Make rand_pool buffers more dynamic in their sizing.

[openssl.git] / crypto / rand / rand_lcl.h

diff --git a/crypto/rand/rand_lcl.h b/crypto/rand/rand_lcl.h
index 3ec7189d7d4e292238a874987b0d27c863dec361..e425d41090b048be7ce9662b63958b18f47451e6 100644 (file)
--- a/crypto/rand/rand_lcl.h
+++ b/crypto/rand/rand_lcl.h
@@ -1,7 +1,7 @@
 /*
  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
- * Licensed under the OpenSSL license (the "License").  You may not use
+ * Licensed under the Apache License 2.0 (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
@@ -17,6 +17,7 @@
 # include <openssl/ec.h>
 # include <openssl/rand_drbg.h>
 # include "internal/tsan_assist.h"
+# include "internal/rand_int.h"
 
 # include "internal/numbers.h"
 
@@ -33,7 +34,15 @@
 # define MASTER_RESEED_TIME_INTERVAL             (60*60)   /* 1 hour */
 # define SLAVE_RESEED_TIME_INTERVAL              (7*60)    /* 7 minutes */
 
-
+/*
+ * The number of bytes that constitutes an atomic lump of entropy with respect
+ * to the FIPS 140-2 section 4.9.2 Conditional Tests.  The size is somewhat
+ * arbitrary, the smaller the value, the less entropy is consumed on first
+ * read but the higher the probability of the test failing by accident.
+ *
+ * The value is in bytes.
+ */
+#define CRNGT_BUFSIZ    16
 
 /*
  * Maximum input size for the DRBG (entropy, nonce, personalization string)
@@ -44,7 +53,8 @@
  */
 # define DRBG_MAX_LENGTH                         INT32_MAX
 
-
+/* The default nonce */
+# define DRBG_DEFAULT_PERS_STRING                "OpenSSL NIST SP 800-90A DRBG"
 
 /*
  * Maximum allocation size for RANDOM_POOL buffers
@@ -72,6 +82,24 @@
  *                                1.5 * (RAND_DRBG_STRENGTH / 8))
  */
 
+/*
+ * Initial allocation minimum.
+ *
+ * There is a distinction between the secure and normal allocation minimums.
+ * Ideally, the secure allocation size should be a power of two.  The normal
+ * allocation size doesn't have any such restriction.
+ *
+ * The secure value is based on 128 bits of secure material, which is 16 bytes.
+ * Typically, the DRBGs will set a minimum larger than this so optimal
+ * allocation ought to take place (for full quality seed material).
+ *
+ * The normal value has been chosed by noticing that the rand_drbg_get_nonce
+ * function is usually the largest of the built in allocation (twenty four
+ * bytes and then appending another sixteen bytes).  This means the buffer ends
+ * with 40 bytes.  The value of forty eight is comfortably above this which
+ * allows some slack in the platform specific values used.
+ */
+# define RAND_POOL_MIN_ALLOCATION(secure) ((secure) ? 16 : 48)
 
 /* DRBG status values */
 typedef enum drbg_status_e {
@@ -120,7 +148,7 @@ typedef struct rand_drbg_method_st {
 #define HASH_PRNG_MAX_SEEDLEN    (888/8)
 
 typedef struct rand_drbg_hash_st {
-    const EVP_MD *md;
+    EVP_MD *md;
     EVP_MD_CTX *ctx;
     size_t blocklen;
     unsigned char V[HASH_PRNG_MAX_SEEDLEN];
@@ -130,7 +158,7 @@ typedef struct rand_drbg_hash_st {
 } RAND_DRBG_HASH;
 
 typedef struct rand_drbg_hmac_st {
-    const EVP_MD *md;
+    EVP_MD *md;
     HMAC_CTX *ctx;
     size_t blocklen;
     unsigned char K[EVP_MAX_MD_SIZE];
@@ -143,7 +171,7 @@ typedef struct rand_drbg_hmac_st {
 typedef struct rand_drbg_ctr_st {
     EVP_CIPHER_CTX *ctx;
     EVP_CIPHER_CTX *ctx_df;
-    const EVP_CIPHER *cipher;
+    EVP_CIPHER *cipher;
     size_t keylen;
     unsigned char K[32];
     unsigned char V[16];
@@ -170,9 +198,11 @@ struct rand_pool_st {
     size_t len; /* current number of random bytes contained in the pool */
 
     int attached;  /* true pool was attached to existing buffer */
+    int secure;    /* 1: allocated on the secure heap, 0: otherwise */
 
     size_t min_len; /* minimum number of random bytes requested */
     size_t max_len; /* maximum number of random bytes (allocated buffer size) */
+    size_t alloc_len; /* current number of bytes allocated */
     size_t entropy; /* current entropy count in bits */
     size_t entropy_requested; /* requested entropy count in bits */
 };
@@ -183,6 +213,8 @@ struct rand_pool_st {
  */
 struct rand_drbg_st {
     CRYPTO_RWLOCK *lock;
+    /* The library context this DRBG is associated with, if any */
+    OPENSSL_CTX *libctx;
     RAND_DRBG *parent;
     int secure; /* 1: allocated on the secure heap, 0: otherwise */
     int type; /* the nid of the underlying algorithm */
@@ -321,4 +353,15 @@ int drbg_ctr_init(RAND_DRBG *drbg);
 int drbg_hash_init(RAND_DRBG *drbg);
 int drbg_hmac_init(RAND_DRBG *drbg);
 
+/*
+ * Entropy call back for the FIPS 140-2 section 4.9.2 Conditional Tests.
+ * These need to be exposed for the unit tests.
+ */
+int rand_crngt_get_entropy_cb(OPENSSL_CTX *ctx, RAND_POOL *pool,
+                              unsigned char *buf, unsigned char *md,
+                              unsigned int *md_size);
+extern int (*crngt_get_entropy)(OPENSSL_CTX *ctx, RAND_POOL *pool,
+                                unsigned char *buf, unsigned char *md,
+                                unsigned int *md_size);
+
 #endif