1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file openssl.c Openssl-based encryption/decryption routines. */
7 #include <sys/socket.h>
8 #include <openssl/rand.h>
9 #include <openssl/err.h>
10 #include <openssl/pem.h>
11 #include <openssl/sha.h>
12 #include <openssl/bn.h>
13 #include <openssl/aes.h>
19 #include "crypt_backend.h"
20 #include "portable_io.h"
22 struct asymmetric_key {
26 void get_random_bytes_or_die(unsigned char *buf, int num)
30 /* RAND_bytes() returns 1 on success, 0 otherwise. */
31 if (RAND_bytes(buf, num) == 1)
33 err = ERR_get_error();
34 PARA_EMERG_LOG("%s\n", ERR_reason_error_string(err));
39 * Read 64 bytes from /dev/urandom and add them to the SSL PRNG. Seed the PRNG
40 * used by random(3) with a random seed obtained from SSL. If /dev/urandom is
41 * not readable, the function calls exit().
43 * \sa RAND_load_file(3), \ref get_random_bytes_or_die(), srandom(3),
44 * random(3), \ref para_random().
48 int seed, ret = RAND_load_file("/dev/urandom", 64);
51 PARA_EMERG_LOG("could not seed PRNG (ret = %d)\n", ret);
54 get_random_bytes_or_die((unsigned char *)&seed, sizeof(seed));
58 void crypt_shutdown(void)
60 #ifdef HAVE_CRYPTO_CLEANUP_ALL_EX_DATA
61 CRYPTO_cleanup_all_ex_data();
63 #ifdef HAVE_OPENSSL_THREAD_STOP /* openssl-1.1 or later */
64 OPENSSL_thread_stop();
65 #else /* openssl-1.0 */
66 ERR_remove_thread_state(NULL);
72 * The public key loading functions below were inspired by corresponding code
73 * of openssh-5.2p1, Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo,
74 * Finland. However, not much of the original code remains.
77 static int read_bignum(const unsigned char *buf, size_t len, BIGNUM **result)
79 const unsigned char *p = buf, *end = buf + len;
87 bnsize = read_u32_be(p);
88 PARA_DEBUG_LOG("bnsize: %u\n", bnsize);
96 bn = BN_bin2bn(p, bnsize, NULL);
103 static int read_rsa_bignums(const unsigned char *blob, int blen, RSA **result)
108 const unsigned char *p = blob, *end = blob + blen;
113 ret = read_bignum(p, end - p, &e);
117 ret = read_bignum(p, end - p, &n);
120 #ifdef HAVE_RSA_SET0_KEY
121 RSA_set0_key(rsa, n, e, NULL);
135 static int read_pem_private_key(const char *path, RSA **rsa)
138 BIO *bio = BIO_new(BIO_s_file());
142 return -E_PRIVATE_KEY;
143 if (BIO_read_filename(bio, path) <= 0)
145 pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
148 *rsa = EVP_PKEY_get1_RSA(pkey);
152 return *rsa? RSA_size(*rsa) : -E_PRIVATE_KEY;
155 static int read_private_rsa_params(const unsigned char *blob,
156 const unsigned char *end, RSA **result)
161 BIGNUM *n, *e, *d, *iqmp, *p, *q; /* stored in the key file */
162 BIGNUM *dmp1, *dmq1; /* these will be computed */
164 const unsigned char *cp = blob;
182 ret = read_bignum(cp, end - cp, &n);
186 ret = read_bignum(cp, end - cp, &e);
190 ret = read_bignum(cp, end - cp, &d);
194 ret = read_bignum(cp, end - cp, &iqmp);
198 ret = read_bignum(cp, end - cp, &p);
202 ret = read_bignum(cp, end - cp, &q);
206 if (!BN_sub(tmp, q, BN_value_one()))
208 if (!BN_mod(dmp1, d, tmp, ctx))
210 if (!BN_sub(tmp, q, BN_value_one()))
212 if (!BN_mod(dmq1, d, tmp, ctx))
214 #ifdef HAVE_RSA_SET0_KEY
215 RSA_set0_key(rsa, n, e, d);
216 RSA_set0_factors(rsa, p, q);
217 RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp);
257 static int get_private_key(const char *path, RSA **rsa)
260 unsigned char *blob, *end;
264 ret = decode_private_key(path, &blob, &blob_size);
267 end = blob + blob_size;
268 if (ret == PKT_OPENSSH) {
269 ret = find_openssh_bignum_offset(blob, blob_size);
272 PARA_INFO_LOG("reading RSA params at offset %d\n", ret);
273 ret = read_private_rsa_params(blob + ret, end, rsa);
275 ret = read_pem_private_key(path, rsa);
281 int apc_get_pubkey(const char *key_file, struct asymmetric_key **result)
286 struct asymmetric_key *key = para_malloc(sizeof(*key));
288 ret = decode_public_key(key_file, &blob, &decoded_size);
291 ret = read_rsa_bignums(blob + ret, decoded_size - ret, &key->rsa);
294 ret = RSA_size(key->rsa);
303 PARA_ERROR_LOG("can not load key %s\n", key_file);
308 void apc_free_pubkey(struct asymmetric_key *key)
316 int apc_priv_decrypt(const char *key_file, unsigned char *outbuf,
317 unsigned char *inbuf, int inlen)
319 struct asymmetric_key *priv;
322 ret = check_private_key_file(key_file);
327 priv = para_malloc(sizeof(*priv));
328 ret = get_private_key(key_file, &priv->rsa);
334 * RSA is vulnerable to timing attacks. Generate a random blinding
335 * factor to protect against this kind of attack.
338 if (RSA_blinding_on(priv->rsa, NULL) == 0)
340 ret = RSA_private_decrypt(inlen, inbuf, outbuf, priv->rsa,
341 RSA_PKCS1_OAEP_PADDING);
342 RSA_blinding_off(priv->rsa);
351 int apc_pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
352 unsigned len, unsigned char *outbuf)
354 int ret, flen = len; /* RSA_public_encrypt expects a signed int */
358 ret = RSA_public_encrypt(flen, inbuf, outbuf, pub->rsa,
359 RSA_PKCS1_OAEP_PADDING);
360 return ret < 0? -E_ENCRYPT : ret;
363 struct stream_cipher {
367 struct stream_cipher *sc_new(const unsigned char *data, int len)
369 struct stream_cipher *sc = para_malloc(sizeof(*sc));
371 assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
372 sc->aes = EVP_CIPHER_CTX_new();
373 EVP_EncryptInit_ex(sc->aes, EVP_aes_128_ctr(), NULL, data,
374 data + AES_CRT128_BLOCK_SIZE);
378 void sc_free(struct stream_cipher *sc)
382 EVP_CIPHER_CTX_free(sc->aes);
386 static void aes_ctr128_crypt(EVP_CIPHER_CTX *ctx, struct iovec *src,
389 int ret, inlen = src->iov_len, outlen, tmplen;
391 *dst = (typeof(*dst)) {
392 /* Add one for the terminating zero byte. */
393 .iov_base = para_malloc(inlen + 1),
396 ret = EVP_EncryptUpdate(ctx, dst->iov_base, &outlen, src->iov_base, inlen);
398 ret = EVP_EncryptFinal_ex(ctx, dst->iov_base + outlen, &tmplen);
401 ((char *)dst->iov_base)[outlen] = '\0';
402 dst->iov_len = outlen;
405 void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
407 return aes_ctr128_crypt(sc->aes, src, dst);
410 void hash_function(const char *data, unsigned long len, unsigned char *hash)
414 SHA1_Update(&c, data, len);
415 SHA1_Final(hash, &c);
418 void hash2_function(const char *data, unsigned long len, unsigned char *hash)
422 SHA256_Update(&c, data, len);
423 SHA256_Final(hash, &c);