X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=crypt.c;h=b3bac46697765c02132c7a18603f102516d360c7;hp=cf1cabecbad80cdca6d69cf2bbc2165427a84ed8;hb=ae0e4594c6a0312c5b4b4c0bde86f9c12253d11b;hpb=3580fe47cc87b25aa0497eb54387e1165ba17407

diff --git a/crypt.c b/crypt.c
index cf1cabec..b3bac466 100644
--- a/crypt.c
+++ b/crypt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
  *
  *     This program is free software; you can redistribute it and/or modify
  *     it under the terms of the GNU General Public License as published by
@@ -41,7 +41,17 @@ static EVP_PKEY *load_key(const char *file, int private)
 	return pkey;
 }
 
-
+/**
+ * read an RSA key from a file
+ *
+ * \param key_file the file containing the key
+ * \param rsa RSA structure is returned here
+ * \param private if non-zero, read the private key, otherwise the public key
+ *
+ * \return The size of the RSA key on success, negative on errors.
+ *
+ * \sa openssl(1), rsa(1).
+ */
 int get_rsa_key(char *key_file, RSA **rsa, int private)
 {
 	EVP_PKEY *key = load_key(key_file, private);
@@ -55,6 +65,19 @@ int get_rsa_key(char *key_file, RSA **rsa, int private)
 	return RSA_size(*rsa);
 }
 
+/**
+ * free an RSA structure
+ *
+ * \param rsa pointer to the RSA struct to free
+ *
+ * This must be called for any key obtained by get_rsa_key().
+ */
+void rsa_free(RSA *rsa)
+{
+	if (rsa)
+		RSA_free(rsa);
+}
+
 /**
  * decrypt a buffer using an RSA key
  *
@@ -70,14 +93,18 @@ int get_rsa_key(char *key_file, RSA **rsa, int private)
  * \sa RSA_private_decrypt(3)
  **/
 int para_decrypt_buffer(char *key_file, unsigned char *outbuf, unsigned char *inbuf,
-			int rsa_inlen)
+			unsigned rsa_inlen)
 {
 	RSA *rsa;
-	int ret = get_rsa_key(key_file, &rsa, LOAD_PRIVATE_KEY);
+	int ret, inlen = rsa_inlen;
 
+	if (inlen < 0)
+		return -E_RSA;
+	ret = get_rsa_key(key_file, &rsa, LOAD_PRIVATE_KEY);
 	if (ret < 0)
 		return ret;
-	ret = RSA_private_decrypt(rsa_inlen, inbuf, outbuf, rsa, RSA_PKCS1_PADDING);
+	ret = RSA_private_decrypt(inlen, inbuf, outbuf, rsa, RSA_PKCS1_PADDING);
+	rsa_free(rsa);
 	return (ret > 0)? ret : -E_DECRYPT;
 }
 
@@ -94,7 +121,7 @@ int para_decrypt_buffer(char *key_file, unsigned char *outbuf, unsigned char *in
  * \sa para_decrypt_buffer()
  */
 int para_decrypt_challenge(char *key_file, long unsigned *challenge_nr,
-		unsigned char *inbuf, int rsa_inlen)
+		unsigned char *inbuf, unsigned rsa_inlen)
 {
 	unsigned char *rsa_out = OPENSSL_malloc(rsa_inlen + 1);
 	int ret = para_decrypt_buffer(key_file, rsa_out, inbuf, rsa_inlen);
@@ -121,10 +148,13 @@ int para_decrypt_challenge(char *key_file, long unsigned *challenge_nr,
  * \sa RSA_public_encrypt(3)
  */
 int para_encrypt_buffer(RSA *rsa, unsigned char *inbuf,
-		const unsigned len, unsigned char *outbuf)
+		unsigned len, unsigned char *outbuf)
 {
-	int ret = RSA_public_encrypt(len, inbuf, outbuf, rsa,
-		RSA_PKCS1_PADDING);
+	int ret, flen = len; /* RSA_public_encrypt expects a signed int */
+
+	if (flen < 0)
+		return -E_ENCRYPT;
+	ret = RSA_public_encrypt(flen, inbuf, outbuf, rsa, RSA_PKCS1_PADDING);
 	return ret < 0?  -E_ENCRYPT : ret;
 }