Adds libgcrypt implementation for elgamal in multiplicative group.

Also adapts the API to both handle sodium and gcrypt libraries.

1 files changed, 126 insertions, 25 deletions

diff --git a/scratchpad/scratchpad.c b/scratchpad/scratchpad.c
index c0730fd..aadf3f0 100644
--- a/scratchpad/scratchpad.c
+++ b/scratchpad/scratchpad.c
@@ -2,14 +2,125 @@
 #include "cmix.h"
 #include "message.h"
 
-#include "curve25519.h"
+#include "api.h"
+
+#include <gcrypt.h>
 
 #include <stdio.h>
 #include <string.h>
 
+void cmix_buffer_scratch();
+void crypto_api_scratch();
+void gcrypt_scratch();
+
 int main(int argc, char* argv[]) {
+	gcrypt_scratch();
 	
-	struct Api api = get_curve25519_implementation();
+	return 0;
+}
+
+void check(gcry_error_t error) {
+	if (error) {
+		fprintf (stderr, "Error: %s/%s\n", gcry_strsource (error), gcry_strerror (error));
+		exit(1);
+	}
+}
+
+void print_sexp(gcry_sexp_t exp) {
+	size_t required_size = gcry_sexp_sprint(exp, GCRYSEXP_FMT_ADVANCED, NULL, 0); //passing NULL as the buffer will return the size needed.
+
+	char* str = (char *) malloc(sizeof(char)*required_size);
+
+	gcry_sexp_sprint(exp, GCRYSEXP_FMT_ADVANCED, str, 2000); //So we ignore the size here.
+	
+	printf("size = %zu\n", required_size);
+	for(size_t i = 0; i < required_size; i++)
+		printf("%c", str[i]);
+	printf("\n");
+
+	free(str);
+}
+
+void gcrypt_scratch() {
+
+	if (!gcry_check_version (GCRYPT_VERSION)) {
+		fprintf(stderr, "libgcrypt version mismatch\n");
+		exit(-1);
+	}
+	
+	gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
+	gcry_control (GCRYCTL_INIT_SECMEM, 16384, 0);
+	gcry_control (GCRYCTL_RESUME_SECMEM_WARN);
+	gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
+
+	size_t parse_error_offset;
+	gcry_error_t error;
+
+	gcry_sexp_t key_generator;
+	error = gcry_sexp_build(&key_generator, &parse_error_offset, "(genkey (%s (nbits %s)))", "elg", "2048");
+	check(error);
+	
+	gcry_sexp_t key_pair;
+	error = gcry_pk_genkey(&key_pair, key_generator);
+	check(error);
+	
+	gcry_sexp_t pub_key = gcry_sexp_find_token(key_pair, "public-key", 0);
+	gcry_sexp_t sec_key = gcry_sexp_find_token(key_pair, "private-key", 0);
+	
+	char message_string[] = "hello world!";
+	
+	gcry_sexp_t message;
+	error = gcry_sexp_build(&message, &parse_error_offset, "(data (flags %s) (value %b))", "raw", sizeof(message_string), message_string);
+	check(error);
+	
+	gcry_sexp_t cipher;
+	error = gcry_pk_encrypt(&cipher, message, pub_key);
+	check(error);
+	
+	gcry_sexp_t raw_cipher;
+	raw_cipher = gcry_sexp_find_token(cipher, "elg", 0);
+	
+	gcry_sexp_t decryption_sexpr;
+	error = gcry_sexp_build(&decryption_sexpr, &parse_error_offset, "(enc-val (flags %s) %S)", "raw", raw_cipher);
+	check(error);
+	
+	gcry_sexp_t plain_sexpr;
+	error = gcry_pk_decrypt(&plain_sexpr, decryption_sexpr, sec_key);
+	check(error);
+	
+	print_sexp(plain_sexpr);
+	
+	gcry_sexp_release(key_generator);
+	gcry_sexp_release(key_pair);
+	gcry_sexp_release(pub_key);
+	gcry_sexp_release(sec_key);
+	gcry_sexp_release(message);
+	gcry_sexp_release(cipher);
+	gcry_sexp_release(raw_cipher);
+	gcry_sexp_release(decryption_sexpr);
+	gcry_sexp_release(plain_sexpr);
+}
+
+void cmix_buffer_scratch() {
+	struct CmixBufferImpl buffer_impl = get_cmix_Curve25519_buffer_implementation();
+	char* buffer = buffer_impl.allocate_cmix_buffer(3);
+	
+	int message_size = buffer_impl.message_length();
+	
+	for(int i=0; i < 3; i++) {
+		buffer[i*message_size] = 'h';
+	}
+	
+	for(int i=0; i < 3; i++) {
+		putc(buffer[i*message_size], stdout);
+		putc('\n', stdout);
+	}
+	
+	buffer_impl.deallocate_cmix_buffer(buffer);
+}
+
+void crypto_api_scratch() {
+	struct Api api = get_implementation();
 
 	struct KeyPair pair1 = api.create_key_pair();
 	struct KeyPair pair2 = api.create_key_pair();
@@ -17,34 +128,24 @@ int main(int argc, char* argv[]) {
 	struct SharedKey sk1 = api.derive_shared_key(pair1, pair2.pub, false);
 	struct SharedKey sk2 = api.derive_shared_key(pair2, pair1.pub, true);
 
-	if(memcmp(sk1.shared, sk2.shared, sk1.shared_len) != 0) {
+	char* buffer1;
+	size_t len1;
+	api.get_key_array(&buffer1, &len1, sk1.shared);
+	
+	char* buffer2;
+	size_t len2;
+	api.get_key_array(&buffer2, &len2, sk2.shared);
+
+	if(len1 == len2 && memcmp(buffer1, buffer2, len1) != 0) {
 		exit(-1);
 	} else {
 		printf("Yoepie!");
 	}
 
-	api.free_key_pair(pair1);
-	api.free_key_pair(pair2);
-
-	api.free_shared_key(sk1);
-	api.free_shared_key(sk2);
+	api.free_key_pair(&pair1);
+	api.free_key_pair(&pair2);
 
-
-//	struct CmixBufferImpl buffer_impl = get_cmix_Curve25519_buffer_implementation();
-//	char* buffer = buffer_impl.allocate_cmix_buffer(3);
-	
-//	int message_size = buffer_impl.message_length();
-	
-//	for(int i=0; i < 3; i++) {
-//		buffer[i*message_size] = 'h';
-//	}
+	api.free_shared_key(&sk1);
+	api.free_shared_key(&sk2);
 	
-//	for(int i=0; i < 3; i++) {
-//		putc(buffer[i*message_size], stdout);
-//		putc('\n', stdout);
-//	}
-	
-//	buffer_impl.deallocate_cmix_buffer(buffer);
-	
-	return 0;
 }