build: Compile with -Wdiscarded-qualifiers.

[paraslash.git] / crypt.c

diff --git a/crypt.c b/crypt.c
index cae47046fe0c8e3f0ebf2c1a479d3343c3955465..b8a587cd0e55114f1ced030d5284adcd2d4a96b4 100644 (file)
--- a/crypt.c
+++ b/crypt.c
@@ -1,8 +1,4 @@
-/*
- * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
 
 /** \file crypt.c Openssl-based encryption/decryption routines. */
 
@@ -23,6 +19,7 @@
 #include "fd.h"
 #include "crypt_backend.h"
 #include "base64.h"
+#include "portable_io.h"
 
 struct asymmetric_key {
        RSA *rsa;
@@ -41,9 +38,9 @@ void get_random_bytes_or_die(unsigned char *buf, int num)
 }
 
 /*
- * Read 64 bytes from /dev/urandom and adds them to the SSL PRNG. Seed the PRNG
- * used by random() with a random seed obtained from SSL. If /dev/random is not
- * readable the function calls exit().
+ * Read 64 bytes from /dev/urandom and add them to the SSL PRNG. Seed the PRNG
+ * used by random(3) with a random seed obtained from SSL. If /dev/urandom is
+ * not readable, the function calls exit().
  *
  * \sa RAND_load_file(3), \ref get_random_bytes_or_die(), srandom(3),
  * random(3), \ref para_random().
@@ -60,41 +57,24 @@ void init_random_seed_or_die(void)
        srandom(seed);
 }
 
-static EVP_PKEY *load_key(const char *file, int private)
+static int get_private_key(const char *path, RSA **rsa)
 {
-       BIO *key;
-       EVP_PKEY *pkey = NULL;
-       int ret = check_key_file(file, private);
-
-       if (ret < 0) {
-               PARA_ERROR_LOG("%s\n", para_strerror(-ret));
-               return NULL;
-       }
-       key = BIO_new(BIO_s_file());
-       if (!key)
-               return NULL;
-       if (BIO_read_filename(key, file) > 0) {
-               if (private == LOAD_PRIVATE_KEY)
-                       pkey = PEM_read_bio_PrivateKey(key, NULL, NULL, NULL);
-               else
-                       pkey = PEM_read_bio_PUBKEY(key, NULL, NULL, NULL);
-       }
-       BIO_free(key);
-       return pkey;
-}
-
-static int get_openssl_key(const char *key_file, RSA **rsa, int private)
-{
-       EVP_PKEY *key = load_key(key_file, private);
-
-       if (!key)
-               return (private == LOAD_PRIVATE_KEY)? -E_PRIVATE_KEY
-                       : -E_PUBLIC_KEY;
-       *rsa = EVP_PKEY_get1_RSA(key);
-       EVP_PKEY_free(key);
-       if (!*rsa)
-               return -E_RSA;
-       return RSA_size(*rsa);
+       EVP_PKEY *pkey;
+       BIO *bio = BIO_new(BIO_s_file());
+
+       *rsa = NULL;
+       if (!bio)
+               return -E_PRIVATE_KEY;
+       if (BIO_read_filename(bio, path) <= 0)
+               goto bio_free;
+       pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
+       if (!pkey)
+               goto bio_free;
+       *rsa = EVP_PKEY_get1_RSA(pkey);
+       EVP_PKEY_free(pkey);
+bio_free:
+       BIO_free(bio);
+       return *rsa? RSA_size(*rsa) : -E_PRIVATE_KEY;
 }
 
 /*
@@ -113,7 +93,7 @@ static int read_bignum(const unsigned char *buf, size_t len, BIGNUM **result)
                return -E_BIGNUM;
        if (p + 4 > end)
                return -E_BIGNUM;
-       bnsize = read_ssh_u32(p);
+       bnsize = read_u32_be(p);
        PARA_DEBUG_LOG("bnsize: %u\n", bnsize);
        p += 4;
        if (p + bnsize < p)
@@ -159,8 +139,7 @@ fail:
        return ret;
 }
 
-int get_asymmetric_key(const char *key_file, int private,
-               struct asymmetric_key **result)
+int get_public_key(const char *key_file, struct asymmetric_key **result)
 {
        struct asymmetric_key *key = NULL;
        void *map = NULL;
@@ -170,21 +149,13 @@ int get_asymmetric_key(const char *key_file, int private,
        char *cp;
 
        key = para_malloc(sizeof(*key));
-       if (private) {
-               ret = get_openssl_key(key_file, &key->rsa, LOAD_PRIVATE_KEY);
-               goto out;
-       }
        ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
        if (ret < 0)
                goto out;
        ret = is_ssh_rsa_key(map, map_size);
        if (!ret) {
-               ret = para_munmap(map, map_size);
-               map = NULL;
-               if (ret < 0)
-                       goto out;
-               ret = get_openssl_key(key_file, &key->rsa, LOAD_PUBLIC_KEY);
-               goto out;
+               ret = -E_SSH_PARSE;
+               goto out_unmap;
        }
        cp = map + ret;
        encoded_size = map_size - ret;
@@ -214,7 +185,7 @@ out:
        return ret;
 }
 
-void free_asymmetric_key(struct asymmetric_key *key)
+void free_public_key(struct asymmetric_key *key)
 {
        if (!key)
                return;
@@ -228,11 +199,17 @@ int priv_decrypt(const char *key_file, unsigned char *outbuf,
        struct asymmetric_key *priv;
        int ret;
 
+       ret = check_private_key_file(key_file);
+       if (ret < 0)
+               return ret;
        if (inlen < 0)
                return -E_RSA;
-       ret = get_asymmetric_key(key_file, LOAD_PRIVATE_KEY, &priv);
-       if (ret < 0)
+       priv = para_malloc(sizeof(*priv));
+       ret = get_private_key(key_file, &priv->rsa);
+       if (ret < 0) {
+               free(priv);
                return ret;
+       }
        /*
         * RSA is vulnerable to timing attacks. Generate a random blinding
         * factor to protect against this kind of attack.
@@ -246,7 +223,8 @@ int priv_decrypt(const char *key_file, unsigned char *outbuf,
        if (ret <= 0)
                ret = -E_DECRYPT;
 out:
-       free_asymmetric_key(priv);
+       RSA_free(priv->rsa);
+       free(priv);
        return ret;
 }