openssl/crypto/rand/rand_vms.c

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/*
* Copyright 2001-2018 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 "e_os.h"
#if defined(OPENSSL_SYS_VMS)
DRBG: implement a get_nonce() callback Fixes #5849 In pull request #5503 a fallback was added which adds a random nonce of security_strength/2 bits if no nonce callback is provided. This change raised the entropy requirements form 256 to 384 bit, which can cause problems on some platforms (e.g. VMS, see issue #5849). The requirements for the nonce are given in section 8.6.7 of NIST SP 800-90Ar1: A nonce may be required in the construction of a seed during instantiation in order to provide a security cushion to block certain attacks. The nonce shall be either: a) A value with at least (security_strength/2) bits of entropy, or b) A value that is expected to repeat no more often than a (security_strength/2)-bit random string would be expected to repeat. Each nonce shall be unique to the cryptographic module in which instantiation is performed, but need not be secret. When used, the nonce shall be considered to be a critical security parameter. This commit implements a nonce of type b) in order to lower the entropy requirements during instantiation back to 256 bits. The formulation "shall be unique to the cryptographic module" above implies that the nonce needs to be unique among (with high probability) among all DRBG instances in "space" and "time". We try to achieve this goal by creating a nonce of the following form nonce = app-specific-data || high-resolution-utc-timestamp || counter Where || denotes concatenation. The application specific data can be something like the process or group id of the application. A utc timestamp is used because it increases monotonically, provided the system time is synchronized. This approach may not be perfect yet for a FIPS evaluation, but it should be good enough for the moment. This commit also harmonizes the implementation of the get_nonce() and the get_additional_data() callbacks and moves the platform specific parts from rand_lib.c into rand_unix.c, rand_win.c, and rand_vms.c. Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/5920)
2018-04-10 16:22:52 +08:00
# include <unistd.h>
# include "internal/cryptlib.h"
# include <openssl/rand.h>
# include "internal/rand_int.h"
# include "rand_lcl.h"
# include <descrip.h>
# include <jpidef.h>
# include <ssdef.h>
# include <starlet.h>
# include <efndef>
# ifdef __DECC
# pragma message disable DOLLARID
# endif
# ifndef OPENSSL_RAND_SEED_OS
# error "Unsupported seeding method configured; must be os"
# endif
/*
* Use 32-bit pointers almost everywhere. Define the type to which to cast a
* pointer passed to an external function.
*/
# if __INITIAL_POINTER_SIZE == 64
# define PTR_T __void_ptr64
# pragma pointer_size save
# pragma pointer_size 32
# else
# define PTR_T void *
# endif
static struct items_data_st {
short length, code; /* length is number of bytes */
} items_data[] = {
{4, JPI$_BUFIO},
{4, JPI$_CPUTIM},
{4, JPI$_DIRIO},
{4, JPI$_IMAGECOUNT},
{8, JPI$_LAST_LOGIN_I},
{8, JPI$_LOGINTIM},
{4, JPI$_PAGEFLTS},
{4, JPI$_PID},
{4, JPI$_PPGCNT},
{4, JPI$_WSPEAK},
{4, JPI$_FINALEXC},
{0, 0}
};
/*
* We assume there we get about 4 bits of entropy per byte from the items
* above, with a bit of scrambling added rand_pool_acquire_entropy()
*/
#define ENTROPY_BITS_PER_BYTE 4
size_t rand_pool_acquire_entropy(RAND_POOL *pool)
{
/* determine the number of items in the JPI array */
struct items_data_st item_entry;
size_t item_entry_count = OSSL_NELEM(items_data);
/* Create the 32-bit JPI itemlist array to hold item_data content */
struct {
uint16_t length, code;
uint32_t *buffer;
uint32_t *retlen;
} item[item_entry_count], *pitem;
struct items_data_st *pitems_data;
/* 8 bytes (two longs) per entry max */
uint32_t data_buffer[(item_entry_count * 2) + 4];
uint32_t iosb[2];
uint32_t sys_time[2];
uint32_t *ptr;
size_t i, j ;
size_t tmp_length = 0;
size_t total_length = 0;
size_t bytes_needed = rand_pool_bytes_needed(pool, ENTROPY_BITS_PER_BYTE);
size_t bytes_remaining = rand_pool_bytes_remaining(pool);
/* Setup itemlist for GETJPI */
pitems_data = items_data;
for (pitem = item; pitems_data->length != 0; pitem++) {
pitem->length = pitems_data->length;
pitem->code = pitems_data->code;
pitem->buffer = &data_buffer[total_length];
pitem->retlen = 0;
/* total_length is in longwords */
total_length += pitems_data->length / 4;
pitems_data++;
}
pitem->length = pitem->code = 0;
/* Fill data_buffer with various info bits from this process */
if (sys$getjpiw(EFN$C_ENF, NULL, NULL, item, &iosb, 0, 0) != SS$_NORMAL)
return 0;
/* Now twist that data to seed the SSL random number init */
for (i = 0; i < total_length; i++) {
sys$gettim((struct _generic_64 *)&sys_time[0]);
srand(sys_time[0] * data_buffer[0] * data_buffer[1] + i);
if (i == (total_length - 1)) { /* for JPI$_FINALEXC */
ptr = &data_buffer[i];
for (j = 0; j < 4; j++) {
data_buffer[i + j] = ptr[j];
/* OK to use rand() just to scramble the seed */
data_buffer[i + j] ^= (sys_time[0] ^ rand());
tmp_length++;
}
} else {
/* OK to use rand() just to scramble the seed */
data_buffer[i] ^= (sys_time[0] ^ rand());
}
}
total_length += (tmp_length - 1);
/* Change the total length to number of bytes */
total_length *= 4;
Fix reseeding issues of the public RAND_DRBG Reseeding is handled very differently by the classic RAND_METHOD API and the new RAND_DRBG api. These differences led to some problems when the new RAND_DRBG was made the default OpenSSL RNG. In particular, RAND_add() did not work as expected anymore. These issues are discussed on the thread '[openssl-dev] Plea for a new public OpenSSL RNG API' and in Pull Request #4328. This commit fixes the mentioned issues, introducing the following changes: - Replace the fixed size RAND_BYTES_BUFFER by a new RAND_POOL API which facilitates collecting entropy by the get_entropy() callback. - Don't use RAND_poll()/RAND_add() for collecting entropy from the get_entropy() callback anymore. Instead, replace RAND_poll() by RAND_POOL_acquire_entropy(). - Add a new function rand_drbg_restart() which tries to get the DRBG in an instantiated state by all means, regardless of the current state (uninstantiated, error, ...) the DRBG is in. If the caller provides entropy or additional input, it will be used for reseeding. - Restore the original documented behaviour of RAND_add() and RAND_poll() (namely to reseed the DRBG immediately) by a new implementation based on rand_drbg_restart(). - Add automatic error recovery from temporary failures of the entropy source to RAND_DRBG_generate() using the rand_drbg_restart() function. Reviewed-by: Paul Dale <paul.dale@oracle.com> Reviewed-by: Kurt Roeckx <kurt@roeckx.be> Reviewed-by: Rich Salz <rsalz@openssl.org> Reviewed-by: Ben Kaduk <kaduk@mit.edu> (Merged from https://github.com/openssl/openssl/pull/4328)
2017-09-01 05:16:22 +08:00
/*
* If we can't feed the requirements from the caller, we're in deep trouble.
Fix reseeding issues of the public RAND_DRBG Reseeding is handled very differently by the classic RAND_METHOD API and the new RAND_DRBG api. These differences led to some problems when the new RAND_DRBG was made the default OpenSSL RNG. In particular, RAND_add() did not work as expected anymore. These issues are discussed on the thread '[openssl-dev] Plea for a new public OpenSSL RNG API' and in Pull Request #4328. This commit fixes the mentioned issues, introducing the following changes: - Replace the fixed size RAND_BYTES_BUFFER by a new RAND_POOL API which facilitates collecting entropy by the get_entropy() callback. - Don't use RAND_poll()/RAND_add() for collecting entropy from the get_entropy() callback anymore. Instead, replace RAND_poll() by RAND_POOL_acquire_entropy(). - Add a new function rand_drbg_restart() which tries to get the DRBG in an instantiated state by all means, regardless of the current state (uninstantiated, error, ...) the DRBG is in. If the caller provides entropy or additional input, it will be used for reseeding. - Restore the original documented behaviour of RAND_add() and RAND_poll() (namely to reseed the DRBG immediately) by a new implementation based on rand_drbg_restart(). - Add automatic error recovery from temporary failures of the entropy source to RAND_DRBG_generate() using the rand_drbg_restart() function. Reviewed-by: Paul Dale <paul.dale@oracle.com> Reviewed-by: Kurt Roeckx <kurt@roeckx.be> Reviewed-by: Rich Salz <rsalz@openssl.org> Reviewed-by: Ben Kaduk <kaduk@mit.edu> (Merged from https://github.com/openssl/openssl/pull/4328)
2017-09-01 05:16:22 +08:00
*/
if (!ossl_assert(total_length >= bytes_needed)) {
char neededstr[20];
char availablestr[20];
BIO_snprintf(neededstr, sizeof(neededstr), "%zu", bytes_needed);
BIO_snprintf(availablestr, sizeof(availablestr), "%zu", total_length);
RANDerr(RAND_F_RAND_POOL_ACQUIRE_ENTROPY,
RAND_R_RANDOM_POOL_UNDERFLOW);
ERR_add_error_data(4, "Needed: ", neededstr, ", Available: ",
availablestr);
return 0;
}
/*
* Try not to overfeed the pool
*/
if (total_length > bytes_remaining)
total_length = bytes_remaining;
rand_pool_add(pool, (PTR_T)data_buffer, total_length,
total_length * ENTROPY_BITS_PER_BYTE);
return rand_pool_entropy_available(pool);
}
DRBG: implement a get_nonce() callback Fixes #5849 In pull request #5503 a fallback was added which adds a random nonce of security_strength/2 bits if no nonce callback is provided. This change raised the entropy requirements form 256 to 384 bit, which can cause problems on some platforms (e.g. VMS, see issue #5849). The requirements for the nonce are given in section 8.6.7 of NIST SP 800-90Ar1: A nonce may be required in the construction of a seed during instantiation in order to provide a security cushion to block certain attacks. The nonce shall be either: a) A value with at least (security_strength/2) bits of entropy, or b) A value that is expected to repeat no more often than a (security_strength/2)-bit random string would be expected to repeat. Each nonce shall be unique to the cryptographic module in which instantiation is performed, but need not be secret. When used, the nonce shall be considered to be a critical security parameter. This commit implements a nonce of type b) in order to lower the entropy requirements during instantiation back to 256 bits. The formulation "shall be unique to the cryptographic module" above implies that the nonce needs to be unique among (with high probability) among all DRBG instances in "space" and "time". We try to achieve this goal by creating a nonce of the following form nonce = app-specific-data || high-resolution-utc-timestamp || counter Where || denotes concatenation. The application specific data can be something like the process or group id of the application. A utc timestamp is used because it increases monotonically, provided the system time is synchronized. This approach may not be perfect yet for a FIPS evaluation, but it should be good enough for the moment. This commit also harmonizes the implementation of the get_nonce() and the get_additional_data() callbacks and moves the platform specific parts from rand_lib.c into rand_unix.c, rand_win.c, and rand_vms.c. Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/5920)
2018-04-10 16:22:52 +08:00
int rand_pool_add_nonce_data(RAND_POOL *pool)
{
struct {
pid_t pid;
CRYPTO_THREAD_ID tid;
uint64_t time;
} data = { 0 };
/*
* Add process id, thread id, and a high resolution timestamp to
* ensure that the nonce is unique whith high probability for
* different process instances.
*/
data.pid = getpid();
data.tid = CRYPTO_THREAD_get_current_id();
sys$gettim_prec((struct _generic_64 *)&data.time);
return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
}
int rand_pool_add_additional_data(RAND_POOL *pool)
{
struct {
CRYPTO_THREAD_ID tid;
uint64_t time;
} data = { 0 };
/*
* Add some noise from the thread id and a high resolution timer.
* The thread id adds a little randomness if the drbg is accessed
* concurrently (which is the case for the <master> drbg).
*/
data.tid = CRYPTO_THREAD_get_current_id();
sys$gettim_prec((struct _generic_64 *)&data.time);
return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
}
#endif