/*
- *
- * cipher.c
- *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- *
- * Created: Wed Apr 19 17:41:39 1995 ylo
- *
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ *
+ * Copyright (c) 1999 Niels Provos. All rights reserved.
+ * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
-RCSID("$Id$");
+RCSID("$OpenBSD: cipher.c,v 1.63 2003/04/12 10:13:57 markus Exp $");
-#include "ssh.h"
+#include "xmalloc.h"
+#include "log.h"
#include "cipher.h"
-#include "config.h"
-#ifdef HAVE_OPENSSL
#include <openssl/md5.h>
+
+#if OPENSSL_VERSION_NUMBER < 0x00906000L
+#define SSH_OLD_EVP
+#define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data)
+#endif
+
+#if OPENSSL_VERSION_NUMBER < 0x00907000L
+#include "rijndael.h"
+static const EVP_CIPHER *evp_rijndael(void);
+#endif
+static const EVP_CIPHER *evp_ssh1_3des(void);
+static const EVP_CIPHER *evp_ssh1_bf(void);
+
+struct Cipher {
+ char *name;
+ int number; /* for ssh1 only */
+ u_int block_size;
+ u_int key_len;
+ const EVP_CIPHER *(*evptype)(void);
+} ciphers[] = {
+ { "none", SSH_CIPHER_NONE, 8, 0, EVP_enc_null },
+ { "des", SSH_CIPHER_DES, 8, 8, EVP_des_cbc },
+ { "3des", SSH_CIPHER_3DES, 8, 16, evp_ssh1_3des },
+ { "blowfish", SSH_CIPHER_BLOWFISH, 8, 32, evp_ssh1_bf },
+
+ { "3des-cbc", SSH_CIPHER_SSH2, 8, 24, EVP_des_ede3_cbc },
+ { "blowfish-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_bf_cbc },
+ { "cast128-cbc", SSH_CIPHER_SSH2, 8, 16, EVP_cast5_cbc },
+ { "arcfour", SSH_CIPHER_SSH2, 8, 16, EVP_rc4 },
+#if OPENSSL_VERSION_NUMBER < 0x00907000L
+ { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, evp_rijndael },
+ { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, evp_rijndael },
+ { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
+ { "rijndael-cbc@lysator.liu.se",
+ SSH_CIPHER_SSH2, 16, 32, evp_rijndael },
+#else
+ { "aes128-cbc", SSH_CIPHER_SSH2, 16, 16, EVP_aes_128_cbc },
+ { "aes192-cbc", SSH_CIPHER_SSH2, 16, 24, EVP_aes_192_cbc },
+ { "aes256-cbc", SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
+ { "rijndael-cbc@lysator.liu.se",
+ SSH_CIPHER_SSH2, 16, 32, EVP_aes_256_cbc },
+#endif
+
+ { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL }
+};
+
+/*--*/
+
+u_int
+cipher_blocksize(Cipher *c)
+{
+ return (c->block_size);
+}
+
+u_int
+cipher_keylen(Cipher *c)
+{
+ return (c->key_len);
+}
+
+u_int
+cipher_get_number(Cipher *c)
+{
+ return (c->number);
+}
+
+u_int
+cipher_mask_ssh1(int client)
+{
+ u_int mask = 0;
+ mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
+ mask |= 1 << SSH_CIPHER_BLOWFISH;
+ if (client) {
+ mask |= 1 << SSH_CIPHER_DES;
+ }
+ return mask;
+}
+
+Cipher *
+cipher_by_name(const char *name)
+{
+ Cipher *c;
+ for (c = ciphers; c->name != NULL; c++)
+ if (strcasecmp(c->name, name) == 0)
+ return c;
+ return NULL;
+}
+
+Cipher *
+cipher_by_number(int id)
+{
+ Cipher *c;
+ for (c = ciphers; c->name != NULL; c++)
+ if (c->number == id)
+ return c;
+ return NULL;
+}
+
+#define CIPHER_SEP ","
+int
+ciphers_valid(const char *names)
+{
+ Cipher *c;
+ char *ciphers, *cp;
+ char *p;
+
+ if (names == NULL || strcmp(names, "") == 0)
+ return 0;
+ ciphers = cp = xstrdup(names);
+ for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
+ (p = strsep(&cp, CIPHER_SEP))) {
+ c = cipher_by_name(p);
+ if (c == NULL || c->number != SSH_CIPHER_SSH2) {
+ debug("bad cipher %s [%s]", p, names);
+ xfree(ciphers);
+ return 0;
+ } else {
+ debug3("cipher ok: %s [%s]", p, names);
+ }
+ }
+ debug3("ciphers ok: [%s]", names);
+ xfree(ciphers);
+ return 1;
+}
+
+/*
+ * Parses the name of the cipher. Returns the number of the corresponding
+ * cipher, or -1 on error.
+ */
+
+int
+cipher_number(const char *name)
+{
+ Cipher *c;
+ if (name == NULL)
+ return -1;
+ c = cipher_by_name(name);
+ return (c==NULL) ? -1 : c->number;
+}
+
+char *
+cipher_name(int id)
+{
+ Cipher *c = cipher_by_number(id);
+ return (c==NULL) ? "<unknown>" : c->name;
+}
+
+void
+cipher_init(CipherContext *cc, Cipher *cipher,
+ const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
+ int encrypt)
+{
+ static int dowarn = 1;
+#ifdef SSH_OLD_EVP
+ EVP_CIPHER *type;
+#else
+ const EVP_CIPHER *type;
#endif
-#ifdef HAVE_SSL
-#include <ssl/md5.h>
+ int klen;
+
+ if (cipher->number == SSH_CIPHER_DES) {
+ if (dowarn) {
+ error("Warning: use of DES is strongly discouraged "
+ "due to cryptographic weaknesses");
+ dowarn = 0;
+ }
+ if (keylen > 8)
+ keylen = 8;
+ }
+ cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
+
+ if (keylen < cipher->key_len)
+ fatal("cipher_init: key length %d is insufficient for %s.",
+ keylen, cipher->name);
+ if (iv != NULL && ivlen < cipher->block_size)
+ fatal("cipher_init: iv length %d is insufficient for %s.",
+ ivlen, cipher->name);
+ cc->cipher = cipher;
+
+ type = (*cipher->evptype)();
+
+ EVP_CIPHER_CTX_init(&cc->evp);
+#ifdef SSH_OLD_EVP
+ if (type->key_len > 0 && type->key_len != keylen) {
+ debug("cipher_init: set keylen (%d -> %d)",
+ type->key_len, keylen);
+ type->key_len = keylen;
+ }
+ EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv,
+ (encrypt == CIPHER_ENCRYPT));
+#else
+ if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
+ (encrypt == CIPHER_ENCRYPT)) == 0)
+ fatal("cipher_init: EVP_CipherInit failed for %s",
+ cipher->name);
+ klen = EVP_CIPHER_CTX_key_length(&cc->evp);
+ if (klen > 0 && keylen != klen) {
+ debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
+ if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
+ fatal("cipher_init: set keylen failed (%d -> %d)",
+ klen, keylen);
+ }
+ if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
+ fatal("cipher_init: EVP_CipherInit: set key failed for %s",
+ cipher->name);
#endif
+}
+
+void
+cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+{
+ if (len % cc->cipher->block_size)
+ fatal("cipher_encrypt: bad plaintext length %d", len);
+#ifdef SSH_OLD_EVP
+ EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
+#else
+ if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
+ fatal("evp_crypt: EVP_Cipher failed");
+#endif
+}
+
+void
+cipher_cleanup(CipherContext *cc)
+{
+#ifdef SSH_OLD_EVP
+ EVP_CIPHER_CTX_cleanup(&cc->evp);
+#else
+ if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
+ error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
+#endif
+}
+
+/*
+ * Selects the cipher, and keys if by computing the MD5 checksum of the
+ * passphrase and using the resulting 16 bytes as the key.
+ */
+
+void
+cipher_set_key_string(CipherContext *cc, Cipher *cipher,
+ const char *passphrase, int encrypt)
+{
+ MD5_CTX md;
+ u_char digest[16];
+
+ MD5_Init(&md);
+ MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
+ MD5_Final(digest, &md);
+
+ cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt);
+
+ memset(digest, 0, sizeof(digest));
+ memset(&md, 0, sizeof(md));
+}
+
+/* Implementations for other non-EVP ciphers */
/*
- * What kind of tripple DES are these 2 routines?
+ * This is used by SSH1:
+ *
+ * What kind of triple DES are these 2 routines?
*
* Why is there a redundant initialization vector?
*
* result of that there is no longer any known iv1 to use when
* choosing the X block.
*/
-void
-SSH_3CBC_ENCRYPT(des_key_schedule ks1,
- des_key_schedule ks2, des_cblock * iv2,
- des_key_schedule ks3, des_cblock * iv3,
- unsigned char *dest, unsigned char *src,
- unsigned int len)
+struct ssh1_3des_ctx
{
- des_cblock iv1;
+ EVP_CIPHER_CTX k1, k2, k3;
+};
- memcpy(&iv1, iv2, 8);
+static int
+ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
+ int enc)
+{
+ struct ssh1_3des_ctx *c;
+ u_char *k1, *k2, *k3;
- des_cbc_encrypt(src, dest, len, ks1, &iv1, DES_ENCRYPT);
- memcpy(&iv1, dest + len - 8, 8);
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
+ c = xmalloc(sizeof(*c));
+ EVP_CIPHER_CTX_set_app_data(ctx, c);
+ }
+ if (key == NULL)
+ return (1);
+ if (enc == -1)
+ enc = ctx->encrypt;
+ k1 = k2 = k3 = (u_char *) key;
+ k2 += 8;
+ if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
+ if (enc)
+ k3 += 16;
+ else
+ k1 += 16;
+ }
+ EVP_CIPHER_CTX_init(&c->k1);
+ EVP_CIPHER_CTX_init(&c->k2);
+ EVP_CIPHER_CTX_init(&c->k3);
+#ifdef SSH_OLD_EVP
+ EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
+ EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
+ EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
+#else
+ if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 ||
+ EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 ||
+ EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
+ memset(c, 0, sizeof(*c));
+ xfree(c);
+ EVP_CIPHER_CTX_set_app_data(ctx, NULL);
+ return (0);
+ }
+#endif
+ return (1);
+}
- des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_DECRYPT);
- memcpy(iv2, &iv1, 8); /* Note how iv1 == iv2 on entry and exit. */
+static int
+ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len)
+{
+ struct ssh1_3des_ctx *c;
- des_cbc_encrypt(dest, dest, len, ks3, iv3, DES_ENCRYPT);
- memcpy(iv3, dest + len - 8, 8);
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
+ error("ssh1_3des_cbc: no context");
+ return (0);
+ }
+#ifdef SSH_OLD_EVP
+ EVP_Cipher(&c->k1, dest, (u_char *)src, len);
+ EVP_Cipher(&c->k2, dest, dest, len);
+ EVP_Cipher(&c->k3, dest, dest, len);
+#else
+ if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
+ EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
+ EVP_Cipher(&c->k3, dest, dest, len) == 0)
+ return (0);
+#endif
+ return (1);
}
-void
-SSH_3CBC_DECRYPT(des_key_schedule ks1,
- des_key_schedule ks2, des_cblock * iv2,
- des_key_schedule ks3, des_cblock * iv3,
- unsigned char *dest, unsigned char *src,
- unsigned int len)
+static int
+ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
{
- des_cblock iv1;
-
- memcpy(&iv1, iv2, 8);
+ struct ssh1_3des_ctx *c;
- des_cbc_encrypt(src, dest, len, ks3, iv3, DES_DECRYPT);
- memcpy(iv3, src + len - 8, 8);
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
+ memset(c, 0, sizeof(*c));
+ xfree(c);
+ EVP_CIPHER_CTX_set_app_data(ctx, NULL);
+ }
+ return (1);
+}
- des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_ENCRYPT);
- memcpy(iv2, dest + len - 8, 8);
+static void
+ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len)
+{
+ struct ssh1_3des_ctx *c;
+
+ if (len != 24)
+ fatal("%s: bad 3des iv length: %d", __func__, len);
+ if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
+ fatal("%s: no 3des context", __func__);
+ if (doset) {
+ debug3("%s: Installed 3DES IV", __func__);
+ memcpy(c->k1.iv, iv, 8);
+ memcpy(c->k2.iv, iv + 8, 8);
+ memcpy(c->k3.iv, iv + 16, 8);
+ } else {
+ debug3("%s: Copying 3DES IV", __func__);
+ memcpy(iv, c->k1.iv, 8);
+ memcpy(iv + 8, c->k2.iv, 8);
+ memcpy(iv + 16, c->k3.iv, 8);
+ }
+}
- des_cbc_encrypt(dest, dest, len, ks1, &iv1, DES_DECRYPT);
- /* memcpy(&iv1, iv2, 8); */
- /* Note how iv1 == iv2 on entry and exit. */
+static const EVP_CIPHER *
+evp_ssh1_3des(void)
+{
+ static EVP_CIPHER ssh1_3des;
+
+ memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
+ ssh1_3des.nid = NID_undef;
+ ssh1_3des.block_size = 8;
+ ssh1_3des.iv_len = 0;
+ ssh1_3des.key_len = 16;
+ ssh1_3des.init = ssh1_3des_init;
+ ssh1_3des.cleanup = ssh1_3des_cleanup;
+ ssh1_3des.do_cipher = ssh1_3des_cbc;
+#ifndef SSH_OLD_EVP
+ ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH;
+#endif
+ return (&ssh1_3des);
}
/*
- * SSH uses a variation on Blowfish, all bytes must be swapped before
+ * SSH1 uses a variation on Blowfish, all bytes must be swapped before
* and after encryption/decryption. Thus the swap_bytes stuff (yuk).
*/
static void
-swap_bytes(const unsigned char *src, unsigned char *dst_, int n)
-{
- /* dst must be properly aligned. */
- u_int32_t *dst = (u_int32_t *) dst_;
- union {
- u_int32_t i;
- char c[4];
- } t;
-
- /* Process 8 bytes every lap. */
- for (n = n / 8; n > 0; n--) {
- t.c[3] = *src++;
- t.c[2] = *src++;
- t.c[1] = *src++;
- t.c[0] = *src++;
- *dst++ = t.i;
-
- t.c[3] = *src++;
- t.c[2] = *src++;
- t.c[1] = *src++;
- t.c[0] = *src++;
- *dst++ = t.i;
+swap_bytes(const u_char *src, u_char *dst, int n)
+{
+ u_char c[4];
+
+ /* Process 4 bytes every lap. */
+ for (n = n / 4; n > 0; n--) {
+ c[3] = *src++;
+ c[2] = *src++;
+ c[1] = *src++;
+ c[0] = *src++;
+
+ *dst++ = c[0];
+ *dst++ = c[1];
+ *dst++ = c[2];
+ *dst++ = c[3];
}
}
-void (*cipher_attack_detected) (const char *fmt,...) = fatal;
+#ifdef SSH_OLD_EVP
+static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
+ const unsigned char *iv, int enc)
+{
+ if (iv != NULL)
+ memcpy (&(ctx->oiv[0]), iv, 8);
+ memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
+ if (key != NULL)
+ BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
+ key);
+}
+#endif
+static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
-static inline void
-detect_cbc_attack(const unsigned char *src,
- unsigned int len)
+static int
+bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
{
- return;
+ int ret;
- log("CRC-32 CBC insertion attack detected");
- cipher_attack_detected("CRC-32 CBC insertion attack detected");
+ swap_bytes(in, out, len);
+ ret = (*orig_bf)(ctx, out, out, len);
+ swap_bytes(out, out, len);
+ return (ret);
}
-/*
- * Names of all encryption algorithms.
- * These must match the numbers defined in cipher.h.
- */
-static char *cipher_names[] =
-{
- "none",
- "idea",
- "des",
- "3des",
- "tss",
- "rc4",
- "blowfish"
-};
+static const EVP_CIPHER *
+evp_ssh1_bf(void)
+{
+ static EVP_CIPHER ssh1_bf;
-/*
- * Returns a bit mask indicating which ciphers are supported by this
- * implementation. The bit mask has the corresponding bit set of each
- * supported cipher.
- */
+ memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
+ orig_bf = ssh1_bf.do_cipher;
+ ssh1_bf.nid = NID_undef;
+#ifdef SSH_OLD_EVP
+ ssh1_bf.init = bf_ssh1_init;
+#endif
+ ssh1_bf.do_cipher = bf_ssh1_cipher;
+ ssh1_bf.key_len = 32;
+ return (&ssh1_bf);
+}
-unsigned int
-cipher_mask()
+#if OPENSSL_VERSION_NUMBER < 0x00907000L
+/* RIJNDAEL */
+#define RIJNDAEL_BLOCKSIZE 16
+struct ssh_rijndael_ctx
{
- unsigned int mask = 0;
- mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
- mask |= 1 << SSH_CIPHER_BLOWFISH;
- return mask;
+ rijndael_ctx r_ctx;
+ u_char r_iv[RIJNDAEL_BLOCKSIZE];
+};
+
+static int
+ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
+ int enc)
+{
+ struct ssh_rijndael_ctx *c;
+
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
+ c = xmalloc(sizeof(*c));
+ EVP_CIPHER_CTX_set_app_data(ctx, c);
+ }
+ if (key != NULL) {
+ if (enc == -1)
+ enc = ctx->encrypt;
+ rijndael_set_key(&c->r_ctx, (u_char *)key,
+ 8*EVP_CIPHER_CTX_key_length(ctx), enc);
+ }
+ if (iv != NULL)
+ memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE);
+ return (1);
}
-/* Returns the name of the cipher. */
+static int
+ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src,
+ u_int len)
+{
+ struct ssh_rijndael_ctx *c;
+ u_char buf[RIJNDAEL_BLOCKSIZE];
+ u_char *cprev, *cnow, *plain, *ivp;
+ int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
+
+ if (len == 0)
+ return (1);
+ if (len % RIJNDAEL_BLOCKSIZE)
+ fatal("ssh_rijndael_cbc: bad len %d", len);
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
+ error("ssh_rijndael_cbc: no context");
+ return (0);
+ }
+ if (ctx->encrypt) {
+ cnow = dest;
+ plain = (u_char *)src;
+ cprev = c->r_iv;
+ for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
+ cnow+=RIJNDAEL_BLOCKSIZE) {
+ for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
+ buf[j] = plain[j] ^ cprev[j];
+ rijndael_encrypt(&c->r_ctx, buf, cnow);
+ cprev = cnow;
+ }
+ memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE);
+ } else {
+ cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
+ plain = dest+len-RIJNDAEL_BLOCKSIZE;
+
+ memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE);
+ for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE,
+ plain-=RIJNDAEL_BLOCKSIZE) {
+ rijndael_decrypt(&c->r_ctx, cnow, plain);
+ ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE;
+ for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
+ plain[j] ^= ivp[j];
+ }
+ memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE);
+ }
+ return (1);
+}
-const char *
-cipher_name(int cipher)
+static int
+ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx)
{
- if (cipher < 0 || cipher >= sizeof(cipher_names) / sizeof(cipher_names[0]) ||
- cipher_names[cipher] == NULL)
- fatal("cipher_name: bad cipher number: %d", cipher);
- return cipher_names[cipher];
+ struct ssh_rijndael_ctx *c;
+
+ if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
+ memset(c, 0, sizeof(*c));
+ xfree(c);
+ EVP_CIPHER_CTX_set_app_data(ctx, NULL);
+ }
+ return (1);
}
-/*
- * Parses the name of the cipher. Returns the number of the corresponding
- * cipher, or -1 on error.
- */
+static void
+ssh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len)
+{
+ struct ssh_rijndael_ctx *c;
+
+ if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
+ fatal("ssh_rijndael_iv: no context");
+ if (doset)
+ memcpy(c->r_iv, iv, len);
+ else
+ memcpy(iv, c->r_iv, len);
+}
-int
-cipher_number(const char *name)
+static const EVP_CIPHER *
+evp_rijndael(void)
{
- int i;
- for (i = 0; i < sizeof(cipher_names) / sizeof(cipher_names[0]); i++)
- if (strcmp(cipher_names[i], name) == 0 &&
- (cipher_mask() & (1 << i)))
- return i;
- return -1;
+ static EVP_CIPHER rijndal_cbc;
+
+ memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER));
+ rijndal_cbc.nid = NID_undef;
+ rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE;
+ rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE;
+ rijndal_cbc.key_len = 16;
+ rijndal_cbc.init = ssh_rijndael_init;
+ rijndal_cbc.cleanup = ssh_rijndael_cleanup;
+ rijndal_cbc.do_cipher = ssh_rijndael_cbc;
+#ifndef SSH_OLD_EVP
+ rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH |
+ EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV;
+#endif
+ return (&rijndal_cbc);
}
+#endif
/*
- * Selects the cipher, and keys if by computing the MD5 checksum of the
- * passphrase and using the resulting 16 bytes as the key.
+ * Exports an IV from the CipherContext required to export the key
+ * state back from the unprivileged child to the privileged parent
+ * process.
*/
-void
-cipher_set_key_string(CipherContext *context, int cipher,
- const char *passphrase, int for_encryption)
+int
+cipher_get_keyiv_len(CipherContext *cc)
{
- MD5_CTX md;
- unsigned char digest[16];
-
- MD5_Init(&md);
- MD5_Update(&md, (const unsigned char *) passphrase, strlen(passphrase));
- MD5_Final(digest, &md);
-
- cipher_set_key(context, cipher, digest, 16, for_encryption);
-
- memset(digest, 0, sizeof(digest));
- memset(&md, 0, sizeof(md));
+ Cipher *c = cc->cipher;
+ int ivlen;
+
+ if (c->number == SSH_CIPHER_3DES)
+ ivlen = 24;
+ else
+ ivlen = EVP_CIPHER_CTX_iv_length(&cc->evp);
+ return (ivlen);
}
-/* Selects the cipher to use and sets the key. */
-
-void
-cipher_set_key(CipherContext *context, int cipher,
- const unsigned char *key, int keylen, int for_encryption)
+void
+cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len)
{
- unsigned char padded[32];
+ Cipher *c = cc->cipher;
+ int evplen;
- /* Set cipher type. */
- context->type = cipher;
-
- /* Get 32 bytes of key data. Pad if necessary. (So that code
- below does not need to worry about key size). */
- memset(padded, 0, sizeof(padded));
- memcpy(padded, key, keylen < sizeof(padded) ? keylen : sizeof(padded));
-
- /* Initialize the initialization vector. */
- switch (cipher) {
- case SSH_CIPHER_NONE:
- /*
- * Has to stay for authfile saving of private key with no
- * passphrase
- */
- break;
-
- case SSH_CIPHER_3DES:
- /*
- * Note: the least significant bit of each byte of key is
- * parity, and must be ignored by the implementation. 16
- * bytes of key are used (first and last keys are the same).
- */
- if (keylen < 16)
- error("Key length %d is insufficient for 3DES.", keylen);
- des_set_key((void *) padded, context->u.des3.key1);
- des_set_key((void *) (padded + 8), context->u.des3.key2);
- if (keylen <= 16)
- des_set_key((void *) padded, context->u.des3.key3);
+ switch (c->number) {
+ case SSH_CIPHER_SSH2:
+ case SSH_CIPHER_DES:
+ case SSH_CIPHER_BLOWFISH:
+ evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
+ if (evplen == 0)
+ return;
+ if (evplen != len)
+ fatal("%s: wrong iv length %d != %d", __func__,
+ evplen, len);
+#if OPENSSL_VERSION_NUMBER < 0x00907000L
+ if (c->evptype == evp_rijndael)
+ ssh_rijndael_iv(&cc->evp, 0, iv, len);
else
- des_set_key((void *) (padded + 16), context->u.des3.key3);
- memset(context->u.des3.iv2, 0, sizeof(context->u.des3.iv2));
- memset(context->u.des3.iv3, 0, sizeof(context->u.des3.iv3));
+#endif
+ memcpy(iv, cc->evp.iv, len);
break;
-
- case SSH_CIPHER_BLOWFISH:
- BF_set_key(&context->u.bf.key, keylen, padded);
- memset(context->u.bf.iv, 0, 8);
+ case SSH_CIPHER_3DES:
+ ssh1_3des_iv(&cc->evp, 0, iv, 24);
break;
-
default:
- fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
+ fatal("%s: bad cipher %d", __func__, c->number);
}
- memset(padded, 0, sizeof(padded));
}
-/* Encrypts data using the cipher. */
-
-void
-cipher_encrypt(CipherContext *context, unsigned char *dest,
- const unsigned char *src, unsigned int len)
+void
+cipher_set_keyiv(CipherContext *cc, u_char *iv)
{
- if ((len & 7) != 0)
- fatal("cipher_encrypt: bad plaintext length %d", len);
+ Cipher *c = cc->cipher;
+ int evplen = 0;
- switch (context->type) {
- case SSH_CIPHER_NONE:
- memcpy(dest, src, len);
+ switch (c->number) {
+ case SSH_CIPHER_SSH2:
+ case SSH_CIPHER_DES:
+ case SSH_CIPHER_BLOWFISH:
+ evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
+ if (evplen == 0)
+ return;
+#if OPENSSL_VERSION_NUMBER < 0x00907000L
+ if (c->evptype == evp_rijndael)
+ ssh_rijndael_iv(&cc->evp, 1, iv, evplen);
+ else
+#endif
+ memcpy(cc->evp.iv, iv, evplen);
break;
-
case SSH_CIPHER_3DES:
- SSH_3CBC_ENCRYPT(context->u.des3.key1,
- context->u.des3.key2, &context->u.des3.iv2,
- context->u.des3.key3, &context->u.des3.iv3,
- dest, (unsigned char *) src, len);
+ ssh1_3des_iv(&cc->evp, 1, iv, 24);
break;
-
- case SSH_CIPHER_BLOWFISH:
- swap_bytes(src, dest, len);
- BF_cbc_encrypt(dest, dest, len,
- &context->u.bf.key, context->u.bf.iv,
- BF_ENCRYPT);
- swap_bytes(dest, dest, len);
- break;
-
default:
- fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type));
+ fatal("%s: bad cipher %d", __func__, c->number);
}
}
-/* Decrypts data using the cipher. */
+#if OPENSSL_VERSION_NUMBER < 0x00907000L
+#define EVP_X_STATE(evp) &(evp).c
+#define EVP_X_STATE_LEN(evp) sizeof((evp).c)
+#else
+#define EVP_X_STATE(evp) (evp).cipher_data
+#define EVP_X_STATE_LEN(evp) (evp).cipher->ctx_size
+#endif
-void
-cipher_decrypt(CipherContext *context, unsigned char *dest,
- const unsigned char *src, unsigned int len)
+int
+cipher_get_keycontext(CipherContext *cc, u_char *dat)
{
- if ((len & 7) != 0)
- fatal("cipher_decrypt: bad ciphertext length %d", len);
-
- switch (context->type) {
- case SSH_CIPHER_NONE:
- memcpy(dest, src, len);
- break;
-
- case SSH_CIPHER_3DES:
- /* CRC-32 attack? */
- SSH_3CBC_DECRYPT(context->u.des3.key1,
- context->u.des3.key2, &context->u.des3.iv2,
- context->u.des3.key3, &context->u.des3.iv3,
- dest, (unsigned char *) src, len);
- break;
+ Cipher *c = cc->cipher;
+ int plen = 0;
+
+ if (c->evptype == EVP_rc4) {
+ plen = EVP_X_STATE_LEN(cc->evp);
+ if (dat == NULL)
+ return (plen);
+ memcpy(dat, EVP_X_STATE(cc->evp), plen);
+ }
+ return (plen);
+}
- case SSH_CIPHER_BLOWFISH:
- detect_cbc_attack(src, len);
- swap_bytes(src, dest, len);
- BF_cbc_encrypt((void *) dest, dest, len,
- &context->u.bf.key, context->u.bf.iv,
- BF_DECRYPT);
- swap_bytes(dest, dest, len);
- break;
+void
+cipher_set_keycontext(CipherContext *cc, u_char *dat)
+{
+ Cipher *c = cc->cipher;
+ int plen;
- default:
- fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type));
+ if (c->evptype == EVP_rc4) {
+ plen = EVP_X_STATE_LEN(cc->evp);
+ memcpy(EVP_X_STATE(cc->evp), dat, plen);
}
}
andersk / openssh.git / blobdiff