diff options
Diffstat (limited to 'crypto/rand/rand_unix.c')
| -rw-r--r-- | crypto/rand/rand_unix.c | 127 |
1 files changed, 84 insertions, 43 deletions
diff --git a/crypto/rand/rand_unix.c b/crypto/rand/rand_unix.c index 08ea55fbb9..f5a59cb28a 100644 --- a/crypto/rand/rand_unix.c +++ b/crypto/rand/rand_unix.c @@ -14,12 +14,18 @@ #include "rand_lcl.h" #include <stdio.h> -#if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)) +#ifdef OPENSSL_RAND_SEED_GETRANDOM +# include <linux/random.h> +#endif -# if (defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)) && \ +#if (defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)) && \ !defined(OPENSSL_RAND_SEED_NONE) -# error "UEFI and VXWorks only support seeding NONE" -# endif +# error "UEFI and VXWorks only support seeding NONE" +#endif + +#if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) \ + || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) \ + || defined(OPENSSL_SYS_UEFI)) # if defined(OPENSSL_SYS_VOS) @@ -46,16 +52,16 @@ * would be far more predictable. This should only be used for legacy * platforms. * - * As a precaution, we generate four times the required amount of seed - * data. + * As a precaution, we assume only 2 bits of entropy per byte. */ -int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) +size_t RAND_POOL_acquire_entropy(RAND_POOL *pool) { short int code; gid_t curr_gid; pid_t curr_pid; uid_t curr_uid; int i, k; + size_t bytes_needed; struct timespec ts; unsigned char v; # ifdef OPENSSL_SYS_VOS_HPPA @@ -71,13 +77,15 @@ int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) * different processes. */ curr_gid = getgid(); - rand_add(arg, &curr_gid, sizeof curr_gid, 0); + RAND_POOL_add(pool, &curr_gid, sizeof(curr_gid), 0); curr_pid = getpid(); - rand_add(arg, &curr_pid, sizeof curr_pid, 0); + RAND_POOL_add(pool, &curr_pid, sizeof(curr_pid), 0); curr_uid = getuid(); - rand_add(arg, &curr_uid, sizeof curr_uid, 0); + RAND_POOL_add(pool, &curr_uid, sizeof(curr_uid), 0); - for (i = 0; i < (RANDOMNESS_NEEDED * 4); i++) { + bytes_needed = RAND_POOL_bytes_needed(pool, 2 /*entropy_per_byte*/); + + for (i = 0; i < bytes_needed; i++) { /* * burn some cpu; hope for interrupts, cache collisions, bus * interference, etc. @@ -98,9 +106,9 @@ int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) /* Get wall clock time, take 8 bits. */ clock_gettime(CLOCK_REALTIME, &ts); v = (unsigned char)(ts.tv_nsec & 0xFF); - rand_add(arg, &v, sizeof v, 1); + RAND_POOL_add(pool, arg, &v, sizeof(v) , 2); } - return 1; + return RAND_POOL_entropy_available(pool); } # else @@ -127,27 +135,44 @@ int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) # endif /* - * Try the various seeding methods in turn, exit when succesful. + * Try the various seeding methods in turn, exit when successful. + * + * TODO(DRBG): If more than one entropy source is available, is it + * preferable to stop as soon as enough entropy has been collected + * (as favored by @rsalz) or should one rather be defensive and add + * more entropy than requested and/or from different sources? + * + * Currently, the user can select multiple entropy sources in the + * configure step, yet in practice only the first available source + * will be used. A more flexible solution has been requested, but + * currently it is not clear how this can be achieved without + * overengineering the problem. There are many parameters which + * could be taken into account when selecting the order and amount + * of input from the different entropy sources (trust, quality, + * possibility of blocking). */ -int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) +size_t RAND_POOL_acquire_entropy(RAND_POOL *pool) { # ifdef OPENSSL_RAND_SEED_NONE - return 0; + return RAND_POOL_entropy_available(pool); # else - int ok = 1; - char temp[RANDOMNESS_NEEDED]; -# define TEMPSIZE (int)sizeof(temp) + size_t bytes_needed; + size_t entropy_available = 0; + unsigned char *buffer; # ifdef OPENSSL_RAND_SEED_GETRANDOM - { - int i = getrandom(temp, TEMPSIZE, 0); + bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/); + buffer = RAND_POOL_add_begin(pool, bytes_needed); + if (buffer != NULL) { + size_t bytes = 0; - if (i >= 0) { - rand_add(arg, temp, i, i); - if (i == TEMPSIZE) - goto done; - } + if (getrandom(buffer, bytes_needed, 0) == (int)bytes_needed) + bytes = bytes_needed; + + entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes); } + if (entropy_available > 0) + return entropy_available; # endif # if defined(OPENSSL_RAND_SEED_LIBRANDOM) @@ -157,7 +182,8 @@ int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) # endif # ifdef OPENSSL_RAND_SEED_DEVRANDOM - { + bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/); + if (bytes_needed > 0) { static const char *paths[] = { DEVRANDOM, NULL }; FILE *fp; int i; @@ -166,44 +192,59 @@ int RAND_poll_ex(RAND_poll_cb rand_add, void *arg) if ((fp = fopen(paths[i], "rb")) == NULL) continue; setbuf(fp, NULL); - if (fread(temp, 1, TEMPSIZE, fp) == TEMPSIZE) { - rand_add(arg, temp, TEMPSIZE, TEMPSIZE); - fclose(fp); - goto done; + buffer = RAND_POOL_add_begin(pool, bytes_needed); + if (buffer != NULL) { + size_t bytes = 0; + if (fread(buffer, 1, bytes_needed, fp) == bytes_needed) + bytes = bytes_needed; + + entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes); } fclose(fp); + if (entropy_available > 0) + return entropy_available; + + bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/); } } # endif # ifdef OPENSSL_RAND_SEED_RDTSC - rand_read_tsc(rand_add, arg); + entropy_available = rand_acquire_entropy_from_tsc(pool); + if (entropy_available > 0) + return entropy_available; # endif # ifdef OPENSSL_RAND_SEED_RDCPU - if (rand_read_cpu(rand_add, arg)) - goto done; + entropy_available = rand_acquire_entropy_from_cpu(pool); + if (entropy_available > 0) + return entropy_available; # endif # ifdef OPENSSL_RAND_SEED_EGD - { + bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/); + if (bytes_needed > 0) { static const char *paths[] = { DEVRANDOM_EGD, NULL }; int i; for (i = 0; paths[i] != NULL; i++) { - if (RAND_query_egd_bytes(paths[i], temp, TEMPSIZE) == TEMPSIZE) { - rand_add(arg, temp, TEMPSIZE, TEMPSIZE); - goto done; + buffer = RAND_POOL_add_begin(pool, bytes_needed); + if (buffer != NULL) { + size_t bytes = 0; + int num = RAND_query_egd_bytes(paths[i], + buffer, (int)bytes_needed); + if (num == (int)bytes_needed) + bytes = bytes_needed; + + entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes); } + if (entropy_available > 0) + return entropy_available; } } # endif - ok = 0; - -done: - OPENSSL_cleanse(temp, TEMPSIZE); - return ok; + return RAND_POOL_entropy_available(pool); # endif } # endif |