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>
14 #include <openssl/evp.h>
20 #include "crypt_backend.h"
21 #include "portable_io.h"
23 struct asymmetric_key {
27 void get_random_bytes_or_die(unsigned char *buf, int num)
31 /* RAND_bytes() returns 1 on success, 0 otherwise. */
32 if (RAND_bytes(buf, num) == 1)
34 err = ERR_get_error();
35 PARA_EMERG_LOG("%s\n", ERR_reason_error_string(err));
40 * Read 64 bytes from /dev/urandom and add them to the SSL PRNG. Seed the PRNG
41 * used by random(3) with a random seed obtained from SSL. If /dev/urandom is
42 * not readable, the function calls exit().
44 * \sa RAND_load_file(3), \ref get_random_bytes_or_die(), srandom(3),
45 * random(3), \ref para_random().
49 int seed, ret = RAND_load_file("/dev/urandom", 64);
52 PARA_EMERG_LOG("could not seed PRNG (ret = %d)\n", ret);
55 get_random_bytes_or_die((unsigned char *)&seed, sizeof(seed));
59 void crypt_shutdown(void)
61 #ifdef HAVE_CRYPTO_CLEANUP_ALL_EX_DATA
62 CRYPTO_cleanup_all_ex_data();
64 #ifdef HAVE_OPENSSL_THREAD_STOP /* openssl-1.1 or later */
65 OPENSSL_thread_stop();
66 #else /* openssl-1.0 */
67 ERR_remove_thread_state(NULL);
73 * The public key loading functions below were inspired by corresponding code
74 * of openssh-5.2p1, Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo,
75 * Finland. However, not much of the original code remains.
78 static int read_bignum(const unsigned char *buf, size_t len, BIGNUM **result)
80 const unsigned char *p = buf, *end = buf + len;
88 bnsize = read_u32_be(p);
89 PARA_DEBUG_LOG("bnsize: %u\n", bnsize);
97 bn = BN_bin2bn(p, bnsize, NULL);
104 static int read_rsa_bignums(const unsigned char *blob, int blen, RSA **result)
109 const unsigned char *p = blob, *end = blob + blen;
114 ret = read_bignum(p, end - p, &e);
118 ret = read_bignum(p, end - p, &n);
121 #ifdef HAVE_RSA_SET0_KEY
122 RSA_set0_key(rsa, n, e, NULL);
136 static int read_pem_private_key(const char *path, RSA **rsa)
139 BIO *bio = BIO_new(BIO_s_file());
143 return -E_PRIVATE_KEY;
144 if (BIO_read_filename(bio, path) <= 0)
146 pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
149 *rsa = EVP_PKEY_get1_RSA(pkey);
153 return *rsa? RSA_size(*rsa) : -E_PRIVATE_KEY;
156 static int read_private_rsa_params(const unsigned char *blob,
157 const unsigned char *end, RSA **result)
162 BIGNUM *n, *e, *d, *iqmp, *p, *q; /* stored in the key file */
163 BIGNUM *dmp1, *dmq1; /* these will be computed */
165 const unsigned char *cp = blob;
183 ret = read_bignum(cp, end - cp, &n);
187 ret = read_bignum(cp, end - cp, &e);
191 ret = read_bignum(cp, end - cp, &d);
195 ret = read_bignum(cp, end - cp, &iqmp);
199 ret = read_bignum(cp, end - cp, &p);
203 ret = read_bignum(cp, end - cp, &q);
207 if (!BN_sub(tmp, q, BN_value_one()))
209 if (!BN_mod(dmp1, d, tmp, ctx))
211 if (!BN_sub(tmp, q, BN_value_one()))
213 if (!BN_mod(dmq1, d, tmp, ctx))
215 #ifdef HAVE_RSA_SET0_KEY
216 RSA_set0_key(rsa, n, e, d);
217 RSA_set0_factors(rsa, p, q);
218 RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp);
258 static int get_private_key(const char *path, RSA **rsa)
261 unsigned char *blob, *end;
265 ret = decode_private_key(path, &blob, &blob_size);
268 end = blob + blob_size;
269 if (ret == PKT_OPENSSH) {
270 ret = find_openssh_bignum_offset(blob, blob_size);
273 PARA_INFO_LOG("reading RSA params at offset %d\n", ret);
274 ret = read_private_rsa_params(blob + ret, end, rsa);
276 ret = read_pem_private_key(path, rsa);
282 int apc_get_pubkey(const char *key_file, struct asymmetric_key **result)
287 struct asymmetric_key *key = alloc(sizeof(*key));
289 ret = decode_public_key(key_file, &blob, &decoded_size);
292 ret = read_rsa_bignums(blob + ret, decoded_size - ret, &key->rsa);
295 ret = RSA_size(key->rsa);
304 PARA_ERROR_LOG("can not load key %s\n", key_file);
309 void apc_free_pubkey(struct asymmetric_key *key)
317 int apc_priv_decrypt(const char *key_file, unsigned char *outbuf,
318 unsigned char *inbuf, int inlen)
320 struct asymmetric_key *priv;
323 ret = check_private_key_file(key_file);
328 priv = alloc(sizeof(*priv));
329 ret = get_private_key(key_file, &priv->rsa);
335 * RSA is vulnerable to timing attacks. Generate a random blinding
336 * factor to protect against this kind of attack.
339 if (RSA_blinding_on(priv->rsa, NULL) == 0)
341 ret = RSA_private_decrypt(inlen, inbuf, outbuf, priv->rsa,
342 RSA_PKCS1_OAEP_PADDING);
343 RSA_blinding_off(priv->rsa);
352 int apc_pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
353 unsigned len, unsigned char *outbuf)
355 int ret, flen = len; /* RSA_public_encrypt expects a signed int */
359 ret = RSA_public_encrypt(flen, inbuf, outbuf, pub->rsa,
360 RSA_PKCS1_OAEP_PADDING);
361 return ret < 0? -E_ENCRYPT : ret;
364 struct stream_cipher {
368 struct stream_cipher *sc_new(const unsigned char *data, int len)
370 struct stream_cipher *sc = alloc(sizeof(*sc));
372 assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
373 sc->aes = EVP_CIPHER_CTX_new();
374 EVP_EncryptInit_ex(sc->aes, EVP_aes_128_ctr(), NULL, data,
375 data + AES_CRT128_BLOCK_SIZE);
379 void sc_free(struct stream_cipher *sc)
383 EVP_CIPHER_CTX_free(sc->aes);
387 static void aes_ctr128_crypt(EVP_CIPHER_CTX *ctx, struct iovec *src,
390 int ret, inlen = src->iov_len, outlen, tmplen;
392 *dst = (typeof(*dst)) {
393 /* Add one for the terminating zero byte. */
394 .iov_base = alloc(inlen + 1),
397 ret = EVP_EncryptUpdate(ctx, dst->iov_base, &outlen, src->iov_base, inlen);
399 ret = EVP_EncryptFinal_ex(ctx, dst->iov_base + outlen, &tmplen);
402 ((char *)dst->iov_base)[outlen] = '\0';
403 dst->iov_len = outlen;
406 void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
408 return aes_ctr128_crypt(sc->aes, src, dst);
411 void hash_function(const char *data, unsigned long len, unsigned char *hash)
413 EVP_MD_CTX *c = EVP_MD_CTX_new();
414 int ret = EVP_DigestInit_ex(c, EVP_sha1(), NULL);
416 ret = EVP_DigestUpdate(c, data, len);
418 ret = EVP_DigestFinal_ex(c, hash, NULL);
423 void hash2_function(const char *data, unsigned long len, unsigned char *hash)
425 EVP_MD_CTX *c = EVP_MD_CTX_new();
426 int ret = EVP_DigestInit_ex(c, EVP_sha256(), NULL);
428 ret = EVP_DigestUpdate(c, data, len);
430 ret = EVP_DigestFinal_ex(c, hash, NULL);