1 files changed, 139 insertions, 0 deletions

diff --git a/src/io/cli.c b/src/io/cli.c
new file mode 100644
index 0000000..12ceabd
--- /dev/null
+++ b/src/io/cli.c
@@ -0,0 +1,139 @@
+/*
+ * ecgen, tool for generating Elliptic curve domain parameters
+ * Copyright (C) 2017 J08nY
+ */
+#include "cli.h"
+#include <string.h>
+
+char doc[] =
+    "ecgen, tool for generating Elliptic curve domain parameters.\v(C) 2017 "
+    "Eastern Seaboard Phishing Authority";
+char args_doc[] = "bits";
+
+enum opt_keys {
+	OPT_DATADIR = 'd',
+	OPT_PRIME = 'p',
+	OPT_RANDOM = 'r',
+	OPT_SEED = 's',
+	OPT_INVALID = 'i',
+	OPT_ORDER = 'n',
+	OPT_KOBLITZ = 'k',
+	OPT_OUTPUT = 'o',
+	OPT_INPUT = 'f',
+	OPT_APPEND = 'a',
+	OPT_FP = 1,
+	OPT_F2M = 2,
+};
+
+// clang-format off
+struct argp_option options[] = {
+	// Field specification
+	{"fp",       OPT_FP,      0,       0,                  "Prime field."},
+	{"f2m",      OPT_F2M,     0,       0,                  "Binary field."},
+	// Curve specification
+	{"random",   OPT_RANDOM,  0,       0,                  "Generate a random curve."},
+	{"prime",    OPT_PRIME,   0,       0,                  "Generate a curve with prime order."},
+	{"seed",     OPT_SEED,    "SEED", OPTION_ARG_OPTIONAL, "Generate a curve from SEED (ANSI X9.62 verifiable procedure)."},
+	{"invalid",  OPT_INVALID, 0,       0,                  "Generate a set of invalid curves (for a given curve)."},
+	{"order",    OPT_ORDER,   "ORDER", 0,                  "Generate a curve with given order (using Complex Multiplication)."},
+	{"koblitz",  OPT_KOBLITZ, 0,       0,                  "Generate a Koblitz curve."},
+	// Other
+	{"data-dir", OPT_DATADIR, "DIR",   0,                  "PARI/GP data directory (containing seadata package)."},
+	{"input",    OPT_INPUT,   "FILE",  0,                  "Input from file."},
+	{"output",   OPT_OUTPUT,  "FILE",  0,                  "Output into file. Overwrites any existing file!"},
+	{"append",   OPT_APPEND,  0,       0,                  "Append to output file (don't overwrite)."},
+	{0}};
+// clang-format on
+
+error_t parse_opt(int key, char *arg, struct argp_state *state) {
+	struct config_t *cfg = state->input;
+
+	switch (key) {
+		case OPT_DATADIR:
+			cfg->datadir = arg;
+			break;
+		case OPT_INPUT:
+			cfg->input = arg;
+			break;
+		case OPT_OUTPUT:
+			cfg->output = arg;
+			break;
+		case OPT_APPEND:
+			cfg->append = true;
+			break;
+		case OPT_RANDOM:
+			cfg->random = true;
+			break;
+		case OPT_PRIME:
+			cfg->prime = true;
+			break;
+		case OPT_INVALID:
+			cfg->invalid = true;
+			break;
+		case OPT_ORDER:
+			cfg->cm = true;
+			if (arg) {
+				cfg->order = arg;
+			}
+			break;
+		case OPT_KOBLITZ:
+			cfg->koblitz = true;
+			break;
+		case OPT_SEED:
+			cfg->from_seed = true;
+			if (arg) {
+				// ANSI X9.62 specifies seed as at least 160 bits in length.
+				if (strlen(arg) < 20) {
+					argp_failure(
+					    state, 1, 0,
+					    "SEED must be at least 160 bits(20 characters).");
+				}
+				cfg->seed = arg;
+			}
+			break;
+		case OPT_FP:
+			cfg->field = FIELD_PRIME;
+			cfg->prime_field = true;
+			break;
+		case OPT_F2M:
+			cfg->field = FIELD_BINARY;
+			cfg->binary_field = true;
+			break;
+		case ARGP_KEY_ARG:
+			if (state->arg_num >= 1) {
+				argp_usage(state);
+			}
+
+			cfg->bits = strtol(arg, NULL, 10);
+			break;
+		case ARGP_KEY_END:
+			// validate all option states here.
+			// Only one field
+			if (!cfg->prime_field && !cfg->binary_field) {
+				argp_failure(state, 1, 0,
+				             "Specify field type, prime or binary, with --fp / "
+				             "--f2m(but not both).");
+			}
+			// Invalid is not prime or seed or random by definition.
+			if (cfg->invalid && (cfg->prime || cfg->from_seed || cfg->random)) {
+				// not seed, not prime, not random
+				argp_failure(state, 1, 0,
+				             "Invalid curve generation can not generate curves "
+				             "from seed, random or prime order.");
+			}
+			if (cfg->cm && (cfg->prime || cfg->from_seed || cfg->invalid)) {
+				argp_failure(state, 1, 0,
+				             "Fixed order curve generation can not generate "
+				             "curves from seed, or invalid curves. Prime order "
+				             "also doesn't make sense if the given one isn't "
+				             "prime.");
+			}
+			break;
+		case ARGP_KEY_NO_ARGS:
+			argp_usage(state);
+			break;
+		default:
+			return ARGP_ERR_UNKNOWN;
+	}
+	return 0;
+}