5 files changed, 108 insertions, 81 deletions

diff --git a/src/io/cli.c b/src/io/cli.c
index 374b949..efebfbc 100644
--- a/src/io/cli.c
+++ b/src/io/cli.c
@@ -6,19 +6,20 @@
 #include <string.h>
 
 char doc[] =
-	"ecgen, tool for generating Elliptic curve domain parameters.\v(C) 2017 "
-		"Eastern Seaboard Phishing Authority";
+    "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_COUNT = 'c',
 	OPT_PRIME = 'p',
+	OPT_COFACTOR = 'k',
 	OPT_RANDOM = 'r',
 	OPT_SEED = 's',
 	OPT_INVALID = 'i',
 	OPT_ORDER = 'n',
-	OPT_KOBLITZ = 'k',
+	OPT_KOBLITZ = 'K',
 	OPT_UNIQUE = 'u',
 	OPT_FORMAT = 't',
 	OPT_OUTPUT = 'o',
@@ -32,27 +33,28 @@ enum opt_keys {
 
 // clang-format off
 struct argp_option options[] = {
-	{0,          0,           0,        0,                 "Field specification:",                                              1},
-	{"fp",       OPT_FP,      0,        0,                 "Prime field.",                                                      1},
-	{"f2m",      OPT_F2M,     0,        0,                 "Binary field.",                                                     1},
-	{0,          0,           0,        0,                 "Generation options:",                                               2},
-	{"random",   OPT_RANDOM,  0,        0,                 "Generate a random curve.",                                          2},
-	{"prime",    OPT_PRIME,   0,        0,                 "Generate a curve with prime order.",                                2},
-	{"seed",     OPT_SEED,    "SEED", OPTION_ARG_OPTIONAL, "Generate a curve from SEED (ANSI X9.62 verifiable procedure).",     2},
-	{"invalid",  OPT_INVALID, 0,        0,                 "Generate a set of invalid curves (for a given curve).",             2},
-	{"order",    OPT_ORDER,   "ORDER",  0,                 "Generate a curve with given order (using Complex Multiplication).", 2},
-	{"koblitz",  OPT_KOBLITZ, 0,        0,                 "Generate a Koblitz curve (a = 0).",                                 2},
-	{"unique",   OPT_UNIQUE,  0,        0,                 "Generate a curve with only one generator.",                         2},
-	{"points",   OPT_POINTS,  "TYPE",   0,                 "Generate points of given type (random/prime).",                     2},
-	{"count",    OPT_COUNT,   "COUNT",  0,                 "Generate multiple curves.",                                         2},
-	{0,          0,           0,        0,                 "Input/Output options:",                                             3},
-	{"format",   OPT_FORMAT,  "FORMAT", 0,                 "Format to output in. One of [csv,json], default is json.",          3},
-	{"input",    OPT_INPUT,   "FILE",   0,                 "Input from file.",                                                  3},
-	{"output",   OPT_OUTPUT,  "FILE",   0,                 "Output into file. Overwrites any existing file!",                   3},
-	{"append",   OPT_APPEND,  0,        0,                 "Append to output file (don't overwrite).",                          3},
-	{"verbose",  OPT_VERBOSE, "FILE", OPTION_ARG_OPTIONAL, "Verbose logging (to stdout or file).",                              3},
-	{0,          0,           0,        0,                 "Other:",                                                            4},
-	{"data-dir", OPT_DATADIR, "DIR",    0,                 "PARI/GP data directory (containing seadata package).",              4},
+	{0,          0,            0,        0,                 "Field specification:",                                                                 1},
+	{"fp",       OPT_FP,       0,        0,                 "Prime field.",                                                                         1},
+	{"f2m",      OPT_F2M,      0,        0,                 "Binary field.",                                                                        1},
+	{0,          0,            0,        0,                 "Generation options:",                                                                  2},
+	{"random",   OPT_RANDOM,   0,        0,                 "Generate a random curve (using Random approach).",                                     2},
+	{"prime",    OPT_PRIME,    0,        0,                 "Generate a curve with prime order.",                                                   2},
+	{"cofactor", OPT_COFACTOR, "BOUND",  0,                 "Generate a curve with cofactor up to BOUND.",                                          2},
+	{"seed",     OPT_SEED,     "SEED", OPTION_ARG_OPTIONAL, "Generate a curve from SEED (ANSI X9.62 verifiable procedure).",                        2},
+	{"invalid",  OPT_INVALID,  0,        0,                 "Generate a set of invalid curves, for a given curve (using Invalid curve algorithm).", 2},
+	{"order",    OPT_ORDER,    "ORDER",  0,                 "Generate a curve with given order (using Complex Multiplication).",                    2},
+	{"koblitz",  OPT_KOBLITZ,  0,        0,                 "Generate a Koblitz curve (a = 0).",                                                    2},
+	{"unique",   OPT_UNIQUE,   0,        0,                 "Generate a curve with only one generator.",                                            2},
+	{"points",   OPT_POINTS,   "TYPE",   0,                 "Generate points of given type (random/prime).",                                        2},
+	{"count",    OPT_COUNT,    "COUNT",  0,                 "Generate multiple curves.",                                                            2},
+	{0,          0,            0,        0,                 "Input/Output options:",                                                                3},
+	{"format",   OPT_FORMAT,   "FORMAT", 0,                 "Format to output in. One of [csv,json], default is json.",                             3},
+	{"input",    OPT_INPUT,    "FILE",   0,                 "Input from file.",                                                                     3},
+	{"output",   OPT_OUTPUT,   "FILE",   0,                 "Output into file. Overwrites any existing file!",                                      3},
+	{"append",   OPT_APPEND,   0,        0,                 "Append to output file (don't overwrite).",                                             3},
+	{"verbose",  OPT_VERBOSE,  "FILE", OPTION_ARG_OPTIONAL, "Verbose logging (to stdout or file).",                                                 3},
+	{0,          0,            0,        0,                 "Other:",                                                                               4},
+	{"data-dir", OPT_DATADIR,  "DIR",    0,                 "PARI/GP data directory (containing seadata package).",                                 4},
 	{0}
 };
 // clang-format on
@@ -61,7 +63,8 @@ error_t cli_parse(int key, char *arg, struct argp_state *state) {
 	struct config_t *cfg = state->input;
 
 	switch (key) {
-		case OPT_DATADIR: cfg->datadir = arg;
+		case OPT_DATADIR:
+			cfg->datadir = arg;
 			break;
 		case OPT_COUNT:
 			if (arg) {
@@ -76,40 +79,55 @@ error_t cli_parse(int key, char *arg, struct argp_state *state) {
 					cfg->format = FORMAT_JSON;
 				} else {
 					argp_failure(state, 1, 0,
-								 "Invalid format specified. One of [csv, json] "
-									 "is valid.");
+					             "Invalid format specified. One of [csv, json] "
+					             "is valid.");
 				}
 			} else {
 				argp_failure(
-					state, 1, 0,
-					"You have to specify a format with the format option.");
+				    state, 1, 0,
+				    "You have to specify a format with the format option.");
 			}
 			break;
-		case OPT_INPUT: cfg->input = arg;
+		case OPT_INPUT:
+			cfg->input = arg;
 			break;
-		case OPT_OUTPUT: cfg->output = arg;
+		case OPT_OUTPUT:
+			cfg->output = arg;
 			break;
-		case OPT_APPEND: cfg->append = true;
+		case OPT_APPEND:
+			cfg->append = true;
 			break;
-		case OPT_VERBOSE: cfg->verbose++;
+		case OPT_VERBOSE:
+			cfg->verbose++;
 			if (arg) {
 				cfg->debug = arg;
 			}
 			break;
-		case OPT_RANDOM: cfg->random = true;
+		case OPT_RANDOM:
+			cfg->random = true;
 			break;
-		case OPT_PRIME: cfg->prime = true;
+		case OPT_PRIME:
+			cfg->prime = true;
 			break;
-		case OPT_INVALID: cfg->invalid = true;
+		case OPT_COFACTOR:
+			cfg->cofactor = true;
+			if (arg) {
+				cfg->cofactor_bound = strtol(arg, NULL, 10);
+			}
+		case OPT_INVALID:
+			cfg->invalid = true;
 			break;
-		case OPT_ORDER: cfg->cm = true;
+		case OPT_ORDER:
+			cfg->cm = true;
 			if (arg) {
 				cfg->order = arg;
 			}
 			break;
-		case OPT_KOBLITZ: cfg->koblitz = true;
+		case OPT_KOBLITZ:
+			cfg->koblitz = true;
 			break;
-		case OPT_UNIQUE: cfg->unique = true;
+		case OPT_UNIQUE:
+			cfg->unique = true;
 			break;
 		case OPT_POINTS:
 			if (arg) {
@@ -123,24 +141,28 @@ error_t cli_parse(int key, char *arg, struct argp_state *state) {
 					argp_failure(state, 1, 0, "Unknow point type");
 				}
 			} else {
-				argp_failure(state, 1, 0, "You have to specify what points you want.");
+				argp_failure(state, 1, 0,
+				             "You have to specify what points you want.");
 			}
 			break;
-		case OPT_SEED: cfg->from_seed = true;
+		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).");
+					    state, 1, 0,
+					    "SEED must be at least 160 bits (20 characters).");
 				}
 				cfg->seed = arg;
 			}
 			break;
-		case OPT_FP: cfg->field = FIELD_PRIME;
+		case OPT_FP:
+			cfg->field = FIELD_PRIME;
 			cfg->prime_field = true;
 			break;
-		case OPT_F2M: cfg->field = FIELD_BINARY;
+		case OPT_F2M:
+			cfg->field = FIELD_BINARY;
 			cfg->binary_field = true;
 			break;
 		case ARGP_KEY_ARG:
@@ -155,31 +177,35 @@ error_t cli_parse(int key, char *arg, struct argp_state *state) {
 			// 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).");
+				             "Specify field type, prime or binary, with --fp / "
+				             "--f2m (but not both).");
 			}
 			// Invalid is not prime or seed by definition.
-			if (cfg->invalid && (cfg->prime || cfg->from_seed)) {
+			if (cfg->invalid &&
+			    (cfg->prime || cfg->from_seed || cfg->cofactor)) {
 				// not seed, not prime
 				argp_failure(state, 1, 0,
-							 "Invalid curve generation can not generate curves "
-								 "from seed, exhaustive or prime order.");
+				             "Invalid curve generation can not generate curves "
+				             "from seed, exhaustive or prime order.");
 			}
-			if (cfg->cm && (cfg->prime || cfg->from_seed || cfg->invalid)) {
+			if (cfg->cm && (cfg->prime || cfg->from_seed || cfg->invalid ||
+			                cfg->cofactor)) {
 				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.");
+				             "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.");
 			}
 			// default values
 			if (!cfg->count) {
 				cfg->count = 1;
 			}
 			break;
-		case ARGP_KEY_NO_ARGS: argp_usage(state);
+		case ARGP_KEY_NO_ARGS:
+			argp_usage(state);
 			break;
-		default: return ARGP_ERR_UNKNOWN;
+		default:
+			return ARGP_ERR_UNKNOWN;
 	}
 	return 0;
 }
diff --git a/src/io/cli.h b/src/io/cli.h
index 3facaff..c65f125 100644
--- a/src/io/cli.h
+++ b/src/io/cli.h
@@ -36,6 +36,8 @@ typedef struct config_t {
 	bool cm;
 	char *order;
 	bool koblitz;
+	bool cofactor;
+	long cofactor_bound;
 	bool from_seed;
 	char *seed;
 	bool unique;
diff --git a/src/io/input.c b/src/io/input.c
index 3865d79..34aeb5a 100644
--- a/src/io/input.c
+++ b/src/io/input.c
@@ -22,7 +22,8 @@ GEN input_i(const char *prompt, long bits) {
 		free(line);
 		return gen_m1;
 	}
-	for (size_t i = 0, j = 0; (line[j] = line[i]); j += !isspace(line[i++]));
+	for (size_t i = 0, j = 0; (line[j] = line[i]); j += !isspace(line[i++]))
+		;
 
 	pari_sp ltop = avma;
 	GEN in = strtoi(line);
diff --git a/src/io/output.c b/src/io/output.c
index 88b120e..cb718fa 100644
--- a/src/io/output.c
+++ b/src/io/output.c
@@ -11,7 +11,7 @@
 FILE *out;
 FILE *debug;
 
-char *output_scsv(curve_t *curve, config_t *config) {
+char *output_scsv(curve_t *curve, config_t *cfg) {
 	pari_sp ltop = avma;
 	GEN vector = curve_params(curve);
 
@@ -48,23 +48,21 @@ char *output_scsv(curve_t *curve, config_t *config) {
 	return result;
 }
 
-void output_fcsv(FILE *out, curve_t *curve, config_t *config) {
-	char *string = output_scsv(curve, config);
+void output_fcsv(FILE *out, curve_t *curve, config_t *cfg) {
+	char *string = output_scsv(curve, cfg);
 	fprintf(out, "%s\n", string);
 	free(string);
 }
 
-void output_csv(curve_t *curve, config_t *config) {
-	output_fcsv(out, curve, config);
-}
+void output_csv(curve_t *curve, config_t *cfg) { output_fcsv(out, curve, cfg); }
 
-JSON_Value *output_jjson(curve_t *curve, config_t *config) {
+JSON_Value *output_jjson(curve_t *curve, config_t *cfg) {
 	pari_sp ltop = avma;
 	// root object/value is curve
 	JSON_Value *root_value = json_value_init_object();
 	JSON_Object *root_object = json_value_get_object(root_value);
 
-	switch (config->field) {
+	switch (cfg->field) {
 		case FIELD_PRIME: {
 			char *prime = pari_sprintf("%P#x", curve->field);
 			json_object_dotset_string(root_object, "field.p", prime);
@@ -168,22 +166,22 @@ JSON_Value *output_jjson(curve_t *curve, config_t *config) {
 	return root_value;
 }
 
-char *output_sjson(curve_t *curve, config_t *config) {
-	JSON_Value *root_value = output_jjson(curve, config);
+char *output_sjson(curve_t *curve, config_t *cfg) {
+	JSON_Value *root_value = output_jjson(curve, cfg);
 	char *result = json_serialize_to_string_pretty(root_value);
 	json_value_free(root_value);
 
 	return result;
 }
 
-void output_fjson(FILE *out, curve_t *curve, config_t *config) {
-	char *s = output_sjson(curve, config);
+void output_fjson(FILE *out, curve_t *curve, config_t *cfg) {
+	char *s = output_sjson(curve, cfg);
 	fprintf(out, "%s\n", s);
 	json_free_serialized_string(s);
 }
 
-void output_json(curve_t *curve, config_t *config) {
-	output_fjson(out, curve, config);
+void output_json(curve_t *curve, config_t *cfg) {
+	output_fjson(out, curve, cfg);
 }
 
 void output_init(config_t *cfg) {
diff --git a/src/io/output.h b/src/io/output.h
index ea9a97e..283b701 100644
--- a/src/io/output.h
+++ b/src/io/output.h
@@ -18,7 +18,7 @@
  * @param config
  * @return
  */
-char *output_scsv(curve_t *curve, config_t *config);
+char *output_scsv(curve_t *curve, config_t *cfg);
 
 /**
  *
@@ -26,14 +26,14 @@ char *output_scsv(curve_t *curve, config_t *config);
  * @param curve
  * @param config
  */
-void output_fcsv(FILE *out, curve_t *curve, config_t *config);
+void output_fcsv(FILE *out, curve_t *curve, config_t *cfg);
 
 /**
  *
  * @param curve
  * @param config
  */
-void output_csv(curve_t *curve, config_t *config);
+void output_csv(curve_t *curve, config_t *cfg);
 
 /**
  *
@@ -41,7 +41,7 @@ void output_csv(curve_t *curve, config_t *config);
  * @param config
  * @return
  */
-char *output_sjson(curve_t *curve, config_t *config);
+char *output_sjson(curve_t *curve, config_t *cfg);
 
 /**
  *
@@ -49,14 +49,14 @@ char *output_sjson(curve_t *curve, config_t *config);
  * @param curve
  * @param config
  */
-void output_fjson(FILE *out, curve_t *curve, config_t *config);
+void output_fjson(FILE *out, curve_t *curve, config_t *cfg);
 
 /**
  *
  * @param curve
  * @param config
  */
-void output_json(curve_t *curve, config_t *config);
+void output_json(curve_t *curve, config_t *cfg);
 
 /**
  *
@@ -64,7 +64,7 @@ void output_json(curve_t *curve, config_t *config);
  * @param config
  * @return
  */
-char *(*output_s)(curve_t *curve, config_t *config);
+char *(*output_s)(curve_t *curve, config_t *cfg);
 
 /**
  *
@@ -72,14 +72,14 @@ char *(*output_s)(curve_t *curve, config_t *config);
  * @param curve
  * @param config
  */
-void (*output_f)(FILE *out, curve_t *curve, config_t *config);
+void (*output_f)(FILE *out, curve_t *curve, config_t *cfg);
 
 /**
  *
  * @param curve
  * @param config
  */
-void (*output_o)(curve_t *curve, config_t *config);
+void (*output_o)(curve_t *curve, config_t *cfg);
 
 /**
  *