tpm2_getrandom: update help and simplify interface

Make argument options optional for tpm2_getrandom. Size is a required
argument, so make it a required positional arg. Now, the only option
is -o or --output, which optionally specifies an output file. If an
output file is specified, it writes all output to that file, else
it prints hex values of the bytes to the terminal.

Fixes 251

This patch requires a significant version bump as this version of
tpm2_getrandom is not "api" compatable with older versions.

Signed-off-by: William Roberts <william.c.roberts@intel.com>

man/tpm2_getrandom.8.in

@@ -28,20 +28,17 @@
 .\" THE POSSIBILITY OF SUCH DAMAGE.
 .TH tpm2_getrandom 8 "DECEMBER 2016" Intel "tpm2.0-tools"
 .SH NAME
-tpm2_getrandom\ - returns the next bytesRequested octets from the random number generator.
+tpm2_getrandom\ - returns the next SIZE octets from the random number generator.
 .SH SYNOPSIS
-.B tpm2_getrandom[ COMMON OPTIONS ] [ TCTI OPTIONS ] [ \fB\-\-size\fR|\fB\-\-of\fR|\fB ]
+.B tpm2_getrandom[ COMMON OPTIONS ] [ TCTI OPTIONS ] [ -\-output\fR|\fB ] SIZE
 .PP
-returns the next bytesRequested octets from the random number generator.
+returns the next SIZE octets from the random number generator.
 .SH DESCRIPTION
 .B tpm2_getrandom
-returns the next bytesRequested octets from the random number generator.
+returns the next SIZE octets from the random number generator.
 .SH OPTIONS
 .TP
-\fB\-s ,\-\-size\fR
-specifies the size of the bytesRequested.
-.TP
-\fB\-o ,\-\-of\fR
+\fB\-o ,\-\-output\fR
 specifies the filename of output.
 @COMMON_OPTIONS_INCLUDE@
 @TCTI_OPTIONS_INCLUDE@
@@ -51,6 +48,7 @@ specifies the filename of output.
 .PP
 .nf
 .RS
-tpm2_getrandom -s 20 -o random.out
+tpm2_getrandom -o random.out 20
+tpm2_getrandom 8
 .RE
 .fi

test/system/test_smoking.sh

@@ -93,7 +93,7 @@ tpm2_akparse -f ak.pub1.out  -k akparse.out
   fi
 
 ##### getrandom & hash  
-tpm2_getrandom -s 20 -o random.out
+tpm2_getrandom -o random.out 20
   if [ $? != 0 ];then
 	fail getrandom 
   fi

test/system/test_tpm2_getrandom.sh

@@ -35,7 +35,7 @@ size=32
 
 rm -f  random.out
 
-tpm2_getrandom -s 32  -o random.out 
+tpm2_getrandom -o random.out 32
 if [ $? != 0 ];then
 	    echo "getrandom test fail, please check the environment or parameters!"
 		exit 1

test/system/test_tpm2_getrandom_func.sh

@@ -40,7 +40,7 @@ i=
 
 #for((i=1;i<=10;i++)); do
 for i in `seq 100`; do
-	tpm2_getrandom -s 32  -o random_"$i".out 
+	tpm2_getrandom o random_"$i".out 32
 	 if  [ $? != 0 ];then
 	  echo " create random_"$i".out fail, please check the environment or parameters!"
 	  exit 2

tools/tpm2_getrandom.c

@@ -47,6 +47,7 @@
 
 typedef struct tpm_random_ctx tpm_random_ctx;
 struct tpm_random_ctx {
+    bool output_file_specified;
     char output_file[PATH_MAX];
     UINT16 num_of_bytes;
     TSS2_SYS_CONTEXT *sapi_context;
@@ -63,11 +64,14 @@ static bool get_random_and_save(tpm_random_ctx *ctx) {
         return false;
     }
 
-    printf("byte size: %d\n", random_bytes.t.size);
-    UINT16 i;
-    for (i = 0; i < random_bytes.t.size; i++)
-        printf(" 0x%2.2X", random_bytes.t.buffer[i]);
-    printf("\n");
+    if (!ctx->output_file_specified) {
+        UINT16 i;
+        for (i = 0; i < random_bytes.t.size; i++) {
+            printf("%s0x%2.2X", i ? " " : "", random_bytes.t.buffer[i]);
+        }
+        printf("\n");
+        return true;
+    }
 
     return files_save_bytes_to_file(ctx->output_file, (UINT8 *) random_bytes.t.buffer,
             random_bytes.t.size);
@@ -77,45 +81,25 @@ static bool get_random_and_save(tpm_random_ctx *ctx) {
 
 static bool init(int argc, char *argv[], tpm_random_ctx *ctx) {
 
-    static const char *short_options = "s:o:p:d:hv";
+    static const char *short_options = "o:";
     static const struct option long_options[] = {
-        { "size", required_argument, NULL, 's' },
-        { "of",   required_argument, NULL, 'o' },
+        { "output",   required_argument, NULL, 'o' },
         { NULL,   no_argument,       NULL,  '\0' },
     };
 
-    struct {
-        UINT8 s      : 1;
-        UINT8 o      : 1;
-        UINT8 unused : 6;
-    } flags = { 0 };
-
-    /*
-     * subtract 1 from argc to disregard argv[0]
-     * ALL options are required.
-     * */
-    if ((argc - 1) != ARG_CNT) {
+    if (argc !=2 && argc != 4) {
         showArgMismatch(argv[0]);
         return false;
     }
 
     int opt;
-    bool result;
+    optind = 0; /* force reset of getopt() since we used gnu extensionsin main, sic */
     while ((opt = getopt_long(argc, argv, short_options, long_options, NULL))
             != -1) {
         switch (opt) {
-        case 's':
-            result = string_bytes_get_uint16(optarg, &ctx->num_of_bytes);
-            if (!result) {
-                LOG_ERR("Error converting size to a number, got: \"%s\".",
-                        optarg);
-                return false;
-            }
-            flags.s = 1;
-            break;
         case 'o':
+            ctx->output_file_specified = true;
             snprintf(ctx->output_file, sizeof(ctx->output_file), "%s", optarg);
-            flags.o = 1;
             break;
         case ':':
             LOG_ERR("Argument %c needs a value!\n", optopt);
@@ -129,8 +113,10 @@ static bool init(int argc, char *argv[], tpm_random_ctx *ctx) {
         }
     }
 
-    if (!(flags.s && flags.o)) {
-        LOG_ERR("Must specify size and output file");
+    bool result = string_bytes_get_uint16(argv[optind], &ctx->num_of_bytes);
+    if (!result) {
+        LOG_ERR("Error converting size to a number, got: \"%s\".",
+                argv[optind]);
         return false;
     }
 
@@ -144,6 +130,7 @@ int execute_tool(int argc, char *argv[], char *envp[], common_opts_t *opts,
     (void)envp;
 
     tpm_random_ctx ctx = {
+            .output_file_specified = false,
             .num_of_bytes = 0,
             .output_file = { 0 },
             .sapi_context = sapi_context