Fixes a bug which would crash the server when an ID started with 0x00.

1 files changed, 11 insertions, 6 deletions

diff --git a/libcmix-crypto/ed25519/gcrypt/gcrypt_ed25519.c b/libcmix-crypto/ed25519/gcrypt/gcrypt_ed25519.c
index 4839ce5..8807282 100644
--- a/libcmix-crypto/ed25519/gcrypt/gcrypt_ed25519.c
+++ b/libcmix-crypto/ed25519/gcrypt/gcrypt_ed25519.c
@@ -154,7 +154,7 @@ GroupElement DEF(message_to_element)(char const* buffer, size_t len, bool secure
 	(void) secure;
 	gcry_error_t error;
 	
-	//assert(len == 31);
+	assert(len == 31);
 	
 	gcry_mpi_t mpi;
 	gcry_mpi_scan(&mpi, GCRYMPI_FMT_USG, buffer, len, NULL);
@@ -167,11 +167,16 @@ GroupElement DEF(message_to_element)(char const* buffer, size_t len, bool secure
 	unsigned int count = 0;
 	do {
 		encoded_point[0] = 0x40;
-		
-		unsigned int byte_size = (unsigned) ceil(gcry_mpi_get_nbits(mpi) / 8.0);
-		//gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*) encoded_point + 1 + (32 - byte_size), byte_size, NULL, mpi);
-		gcry_mpi_print(GCRYMPI_FMT_USG, (unsigned char*) encoded_point + 1, 32, NULL, mpi);
+		memset(encoded_point + 1, '\0', 32);
 	
+		unsigned char* gcry_buffer;
+		size_t nr_written;
+
+		gcry_mpi_aprint(GCRYMPI_FMT_USG, &gcry_buffer, &nr_written, mpi);
+		
+		memcpy(encoded_point + 1 + (nr_bytes - nr_written), gcry_buffer, nr_written);
+		gcry_free(gcry_buffer);
+		
 		for(int i = 0; i < 16; i++) {
 			char temp = encoded_point[i+1];
 			encoded_point[i+1] = encoded_point[32-i];
@@ -222,7 +227,7 @@ void DEF(element_to_message)(unsigned char** buffer, const GroupElement el) {
 	size_t nr_written;
 	gcry_mpi_aprint(GCRYMPI_FMT_USG, &buffer2, &nr_written, y);
 	
-	memcpy(*buffer, buffer2, mes_len);
+	memcpy(*buffer + (mes_len - nr_written), buffer2, nr_written);
 	
 	gcry_free(buffer2);
 	gcry_mpi_release(y);