added base64_decode fn

and tweaked the encode fn a bit

include/chat/crypto.h

@@ -29,12 +29,13 @@ extern "C" {
 #define WHY2_CHAT_ECC NID_secp521r1 //CURVE NAME
 
 #define WHY2_CHAT_KEY_LOCATION WHY2_CONFIG_DIR "/keys" //KEYS LOCATION
-#define WHY2_CHAT_PUB_KEY "pub"
-#define WHY2_CHAT_PRI_KEY "pri"
+#define WHY2_CHAT_KEY "secp521r1.pem"
 
 void why2_chat_init_keys(void); //INIT (POSSIBLY GENERATE) ECC KEYS
 void why2_chat_deallocate_keys(void); //DEALLOCATE :) (NO SLUR HERE)
 
+char *why2_chat_ecc_sign(char *message); //SIGN message WITH ECC KEY
+
 char *why2_sha256(char *input); //HASH input USING SHA256 AND RETURN IN STRING
 
 #ifdef __cplusplus

src/chat/crypto.c

@@ -32,100 +32,135 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include <openssl/pem.h>
 #include <openssl/ec.h>
 
-char *ecc_pub = NULL;
-char *ecc_pri = NULL;
+EVP_PKEY *keypair = NULL; //KEYPAIR
 
-void read_file(FILE *file, char **output)
+//LOCAL
+char* base64_encode(char *message)
 {
     //VARIABLES
-    int buffer_size;
-    char *buffer;
+    BIO *bio;
+    BIO *b64;
+    BUF_MEM *buffer_ptr;
+    char* encoded_message;
 
-    //GET LENGTH
-    fseek(file, 0, SEEK_END);
-    buffer_size = ftell(file);
-    rewind(file);
+    //INIT BIOs
+    b64 = BIO_new(BIO_f_base64());
+    bio = BIO_new(BIO_s_mem());
+    bio = BIO_push(b64, bio);
 
-    //READ
-    buffer = why2_calloc(buffer_size + 1, sizeof(char));
-    if (fread(buffer, buffer_size, 1, file) != 1) why2_die("Reading keyfile failed!");
-    buffer[buffer_size] = '\0';
+    //ENCODE
+    BIO_write(bio, message, strlen(message));
+    BIO_flush(bio);
+    BIO_get_mem_ptr(bio, &buffer_ptr);
 
-    //ASSIGN OUTPUT
-    *output = buffer;
+    //COPY
+    encoded_message = why2_malloc(buffer_ptr -> length + 1);
+    memcpy(encoded_message, buffer_ptr -> data, buffer_ptr -> length);
+    encoded_message[buffer_ptr -> length] = '\0';
+
+    //DEALLOCATION
+    BIO_free_all(bio);
+
+    return encoded_message;
+}
+
+char* base64_decode(char *encoded_message)
+{
+    //VARIABLES
+    BIO *bio;
+    BIO *b64;
+    size_t length = strlen(encoded_message);
+    char* decoded_message = why2_malloc(length);
+
+    //INIT BIOs
+    b64 = BIO_new(BIO_f_base64());
+    bio = BIO_new_mem_buf(encoded_message, length);
+    bio = BIO_push(b64, bio);
+
+    //NULL-TERM
+    decoded_message[BIO_read(bio, decoded_message, length)] = '\0';
+
+    //DEALLOCATION
+    BIO_free_all(bio);
+
+    return decoded_message;
 }
 
 //GLOBAL
 void why2_chat_init_keys(void)
 {
-    //KEY FILES
-    FILE *public;
-    FILE *private;
+    FILE *key; //KEY FILE
 
-    //GET PATH TO KEY DIR
-    char *path = why2_replace(WHY2_CHAT_KEY_LOCATION, "{HOME}", getenv("HOME"));
+    char *path = why2_replace(WHY2_CHAT_KEY_LOCATION, "{HOME}", getenv("HOME")); //GET PATH TO KEY DIR
+    char *key_path = why2_malloc(strlen(path) + strlen(WHY2_CHAT_KEY) + 3); //ALLOCATE THE KEY PATH
 
-    //ALLOCATE THE KEY PATHS
-    char *public_path = why2_malloc(strlen(path) + strlen(WHY2_CHAT_PUB_KEY) + 3);
-    char *private_path = why2_malloc(strlen(path) + strlen(WHY2_CHAT_PRI_KEY) + 3);
+    //GET THE ACTUAL KEY PATH
+    sprintf(key_path, "%s/%s%c", path, WHY2_CHAT_KEY, '\0');
 
-    //GET THE ACTUAL KEY PATHS
-    sprintf(public_path, "%s/%s%c", path, WHY2_CHAT_PUB_KEY, '\0');
-    sprintf(private_path, "%s/%s%c", path, WHY2_CHAT_PRI_KEY, '\0');
-
-    //CHECK IF KEYS EXIST
-    if (access(path, R_OK) != 0)
+    //CHECK IF KEY EXIST
+    if (access(path, R_OK) != 0) //NOT FOUND - CREATE IT
     {
         mkdir(path, 0700);
 
         //SOME USER OUTPUT
-        printf("You are probably running WHY2-Chat for the first time now.\nGenerating ECC keys...\n");
+        printf("No ECC key found.\nGenerating...\n\n");
 
-        //VARIABLES
-        EVP_PKEY *pkey = NULL; //KEYPAIR
         EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL); //CREATE CTX
-
         EVP_PKEY_keygen_init(ctx); //INIT KEYGEN
 
         EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, WHY2_CHAT_ECC); //SETUP ECC
+        EVP_PKEY_keygen(ctx, &keypair); //GENERATE ECC KEYPAIR
 
-        EVP_PKEY_keygen(ctx, &pkey); //GENERATE ECC KEYPAIR
-
-        printf("Saving keys...\n");
-
-        //WRITE THE KEYS INTO KEY-FILES
-        public = why2_fopen(public_path, "w+");
-        private = why2_fopen(private_path, "w+");
-
-        PEM_write_PrivateKey(private, pkey, NULL, NULL, 0, NULL, NULL); //WRITE PRI KEY
-        PEM_write_PUBKEY(public, pkey); //WRITE PUB KEY
+        //WRITE THE KEYS INTO KEY-FILE
+        key = why2_fopen(key_path, "w+");
+        PEM_write_PrivateKey(key, keypair, NULL, NULL, 0, NULL, NULL); //WRITE THE KEY
 
         //DEALLOCATION
         EVP_PKEY_CTX_free(ctx);
-        EVP_PKEY_free(pkey);
     } else
     {
-        //OPEN FILES
-        public = why2_fopen(public_path, "r");
-        private = why2_fopen(private_path, "r");
-
-        //READ THE KEYS
-        read_file(public, &ecc_pub);
-        read_file(private, &ecc_pri);
+        key = why2_fopen(key_path, "r"); //OPEN KEY FILE
+        keypair = PEM_read_PrivateKey(key, NULL, NULL, NULL); //LOAD KEYPAIR
     }
 
     //DEALLOCATION
     why2_deallocate(path);
-    why2_deallocate(public_path);
-    why2_deallocate(private_path);
-    why2_deallocate(public);
-    why2_deallocate(private);
+    why2_deallocate(key_path);
+    why2_deallocate(key);
+}
+
+char *why2_chat_ecc_sign(char *message)
+{
+    //VARIABLES
+    EVP_MD_CTX *mdctx = NULL; //SIGNING CONTEXT
+    size_t siglen;
+    char *sig; //SIGNATURE
+    char *encoded_sig; //FINAL (ENCODED) SIGNATURE
+
+    //INIT mdctx
+    mdctx = EVP_MD_CTX_new();
+    EVP_DigestSignInit(mdctx, NULL, EVP_sha256(), NULL, keypair);
+
+    EVP_DigestSignUpdate(mdctx, message, strlen(message)); //UPDATE MESSAGE TO SIGN
+    EVP_DigestSignFinal(mdctx, NULL, &siglen); //COUNT LENGTH
+
+    //GENERATE SIGNATURE
+    sig = why2_malloc(siglen); //ALLOCATE SIGNATURE
+    EVP_DigestSignFinal(mdctx, (unsigned char*) sig, &siglen);
+
+    encoded_sig = base64_encode(sig); //CONVERT sig TO BASE64
+
+    //DEALLOCATION
+    why2_deallocate(sig);
+    EVP_MD_CTX_free(mdctx);
+
+    return encoded_sig;
 }
 
 void why2_chat_deallocate_keys(void)
 {
-    why2_deallocate(ecc_pub);
-    why2_deallocate(ecc_pri);
+    //DEALLOCATE THE pkey
+    EVP_PKEY_free(keypair);
 }
 
 char *why2_sha256(char *input)