+++ /dev/null
-/*
- * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
- *
- * 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/pem.h>
-#include <openssl/sha.h>
-#include <openssl/bn.h>
-#include <openssl/aes.h>
-
-#include "para.h"
-#include "error.h"
-#include "string.h"
-#include "crypt.h"
-#include "fd.h"
-#include "crypt_backend.h"
-#include "base64.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 int get_private_key(const char *path, RSA **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;
-}
-
-/*
- * 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;
- 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, &e);
- if (ret < 0)
- goto fail;
- p += ret;
- 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:
- RSA_free(rsa);
- return ret;
-}
-
-int get_public_key(const char *key_file, struct asymmetric_key **result)
-{
- struct asymmetric_key *key = NULL;
- void *map = NULL;
- unsigned char *blob = NULL;
- size_t map_size, encoded_size, decoded_size;
- int ret, ret2;
- char *cp;
-
- key = para_malloc(sizeof(*key));
- 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) {
- para_munmap(map, map_size);
- return -E_SSH_PARSE;
- }
- cp = map + ret;
- encoded_size = map_size - ret;
- PARA_INFO_LOG("decoding public rsa-ssh key %s\n", key_file);
- ret = uudecode(cp, encoded_size, (char **)&blob, &decoded_size);
- if (ret < 0)
- goto out_unmap;
- 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_public_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;
-
- ret = check_private_key_file(key_file);
- if (ret < 0)
- return ret;
- if (inlen < 0)
- return -E_RSA;
- 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.
- */
- 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:
- RSA_free(priv->rsa);
- free(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 {
- EVP_CIPHER_CTX *aes;
-};
-
-struct stream_cipher *sc_new(const unsigned char *data, int len)
-{
- struct stream_cipher *sc = para_malloc(sizeof(*sc));
-
- 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);
-}
-
-static void aes_ctr128_crypt(EVP_CIPHER_CTX *ctx, struct iovec *src,
- struct iovec *dst)
-{
- 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;
-}
-
-void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
-{
- return aes_ctr128_crypt(sc->aes, src, dst);
-}
-
-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