+++ /dev/null
-/*
- * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
-
-/** \file crypt.c Openssl-based encryption/decryption routines. */
-
-#include <regex.h>
-#include <sys/types.h>
-#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 "para.h"
-#include "error.h"
-#include "string.h"
-#include "crypt.h"
-#include "fd.h"
-#include "crypt_backend.h"
-
-struct asymmetric_key {
- RSA *rsa;
-};
-
-void get_random_bytes_or_die(unsigned char *buf, int num)
-{
- unsigned long err;
-
- /* RAND_bytes() returns 1 on success, 0 otherwise. */
- if (RAND_bytes(buf, num) == 1)
- return;
- err = ERR_get_error();
- PARA_EMERG_LOG("%s\n", ERR_reason_error_string(err));
- exit(EXIT_FAILURE);
-}
-
-/*
- * 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().
- *
- * \sa RAND_load_file(3), \ref get_random_bytes_or_die(), srandom(3),
- * random(3), \ref para_random().
- */
-void init_random_seed_or_die(void)
-{
- int seed, ret = RAND_load_file("/dev/urandom", 64);
-
- if (ret != 64) {
- PARA_EMERG_LOG("could not seed PRNG (ret = %d)\n", ret);
- exit(EXIT_FAILURE);
- }
- get_random_bytes_or_die((unsigned char *)&seed, sizeof(seed));
- srandom(seed);
-}
-
-static EVP_PKEY *load_key(const char *file, int private)
-{
- 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);
-}
-
-/*
- * The public key loading functions below were inspired by corresponding code
- * of openssh-5.2p1, Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo,
- * Finland. However, not much of the original code remains.
- */
-
-static int read_bignum(const unsigned char *buf, size_t len, BIGNUM **result)
-{
- const unsigned char *p = buf, *end = buf + len;
- uint32_t bnsize;
- BIGNUM *bn;
-
- if (p + 4 < p)
- return -E_BIGNUM;
- if (p + 4 > end)
- return -E_BIGNUM;
- bnsize = read_ssh_u32(p);
- PARA_DEBUG_LOG("bnsize: %u\n", bnsize);
- p += 4;
- if (p + bnsize < p)
- return -E_BIGNUM;
- if (p + bnsize > end)
- return -E_BIGNUM;
- if (bnsize > 8192)
- return -E_BIGNUM;
- bn = BN_bin2bn(p, bnsize, NULL);
- if (!bn)
- return -E_BIGNUM;
- *result = bn;
- return bnsize + 4;
-}
-
-static int read_rsa_bignums(const unsigned char *blob, int blen, RSA **result)
-{
- int ret;
- RSA *rsa;
- const unsigned char *p = blob, *end = blob + blen;
-
- rsa = RSA_new();
- if (!rsa)
- return -E_BIGNUM;
- ret = read_bignum(p, end - p, &rsa->e);
- if (ret < 0)
- goto fail;
- p += ret;
- ret = read_bignum(p, end - p, &rsa->n);
- if (ret < 0)
- goto fail;
- *result = rsa;
- return 1;
-fail:
- RSA_free(rsa);
- return ret;
-}
-
-int get_asymmetric_key(const char *key_file, int private,
- struct asymmetric_key **result)
-{
- struct asymmetric_key *key = NULL;
- void *map = NULL;
- unsigned char *blob = NULL;
- size_t map_size, blob_size, decoded_size;
- int ret, ret2;
- 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;
- }
- cp = map + 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);
- if (ret < 0)
- goto out_unmap;
- decoded_size = ret;
- ret = check_ssh_key_header(blob, decoded_size);
- if (ret < 0)
- goto out_unmap;
- ret = read_rsa_bignums(blob + ret, decoded_size - ret, &key->rsa);
- if (ret < 0)
- goto out_unmap;
- ret = RSA_size(key->rsa);
-out_unmap:
- ret2 = para_munmap(map, map_size);
- if (ret >= 0 && ret2 < 0)
- ret = ret2;
-out:
- if (ret < 0) {
- free(key);
- *result = NULL;
- PARA_ERROR_LOG("key %s: %s\n", key_file, para_strerror(-ret));
- } else
- *result = key;
- free(blob);
- return ret;
-}
-
-void free_asymmetric_key(struct asymmetric_key *key)
-{
- if (!key)
- return;
- RSA_free(key->rsa);
- free(key);
-}
-
-int priv_decrypt(const char *key_file, unsigned char *outbuf,
- unsigned char *inbuf, int inlen)
-{
- struct asymmetric_key *priv;
- int ret;
-
- if (inlen < 0)
- return -E_RSA;
- ret = get_asymmetric_key(key_file, LOAD_PRIVATE_KEY, &priv);
- if (ret < 0)
- return ret;
- /*
- * RSA is vulnerable to timing attacks. Generate a random blinding
- * factor to protect against this kind of attack.
- */
- ret = -E_BLINDING;
- if (RSA_blinding_on(priv->rsa, NULL) == 0)
- goto out;
- ret = RSA_private_decrypt(inlen, inbuf, outbuf, priv->rsa,
- RSA_PKCS1_OAEP_PADDING);
- RSA_blinding_off(priv->rsa);
- if (ret <= 0)
- ret = -E_DECRYPT;
-out:
- free_asymmetric_key(priv);
- return ret;
-}
-
-int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
- unsigned len, unsigned char *outbuf)
-{
- int ret, flen = len; /* RSA_public_encrypt expects a signed int */
-
- if (flen < 0)
- return -E_ENCRYPT;
- ret = RSA_public_encrypt(flen, inbuf, outbuf, pub->rsa,
- RSA_PKCS1_OAEP_PADDING);
- return ret < 0? -E_ENCRYPT : ret;
-}
-
-struct stream_cipher {
- RC4_KEY key;
-};
-
-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);
- return sc;
-}
-
-void sc_free(struct stream_cipher *sc)
-{
- 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
-
-void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
-{
- size_t len = src->iov_len, l1, l2;
- RC4_KEY *key = &sc->key;
-
- assert(len > 0);
- assert(len < ((typeof(src->iov_len))-1) / 2);
- l1 = ROUND_DOWN(len, RC4_ALIGN);
- l2 = ROUND_UP(len, RC4_ALIGN);
-
- *dst = (typeof(*dst)) {
- /* Add one for the terminating zero byte. */
- .iov_base = para_malloc(l2 + 1),
- .iov_len = len
- };
- RC4(key, l1, src->iov_base, dst->iov_base);
- if (len > l1) {
- unsigned char remainder[RC4_ALIGN] = "";
- memcpy(remainder, src->iov_base + l1, len - l1);
- RC4(key, len - l1, remainder, dst->iov_base + l1);
- }
- ((char *)dst->iov_base)[len] = '\0';
-}
-
-void hash_function(const char *data, unsigned long len, unsigned char *hash)
-{
- SHA_CTX c;
- SHA1_Init(&c);
- SHA1_Update(&c, data, len);
- SHA1_Final(hash, &c);
-}
projects / paraslash.git / blobdiff