From fe60669d0308bfdd1423976ac24b54c2c386f736 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 15 Dec 2022 21:53:37 +0000 Subject: [PATCH] ANDROID: fips140: add dump_jitterentropy command to fips140_lab_util For the entropy analysis, we must provide some output from the Jitter RNG: a large amount of output from one instance, and a smaller amount of output from each of a certain number of instances. The original plan was to use a build of the userspace jitterentropy library that matches the kernel's jitterentropy_rng as closely as possible. However, it's now being requested that the output be gotten from the kernel instead. Now that fips140_lab_util depends on AF_ALG anyway, it's straightforward to dump output from jitterentropy_rng instances using AF_ALG. Therefore, add a command dump_jitterentropy which supports this. Bug: 188620248 Change-Id: I78eb26250e88f2fc28fc44aa201acbe5b84df8bb Signed-off-by: Eric Biggers (cherry picked from commit dc015032666ece133065b7fea73f5709f735c9b0) --- samples/crypto/fips140_lab_util.c | 88 +++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/samples/crypto/fips140_lab_util.c b/samples/crypto/fips140_lab_util.c index 996839dbd2e3..5f8e9018013a 100644 --- a/samples/crypto/fips140_lab_util.c +++ b/samples/crypto/fips140_lab_util.c @@ -24,6 +24,7 @@ #include #include +#include #include #include #include @@ -45,6 +46,8 @@ * ---------------------------------------------------------------------------*/ #define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0])) +#define MIN(a, b) ((a) < (b) ? (a) : (b)) +#define MAX(a, b) ((a) > (b) ? (a) : (b)) static void __attribute__((noreturn)) do_die(const char *format, va_list va, int err) @@ -109,6 +112,23 @@ static const char *bytes_to_hex(const uint8_t *bytes, size_t count) return hex; } +static void full_write(int fd, const void *buf, size_t count) +{ + while (count) { + ssize_t ret = write(fd, buf, count); + + if (ret < 0) + die_errno("write failed"); + buf += ret; + count -= ret; + } +} + +enum { + OPT_AMOUNT, + OPT_ITERATIONS, +}; + static void usage(void); /* --------------------------------------------------------------------------- @@ -226,6 +246,68 @@ static int get_req_fd(int alg_fd, const char *alg_name) return req_fd; } +/* --------------------------------------------------------------------------- + * dump_jitterentropy command + * ---------------------------------------------------------------------------*/ + +static void dump_from_jent_fd(int fd, size_t count) +{ + uint8_t buf[AF_ALG_MAX_RNG_REQUEST_SIZE]; + + while (count) { + ssize_t ret; + + memset(buf, 0, sizeof(buf)); + ret = read(fd, buf, MIN(count, sizeof(buf))); + if (ret < 0) + die_errno("error reading from jitterentropy_rng"); + full_write(STDOUT_FILENO, buf, ret); + count -= ret; + } +} + +static int cmd_dump_jitterentropy(int argc, char *argv[]) +{ + static const struct option longopts[] = { + { "amount", required_argument, NULL, OPT_AMOUNT }, + { "iterations", required_argument, NULL, OPT_ITERATIONS }, + { NULL, 0, NULL, 0 }, + }; + size_t amount = 128; + size_t iterations = 1; + size_t i; + int c; + + while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) { + switch (c) { + case OPT_AMOUNT: + amount = strtoul(optarg, NULL, 0); + if (amount <= 0 || amount >= ULONG_MAX) + die("invalid argument to --amount"); + break; + case OPT_ITERATIONS: + iterations = strtoul(optarg, NULL, 0); + if (iterations <= 0 || iterations >= ULONG_MAX) + die("invalid argument to --iterations"); + break; + default: + usage(); + return 1; + } + } + + for (i = 0; i < iterations; i++) { + int alg_fd = get_alg_fd("rng", "jitterentropy_rng"); + int req_fd = get_req_fd(alg_fd, "jitterentropy_rng"); + + dump_from_jent_fd(req_fd, amount); + + close(req_fd); + close(alg_fd); + } + return 0; +} + /* --------------------------------------------------------------------------- * show_invalid_inputs command * ---------------------------------------------------------------------------*/ @@ -510,6 +592,7 @@ static const struct command { const char *name; int (*func)(int argc, char *argv[]); } commands[] = { + { "dump_jitterentropy", cmd_dump_jitterentropy }, { "show_invalid_inputs", cmd_show_invalid_inputs }, { "show_module_version", cmd_show_module_version }, { "show_service_indicators", cmd_show_service_indicators }, @@ -519,9 +602,14 @@ static void usage(void) { fprintf(stderr, "Usage:\n" +" fips140_lab_util dump_jitterentropy [OPTION]...\n" " fips140_lab_util show_invalid_inputs\n" " fips140_lab_util show_module_version\n" " fips140_lab_util show_service_indicators [SERVICE]...\n" +"\n" +"Options for dump_jitterentropy:\n" +" --amount=AMOUNT Amount to dump in bytes per iteration (default 128)\n" +" --iterations=COUNT Number of start-up iterations (default 1)\n" ); }