summaryrefslogtreecommitdiff
path: root/src/openvpn/crypto.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/openvpn/crypto.c')
-rw-r--r--src/openvpn/crypto.c1724
1 files changed, 0 insertions, 1724 deletions
diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
deleted file mode 100644
index 4f07651..0000000
--- a/src/openvpn/crypto.c
+++ /dev/null
@@ -1,1724 +0,0 @@
-/*
- * OpenVPN -- An application to securely tunnel IP networks
- * over a single TCP/UDP port, with support for SSL/TLS-based
- * session authentication and key exchange,
- * packet encryption, packet authentication, and
- * packet compression.
- *
- * Copyright (C) 2002-2005 OpenVPN Solutions LLC <info@openvpn.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program (see the file COPYING included with this
- * distribution); if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#ifdef WIN32
-#include "config-win32.h"
-#else
-#include "config.h"
-#endif
-
-#ifdef USE_CRYPTO
-
-#include "syshead.h"
-
-#include "crypto.h"
-#include "error.h"
-#include "misc.h"
-#include "thread.h"
-
-#include "memdbg.h"
-
-/*
- * Check for key size creepage.
- */
-
-#if MAX_CIPHER_KEY_LENGTH < EVP_MAX_KEY_LENGTH
-#warning Some OpenSSL EVP ciphers now support key lengths greater than MAX_CIPHER_KEY_LENGTH -- consider increasing MAX_CIPHER_KEY_LENGTH
-#endif
-
-#if MAX_HMAC_KEY_LENGTH < EVP_MAX_MD_SIZE
-#warning Some OpenSSL HMAC message digests now support key lengths greater than MAX_HMAC_KEY_LENGTH -- consider increasing MAX_HMAC_KEY_LENGTH
-#endif
-
-/*
- * Encryption and Compression Routines.
- *
- * On entry, buf contains the input data and length.
- * On exit, it should be set to the output data and length.
- *
- * If buf->len is <= 0 we should return
- * If buf->len is set to 0 on exit it tells the caller to ignore the packet.
- *
- * work is a workspace buffer we are given of size BUF_SIZE.
- * work may be used to return output data, or the input buffer
- * may be modified and returned as output. If output data is
- * returned in work, the data should start after FRAME_HEADROOM bytes
- * of padding to leave room for downstream routines to prepend.
- *
- * Up to a total of FRAME_HEADROOM bytes may be prepended to the input buf
- * by all routines (encryption, decryption, compression, and decompression).
- *
- * Note that the buf_prepend return will assert if we try to
- * make a header bigger than FRAME_HEADROOM. This should not
- * happen unless the frame parameters are wrong.
- */
-
-#define CRYPT_ERROR(format) \
- do { msg (D_CRYPT_ERRORS, "%s: " format, error_prefix); goto error_exit; } while (false)
-
-void
-openvpn_encrypt (struct buffer *buf, struct buffer work,
- const struct crypto_options *opt,
- const struct frame* frame)
-{
- struct gc_arena gc;
- gc_init (&gc);
-
- if (buf->len > 0 && opt->key_ctx_bi)
- {
- struct key_ctx *ctx = &opt->key_ctx_bi->encrypt;
-
- /* Do Encrypt from buf -> work */
- if (ctx->cipher)
- {
- uint8_t iv_buf[EVP_MAX_IV_LENGTH];
- const int iv_size = EVP_CIPHER_CTX_iv_length (ctx->cipher);
- const unsigned int mode = EVP_CIPHER_CTX_mode (ctx->cipher);
- int outlen;
-
- if (mode == EVP_CIPH_CBC_MODE)
- {
- CLEAR (iv_buf);
-
- /* generate pseudo-random IV */
- if (opt->flags & CO_USE_IV)
- prng_bytes (iv_buf, iv_size);
-
- /* Put packet ID in plaintext buffer or IV, depending on cipher mode */
- if (opt->packet_id)
- {
- struct packet_id_net pin;
- packet_id_alloc_outgoing (&opt->packet_id->send, &pin, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM));
- ASSERT (packet_id_write (&pin, buf, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM), true));
- }
- }
- else if (mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE)
- {
- struct packet_id_net pin;
- struct buffer b;
-
- ASSERT (opt->flags & CO_USE_IV); /* IV and packet-ID required */
- ASSERT (opt->packet_id); /* for this mode. */
-
- packet_id_alloc_outgoing (&opt->packet_id->send, &pin, true);
- memset (iv_buf, 0, iv_size);
- buf_set_write (&b, iv_buf, iv_size);
- ASSERT (packet_id_write (&pin, &b, true, false));
- }
- else /* We only support CBC, CFB, or OFB modes right now */
- {
- ASSERT (0);
- }
-
- /* initialize work buffer with FRAME_HEADROOM bytes of prepend capacity */
- ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
-
- /* set the IV pseudo-randomly */
- if (opt->flags & CO_USE_IV)
- dmsg (D_PACKET_CONTENT, "ENCRYPT IV: %s", format_hex (iv_buf, iv_size, 0, &gc));
-
- dmsg (D_PACKET_CONTENT, "ENCRYPT FROM: %s",
- format_hex (BPTR (buf), BLEN (buf), 80, &gc));
-
- /* cipher_ctx was already initialized with key & keylen */
- ASSERT (EVP_CipherInit_ov (ctx->cipher, NULL, NULL, iv_buf, DO_ENCRYPT));
-
- /* Buffer overflow check */
- if (!buf_safe (&work, buf->len + EVP_CIPHER_CTX_block_size (ctx->cipher)))
- {
- msg (D_CRYPT_ERRORS, "ENCRYPT: buffer size error, bc=%d bo=%d bl=%d wc=%d wo=%d wl=%d cbs=%d",
- buf->capacity,
- buf->offset,
- buf->len,
- work.capacity,
- work.offset,
- work.len,
- EVP_CIPHER_CTX_block_size (ctx->cipher));
- goto err;
- }
-
- /* Encrypt packet ID, payload */
- ASSERT (EVP_CipherUpdate_ov (ctx->cipher, BPTR (&work), &outlen, BPTR (buf), BLEN (buf)));
- work.len += outlen;
-
- /* Flush the encryption buffer */
- ASSERT (EVP_CipherFinal (ctx->cipher, BPTR (&work) + outlen, &outlen));
- work.len += outlen;
- ASSERT (outlen == iv_size);
-
- /* prepend the IV to the ciphertext */
- if (opt->flags & CO_USE_IV)
- {
- uint8_t *output = buf_prepend (&work, iv_size);
- ASSERT (output);
- memcpy (output, iv_buf, iv_size);
- }
-
- dmsg (D_PACKET_CONTENT, "ENCRYPT TO: %s",
- format_hex (BPTR (&work), BLEN (&work), 80, &gc));
- }
- else /* No Encryption */
- {
- if (opt->packet_id)
- {
- struct packet_id_net pin;
- packet_id_alloc_outgoing (&opt->packet_id->send, &pin, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM));
- ASSERT (packet_id_write (&pin, buf, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM), true));
- }
- work = *buf;
- }
-
- /* HMAC the ciphertext (or plaintext if !cipher) */
- if (ctx->hmac)
- {
- int hmac_len;
- uint8_t *output;
-
- HMAC_Init_ex (ctx->hmac, NULL, 0, NULL, NULL);
- HMAC_Update (ctx->hmac, BPTR (&work), BLEN (&work));
- output = buf_prepend (&work, HMAC_size (ctx->hmac));
- ASSERT (output);
- HMAC_Final (ctx->hmac, output, (unsigned int *)&hmac_len);
- ASSERT (hmac_len == HMAC_size (ctx->hmac));
- }
-
- *buf = work;
- }
-
- gc_free (&gc);
- return;
-
- err:
- ERR_clear_error ();
- buf->len = 0;
- gc_free (&gc);
- return;
-}
-
-/*
- * If (opt->flags & CO_USE_IV) is not NULL, we will read an IV from the packet.
- *
- * Set buf->len to 0 and return false on decrypt error.
- *
- * On success, buf is set to point to plaintext, true
- * is returned.
- */
-bool
-openvpn_decrypt (struct buffer *buf, struct buffer work,
- const struct crypto_options *opt,
- const struct frame* frame)
-{
- static const char error_prefix[] = "Authenticate/Decrypt packet error";
- struct gc_arena gc;
- gc_init (&gc);
-
- if (buf->len > 0 && opt->key_ctx_bi)
- {
- struct key_ctx *ctx = &opt->key_ctx_bi->decrypt;
- struct packet_id_net pin;
- bool have_pin = false;
-
- /* Verify the HMAC */
- if (ctx->hmac)
- {
- int hmac_len;
- uint8_t local_hmac[MAX_HMAC_KEY_LENGTH]; /* HMAC of ciphertext computed locally */
- int in_hmac_len;
-
- HMAC_Init_ex (ctx->hmac, NULL, 0, NULL, NULL);
-
- /* Assume the length of the input HMAC */
- hmac_len = HMAC_size (ctx->hmac);
-
- /* Authentication fails if insufficient data in packet for HMAC */
- if (buf->len < hmac_len)
- CRYPT_ERROR ("missing authentication info");
-
- HMAC_Update (ctx->hmac, BPTR (buf) + hmac_len,
- BLEN (buf) - hmac_len);
- HMAC_Final (ctx->hmac, local_hmac, (unsigned int *)&in_hmac_len);
- ASSERT (hmac_len == in_hmac_len);
-
- /* Compare locally computed HMAC with packet HMAC */
- if (memcmp (local_hmac, BPTR (buf), hmac_len))
- CRYPT_ERROR ("packet HMAC authentication failed");
-
- ASSERT (buf_advance (buf, hmac_len));
- }
-
- /* Decrypt packet ID + payload */
-
- if (ctx->cipher)
- {
- const unsigned int mode = EVP_CIPHER_CTX_mode (ctx->cipher);
- const int iv_size = EVP_CIPHER_CTX_iv_length (ctx->cipher);
- uint8_t iv_buf[EVP_MAX_IV_LENGTH];
- int outlen;
-
- /* initialize work buffer with FRAME_HEADROOM bytes of prepend capacity */
- ASSERT (buf_init (&work, FRAME_HEADROOM_ADJ (frame, FRAME_HEADROOM_MARKER_DECRYPT)));
-
- /* use IV if user requested it */
- CLEAR (iv_buf);
- if (opt->flags & CO_USE_IV)
- {
- if (buf->len < iv_size)
- CRYPT_ERROR ("missing IV info");
- memcpy (iv_buf, BPTR (buf), iv_size);
- ASSERT (buf_advance (buf, iv_size));
- }
-
- /* show the IV's initial state */
- if (opt->flags & CO_USE_IV)
- dmsg (D_PACKET_CONTENT, "DECRYPT IV: %s", format_hex (iv_buf, iv_size, 0, &gc));
-
- if (buf->len < 1)
- CRYPT_ERROR ("missing payload");
-
- /* ctx->cipher was already initialized with key & keylen */
- if (!EVP_CipherInit_ov (ctx->cipher, NULL, NULL, iv_buf, DO_DECRYPT))
- CRYPT_ERROR ("cipher init failed");
-
- /* Buffer overflow check (should never happen) */
- if (!buf_safe (&work, buf->len))
- CRYPT_ERROR ("buffer overflow");
-
- /* Decrypt packet ID, payload */
- if (!EVP_CipherUpdate_ov (ctx->cipher, BPTR (&work), &outlen, BPTR (buf), BLEN (buf)))
- CRYPT_ERROR ("cipher update failed");
- work.len += outlen;
-
- /* Flush the decryption buffer */
- if (!EVP_CipherFinal (ctx->cipher, BPTR (&work) + outlen, &outlen))
- CRYPT_ERROR ("cipher final failed");
- work.len += outlen;
-
- dmsg (D_PACKET_CONTENT, "DECRYPT TO: %s",
- format_hex (BPTR (&work), BLEN (&work), 80, &gc));
-
- /* Get packet ID from plaintext buffer or IV, depending on cipher mode */
- {
- if (mode == EVP_CIPH_CBC_MODE)
- {
- if (opt->packet_id)
- {
- if (!packet_id_read (&pin, &work, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM)))
- CRYPT_ERROR ("error reading CBC packet-id");
- have_pin = true;
- }
- }
- else if (mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE)
- {
- struct buffer b;
-
- ASSERT (opt->flags & CO_USE_IV); /* IV and packet-ID required */
- ASSERT (opt->packet_id); /* for this mode. */
-
- buf_set_read (&b, iv_buf, iv_size);
- if (!packet_id_read (&pin, &b, true))
- CRYPT_ERROR ("error reading CFB/OFB packet-id");
- have_pin = true;
- }
- else /* We only support CBC, CFB, or OFB modes right now */
- {
- ASSERT (0);
- }
- }
- }
- else
- {
- work = *buf;
- if (opt->packet_id)
- {
- if (!packet_id_read (&pin, &work, BOOL_CAST (opt->flags & CO_PACKET_ID_LONG_FORM)))
- CRYPT_ERROR ("error reading packet-id");
- have_pin = !BOOL_CAST (opt->flags & CO_IGNORE_PACKET_ID);
- }
- }
-
- if (have_pin)
- {
- packet_id_reap_test (&opt->packet_id->rec);
- if (packet_id_test (&opt->packet_id->rec, &pin))
- {
- packet_id_add (&opt->packet_id->rec, &pin);
- if (opt->pid_persist && (opt->flags & CO_PACKET_ID_LONG_FORM))
- packet_id_persist_save_obj (opt->pid_persist, opt->packet_id);
- }
- else
- {
- if (!(opt->flags & CO_MUTE_REPLAY_WARNINGS))
- msg (D_REPLAY_ERRORS, "%s: bad packet ID (may be a replay): %s -- see the man page entry for --no-replay and --replay-window for more info or silence this warning with --mute-replay-warnings",
- error_prefix, packet_id_net_print (&pin, true, &gc));
- goto error_exit;
- }
- }
- *buf = work;
- }
-
- gc_free (&gc);
- return true;
-
- error_exit:
- ERR_clear_error ();
- buf->len = 0;
- gc_free (&gc);
- return false;
-}
-
-/*
- * How many bytes will we add to frame buffer for a given
- * set of crypto options?
- */
-void
-crypto_adjust_frame_parameters(struct frame *frame,
- const struct key_type* kt,
- bool cipher_defined,
- bool use_iv,
- bool packet_id,
- bool packet_id_long_form)
-{
- frame_add_to_extra_frame (frame,
- (packet_id ? packet_id_size (packet_id_long_form) : 0) +
- ((cipher_defined && use_iv) ? EVP_CIPHER_iv_length (kt->cipher) : 0) +
- (cipher_defined ? EVP_CIPHER_block_size (kt->cipher) : 0) + /* worst case padding expansion */
- kt->hmac_length);
-}
-
-static const EVP_CIPHER *
-get_cipher (const char *ciphername)
-{
- const EVP_CIPHER *cipher = NULL;
- ASSERT (ciphername);
- cipher = EVP_get_cipherbyname (ciphername);
- if ( !(cipher && cipher_ok (OBJ_nid2sn (EVP_CIPHER_nid (cipher)))))
- msg (M_SSLERR, "Cipher algorithm '%s' not found", ciphername);
- if (EVP_CIPHER_key_length (cipher) > MAX_CIPHER_KEY_LENGTH)
- msg (M_FATAL, "Cipher algorithm '%s' uses a default key size (%d bytes) which is larger than " PACKAGE_NAME "'s current maximum key size (%d bytes)",
- ciphername,
- EVP_CIPHER_key_length (cipher),
- MAX_CIPHER_KEY_LENGTH);
- return cipher;
-}
-
-static const EVP_MD *
-get_md (const char *digest)
-{
- const EVP_MD *md = NULL;
- ASSERT (digest);
- md = EVP_get_digestbyname (digest);
- if (!md)
- msg (M_SSLERR, "Message hash algorithm '%s' not found", digest);
- if (EVP_MD_size (md) > MAX_HMAC_KEY_LENGTH)
- msg (M_FATAL, "Message hash algorithm '%s' uses a default hash size (%d bytes) which is larger than " PACKAGE_NAME "'s current maximum hash size (%d bytes)",
- digest,
- EVP_MD_size (md),
- MAX_HMAC_KEY_LENGTH);
- return md;
-}
-
-static void
-init_cipher (EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
- struct key *key, const struct key_type *kt, int enc,
- const char *prefix)
-{
- struct gc_arena gc = gc_new ();
-
- EVP_CIPHER_CTX_init (ctx);
- if (!EVP_CipherInit_ov (ctx, cipher, NULL, NULL, enc))
- msg (M_SSLERR, "EVP cipher init #1");
-#ifdef HAVE_EVP_CIPHER_CTX_SET_KEY_LENGTH
- if (!EVP_CIPHER_CTX_set_key_length (ctx, kt->cipher_length))
- msg (M_SSLERR, "EVP set key size");
-#endif
- if (!EVP_CipherInit_ov (ctx, NULL, key->cipher, NULL, enc))
- msg (M_SSLERR, "EVP cipher init #2");
-
- msg (D_HANDSHAKE, "%s: Cipher '%s' initialized with %d bit key",
- prefix,
- OBJ_nid2sn (EVP_CIPHER_CTX_nid (ctx)),
- EVP_CIPHER_CTX_key_length (ctx) * 8);
-
- /* make sure we used a big enough key */
- ASSERT (EVP_CIPHER_CTX_key_length (ctx) <= kt->cipher_length);
-
- dmsg (D_SHOW_KEYS, "%s: CIPHER KEY: %s", prefix,
- format_hex (key->cipher, kt->cipher_length, 0, &gc));
- dmsg (D_CRYPTO_DEBUG, "%s: CIPHER block_size=%d iv_size=%d",
- prefix,
- EVP_CIPHER_CTX_block_size (ctx),
- EVP_CIPHER_CTX_iv_length (ctx));
-
- gc_free (&gc);
-}
-
-static void
-init_hmac (HMAC_CTX *ctx, const EVP_MD *digest,
- struct key *key, const struct key_type *kt, const char *prefix)
-{
- struct gc_arena gc = gc_new ();
-
- HMAC_CTX_init (ctx);
- HMAC_Init_ex (ctx, key->hmac, kt->hmac_length, digest, NULL);
- msg (D_HANDSHAKE,
- "%s: Using %d bit message hash '%s' for HMAC authentication",
- prefix, HMAC_size (ctx) * 8, OBJ_nid2sn (EVP_MD_type (digest)));
-
- /* make sure we used a big enough key */
- ASSERT (HMAC_size (ctx) <= kt->hmac_length);
-
- dmsg (D_SHOW_KEYS, "%s: HMAC KEY: %s", prefix,
- format_hex (key->hmac, kt->hmac_length, 0, &gc));
- dmsg (D_CRYPTO_DEBUG, "%s: HMAC size=%d block_size=%d",
- prefix,
- EVP_MD_size (digest),
- EVP_MD_block_size (digest));
-
- gc_free (&gc);
-}
-
-/*
- * Build a struct key_type.
- */
-void
-init_key_type (struct key_type *kt, const char *ciphername,
- bool ciphername_defined, const char *authname,
- bool authname_defined, int keysize,
- bool cfb_ofb_allowed, bool warn)
-{
- CLEAR (*kt);
- if (ciphername && ciphername_defined)
- {
- kt->cipher = get_cipher (ciphername);
- kt->cipher_length = EVP_CIPHER_key_length (kt->cipher);
- if (keysize > 0 && keysize <= MAX_CIPHER_KEY_LENGTH)
- kt->cipher_length = keysize;
-
- /* check legal cipher mode */
- {
- const unsigned int mode = EVP_CIPHER_mode (kt->cipher);
- if (!(mode == EVP_CIPH_CBC_MODE
-#ifdef ALLOW_NON_CBC_CIPHERS
- || (cfb_ofb_allowed && (mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE))
-#endif
- ))
-#ifdef ENABLE_SMALL
- msg (M_FATAL, "Cipher '%s' mode not supported", ciphername);
-#else
- msg (M_FATAL, "Cipher '%s' uses a mode not supported by " PACKAGE_NAME " in your current configuration. CBC mode is always supported, while CFB and OFB modes are supported only when using SSL/TLS authentication and key exchange mode, and when " PACKAGE_NAME " has been built with ALLOW_NON_CBC_CIPHERS.", ciphername);
-#endif
- }
- }
- else
- {
- if (warn)
- msg (M_WARN, "******* WARNING *******: null cipher specified, no encryption will be used");
- }
- if (authname && authname_defined)
- {
- kt->digest = get_md (authname);
- kt->hmac_length = EVP_MD_size (kt->digest);
- }
- else
- {
- if (warn)
- msg (M_WARN, "******* WARNING *******: null MAC specified, no authentication will be used");
- }
-}
-
-const char *
-kt_cipher_name (const struct key_type *kt)
-{
- if (kt->cipher)
- return EVP_CIPHER_name (kt->cipher);
- else
- return "[null-cipher]";
-}
-
-const char *
-kt_digest_name (const struct key_type *kt)
-{
- if (kt->digest)
- return EVP_MD_name (kt->digest);
- else
- return "[null-digest]";
-}
-
-int
-kt_key_size (const struct key_type *kt)
-{
- if (kt->cipher_length)
- return kt->cipher_length * 8;
- else if (kt->cipher)
- return EVP_CIPHER_key_length (kt->cipher) * 8;
- else
- return 0;
-}
-
-/* given a key and key_type, build a key_ctx */
-void
-init_key_ctx (struct key_ctx *ctx, struct key *key,
- const struct key_type *kt, int enc,
- const char *prefix)
-{
- CLEAR (*ctx);
- if (kt->cipher && kt->cipher_length > 0)
- {
- ALLOC_OBJ (ctx->cipher, EVP_CIPHER_CTX);
- init_cipher (ctx->cipher, kt->cipher, key, kt, enc, prefix);
- }
- if (kt->digest && kt->hmac_length > 0)
- {
- ALLOC_OBJ (ctx->hmac, HMAC_CTX);
- init_hmac (ctx->hmac, kt->digest, key, kt, prefix);
- }
-}
-
-void
-free_key_ctx (struct key_ctx *ctx)
-{
- if (ctx->cipher)
- {
- EVP_CIPHER_CTX_cleanup (ctx->cipher);
- free (ctx->cipher);
- ctx->cipher = NULL;
- }
- if (ctx->hmac)
- {
- HMAC_CTX_cleanup (ctx->hmac);
- free (ctx->hmac);
- ctx->hmac = NULL;
- }
-}
-
-void
-free_key_ctx_bi (struct key_ctx_bi *ctx)
-{
- free_key_ctx(&ctx->encrypt);
- free_key_ctx(&ctx->decrypt);
-}
-
-/*
- * Return number of DES cblocks for the current
- * key type or 0 if not a DES cipher.
- */
-static int
-n_DES_cblocks (const struct key_type *kt)
-{
- int ret = 0;
- const char *name = OBJ_nid2sn (EVP_CIPHER_nid (kt->cipher));
- if (name)
- {
- if (!strncmp (name, "DES-", 4))
- {
- ret = EVP_CIPHER_key_length (kt->cipher) / sizeof (DES_cblock);
- }
- else if (!strncmp (name, "DESX-", 5))
- {
- ret = 1;
- }
- }
- dmsg (D_CRYPTO_DEBUG, "CRYPTO INFO: n_DES_cblocks=%d", ret);
- return ret;
-}
-
-static bool
-check_key_DES (struct key *key, const struct key_type *kt, int ndc)
-{
- int i;
- struct buffer b;
-
- buf_set_read (&b, key->cipher, kt->cipher_length);
-
- for (i = 0; i < ndc; ++i)
- {
- DES_cblock *dc = (DES_cblock*) buf_read_alloc (&b, sizeof (DES_cblock));
- if (!dc)
- {
- msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: insufficient key material");
- goto err;
- }
- if (DES_is_weak_key(dc))
- {
- msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: weak key detected");
- goto err;
- }
- if (!DES_check_key_parity (dc))
- {
- msg (D_CRYPT_ERRORS, "CRYPTO INFO: check_key_DES: bad parity detected");
- goto err;
- }
- }
- return true;
-
- err:
- ERR_clear_error ();
- return false;
-}
-
-static void
-fixup_key_DES (struct key *key, const struct key_type *kt, int ndc)
-{
- int i;
- struct buffer b;
-
- buf_set_read (&b, key->cipher, kt->cipher_length);
- for (i = 0; i < ndc; ++i)
- {
- DES_cblock *dc = (DES_cblock*) buf_read_alloc(&b, sizeof(DES_cblock));
- if (!dc)
- {
- msg (D_CRYPT_ERRORS, "CRYPTO INFO: fixup_key_DES: insufficient key material");
- ERR_clear_error ();
- return;
- }
- DES_set_odd_parity (dc);
- }
-}
-
-static bool
-key_is_zero (struct key *key, const struct key_type *kt)
-{
- int i;
- for (i = 0; i < kt->cipher_length; ++i)
- if (key->cipher[i])
- return false;
- msg (D_CRYPT_ERRORS, "CRYPTO INFO: WARNING: zero key detected");
- return true;
-}
-
-/*
- * Make sure that cipher key is a valid key for current key_type.
- */
-bool
-check_key (struct key *key, const struct key_type *kt)
-{
- if (kt->cipher)
- {
- /*
- * Check for zero key
- */
- if (key_is_zero(key, kt))
- return false;
-
- /*
- * Check for weak or semi-weak DES keys.
- */
- {
- const int ndc = n_DES_cblocks (kt);
- if (ndc)
- return check_key_DES (key, kt, ndc);
- else
- return true;
- }
- }
- return true;
-}
-
-/*
- * Make safe mutations to key to ensure it is valid,
- * such as ensuring correct parity on DES keys.
- *
- * This routine cannot guarantee it will generate a good
- * key. You must always call check_key after this routine
- * to make sure.
- */
-void
-fixup_key (struct key *key, const struct key_type *kt)
-{
- struct gc_arena gc = gc_new ();
- if (kt->cipher)
- {
-#ifdef ENABLE_DEBUG
- const struct key orig = *key;
-#endif
- const int ndc = n_DES_cblocks (kt);
-
- if (ndc)
- fixup_key_DES (key, kt, ndc);
-
-#ifdef ENABLE_DEBUG
- if (check_debug_level (D_CRYPTO_DEBUG))
- {
- if (memcmp (orig.cipher, key->cipher, kt->cipher_length))
- dmsg (D_CRYPTO_DEBUG, "CRYPTO INFO: fixup_key: before=%s after=%s",
- format_hex (orig.cipher, kt->cipher_length, 0, &gc),
- format_hex (key->cipher, kt->cipher_length, 0, &gc));
- }
-#endif
- }
- gc_free (&gc);
-}
-
-void
-check_replay_iv_consistency (const struct key_type *kt, bool packet_id, bool use_iv)
-{
- if (cfb_ofb_mode (kt) && !(packet_id && use_iv))
- msg (M_FATAL, "--no-replay or --no-iv cannot be used with a CFB or OFB mode cipher");
-}
-
-bool
-cfb_ofb_mode (const struct key_type* kt)
-{
- if (kt->cipher) {
- const unsigned int mode = EVP_CIPHER_mode (kt->cipher);
- return mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE;
- } else
- return false;
-}
-
-/*
- * Generate a random key. If key_type is provided, make
- * sure generated key is valid for key_type.
- */
-void
-generate_key_random (struct key *key, const struct key_type *kt)
-{
- int cipher_len = MAX_CIPHER_KEY_LENGTH;
- int hmac_len = MAX_HMAC_KEY_LENGTH;
-
- struct gc_arena gc = gc_new ();
-
- do {
- CLEAR (*key);
- if (kt)
- {
- if (kt->cipher && kt->cipher_length > 0 && kt->cipher_length <= cipher_len)
- cipher_len = kt->cipher_length;
-
- if (kt->digest && kt->hmac_length > 0 && kt->hmac_length <= hmac_len)
- hmac_len = kt->hmac_length;
- }
- if (!RAND_bytes (key->cipher, cipher_len)
- || !RAND_bytes (key->hmac, hmac_len))
- msg (M_FATAL, "ERROR: Random number generator cannot obtain entropy for key generation");
-
- dmsg (D_SHOW_KEY_SOURCE, "Cipher source entropy: %s", format_hex (key->cipher, cipher_len, 0, &gc));
- dmsg (D_SHOW_KEY_SOURCE, "HMAC source entropy: %s", format_hex (key->hmac, hmac_len, 0, &gc));
-
- if (kt)
- fixup_key (key, kt);
- } while (kt && !check_key (key, kt));
-
- gc_free (&gc);
-}
-
-/*
- * Print key material
- */
-void
-key2_print (const struct key2* k,
- const struct key_type *kt,
- const char* prefix0,
- const char* prefix1)
-{
- struct gc_arena gc = gc_new ();
- ASSERT (k->n == 2);
- dmsg (D_SHOW_KEY_SOURCE, "%s (cipher): %s",
- prefix0,
- format_hex (k->keys[0].cipher, kt->cipher_length, 0, &gc));
- dmsg (D_SHOW_KEY_SOURCE, "%s (hmac): %s",
- prefix0,
- format_hex (k->keys[0].hmac, kt->hmac_length, 0, &gc));
- dmsg (D_SHOW_KEY_SOURCE, "%s (cipher): %s",
- prefix1,
- format_hex (k->keys[1].cipher, kt->cipher_length, 0, &gc));
- dmsg (D_SHOW_KEY_SOURCE, "%s (hmac): %s",
- prefix1,
- format_hex (k->keys[1].hmac, kt->hmac_length, 0, &gc));
- gc_free (&gc);
-}
-
-void
-test_crypto (const struct crypto_options *co, struct frame* frame)
-{
- int i, j;
- struct gc_arena gc = gc_new ();
- struct buffer src = alloc_buf_gc (TUN_MTU_SIZE (frame), &gc);
- struct buffer work = alloc_buf_gc (BUF_SIZE (frame), &gc);
- struct buffer encrypt_workspace = alloc_buf_gc (BUF_SIZE (frame), &gc);
- struct buffer decrypt_workspace = alloc_buf_gc (BUF_SIZE (frame), &gc);
- struct buffer buf = clear_buf();
-
- /* init work */
- ASSERT (buf_init (&work, FRAME_HEADROOM (frame)));
-
- msg (M_INFO, "Entering " PACKAGE_NAME " crypto self-test mode.");
- for (i = 1; i <= TUN_MTU_SIZE (frame); ++i)
- {
- update_time ();
-
- msg (M_INFO, "TESTING ENCRYPT/DECRYPT of packet length=%d", i);
-
- /*
- * Load src with random data.
- */
- ASSERT (buf_init (&src, 0));
- ASSERT (i <= src.capacity);
- src.len = i;
- ASSERT (RAND_pseudo_bytes (BPTR (&src), BLEN (&src)));
-
- /* copy source to input buf */
- buf = work;
- memcpy (buf_write_alloc (&buf, BLEN (&src)), BPTR (&src), BLEN (&src));
-
- /* encrypt */
- openvpn_encrypt (&buf, encrypt_workspace, co, frame);
-
- /* decrypt */
- openvpn_decrypt (&buf, decrypt_workspace, co, frame);
-
- /* compare */
- if (buf.len != src.len)
- msg (M_FATAL, "SELF TEST FAILED, src.len=%d buf.len=%d", src.len, buf.len);
- for (j = 0; j < i; ++j)
- {
- const uint8_t in = *(BPTR (&src) + j);
- const uint8_t out = *(BPTR (&buf) + j);
- if (in != out)
- msg (M_FATAL, "SELF TEST FAILED, pos=%d in=%d out=%d", j, in, out);
- }
- }
- msg (M_INFO, PACKAGE_NAME " crypto self-test mode SUCCEEDED.");
- gc_free (&gc);
-}
-
-#ifdef USE_SSL
-void
-get_tls_handshake_key (const struct key_type *key_type,
- struct key_ctx_bi *ctx,
- const char *passphrase_file,
- bool key_direction)
-{
- if (passphrase_file && key_type->hmac_length)
- {
- struct key2 key2;
- struct key_type kt = *key_type;
- struct key_direction_state kds;
-
- /* for control channel we are only authenticating, not encrypting */
- kt.cipher_length = 0;
- kt.cipher = NULL;
-
- /* first try to parse as an OpenVPN static key file */
- read_key_file (&key2, passphrase_file, false);
-
- /* succeeded? */
- if (key2.n == 2)
- {
- msg (M_INFO,
- "Control Channel Authentication: using '%s' as a " PACKAGE_NAME " static key file",
- passphrase_file);
- }
- else
- {
- int hash_size;
-
- CLEAR (key2);
-
- /* failed, now try to get hash from a freeform file */
- hash_size = read_passphrase_hash (passphrase_file,
- kt.digest,
- key2.keys[0].hmac,
- MAX_HMAC_KEY_LENGTH);
- ASSERT (hash_size == kt.hmac_length);
-
- /* suceeded */
- key2.n = 1;
-
- msg (M_INFO,
- "Control Channel Authentication: using '%s' as a free-form passphrase file",
- passphrase_file);
- }
-
- /* handle key direction */
-
- key_direction_state_init (&kds, key_direction);
- must_have_n_keys (passphrase_file, "tls-auth", &key2, kds.need_keys);
-
- /* initialize hmac key in both directions */
-
- init_key_ctx (&ctx->encrypt, &key2.keys[kds.out_key], &kt, DO_ENCRYPT,
- "Outgoing Control Channel Authentication");
- init_key_ctx (&ctx->decrypt, &key2.keys[kds.in_key], &kt, DO_DECRYPT,
- "Incoming Control Channel Authentication");
-
- CLEAR (key2);
- }
- else
- {
- CLEAR (*ctx);
- }
-}
-#endif
-
-/* header and footer for static key file */
-static const char static_key_head[] = "-----BEGIN " PACKAGE_NAME " Static key V1-----";
-static const char static_key_foot[] = "-----END " PACKAGE_NAME " Static key V1-----";
-
-static const char printable_char_fmt[] =
- "Non-Hex character ('%c') found at line %d in key file '%s' (%d/%d/%d bytes found/min/max)";
-
-static const char unprintable_char_fmt[] =
- "Non-Hex, unprintable character (0x%02x) found at line %d in key file '%s' (%d/%d/%d bytes found/min/max)";
-
-/* read key from file */
-void
-read_key_file (struct key2 *key2, const char *filename, bool must_succeed)
-{
- struct gc_arena gc = gc_new ();
- struct buffer in = alloc_buf_gc (64, &gc);
- int fd, size;
- uint8_t hex_byte[3] = {0, 0, 0};
-
- /* parse info */
- int hb_index = 0;
- int line_num = 1;
- int line_index = 0;
- int match = 0;
-
- /* output */
- uint8_t* out = (uint8_t*) &key2->keys;
- const int keylen = sizeof (key2->keys);
- int count = 0;
-
- /* parse states */
-# define PARSE_INITIAL 0
-# define PARSE_HEAD 1
-# define PARSE_DATA 2
-# define PARSE_DATA_COMPLETE 3
-# define PARSE_FOOT 4
-# define PARSE_FINISHED 5
- int state = PARSE_INITIAL;
-
- /* constants */
- const int hlen = strlen (static_key_head);
- const int flen = strlen (static_key_foot);
- const int onekeylen = sizeof (key2->keys[0]);
-
- CLEAR (*key2);
-
- fd = open (filename, O_RDONLY);
- if (fd == -1)
- msg (M_ERR, "Cannot open file key file '%s'", filename);
-
- while ((size = read (fd, in.data, in.capacity)))
- {
- const char *cp = (char *)in.data;
- while (size)
- {
- const char c = *cp;
-
-#if 0
- msg (M_INFO, "char='%c' s=%d ln=%d li=%d m=%d c=%d",
- c, state, line_num, line_index, match, count);
-#endif
-
- if (c == '\n')
- {
- line_index = match = 0;
- ++line_num;
- }
- else
- {
- /* first char of new line */
- if (!line_index)
- {
- /* first char of line after header line? */
- if (state == PARSE_HEAD)
- state = PARSE_DATA;
-
- /* first char of footer */
- if ((state == PARSE_DATA || state == PARSE_DATA_COMPLETE) && c == '-')
- state = PARSE_FOOT;
- }
-
- /* compare read chars with header line */
- if (state == PARSE_INITIAL)
- {
- if (line_index < hlen && c == static_key_head[line_index])
- {
- if (++match == hlen)
- state = PARSE_HEAD;
- }
- }
-
- /* compare read chars with footer line */
- if (state == PARSE_FOOT)
- {
- if (line_index < flen && c == static_key_foot[line_index])
- {
- if (++match == flen)
- state = PARSE_FINISHED;
- }
- }
-
- /* reading key */
- if (state == PARSE_DATA)
- {
- if (isxdigit(c))
- {
- ASSERT (hb_index >= 0 && hb_index < 2);
- hex_byte[hb_index++] = c;
- if (hb_index == 2)
- {
- unsigned int u;
- ASSERT(sscanf((const char *)hex_byte, "%x", &u) == 1);
- *out++ = u;
- hb_index = 0;
- if (++count == keylen)
- state = PARSE_DATA_COMPLETE;
- }
- }
- else if (isspace(c))
- ;
- else
- {
- msg (M_FATAL,
- (isprint (c) ? printable_char_fmt : unprintable_char_fmt),
- c, line_num, filename, count, onekeylen, keylen);
- }
- }
- ++line_index;
- }
- ++cp;
- --size;
- }
- }
-
- close (fd);
-
- /*
- * Normally we will read either 1 or 2 keys from file.
- */
- key2->n = count / onekeylen;
-
- ASSERT (key2->n >= 0 && key2->n <= (int) SIZE (key2->keys));
-
- if (must_succeed)
- {
- if (!key2->n)
- msg (M_FATAL, "Insufficient key material or header text not found found in file '%s' (%d/%d/%d bytes found/min/max)",
- filename, count, onekeylen, keylen);
-
- if (state != PARSE_FINISHED)
- msg (M_FATAL, "Footer text not found in file '%s' (%d/%d/%d bytes found/min/max)",
- filename, count, onekeylen, keylen);
- }
-
- /* zero file read buffer */
- buf_clear (&in);
-
- if (key2->n)
- warn_if_group_others_accessible (filename);
-
-#if 0
- /* DEBUGGING */
- {
- int i;
- printf ("KEY READ, n=%d\n", key2->n);
- for (i = 0; i < (int) SIZE (key2->keys); ++i)
- {
- /* format key as ascii */
- const char *fmt = format_hex_ex ((const uint8_t*)&key2->keys[i],
- sizeof (key2->keys[i]),
- 0,
- 16,
- "\n",
- &gc);
- printf ("[%d]\n%s\n\n", i, fmt);
- }
- }
-#endif
-
- /* pop our garbage collection level */
- gc_free (&gc);
-}
-
-int
-read_passphrase_hash (const char *passphrase_file,
- const EVP_MD *digest,
- uint8_t *output,
- int len)
-{
- unsigned int outlen = 0;
- EVP_MD_CTX md;
-
- ASSERT (len >= EVP_MD_size (digest));
- memset (output, 0, len);
-
- EVP_DigestInit (&md, digest);
-
- /* read passphrase file */
- {
- const int min_passphrase_size = 8;
- uint8_t buf[64];
- int total_size = 0;
- int fd = open (passphrase_file, O_RDONLY);
-
- if (fd == -1)
- msg (M_ERR, "Cannot open passphrase file: '%s'", passphrase_file);
-
- for (;;)
- {
- int size = read (fd, buf, sizeof (buf));
- if (size == 0)
- break;
- if (size == -1)
- msg (M_ERR, "Read error on passphrase file: '%s'",
- passphrase_file);
- EVP_DigestUpdate (&md, buf, size);
- total_size += size;
- }
- close (fd);
-
- warn_if_group_others_accessible (passphrase_file);
-
- if (total_size < min_passphrase_size)
- msg (M_FATAL,
- "Passphrase file '%s' is too small (must have at least %d characters)",
- passphrase_file, min_passphrase_size);
- }
-
- EVP_DigestFinal (&md, output, &outlen);
- EVP_MD_CTX_cleanup (&md);
- return outlen;
-}
-
-/*
- * Write key to file, return number of random bits
- * written.
- */
-int
-write_key_file (const int nkeys, const char *filename)
-{
- struct gc_arena gc = gc_new ();
-
- int fd, i;
- int nbits = 0;
-
- /* must be large enough to hold full key file */
- struct buffer out = alloc_buf_gc (2048, &gc);
- struct buffer nbits_head_text = alloc_buf_gc (128, &gc);
-
- /* how to format the ascii file representation of key */
- const int bytes_per_line = 16;
-
- /* open key file */
- fd = open (filename, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
-
- if (fd == -1)
- msg (M_ERR, "Cannot open shared secret file '%s' for write", filename);
-
- buf_printf (&out, "%s\n", static_key_head);
-
- for (i = 0; i < nkeys; ++i)
- {
- struct key key;
- char* fmt;
-
- /* generate random bits */
- generate_key_random (&key, NULL);
-
- /* format key as ascii */
- fmt = format_hex_ex ((const uint8_t*)&key,
- sizeof (key),
- 0,
- bytes_per_line,
- "\n",
- &gc);
-
- /* increment random bits counter */
- nbits += sizeof (key) * 8;
-
- /* write to holding buffer */
- buf_printf (&out, "%s\n", fmt);
-
- /* zero memory which held key component (will be freed by GC) */
- memset (fmt, 0, strlen(fmt));
- CLEAR (key);
- }
-
- buf_printf (&out, "%s\n", static_key_foot);
-
- /* write number of bits */
- buf_printf (&nbits_head_text, "#\n# %d bit " PACKAGE_NAME " static key\n#\n", nbits);
- buf_write_string_file (&nbits_head_text, filename, fd);
-
- /* write key file, now formatted in out, to file */
- buf_write_string_file (&out, filename, fd);
-
- if (close (fd))
- msg (M_ERR, "Close error on shared secret file %s", filename);
-
- /* zero memory which held file content (memory will be freed by GC) */
- buf_clear (&out);
-
- /* pop our garbage collection level */
- gc_free (&gc);
-
- return nbits;
-}
-
-void
-must_have_n_keys (const char *filename, const char *option, const struct key2 *key2, int n)
-{
- if (key2->n < n)
- {
-#ifdef ENABLE_SMALL
- msg (M_FATAL, "Key file '%s' used in --%s contains insufficient key material [keys found=%d required=%d]", filename, option, key2->n, n);
-#else
- msg (M_FATAL, "Key file '%s' used in --%s contains insufficient key material [keys found=%d required=%d] -- try generating a new key file with '" PACKAGE " --genkey --secret [file]', or use the existing key file in bidirectional mode by specifying --%s without a key direction parameter", filename, option, key2->n, n, option);
-#endif
- }
-}
-
-int
-ascii2keydirection (int msglevel, const char *str)
-{
- if (!str)
- return KEY_DIRECTION_BIDIRECTIONAL;
- else if (!strcmp (str, "0"))
- return KEY_DIRECTION_NORMAL;
- else if (!strcmp (str, "1"))
- return KEY_DIRECTION_INVERSE;
- else
- {
- msg (msglevel, "Unknown key direction '%s' -- must be '0' or '1'", str);
- return -1;
- }
- return KEY_DIRECTION_BIDIRECTIONAL; /* NOTREACHED */
-}
-
-const char *
-keydirection2ascii (int kd, bool remote)
-{
- if (kd == KEY_DIRECTION_BIDIRECTIONAL)
- return NULL;
- else if (kd == KEY_DIRECTION_NORMAL)
- return remote ? "1" : "0";
- else if (kd == KEY_DIRECTION_INVERSE)
- return remote ? "0" : "1";
- else
- {
- ASSERT (0);
- }
- return NULL; /* NOTREACHED */
-}
-
-void
-key_direction_state_init (struct key_direction_state *kds, int key_direction)
-{
- CLEAR (*kds);
- switch (key_direction)
- {
- case KEY_DIRECTION_NORMAL:
- kds->out_key = 0;
- kds->in_key = 1;
- kds->need_keys = 2;
- break;
- case KEY_DIRECTION_INVERSE:
- kds->out_key = 1;
- kds->in_key = 0;
- kds->need_keys = 2;
- break;
- case KEY_DIRECTION_BIDIRECTIONAL:
- kds->out_key = 0;
- kds->in_key = 0;
- kds->need_keys = 1;
- break;
- default:
- ASSERT (0);
- }
-}
-
-void
-verify_fix_key2 (struct key2 *key2, const struct key_type *kt, const char *shared_secret_file)
-{
- int i;
-
- for (i = 0; i < key2->n; ++i)
- {
- /* Fix parity for DES keys and make sure not a weak key */
- fixup_key (&key2->keys[i], kt);
-
- /* This should be a very improbable failure */
- if (!check_key (&key2->keys[i], kt))
- msg (M_FATAL, "Key #%d in '%s' is bad. Try making a new key with --genkey.",
- i+1, shared_secret_file);
- }
-}
-
-/* given a key and key_type, write key to buffer */
-bool
-write_key (const struct key *key, const struct key_type *kt,
- struct buffer *buf)
-{
- ASSERT (kt->cipher_length <= MAX_CIPHER_KEY_LENGTH
- && kt->hmac_length <= MAX_HMAC_KEY_LENGTH);
-
- if (!buf_write (buf, &kt->cipher_length, 1))
- return false;
- if (!buf_write (buf, &kt->hmac_length, 1))
- return false;
- if (!buf_write (buf, key->cipher, kt->cipher_length))
- return false;
- if (!buf_write (buf, key->hmac, kt->hmac_length))
- return false;
-
- return true;
-}
-
-/*
- * Given a key_type and buffer, read key from buffer.
- * Return: 1 on success
- * -1 read failure
- * 0 on key length mismatch
- */
-int
-read_key (struct key *key, const struct key_type *kt, struct buffer *buf)
-{
- uint8_t cipher_length;
- uint8_t hmac_length;
-
- CLEAR (*key);
- if (!buf_read (buf, &cipher_length, 1))
- goto read_err;
- if (!buf_read (buf, &hmac_length, 1))
- goto read_err;
-
- if (!buf_read (buf, key->cipher, cipher_length))
- goto read_err;
- if (!buf_read (buf, key->hmac, hmac_length))
- goto read_err;
-
- if (cipher_length != kt->cipher_length || hmac_length != kt->hmac_length)
- goto key_len_err;
-
- return 1;
-
-read_err:
- msg (D_TLS_ERRORS, "TLS Error: error reading key from remote");
- return -1;
-
-key_len_err:
- msg (D_TLS_ERRORS,
- "TLS Error: key length mismatch, local cipher/hmac %d/%d, remote cipher/hmac %d/%d",
- kt->cipher_length, kt->hmac_length, cipher_length, hmac_length);
- return 0;
-}
-
-void
-show_available_ciphers ()
-{
- int nid;
-
-
-#ifndef ENABLE_SMALL
- printf ("The following ciphers and cipher modes are available\n"
- "for use with " PACKAGE_NAME ". Each cipher shown below may be\n"
- "used as a parameter to the --cipher option. The default\n"
- "key size is shown as well as whether or not it can be\n"
- "changed with the --keysize directive. Using a CBC mode\n"
- "is recommended.\n\n");
-#endif
-
- for (nid = 0; nid < 10000; ++nid) /* is there a better way to get the size of the nid list? */
- {
- const EVP_CIPHER *cipher = EVP_get_cipherbynid (nid);
- if (cipher && cipher_ok (OBJ_nid2sn (nid)))
- {
- const unsigned int mode = EVP_CIPHER_mode (cipher);
- if (mode == EVP_CIPH_CBC_MODE
-#ifdef ALLOW_NON_CBC_CIPHERS
- || mode == EVP_CIPH_CFB_MODE || mode == EVP_CIPH_OFB_MODE
-#endif
- )
- printf ("%s %d bit default key (%s)\n",
- OBJ_nid2sn (nid),
- EVP_CIPHER_key_length (cipher) * 8,
- ((EVP_CIPHER_flags (cipher) & EVP_CIPH_VARIABLE_LENGTH) ?
- "variable" : "fixed"));
- }
- }
- printf ("\n");
-}
-
-void
-show_available_digests ()
-{
- int nid;
-
-#ifndef ENABLE_SMALL
- printf ("The following message digests are available for use with\n"
- PACKAGE_NAME ". A message digest is used in conjunction with\n"
- "the HMAC function, to authenticate received packets.\n"
- "You can specify a message digest as parameter to\n"
- "the --auth option.\n\n");
-#endif
-
- for (nid = 0; nid < 10000; ++nid)
- {
- const EVP_MD *digest = EVP_get_digestbynid (nid);
- if (digest)
- {
- printf ("%s %d bit digest size\n",
- OBJ_nid2sn (nid), EVP_MD_size (digest) * 8);
- }
- }
- printf ("\n");
-}
-
-void
-show_available_engines ()
-{
-#if CRYPTO_ENGINE
- ENGINE *e;
-
- printf ("OpenSSL Crypto Engines\n\n");
-
- ENGINE_load_builtin_engines ();
-
- e = ENGINE_get_first ();
- while (e)
- {
- printf ("%s [%s]\n",
- ENGINE_get_name (e),
- ENGINE_get_id (e));
- e = ENGINE_get_next (e);
- }
- ENGINE_cleanup ();
-#else
- printf ("Sorry, OpenSSL hardware crypto engine functionality is not available.\n");
-#endif
-}
-
-/*
- * Enable crypto acceleration, if available
- */
-
-static bool engine_initialized = false; /* GLOBAL */
-
-#if CRYPTO_ENGINE
-
-static ENGINE *engine_persist = NULL; /* GLOBAL */
-
-/* Try to load an engine in a shareable library */
-static ENGINE *
-try_load_engine (const char *engine)
-{
- ENGINE *e = ENGINE_by_id ("dynamic");
- if (e)
- {
- if (!ENGINE_ctrl_cmd_string (e, "SO_PATH", engine, 0)
- || !ENGINE_ctrl_cmd_string (e, "LOAD", NULL, 0))
- {
- ENGINE_free (e);
- e = NULL;
- }
- }
- return e;
-}
-
-static ENGINE *
-setup_engine (const char *engine)
-{
- ENGINE *e = NULL;
-
- ENGINE_load_builtin_engines ();
-
- if (engine)
- {
- if (strcmp (engine, "auto") == 0)
- {
- msg (M_INFO, "Initializing OpenSSL auto engine support");
- ENGINE_register_all_complete ();
- return NULL;
- }
- if ((e = ENGINE_by_id (engine)) == NULL
- && (e = try_load_engine (engine)) == NULL)
- {
- msg (M_FATAL, "OpenSSL error: cannot load engine '%s'", engine);
- }
-
- if (!ENGINE_set_default (e, ENGINE_METHOD_ALL))
- {
- msg (M_FATAL, "OpenSSL error: ENGINE_set_default failed on engine '%s'",
- engine);
- }
-
- msg (M_INFO, "Initializing OpenSSL support for engine '%s'",
- ENGINE_get_id (e));
- }
- return e;
-}
-#endif
-
-void
-init_crypto_lib_engine (const char *engine_name)
-{
- if (!engine_initialized)
- {
-#if CRYPTO_ENGINE
- ASSERT (engine_name);
- ASSERT (!engine_persist);
- engine_persist = setup_engine (engine_name);
-#else
- msg (M_WARN, "Note: OpenSSL hardware crypto engine functionality is not available");
-#endif
- engine_initialized = true;
- }
-}
-
-/*
- * This routine should have additional OpenSSL crypto library initialisations
- * used by both crypto and ssl components of OpenVPN.
- */
-void init_crypto_lib ()
-{
-}
-
-void uninit_crypto_lib ()
-{
-#if CRYPTO_ENGINE
- if (engine_initialized)
- {
- ENGINE_cleanup ();
- engine_persist = NULL;
- engine_initialized = false;
- }
-#endif
-}
-
-/*
- * Random number functions, used in cases where we want
- * reasonably strong cryptographic random number generation
- * without depleting our entropy pool. Used for random
- * IV values and a number of other miscellaneous tasks.
- */
-
-#define NONCE_SECRET_LEN 16
-
-static uint8_t nonce_data [SHA_DIGEST_LENGTH + NONCE_SECRET_LEN]; /* GLOBAL */
-
-void
-prng_init (void)
-{
- if (!RAND_bytes (nonce_data, sizeof(nonce_data)))
- msg (M_FATAL, "ERROR: Random number generator cannot obtain entropy for PRNG");
-}
-
-void
-prng_bytes (uint8_t *output, int len)
-{
- SHA_CTX ctx;
- mutex_lock_static (L_PRNG);
- while (len > 0)
- {
- const int blen = min_int (len, SHA_DIGEST_LENGTH);
- SHA1_Init (&ctx);
- SHA1_Update (&ctx, nonce_data, sizeof (nonce_data));
- SHA1_Final (nonce_data, &ctx);
- memcpy (output, nonce_data, blen);
- output += blen;
- len -= blen;
- }
- mutex_unlock_static (L_PRNG);
-}
-
-/* an analogue to the random() function, but use prng_bytes */
-long int
-get_random()
-{
- long int l;
- prng_bytes ((unsigned char *)&l, sizeof(l));
- if (l < 0)
- l = -l;
- return l;
-}
-
-const char *
-md5sum (uint8_t *buf, int len, int n_print_chars, struct gc_arena *gc)
-{
- uint8_t digest[MD5_DIGEST_LENGTH];
- MD5 (buf, len, digest);
- return format_hex (digest, MD5_DIGEST_LENGTH, n_print_chars, gc);
-}
-
-/*
- * OpenSSL memory debugging. If dmalloc debugging is enabled, tell
- * OpenSSL to use our private malloc/realloc/free functions so that
- * we can dispatch them to dmalloc.
- */
-
-#ifdef DMALLOC
-
-static void *
-crypto_malloc (size_t size, const char *file, int line)
-{
- return dmalloc_malloc(file, line, size, DMALLOC_FUNC_MALLOC, 0, 0);
-}
-
-static void *
-crypto_realloc (void *ptr, size_t size, const char *file, int line)
-{
- return dmalloc_realloc(file, line, ptr, size, DMALLOC_FUNC_REALLOC, 0);
-}
-
-static void
-crypto_free (void *ptr)
-{
- dmalloc_free (__FILE__, __LINE__, ptr, DMALLOC_FUNC_FREE);
-}
-
-void
-openssl_dmalloc_init (void)
-{
- CRYPTO_set_mem_ex_functions (crypto_malloc,
- crypto_realloc,
- crypto_free);
-}
-
-#endif /* DMALLOC */
-
-#ifndef USE_SSL
-
-void
-init_ssl_lib (void)
-{
- ERR_load_crypto_strings ();
- OpenSSL_add_all_algorithms ();
- init_crypto_lib ();
-}
-
-void
-free_ssl_lib (void)
-{
- uninit_crypto_lib ();
- EVP_cleanup ();
- ERR_free_strings ();
-}
-
-#endif /* USE_SSL */
-#endif /* USE_CRYPTO */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 07:14:22 +0000