/* No error, try again */
break;
default:
ret = -1;
goto err; /* failure */
}
}
}
ret += egdbuf[0];
bytes -= egdbuf[0];
if (!buf)
RAND_seed(tempbuf, egdbuf[0]);
}
err:
if (fd != -1)
close(fd);
return (ret);
}
int RAND_egd_bytes(const char *path, int bytes)
{
int num, ret = -1;
num = RAND_query_egd_bytes(path, NULL, bytes);
if (num < 0)
goto err;
if (RAND_status() == 1)
ret = num;
err:
return (ret);
}
int RAND_egd(const char *path)
{
return (RAND_egd_bytes(path, 255));
}
# endif
#endif