crypt: Remove RC4 support.

[paraslash.git] / crypt.c

diff --git a/crypt.c b/crypt.c
index 85ec091d76cf53e99f5bfc1e40eec9c735328a53..cae47046fe0c8e3f0ebf2c1a479d3343c3955465 100644 (file)
--- a/crypt.c
+++ b/crypt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -11,10 +11,10 @@
 #include <sys/socket.h>
 #include <openssl/rand.h>
 #include <openssl/err.h>
-#include <openssl/rc4.h>
 #include <openssl/pem.h>
 #include <openssl/sha.h>
 #include <openssl/bn.h>
+#include <openssl/aes.h>
 
 #include "para.h"
 #include "error.h"
@@ -22,6 +22,7 @@
 #include "crypt.h"
 #include "fd.h"
 #include "crypt_backend.h"
+#include "base64.h"
 
 struct asymmetric_key {
        RSA *rsa;
@@ -132,23 +133,29 @@ static int read_rsa_bignums(const unsigned char *blob, int blen, RSA **result)
 {
        int ret;
        RSA *rsa;
+       BIGNUM *n, *e;
        const unsigned char *p = blob, *end = blob + blen;
 
        rsa = RSA_new();
        if (!rsa)
                return -E_BIGNUM;
-       ret = read_bignum(p, end - p, &rsa->e);
+       ret = read_bignum(p, end - p, &e);
        if (ret < 0)
                goto fail;
        p += ret;
-       ret = read_bignum(p, end - p, &rsa->n);
+       ret = read_bignum(p, end - p, &n);
        if (ret < 0)
                goto fail;
+#ifdef HAVE_RSA_SET0_KEY
+       RSA_set0_key(rsa, n, e, NULL);
+#else
+       rsa->n = n;
+       rsa->e = e;
+#endif
        *result = rsa;
        return 1;
 fail:
-       if (rsa)
-               RSA_free(rsa);
+       RSA_free(rsa);
        return ret;
 }
 
@@ -158,7 +165,7 @@ int get_asymmetric_key(const char *key_file, int private,
        struct asymmetric_key *key = NULL;
        void *map = NULL;
        unsigned char *blob = NULL;
-       size_t map_size, blob_size, decoded_size;
+       size_t map_size, encoded_size, decoded_size;
        int ret, ret2;
        char *cp;
 
@@ -180,16 +187,11 @@ int get_asymmetric_key(const char *key_file, int private,
                goto out;
        }
        cp = map + ret;
+       encoded_size = map_size - ret;
        PARA_INFO_LOG("decoding public rsa-ssh key %s\n", key_file);
-       ret = -ERRNO_TO_PARA_ERROR(EOVERFLOW);
-       if (map_size > INT_MAX / 4)
-               goto out_unmap;
-       blob_size = 2 * map_size;
-       blob = para_malloc(blob_size);
-       ret = uudecode(cp, blob, blob_size);
+       ret = uudecode(cp, encoded_size, (char **)&blob, &decoded_size);
        if (ret < 0)
                goto out_unmap;
-       decoded_size = ret;
        ret = check_ssh_key_header(blob, decoded_size);
        if (ret < 0)
                goto out_unmap;
@@ -261,60 +263,50 @@ int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
 }
 
 struct stream_cipher {
-       RC4_KEY key;
+       EVP_CIPHER_CTX *aes;
 };
 
 struct stream_cipher *sc_new(const unsigned char *data, int len)
 {
        struct stream_cipher *sc = para_malloc(sizeof(*sc));
-       RC4_set_key(&sc->key, len, data);
+
+       assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
+       sc->aes = EVP_CIPHER_CTX_new();
+       EVP_EncryptInit_ex(sc->aes, EVP_aes_128_ctr(), NULL, data,
+               data + AES_CRT128_BLOCK_SIZE);
        return sc;
 }
 
 void sc_free(struct stream_cipher *sc)
 {
+       if (!sc)
+               return;
+       EVP_CIPHER_CTX_free(sc->aes);
        free(sc);
 }
 
-/**
- * The RC4() implementation of openssl apparently reads and writes data in
- * blocks of 8 bytes. So we have to make sure our buffer sizes are a multiple
- * of this.
- */
-#define RC4_ALIGN 8
-
-int sc_send_bin_buffer(struct stream_cipher_context *scc, char *buf,
-               size_t len)
+static void aes_ctr128_crypt(EVP_CIPHER_CTX *ctx, struct iovec *src,
+               struct iovec *dst)
 {
-       int ret;
-       unsigned char *tmp;
-       static unsigned char remainder[RC4_ALIGN];
-       size_t l1 = ROUND_DOWN(len, RC4_ALIGN), l2 = ROUND_UP(len, RC4_ALIGN);
-
-       assert(len);
-       tmp = para_malloc(l2);
-       RC4(&scc->send->key, l1, (const unsigned char *)buf, tmp);
-       if (len > l1) {
-               memcpy(remainder, buf + l1, len - l1);
-               RC4(&scc->send->key, len - l1, remainder, tmp + l1);
-       }
-       ret = write_nonblock(scc->fd, (char *)tmp, len);
-       free(tmp);
-       return ret;
+       int ret, inlen = src->iov_len, outlen, tmplen;
+
+       *dst = (typeof(*dst)) {
+               /* Add one for the terminating zero byte. */
+               .iov_base = para_malloc(inlen + 1),
+               .iov_len = inlen
+       };
+       ret = EVP_EncryptUpdate(ctx, dst->iov_base, &outlen, src->iov_base, inlen);
+       assert(ret != 0);
+       ret = EVP_EncryptFinal_ex(ctx, dst->iov_base + outlen, &tmplen);
+       assert(ret != 0);
+       outlen += tmplen;
+       ((char *)dst->iov_base)[outlen] = '\0';
+       dst->iov_len = outlen;
 }
 
-int sc_recv_bin_buffer(struct stream_cipher_context *scc, char *buf,
-               size_t size)
+void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
 {
-       unsigned char *tmp = para_malloc(ROUND_UP(size, RC4_ALIGN));
-       ssize_t ret = recv(scc->fd, tmp, size, 0);
-
-       if (ret > 0)
-               RC4(&scc->recv->key, ret, tmp, (unsigned char *)buf);
-       else if (ret < 0)
-               ret = -ERRNO_TO_PARA_ERROR(errno);
-       free(tmp);
-       return ret;
+       return aes_ctr128_crypt(sc->aes, src, dst);
 }
 
 void hash_function(const char *data, unsigned long len, unsigned char *hash)