add salt header

openssl_cases.txt

@@ -11,14 +11,14 @@
 	generate key from givent salt and pass, prepend header.
 
 4.	"openssl des-ecb -S a -pass:asd -K 1"
-	encrypt with GIVEN key, prepend GIVEN salt hedaer.
+	encrypt with GIVEN key, prepend GIVEN salt headaer.
 
 5.	"openssl des-ecb -K 1"
 	encrypt with given key, doesn't generate and prepend salt.
 
 6.	"openssl des-ecb -S 0 -pass pass:asd -P -pbkdf2"
 	generate key using PKCS5_PBKDF2_HMAC with 10000 iteration,
-	8 byte salt, 3 byte key, sha256 hash function
+	8 byte salt, 3 byte key, sha256 hash function, prepend salt header.
 
 // DECRYPTING
 
@@ -27,3 +27,7 @@
 
 8.	"echo -n Salted__aaaaaaaa | openssl des-ecb -d"
 	prompts to enter password, generate key but fails to validate padding.
+
+9.	openssl doesn't expect "Salted__" header only when -K or -S flag supplied
+	(or both simultaneously, in this case salt is discarded),
+	in any other case salt should be readed from message.

src/des/ft_des_derive_key.c

@@ -1,8 +1,70 @@
+#include <fcntl.h>
 #include <unistd.h>
+#include <stdio.h>
 #include "ft_des.h"
 #include "ft_pbkdf2.h"
 #include "libft.h"
 
+static void get_pass
+(
+	char pass[128]
+)
+{
+	char *first_try[128];
+	char *second_try[128];
+
+	ft_bzero(first_try, 128);
+	ft_bzero(second_try, 128);
+	ft_strcpy((char *)first_try, getpass("enter password:"));
+	ft_strcpy((char *)second_try, getpass("retype password:"));
+	if (ft_strcmp((const char *)first_try, (const char *)second_try) != 0)
+		ft_des_print_error("passwords doesn't match");
+	ft_strcpy(pass, (const char *)first_try);
+}
+
+static void	generate_salt
+(
+	char salt[FT_DES_BYTE_BLOCK_SIZE]
+)
+{
+	int fd;
+
+	fd = open("/dev/random", O_RDONLY);
+	if (fd == -1)
+	{
+		perror("des");
+		exit(1);
+	}
+	read(fd, salt, FT_DES_BYTE_BLOCK_SIZE);
+}
+
+static void	no_arguments
+(
+	t_des_ctx *ctx,
+	t_pbkdf2_sha256_ctx *pbkdf_ctx
+)
+{
+	char	pass[128];
+	char	salt[FT_DES_BYTE_BLOCK_SIZE];
+	t_byte1	key[FT_DES_BYTE_BLOCK_SIZE];
+
+	get_pass(pass);
+	generate_salt(salt);
+
+	pbkdf_ctx->iterations = 10000;
+	pbkdf_ctx->key = key;
+	pbkdf_ctx->salt_len = FT_DES_BYTE_BLOCK_SIZE;
+	pbkdf_ctx->pass = (t_byte1 *)pass;
+	pbkdf_ctx->salt = (t_byte1 *)salt;
+	pbkdf_ctx->pass_len = ft_strlen((char *)pass);
+	pbkdf_ctx->key_len = FT_DES_BYTE_BLOCK_SIZE;
+	ft_pbkdf2_sha256(pbkdf_ctx);
+	ft_des_byte_to_bits(key, FT_DES_BYTE_BLOCK_SIZE, ctx->key,
+	FT_DES_INITIAL_KEY_SIZE);
+	write(ctx->output_fd, "Salted__", 8);
+	write(ctx->output_fd, salt, FT_DES_BYTE_BLOCK_SIZE);
+}
+
 void	ft_des_derive_key
 (
 	t_des_ctx *ctx
@@ -11,6 +73,12 @@ void	ft_des_derive_key
 	t_pbkdf2_sha256_ctx	pbkdf_ctx;
 	t_byte1				key[FT_DES_BYTE_BLOCK_SIZE];
 
+	if (!ctx->raw_key && !ctx->raw_salt && !ctx->raw_password)
+	{
+		no_arguments(ctx, &pbkdf_ctx);
+		return ;
+	}
+
 	if (ctx->raw_key)
 	{
 		if (ft_des_hex_to_bit(ctx->raw_key, ctx->key, FT_DES_BIT_BLOCK_SIZE))