Add RAND_DRBG_bytes
[openssl.git] / crypto / rand / rand_lcl.h
index 10a6f00a2ddc2d381abf65a940a70a6ee9317704..e3c0b76cde5843ace5d0579684c3f6a56fea81d5 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2018 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
 /* How many times to read the TSC as a randomness source. */
 # define TSC_READ_COUNT                 4
 
-/* Maximum count allowed in reseeding */
-# define MAX_RESEED                     (1 << 24)
+/* Maximum reseed intervals */
+# define MAX_RESEED_INTERVAL                     (1 << 24)
+# define MAX_RESEED_TIME_INTERVAL                (1 << 20) /* approx. 12 days */
+
+/* Default reseed intervals */
+# define MASTER_RESEED_INTERVAL                  (1 << 8)
+# define SLAVE_RESEED_INTERVAL                   (1 << 16)
+# define MASTER_RESEED_TIME_INTERVAL             (60*60)   /* 1 hour */
+# define SLAVE_RESEED_TIME_INTERVAL              (7*60)    /* 7 minutes */
+
+
 
 /* Max size of additional input and personalization string. */
 # define DRBG_MAX_LENGTH                4096
 typedef enum drbg_status_e {
     DRBG_UNINITIALISED,
     DRBG_READY,
-    DRBG_RESEED,
     DRBG_ERROR
 } DRBG_STATUS;
 
 
+/* intantiate */
+typedef int (*RAND_DRBG_instantiate_fn)(RAND_DRBG *ctx,
+                                        const unsigned char *ent,
+                                        size_t entlen,
+                                        const unsigned char *nonce,
+                                        size_t noncelen,
+                                        const unsigned char *pers,
+                                        size_t perslen);
+/* reseed */
+typedef int (*RAND_DRBG_reseed_fn)(RAND_DRBG *ctx,
+                                   const unsigned char *ent,
+                                   size_t entlen,
+                                   const unsigned char *adin,
+                                   size_t adinlen);
+/* generat output */
+typedef int (*RAND_DRBG_generate_fn)(RAND_DRBG *ctx,
+                                     unsigned char *out,
+                                     size_t outlen,
+                                     const unsigned char *adin,
+                                     size_t adinlen);
+/* uninstantiate */
+typedef int (*RAND_DRBG_uninstantiate_fn)(RAND_DRBG *ctx);
+
+
+/*
+ * The DRBG methods
+ */
+
+typedef struct rand_drbg_method_st {
+    RAND_DRBG_instantiate_fn instantiate;
+    RAND_DRBG_reseed_fn reseed;
+    RAND_DRBG_generate_fn generate;
+    RAND_DRBG_uninstantiate_fn uninstantiate;
+} RAND_DRBG_METHOD;
+
+
 /*
  * The state of a DRBG AES-CTR.
  */
@@ -88,7 +132,7 @@ struct rand_drbg_st {
     /*
      * The following parameters are setup by the per-type "init" function.
      *
-     * Currently the only type is CTR_DRBG, its init function is ctr_init().
+     * Currently the only type is CTR_DRBG, its init function is drbg_ctr_init().
      *
      * The parameters are closely related to the ones described in
      * section '10.2.1 CTR_DRBG' of [NIST SP 800-90Ar1], with one
@@ -107,16 +151,46 @@ struct rand_drbg_st {
     size_t min_entropylen, max_entropylen;
     size_t min_noncelen, max_noncelen;
     size_t max_perslen, max_adinlen;
-    unsigned int reseed_counter;
+
+    /* Counts the number of generate requests since the last reseed. */
+    unsigned int generate_counter;
+    /*
+     * Maximum number of generate requests until a reseed is required.
+     * This value is ignored if it is zero.
+     */
     unsigned int reseed_interval;
+    /* Stores the time when the last reseeding occurred */
+    time_t reseed_time;
+    /*
+     * Specifies the maximum time interval (in seconds) between reseeds.
+     * This value is ignored if it is zero.
+     */
+    time_t reseed_time_interval;
+    /*
+     * Counts the number of reseeds since instantiation.
+     * This value is ignored if it is zero.
+     *
+     * This counter is used only for seed propagation from the <master> DRBG
+     * to its two children, the <public> and <private> DRBG. This feature is
+     * very special and its sole purpose is to ensure that any randomness which
+     * is added by RAND_add() or RAND_seed() will have an immediate effect on
+     * the output of RAND_bytes() resp. RAND_priv_bytes().
+     */
+    unsigned int reseed_counter;
+
     size_t seedlen;
     DRBG_STATUS state;
 
     /* Application data, mainly used in the KATs. */
     CRYPTO_EX_DATA ex_data;
 
-    /* Implementation specific structures; was a union, but inline for now */
-    RAND_DRBG_CTR ctr;
+    /* Implementation specific data (currently only one implementation) */
+    union {
+        RAND_DRBG_CTR ctr;
+    } data;
+
+    /* Implementation specific methods */
+    RAND_DRBG_METHOD *meth;
 
     /* Callback functions.  See comments in rand_lib.c */
     RAND_DRBG_get_entropy_fn get_entropy;
@@ -141,23 +215,13 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg,
                              int entropy, size_t min_len, size_t max_len);
 void rand_drbg_cleanup_entropy(RAND_DRBG *drbg,
                                unsigned char *out, size_t outlen);
+size_t rand_drbg_get_additional_data(unsigned char **pout, size_t max_len);
 
 /* DRBG helpers */
 int rand_drbg_restart(RAND_DRBG *drbg,
                       const unsigned char *buffer, size_t len, size_t entropy);
 
-/* DRBG functions implementing AES-CTR */
-int ctr_init(RAND_DRBG *drbg);
-int ctr_uninstantiate(RAND_DRBG *drbg);
-int ctr_instantiate(RAND_DRBG *drbg,
-                    const unsigned char *entropy, size_t entropylen,
-                    const unsigned char *nonce, size_t noncelen,
-                    const unsigned char *pers, size_t perslen);
-int ctr_reseed(RAND_DRBG *drbg,
-               const unsigned char *entropy, size_t entropylen,
-               const unsigned char *adin, size_t adinlen);
-int ctr_generate(RAND_DRBG *drbg,
-                 unsigned char *out, size_t outlen,
-                 const unsigned char *adin, size_t adinlen);
+/* initializes the AES-CTR DRBG implementation */
+int drbg_ctr_init(RAND_DRBG *drbg);
 
 #endif