+++ /dev/null
-From 6efeaa2e4462bc10f395d8aceed363c3e77b35a3 Mon Sep 17 00:00:00 2001
-From: Adriaan de Jong <dejong@fox-it.com>
-Date: Mon, 2 Apr 2012 09:28:02 +0200
-Subject: [PATCH] Added support for new PolarSSL 1.1 RNG
-
-This patch, while retaining PolarSSL 1.0 support, introduces the PolarSSL 1.1 DRBG.
-This RNG adds a number of features, including support for personalisation strings
-and multiple entropy sources.
-
-Personalisation strings have been implemented, based on PID, program name, place
-within memory, and a hash of the user's certificate.
-
-The entropy sources used are the platform default ones. Which ones these are
-depends on how PolarSSL was built, but usually this includes:
-
- - /dev/urandom or the Windows CryptoAPI RNG
- - the HAVEGE RNG
- - the output of PolarSSL's hardclock() call (usually RDTSC)
-
-Finally, this patch moves to only one instance of the RNG per OpenVPN instance,
-instead of one per keystate
-
-Signed-off-by: Adriaan de Jong <dejong@fox-it.com>
-Signed-off-by: Eelse-jan Stutvoet <stutvoet@fox-it.com>
-Acked-by: James Yonan <james@openvpn.net>
-Message-Id: 1333351687-3732-1-git-send-email-dejong@fox-it.com
-URL: http://article.gmane.org/gmane.network.openvpn.devel/6210
-Signed-off-by: David Sommerseth <davids@redhat.com>
----
- crypto_polarssl.c | 84 ++++++++++++++++++++++++++++++++++++-----
- crypto_polarssl.h | 25 ++++++++++++
- ssl.c | 5 ++
- ssl_backend.h | 10 +++++
- ssl_polarssl.c | 44 ++++++++++++++++-----
- ssl_polarssl.h | 2 -
- 6 files changed, 148 insertions(+), 22 deletions(-)
-
---- a/crypto_polarssl.c
-+++ b/crypto_polarssl.c
-@@ -36,12 +36,18 @@
- #include "buffer.h"
- #include "integer.h"
- #include "crypto_backend.h"
-+#include "otime.h"
-+#include "misc.h"
-
- #include <polarssl/des.h>
- #include <polarssl/md5.h>
- #include <polarssl/cipher.h>
- #include <polarssl/havege.h>
-
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+#include <polarssl/entropy.h>
-+#endif
-+
- /*
- *
- * Hardware engine support. Allows loading/unloading of engines.
-@@ -143,7 +149,6 @@ show_available_engines ()
- "available\n");
- }
-
--
- /*
- *
- * Random number functions, used in cases where we want
-@@ -153,29 +158,88 @@ show_available_engines ()
- *
- */
-
--int
--rand_bytes (uint8_t *output, int len)
-+/*
-+ * Initialise the given ctr_drbg context, using a personalisation string and an
-+ * entropy gathering function.
-+ */
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+ctr_drbg_context * rand_ctx_get()
-+{
-+ static entropy_context ec = {0};
-+ static ctr_drbg_context cd_ctx = {0};
-+ static bool rand_initialised = false;
-+
-+ if (!rand_initialised)
-+ {
-+ struct gc_arena gc = gc_new();
-+ struct buffer pers_string = alloc_buf_gc(100, &gc);
-+
-+ /*
-+ * Personalisation string, should be as unique as possible (see NIST
-+ * 800-90 section 8.7.1). We have very little information at this stage.
-+ * Include Program Name, memory address of the context and PID.
-+ */
-+ buf_printf(&pers_string, "OpenVPN %0u %p %s", getpid(), &cd_ctx, time_string(0, 0, 0, &gc));
-+
-+ /* Initialise PolarSSL RNG, and built-in entropy sources */
-+ entropy_init(&ec);
-+
-+ if (0 != ctr_drbg_init(&cd_ctx, entropy_func, &ec, BPTR(&pers_string), BLEN(&pers_string)))
-+ msg (M_FATAL, "Failed to initialize random generator");
-+
-+ gc_free(&gc);
-+ rand_initialised = true;
-+ }
-+
-+ return &cd_ctx;
-+}
-+
-+#else /* (POLARSSL_VERSION_NUMBER < 0x01010000) */
-+
-+havege_state * rand_ctx_get()
- {
- static havege_state hs = {0};
-- static bool hs_initialised = false;
-- const int int_size = sizeof(int);
-+ static bool rand_initialised = false;
-
-- if (!hs_initialised)
-+ if (!rand_initialised)
- {
- /* Initialise PolarSSL RNG */
- havege_init(&hs);
-- hs_initialised = true;
-+ rand_initialised = true;
- }
-
-+ return &hs;
-+}
-+
-+#endif /* (POLARSSL_VERSION_NUMBER >= 0x01010000) */
-+
-+int
-+rand_bytes (uint8_t *output, int len)
-+{
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+ ctr_drbg_context *rng_ctx = rand_ctx_get();
-+#else /* (POLARSSL_VERSION_NUMBER >= 0x01010000) */
-+ havege_state *rng_ctx = rand_ctx_get();
-+#endif /* (POLARSSL_VERSION_NUMBER >= 0x01010000) */
-+
- while (len > 0)
- {
-- const int blen = min_int (len, int_size);
-- const int rand_int = havege_rand(&hs);
--
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+ const size_t blen = min_int (len, CTR_DRBG_MAX_REQUEST);
-+ if (0 != ctr_drbg_random(rng_ctx, output, blen))
-+ return 0;
-+
-+#else /* (POLARSSL_VERSION_NUMBER >= 0x01010000) */
-+ const size_t blen = min_int (len, sizeof(int));
-+ const int rand_int = havege_rand(rng_ctx);
- memcpy (output, &rand_int, blen);
-+
-+#endif /* (POLARSSL_VERSION_NUMBER >= 0x01010000) */
-+
- output += blen;
- len -= blen;
- }
-+
- return 1;
- }
-
---- a/crypto_polarssl.h
-+++ b/crypto_polarssl.h
-@@ -30,9 +30,16 @@
- #ifndef CRYPTO_POLARSSL_H_
- #define CRYPTO_POLARSSL_H_
-
-+#include <polarssl/version.h>
- #include <polarssl/cipher.h>
- #include <polarssl/md.h>
-
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+# include <polarssl/ctr_drbg.h>
-+#else
-+# include <polarssl/havege.h>
-+#endif
-+
- /** Generic cipher key type %context. */
- typedef cipher_info_t cipher_kt_t;
-
-@@ -71,4 +78,22 @@ typedef md_context_t hmac_ctx_t;
- #define SHA_DIGEST_LENGTH 20
- #define DES_KEY_LENGTH 8
-
-+/**
-+ * Returns a singleton instance of the PolarSSL random number generator.
-+ *
-+ * For PolarSSL 1.0, this is the HAVEGE random number generator.
-+ *
-+ * For PolarSSL 1.1+, this is the CTR_DRBG random number generator. If it
-+ * hasn't been initialised yet, the RNG will be initialised using the default
-+ * entropy sources. Aside from the default platform entropy sources, an
-+ * additional entropy source, the HAVEGE random number generator will also be
-+ * added. During initialisation, a personalisation string will be added based
-+ * on the time, the PID, and a pointer to the random context.
-+ */
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+ctr_drbg_context * rand_ctx_get();
-+#else
-+havege_state * rand_ctx_get();
-+#endif
-+
- #endif /* CRYPTO_POLARSSL_H_ */
---- a/ssl.c
-+++ b/ssl.c
-@@ -385,6 +385,11 @@ init_ssl (const struct options *options,
- tls_ctx_restrict_ciphers(new_ctx, options->cipher_list);
- }
-
-+#ifdef ENABLE_CRYPTO_POLARSSL
-+ /* Fox-IT hardening: Personalise the random by mixing in the certificate */
-+ tls_ctx_personalise_random (new_ctx);
-+#endif
-+
- tls_clear_error ();
- return;
-
---- a/ssl_backend.h
-+++ b/ssl_backend.h
-@@ -272,6 +272,16 @@ void tls_ctx_load_extra_certs (struct tl
- #endif
- );
-
-+#ifdef ENABLE_CRYPTO_POLARSSL
-+/**
-+ * Add a personalisation string to the PolarSSL RNG, based on the certificate
-+ * loaded into the given context.
-+ *
-+ * @param ctx TLS context to use
-+ */
-+void tls_ctx_personalise_random(struct tls_root_ctx *ctx);
-+#endif
-+
- /* **************************************
- *
- * Key-state specific functions
---- a/ssl_polarssl.c
-+++ b/ssl_polarssl.c
-@@ -38,6 +38,9 @@
- #include "manage.h"
- #include "ssl_common.h"
-
-+#include <polarssl/sha2.h>
-+#include <polarssl/havege.h>
-+
- #include "ssl_verify_polarssl.h"
- #include <polarssl/pem.h>
-
-@@ -79,9 +82,6 @@ tls_ctx_server_new(struct tls_root_ctx *
- ASSERT(NULL != ctx);
- CLEAR(*ctx);
-
-- ALLOC_OBJ_CLEAR(ctx->hs, havege_state);
-- havege_init(ctx->hs);
--
- ALLOC_OBJ_CLEAR(ctx->dhm_ctx, dhm_context);
- ALLOC_OBJ_CLEAR(ctx->priv_key, rsa_context);
-
-@@ -97,12 +97,8 @@ void
- tls_ctx_client_new(struct tls_root_ctx *ctx)
- {
- ASSERT(NULL != ctx);
--
- CLEAR(*ctx);
-
-- ALLOC_OBJ_CLEAR(ctx->hs, havege_state);
-- havege_init(ctx->hs);
--
- ALLOC_OBJ_CLEAR(ctx->dhm_ctx, dhm_context);
- ALLOC_OBJ_CLEAR(ctx->priv_key, rsa_context);
-
-@@ -137,8 +133,6 @@ tls_ctx_free(struct tls_root_ctx *ctx)
- }
- #endif
-
-- free(ctx->hs);
--
- if (ctx->allowed_ciphers)
- free(ctx->allowed_ciphers);
-
-@@ -496,6 +490,30 @@ static void my_debug( void *ctx, int lev
- }
- }
-
-+/*
-+ * Further personalise the RNG using a hash of the public key
-+ */
-+void tls_ctx_personalise_random(struct tls_root_ctx *ctx)
-+{
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+ static char old_sha256_hash[32] = {0};
-+ char sha256_hash[32] = {0};
-+ ctr_drbg_context *cd_ctx = rand_ctx_get();
-+
-+ if (NULL != ctx->crt_chain)
-+ {
-+ x509_cert *cert = ctx->crt_chain;
-+
-+ sha2(cert->tbs.p, cert->tbs.len, sha256_hash, false);
-+ if ( 0 != memcmp(old_sha256_hash, sha256_hash, sizeof(sha256_hash)))
-+ {
-+ ctr_drbg_update(cd_ctx, sha256_hash, 32);
-+ memcpy(old_sha256_hash, sha256_hash, sizeof(old_sha256_hash));
-+ }
-+ }
-+#endif /* POLARSSL_VERSION_NUMBER >= 0x01010000 */
-+}
-+
- void key_state_ssl_init(struct key_state_ssl *ks_ssl,
- const struct tls_root_ctx *ssl_ctx, bool is_server, void *session)
- {
-@@ -509,7 +527,13 @@ void key_state_ssl_init(struct key_state
- /* Initialise SSL context */
- ssl_set_dbg (ks_ssl->ctx, my_debug, NULL);
- ssl_set_endpoint (ks_ssl->ctx, ssl_ctx->endpoint);
-- ssl_set_rng (ks_ssl->ctx, havege_rand, ssl_ctx->hs);
-+
-+#if (POLARSSL_VERSION_NUMBER >= 0x01010000)
-+ ssl_set_rng (ks_ssl->ctx, ctr_drbg_random, rand_ctx_get());
-+#else /* POLARSSL_VERSION_NUMBER >= 0x01010000 */
-+ ssl_set_rng (ks_ssl->ctx, havege_rand, rand_ctx_get());
-+#endif /* POLARSSL_VERSION_NUMBER >= 0x01010000 */
-+
- ALLOC_OBJ_CLEAR (ks_ssl->ssn, ssl_session);
- ssl_set_session (ks_ssl->ctx, 0, 0, ks_ssl->ssn );
- if (ssl_ctx->allowed_ciphers)
---- a/ssl_polarssl.h
-+++ b/ssl_polarssl.h
-@@ -30,7 +30,6 @@
- #ifndef SSL_POLARSSL_H_
- #define SSL_POLARSSL_H_
-
--#include <polarssl/havege.h>
- #include <polarssl/ssl.h>
- #include "config.h"
-
-@@ -63,7 +62,6 @@ struct tls_root_ctx {
-
- int endpoint; /**< Whether or not this is a server or a client */
-
-- havege_state *hs; /**< HAVEGE random number state */
- dhm_context *dhm_ctx; /**< Diffie-Helmann-Merkle context */
- x509_cert *crt_chain; /**< Local Certificate chain */
- x509_cert *ca_chain; /**< CA chain for remote verification */
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