Make rc4 encryption/decryption more explicit.

[paraslash.git] / crypt.c

diff --git a/crypt.c b/crypt.c
index 580974d7d74a6b97d1f4b2d6a436adc98ba7408b..679ba35dd07d59ec184942524f8a1bb0be786939 100644 (file)
--- a/crypt.c
+++ b/crypt.c
@@ -6,13 +6,18 @@
 
 /** \file crypt.c openssl-based RSA encryption/decryption routines */
 
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <openssl/rand.h>
+#include <openssl/err.h>
+#include <openssl/rc4.h>
+
 #include "para.h"
 #include "error.h"
 #include "string.h"
 #include "crypt.h"
-#include <openssl/rand.h>
-#include <openssl/err.h>
-
+#include "fd.h"
 /**
  * Fill a buffer with random content.
  *
@@ -218,3 +223,110 @@ int para_encrypt_challenge(RSA* rsa, long unsigned challenge_nr,
        return ret;
 }
 
+/**
+ * Encrypt and send a buffer.
+ *
+ * \param rc4c The rc4 crypt context.
+ * \param buf The buffer to send.
+ * \param len The size of \a buf in bytes.
+ *
+ * \return The return value of the underyling call to write_all().
+ *
+ * \sa \ref write_all(), RC4(3).
+ */
+int rc4_send_bin_buffer(struct rc4_context *rc4c, const char *buf, size_t len)
+{
+       int ret;
+       unsigned char *tmp;
+
+       assert(len);
+       tmp = para_malloc(len);
+       RC4(&rc4c->send_key, len, (const unsigned char *)buf, tmp);
+       ret = write_all(rc4c->fd, (char *)tmp, &len);
+       free(tmp);
+       return ret;
+}
+
+/**
+ * Encrypt and send a \p NULL-terminated buffer.
+ *
+ * \param rc4c The rc4 crypt context.
+ * \param buf The buffer to send.
+ *
+ * \return The return value of the underyling call to rc4_send_bin_buffer().
+ */
+int rc4_send_buffer(struct rc4_context *rc4c, const char *buf)
+{
+       return rc4_send_bin_buffer(rc4c, buf, strlen(buf));
+}
+
+/**
+ * Format, encrypt and send a buffer.
+ *
+ * \param rc4c The rc4 crypt context.
+ * \param fmt A format string.
+ *
+ * \return The return value of the underyling call to rc4_send_buffer().
+ */
+__printf_2_3 int rc4_send_va_buffer(struct rc4_context *rc4c, const char *fmt, ...)
+{
+       char *msg;
+       int ret;
+
+       PARA_VSPRINTF(fmt, msg);
+       ret = rc4_send_buffer(rc4c, msg);
+       free(msg);
+       return ret;
+}
+
+/**
+ * Receive a buffer and decrypt it.
+ *
+ * \param rc4c The rc4 crypt context.
+ * \param buf The buffer to write the decrypted data to.
+ * \param size The size of \a buf.
+ *
+ * \return The number of bytes received on success, negative on errors, zero if
+ * the peer has performed an orderly shutdown.
+ *
+ * \sa recv(2), RC4(3).
+ */
+int rc4_recv_bin_buffer(struct rc4_context *rc4c, char *buf, size_t size)
+{
+       unsigned char *tmp = para_malloc(size);
+       ssize_t ret = recv(rc4c->fd, tmp, size, 0);
+
+       if (ret > 0)
+               RC4(&rc4c->recv_key, ret, tmp, (unsigned char *)buf);
+       else if (ret < 0)
+               ret = -ERRNO_TO_PARA_ERROR(errno);
+       free(tmp);
+       return ret;
+}
+
+/**
+ * Receive a buffer, decrypt it and write terminating NULL byte.
+ *
+ * \param rc4c The rc4 crypt context.
+ * \param buf The buffer to write the decrypted data to.
+ * \param size The size of \a buf.
+ *
+ * Read at most \a size - 1 bytes from file descriptor given by \a rc4c,
+ * decrypt the received data and write a NULL byte at the end of the decrypted
+ * data.
+ *
+ * \return The return value of the underlying call to \ref
+ * rc4_recv_bin_buffer().
+ */
+int rc4_recv_buffer(struct rc4_context *rc4c, char *buf, size_t size)
+{
+       int n;
+
+       assert(size);
+       n = rc4_recv_bin_buffer(rc4c, buf, size - 1);
+       if (n >= 0)
+               buf[n] = '\0';
+       else
+               *buf = '\0';
+       return n;
+}