X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Frand_lcl.h;h=8abca4c2906a3d0661b6de774d0f7c7463b2d331;hp=1a09118546f9caddca172f64a201a0ac81502acd;hb=a83dc59afa2e;hpb=8212d50576147cd5db87b1e2f4607a6d5b5f435f diff --git a/crypto/rand/rand_lcl.h b/crypto/rand/rand_lcl.h index 1a09118546..8abca4c290 100644 --- a/crypto/rand/rand_lcl.h +++ b/crypto/rand/rand_lcl.h @@ -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 @@ -15,7 +15,10 @@ # include # include # include -# include "internal/rand.h" +# include +# include "internal/tsan_assist.h" + +# include "internal/numbers.h" /* How many times to read the TSC as a randomness source. */ # define TSC_READ_COUNT 4 @@ -32,18 +35,42 @@ -/* Max size of additional input and personalization string. */ -# define DRBG_MAX_LENGTH 4096 +/* + * Maximum input size for the DRBG (entropy, nonce, personalization string) + * + * NIST SP800 90Ar1 allows a maximum of (1 << 35) bits i.e., (1 << 32) bytes. + * + * We lower it to 'only' INT32_MAX bytes, which is equivalent to 2 gigabytes. + */ +# define DRBG_MAX_LENGTH INT32_MAX + + /* - * The quotient between max_{entropy,nonce}len and min_{entropy,nonce}len + * Maximum allocation size for RANDOM_POOL buffers * - * The current factor is large enough that the RAND_POOL can store a - * random input which has a lousy entropy rate of 0.0625 bits per byte. - * This input will be sent through the derivation function which 'compresses' - * the low quality input into a high quality output. + * The max_len value for the buffer provided to the rand_drbg_get_entropy() + * callback is currently 2^31 bytes (2 gigabytes), if a derivation function + * is used. Since this is much too large to be allocated, the rand_pool_new() + * function chooses more modest values as default pool length, bounded + * by RAND_POOL_MIN_LENGTH and RAND_POOL_MAX_LENGTH + * + * The choice of the RAND_POOL_FACTOR is large enough such that the + * RAND_POOL can store a random input which has a lousy entropy rate of + * 8/256 (= 0.03125) bits per byte. This input will be sent through the + * derivation function which 'compresses' the low quality input into a + * high quality output. + * + * The factor 1.5 below is the pessimistic estimate for the extra amount + * of entropy required when no get_nonce() callback is defined. + */ +# define RAND_POOL_FACTOR 256 +# define RAND_POOL_MAX_LENGTH (RAND_POOL_FACTOR * \ + 3 * (RAND_DRBG_STRENGTH / 16)) +/* + * = (RAND_POOL_FACTOR * \ + * 1.5 * (RAND_DRBG_STRENGTH / 8)) */ -# define DRBG_MINMAX_FACTOR 128 /* DRBG status values */ @@ -54,7 +81,7 @@ typedef enum drbg_status_e { } DRBG_STATUS; -/* intantiate */ +/* instantiate */ typedef int (*RAND_DRBG_instantiate_fn)(RAND_DRBG *ctx, const unsigned char *ent, size_t entlen, @@ -68,7 +95,7 @@ typedef int (*RAND_DRBG_reseed_fn)(RAND_DRBG *ctx, size_t entlen, const unsigned char *adin, size_t adinlen); -/* generat output */ +/* generate output */ typedef int (*RAND_DRBG_generate_fn)(RAND_DRBG *ctx, unsigned char *out, size_t outlen, @@ -89,18 +116,37 @@ typedef struct rand_drbg_method_st { RAND_DRBG_uninstantiate_fn uninstantiate; } RAND_DRBG_METHOD; +/* 888 bits from SP800-90Ar1 10.1 table 2 */ +#define HASH_PRNG_MAX_SEEDLEN (888/8) + +typedef struct rand_drbg_hash_st { + const EVP_MD *md; + EVP_MD_CTX *ctx; + size_t blocklen; + unsigned char V[HASH_PRNG_MAX_SEEDLEN]; + unsigned char C[HASH_PRNG_MAX_SEEDLEN]; + /* Temporary value storage: should always exceed max digest length */ + unsigned char vtmp[HASH_PRNG_MAX_SEEDLEN]; +} RAND_DRBG_HASH; + +typedef struct rand_drbg_hmac_st { + const EVP_MD *md; + HMAC_CTX *ctx; + size_t blocklen; + unsigned char K[EVP_MAX_MD_SIZE]; + unsigned char V[EVP_MAX_MD_SIZE]; +} RAND_DRBG_HMAC; /* * The state of a DRBG AES-CTR. */ typedef struct rand_drbg_ctr_st { - AES_KEY ks; + EVP_CIPHER_CTX *ctx; + EVP_CIPHER_CTX *ctx_df; + const EVP_CIPHER *cipher; size_t keylen; unsigned char K[32]; unsigned char V[16]; - /* Temp variables used by derivation function */ - AES_KEY df_ks; - AES_KEY df_kxks; /* Temporary block storage used by ctr_df */ unsigned char bltmp[16]; size_t bltmp_pos; @@ -108,6 +154,29 @@ typedef struct rand_drbg_ctr_st { } RAND_DRBG_CTR; +/* + * The 'random pool' acts as a dumb container for collecting random + * input from various entropy sources. The pool has no knowledge about + * whether its randomness is fed into a legacy RAND_METHOD via RAND_add() + * or into a new style RAND_DRBG. It is the callers duty to 1) initialize the + * random pool, 2) pass it to the polling callbacks, 3) seed the RNG, and + * 4) cleanup the random pool again. + * + * The random pool contains no locking mechanism because its scope and + * lifetime is intended to be restricted to a single stack frame. + */ +struct rand_pool_st { + unsigned char *buffer; /* points to the beginning of the random pool */ + size_t len; /* current number of random bytes contained in the pool */ + + int attached; /* true pool was attached to existing buffer */ + + size_t min_len; /* minimum number of random bytes requested */ + size_t max_len; /* maximum number of random bytes (allocated buffer size) */ + size_t entropy; /* current entropy count in bits */ + size_t entropy_requested; /* requested entropy count in bits */ +}; + /* * The state of all types of DRBGs, even though we only have CTR mode * right now. @@ -115,24 +184,34 @@ typedef struct rand_drbg_ctr_st { struct rand_drbg_st { CRYPTO_RWLOCK *lock; RAND_DRBG *parent; - int nid; /* the underlying algorithm */ + int secure; /* 1: allocated on the secure heap, 0: otherwise */ + int type; /* the nid of the underlying algorithm */ + /* + * Stores the value of the rand_fork_count global as of when we last + * reseeded. The DRBG reseeds automatically whenever drbg->fork_count != + * rand_fork_count. Used to provide fork-safety and reseed this DRBG in + * the child process. + */ int fork_count; unsigned short flags; /* various external flags */ /* - * The random pool is used by RAND_add()/drbg_add() to attach random + * The random_data is used by RAND_add()/drbg_add() to attach random * data to the global drbg, such that the rand_drbg_get_entropy() callback * can pull it during instantiation and reseeding. This is necessary to * reconcile the different philosophies of the RAND and the RAND_DRBG * with respect to how randomness is added to the RNG during reseeding * (see PR #4328). */ - RAND_POOL *pool; + struct rand_pool_st *pool; /* * The following parameters are setup by the per-type "init" function. * - * Currently the only type is CTR_DRBG, its init function is drbg_ctr_init(). + * The supported types and their init functions are: + * (1) CTR_DRBG: drbg_ctr_init(). + * (2) HMAC_DRBG: drbg_hmac_init(). + * (3) HASH_DRBG: drbg_hash_init(). * * The parameters are closely related to the ones described in * section '10.2.1 CTR_DRBG' of [NIST SP 800-90Ar1], with one @@ -152,8 +231,12 @@ struct rand_drbg_st { size_t min_noncelen, max_noncelen; size_t max_perslen, max_adinlen; - /* Counts the number of generate requests since the last reseed. */ - unsigned int generate_counter; + /* + * Counts the number of generate requests since the last reseed + * (Starts at 1). This value is the reseed_counter as defined in + * NIST SP 800-90Ar1 + */ + unsigned int reseed_gen_counter; /* * Maximum number of generate requests until a reseed is required. * This value is ignored if it is zero. @@ -176,7 +259,8 @@ struct rand_drbg_st { * 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; + TSAN_QUALIFIER unsigned int reseed_prop_counter; + unsigned int reseed_next_counter; size_t seedlen; DRBG_STATUS state; @@ -184,9 +268,11 @@ struct rand_drbg_st { /* Application data, mainly used in the KATs. */ CRYPTO_EX_DATA ex_data; - /* Implementation specific data (currently only one implementation) */ + /* Implementation specific data */ union { RAND_DRBG_CTR ctr; + RAND_DRBG_HASH hash; + RAND_DRBG_HMAC hmac; } data; /* Implementation specific methods */ @@ -202,25 +288,32 @@ struct rand_drbg_st { /* The global RAND method, and the global buffer and DRBG instance. */ extern RAND_METHOD rand_meth; -/* How often we've forked (only incremented in child). */ +/* + * A "generation count" of forks. Incremented in the child process after a + * fork. Since rand_fork_count is increment-only, and only ever written to in + * the child process of the fork, which is guaranteed to be single-threaded, no + * locking is needed for normal (read) accesses; the rest of pthread fork + * processing is assumed to introduce the necessary memory barriers. Sibling + * children of a given parent will produce duplicate values, but this is not + * problematic because the reseeding process pulls input from the system CSPRNG + * and/or other global sources, so the siblings will end up generating + * different output streams. + */ extern int rand_fork_count; -/* Hardware-based seeding functions. */ -size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool); -size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool); - -/* DRBG entropy callbacks. */ -size_t rand_drbg_get_entropy(RAND_DRBG *drbg, - unsigned char **pout, - int entropy, size_t min_len, size_t max_len); -void rand_drbg_cleanup_entropy(RAND_DRBG *drbg, - unsigned char *out, size_t outlen); - /* DRBG helpers */ int rand_drbg_restart(RAND_DRBG *drbg, const unsigned char *buffer, size_t len, size_t entropy); -/* initializes the AES-CTR DRBG implementation */ +/* locking api */ +int rand_drbg_lock(RAND_DRBG *drbg); +int rand_drbg_unlock(RAND_DRBG *drbg); +int rand_drbg_enable_locking(RAND_DRBG *drbg); + + +/* initializes the DRBG implementation */ int drbg_ctr_init(RAND_DRBG *drbg); +int drbg_hash_init(RAND_DRBG *drbg); +int drbg_hmac_init(RAND_DRBG *drbg); #endif