]> andersk Git - openssh.git/blobdiff - cipher.c
- markus@cvs.openbsd.org 2003/05/17 04:27:52
[openssh.git] / cipher.c
index a7aacf284f2d93a730f2ceb9b7440c946e38860c..e7c3c5411e3d6d821c52b6b9aa410cae3ff16ed0 100644 (file)
--- a/cipher.c
+++ b/cipher.c
@@ -11,7 +11,7 @@
  *
  *
  * Copyright (c) 1999 Niels Provos.  All rights reserved.
- * Copyright (c) 1999,2000 Markus Friedl.  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
@@ -35,7 +35,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: cipher.c,v 1.45 2001/06/23 15:12:18 itojun Exp $");
+RCSID("$OpenBSD: cipher.c,v 1.65 2003/05/17 04:27:52 markus Exp $");
 
 #include "xmalloc.h"
 #include "log.h"
@@ -43,382 +43,82 @@ RCSID("$OpenBSD: cipher.c,v 1.45 2001/06/23 15:12:18 itojun Exp $");
 
 #include <openssl/md5.h>
 
-/* no encryption */
-static void
-none_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-}
-static void
-none_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
-}
-static void
-none_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       memcpy(dest, src, len);
-}
-
-/* DES */
-static void
-des_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       static int dowarn = 1;
-       if (dowarn) {
-               error("Warning: use of DES is strongly discouraged "
-                   "due to cryptographic weaknesses");
-               dowarn = 0;
-       }
-       des_set_key((void *)key, cc->u.des.key);
-}
-static void
-des_ssh1_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
-       memset(cc->u.des.iv, 0, sizeof(cc->u.des.iv));
-}
-static void
-des_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
-           DES_ENCRYPT);
-}
-static void
-des_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       des_ncbc_encrypt(src, dest, len, cc->u.des.key, &cc->u.des.iv,
-           DES_DECRYPT);
-}
-
-/* 3DES */
-static void
-des3_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       des_set_key((void *) key, cc->u.des3.key1);
-       des_set_key((void *) (key+8), cc->u.des3.key2);
-       des_set_key((void *) (key+16), cc->u.des3.key3);
-}
-static void
-des3_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
-       memset(cc->u.des3.iv1, 0, sizeof(cc->u.des3.iv1));
-       memset(cc->u.des3.iv2, 0, sizeof(cc->u.des3.iv2));
-       memset(cc->u.des3.iv3, 0, sizeof(cc->u.des3.iv3));
-       if (iv == NULL)
-               return;
-       memcpy(cc->u.des3.iv3, (char *)iv, 8);
-}
-static void
-des3_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       des_ede3_cbc_encrypt(src, dest, len,
-           cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
-           &cc->u.des3.iv3, DES_ENCRYPT);
-}
-static void
-des3_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       des_ede3_cbc_encrypt(src, dest, len,
-           cc->u.des3.key1, cc->u.des3.key2, cc->u.des3.key3,
-           &cc->u.des3.iv3, DES_DECRYPT);
-}
-
-/*
- * This is used by SSH1:
- *
- * What kind of triple DES are these 2 routines?
- *
- * Why is there a redundant initialization vector?
- *
- * If only iv3 was used, then, this would till effect have been
- * outer-cbc. However, there is also a private iv1 == iv2 which
- * perhaps makes differential analysis easier. On the other hand, the
- * private iv1 probably makes the CRC-32 attack ineffective. This is a
- * result of that there is no longer any known iv1 to use when
- * choosing the X block.
- */
-static void
-des3_ssh1_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       des_set_key((void *) key, cc->u.des3.key1);
-       des_set_key((void *) (key+8), cc->u.des3.key2);
-       if (keylen <= 16)
-               des_set_key((void *) key, cc->u.des3.key3);
-       else
-               des_set_key((void *) (key+16), cc->u.des3.key3);
-}
-static void
-des3_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
-    u_int len)
-{
-       des_ncbc_encrypt(src,  dest, len, cc->u.des3.key1, &cc->u.des3.iv1,
-           DES_ENCRYPT);
-       des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, &cc->u.des3.iv2,
-           DES_DECRYPT);
-       des_ncbc_encrypt(dest, dest, len, cc->u.des3.key3, &cc->u.des3.iv3,
-           DES_ENCRYPT);
-}
-static void
-des3_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
-    u_int len)
-{
-       des_ncbc_encrypt(src,  dest, len, cc->u.des3.key3, &cc->u.des3.iv3,
-           DES_DECRYPT);
-       des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, &cc->u.des3.iv2,
-           DES_ENCRYPT);
-       des_ncbc_encrypt(dest, dest, len, cc->u.des3.key1, &cc->u.des3.iv1,
-           DES_DECRYPT);
-}
-
-/* Blowfish */
-static void
-blowfish_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       BF_set_key(&cc->u.bf.key, keylen, (u_char *)key);
-}
-static void
-blowfish_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
-       if (iv == NULL)
-               memset(cc->u.bf.iv, 0, 8);
-       else
-               memcpy(cc->u.bf.iv, (char *)iv, 8);
-}
-static void
-blowfish_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
-     u_int len)
-{
-       BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
-           BF_ENCRYPT);
-}
-static void
-blowfish_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
-     u_int len)
-{
-       BF_cbc_encrypt((void *)src, dest, len, &cc->u.bf.key, cc->u.bf.iv,
-           BF_DECRYPT);
-}
-
-/*
- * 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 u_char *src, u_char *dst, int n)
-{
-       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];
-       }
-}
+#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
+extern const EVP_CIPHER *evp_rijndael(void);
+extern void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);
+#endif
+extern const EVP_CIPHER *evp_ssh1_bf(void);
+extern const EVP_CIPHER *evp_ssh1_3des(void);
+extern void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
+extern const EVP_CIPHER *evp_aes_128_ctr(void);
+extern void ssh_aes_ctr_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);
+
+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
+       { "aes128-ctr",         SSH_CIPHER_SSH2, 16, 16, evp_aes_128_ctr },
+       { "aes192-ctr",         SSH_CIPHER_SSH2, 16, 24, evp_aes_128_ctr },
+       { "aes256-ctr",         SSH_CIPHER_SSH2, 16, 32, evp_aes_128_ctr },
 
-static void
-blowfish_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
-    u_int len)
-{
-       swap_bytes(src, dest, len);
-       BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
-           BF_ENCRYPT);
-       swap_bytes(dest, dest, len);
-}
-static void
-blowfish_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
-    u_int len)
-{
-       swap_bytes(src, dest, len);
-       BF_cbc_encrypt((void *)dest, dest, len, &cc->u.bf.key, cc->u.bf.iv,
-           BF_DECRYPT);
-       swap_bytes(dest, dest, len);
-}
+       { NULL,                 SSH_CIPHER_ILLEGAL, 0, 0, NULL }
+};
 
-/* alleged rc4 */
-static void
-arcfour_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       RC4_set_key(&cc->u.rc4, keylen, (u_char *)key);
-}
-static void
-arcfour_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       RC4(&cc->u.rc4, len, (u_char *)src, dest);
-}
+/*--*/
 
-/* CAST */
-static void
-cast_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       CAST_set_key(&cc->u.cast.key, keylen, (u_char *) key);
-}
-static void
-cast_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
-       if (iv == NULL)
-               fatal("no IV for %s.", cc->cipher->name);
-       memcpy(cc->u.cast.iv, (char *)iv, 8);
-}
-static void
-cast_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
-{
-       CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
-           CAST_ENCRYPT);
-}
-static void
-cast_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+u_int
+cipher_blocksize(Cipher *c)
 {
-       CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
-           CAST_DECRYPT);
+       return (c->block_size);
 }
 
-/* RIJNDAEL */
-
-#define RIJNDAEL_BLOCKSIZE 16
-static void
-rijndael_setkey(CipherContext *cc, const u_char *key, u_int keylen)
-{
-       rijndael_set_key(&cc->u.rijndael.enc, (u4byte *)key, 8*keylen, 1);
-       rijndael_set_key(&cc->u.rijndael.dec, (u4byte *)key, 8*keylen, 0);
-}
-static void
-rijndael_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
-       if (iv == NULL)
-               fatal("no IV for %s.", cc->cipher->name);
-       memcpy((u_char *)cc->u.rijndael.iv, iv, RIJNDAEL_BLOCKSIZE);
-}
-static void
-rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
-    u_int len)
+u_int
+cipher_keylen(Cipher *c)
 {
-       rijndael_ctx *ctx = &cc->u.rijndael.enc;
-       u4byte *iv = cc->u.rijndael.iv;
-       u4byte in[4];
-       u4byte *cprev, *cnow, *plain;
-       int i, blocks = len / RIJNDAEL_BLOCKSIZE;
-       if (len == 0)
-               return;
-       if (len % RIJNDAEL_BLOCKSIZE)
-               fatal("rijndael_cbc_encrypt: bad len %d", len);
-       cnow  = (u4byte*) dest;
-       plain = (u4byte*) src;
-       cprev = iv;
-       for(i = 0; i < blocks; i++, plain+=4, cnow+=4) {
-               in[0] = plain[0] ^ cprev[0];
-               in[1] = plain[1] ^ cprev[1];
-               in[2] = plain[2] ^ cprev[2];
-               in[3] = plain[3] ^ cprev[3];
-               rijndael_encrypt(ctx, in, cnow);
-               cprev = cnow;
-       }
-       memcpy(iv, cprev, RIJNDAEL_BLOCKSIZE);
+       return (c->key_len);
 }
 
-static void
-rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
-    u_int len)
+u_int
+cipher_get_number(Cipher *c)
 {
-       rijndael_ctx *ctx = &cc->u.rijndael.dec;
-       u4byte *iv = cc->u.rijndael.iv;
-       u4byte ivsaved[4];
-       u4byte *cnow =  (u4byte*) (src+len-RIJNDAEL_BLOCKSIZE);
-       u4byte *plain = (u4byte*) (dest+len-RIJNDAEL_BLOCKSIZE);
-       u4byte *ivp;
-       int i, blocks = len / RIJNDAEL_BLOCKSIZE;
-       if (len == 0)
-               return;
-       if (len % RIJNDAEL_BLOCKSIZE)
-               fatal("rijndael_cbc_decrypt: bad len %d", len);
-       memcpy(ivsaved, cnow, RIJNDAEL_BLOCKSIZE);
-       for(i = blocks; i > 0; i--, cnow-=4, plain-=4) {
-               rijndael_decrypt(ctx, cnow, plain);
-               ivp =  (i == 1) ? iv : cnow-4;
-               plain[0] ^= ivp[0];
-               plain[1] ^= ivp[1];
-               plain[2] ^= ivp[2];
-               plain[3] ^= ivp[3];
-       }
-       memcpy(iv, ivsaved, RIJNDAEL_BLOCKSIZE);
+       return (c->number);
 }
 
-Cipher ciphers[] = {
-       { "none",
-               SSH_CIPHER_NONE, 8, 0,
-               none_setkey, none_setiv,
-               none_crypt, none_crypt },
-       { "des",
-               SSH_CIPHER_DES, 8, 8,
-               des_ssh1_setkey, des_ssh1_setiv,
-               des_ssh1_encrypt, des_ssh1_decrypt },
-       { "3des",
-               SSH_CIPHER_3DES, 8, 16,
-               des3_ssh1_setkey, des3_setiv,
-               des3_ssh1_encrypt, des3_ssh1_decrypt },
-       { "blowfish",
-               SSH_CIPHER_BLOWFISH, 8, 16,
-               blowfish_setkey, blowfish_setiv,
-               blowfish_ssh1_encrypt, blowfish_ssh1_decrypt },
-
-       { "3des-cbc",
-               SSH_CIPHER_SSH2, 8, 24,
-               des3_setkey, des3_setiv,
-               des3_cbc_encrypt, des3_cbc_decrypt },
-       { "blowfish-cbc",
-               SSH_CIPHER_SSH2, 8, 16,
-               blowfish_setkey, blowfish_setiv,
-               blowfish_cbc_encrypt, blowfish_cbc_decrypt },
-       { "cast128-cbc",
-               SSH_CIPHER_SSH2, 8, 16,
-               cast_setkey, cast_setiv,
-               cast_cbc_encrypt, cast_cbc_decrypt },
-       { "arcfour",
-               SSH_CIPHER_SSH2, 8, 16,
-               arcfour_setkey, none_setiv,
-               arcfour_crypt, arcfour_crypt },
-       { "aes128-cbc",
-               SSH_CIPHER_SSH2, 16, 16,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { "aes192-cbc",
-               SSH_CIPHER_SSH2, 16, 24,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { "aes256-cbc",
-               SSH_CIPHER_SSH2, 16, 32,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { "rijndael128-cbc",
-               SSH_CIPHER_SSH2, 16, 16,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { "rijndael192-cbc",
-               SSH_CIPHER_SSH2, 16, 24,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { "rijndael256-cbc",
-               SSH_CIPHER_SSH2, 16, 32,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { "rijndael-cbc@lysator.liu.se",
-               SSH_CIPHER_SSH2, 16, 32,
-               rijndael_setkey, rijndael_setiv,
-               rijndael_cbc_encrypt, rijndael_cbc_decrypt },
-       { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL, NULL, NULL, NULL }
-};
-
-/*--*/
-
 u_int
 cipher_mask_ssh1(int client)
 {
        u_int mask = 0;
-       mask |= 1 << SSH_CIPHER_3DES;           /* Mandatory */
+       mask |= 1 << SSH_CIPHER_3DES;           /* Mandatory */
        mask |= 1 << SSH_CIPHER_BLOWFISH;
        if (client) {
                mask |= 1 << SSH_CIPHER_DES;
@@ -458,7 +158,7 @@ ciphers_valid(const char *names)
                return 0;
        ciphers = cp = xstrdup(names);
        for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
-            (p = strsep(&cp, CIPHER_SEP))) {
+           (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);
@@ -497,8 +197,28 @@ cipher_name(int id)
 
 void
 cipher_init(CipherContext *cc, Cipher *cipher,
-    const u_char *key, u_int keylen, const u_char *iv, u_int ivlen)
+    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
+       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);
@@ -506,24 +226,58 @@ cipher_init(CipherContext *cc, Cipher *cipher,
                fatal("cipher_init: iv length %d is insufficient for %s.",
                    ivlen, cipher->name);
        cc->cipher = cipher;
-       cipher->setkey(cc, key, keylen);
-       cipher->setiv(cc, iv, ivlen);
+
+       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_encrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+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);
-       cc->cipher->encrypt(cc, dest, src, 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_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
+cipher_cleanup(CipherContext *cc)
 {
-       if (len % cc->cipher->block_size)
-               fatal("cipher_decrypt: bad ciphertext length %d", len);
-       cc->cipher->decrypt(cc, dest, src, len);
+#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
 }
 
 /*
@@ -533,7 +287,7 @@ cipher_decrypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
 
 void
 cipher_set_key_string(CipherContext *cc, Cipher *cipher,
-    const char *passphrase)
+    const char *passphrase, int encrypt)
 {
        MD5_CTX md;
        u_char digest[16];
@@ -542,8 +296,127 @@ cipher_set_key_string(CipherContext *cc, Cipher *cipher,
        MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase));
        MD5_Final(digest, &md);
 
-       cipher_init(cc, cipher, digest, 16, NULL, 0);
+       cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt);
 
        memset(digest, 0, sizeof(digest));
        memset(&md, 0, sizeof(md));
 }
+
+/*
+ * Exports an IV from the CipherContext required to export the key
+ * state back from the unprivileged child to the privileged parent
+ * process.
+ */
+
+int
+cipher_get_keyiv_len(CipherContext *cc)
+{
+       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);
+}
+
+void
+cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len)
+{
+       Cipher *c = cc->cipher;
+       int evplen;
+
+       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
+#endif
+               if (c->evptype == evp_aes_128_ctr)
+                       ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
+               else
+                       memcpy(iv, cc->evp.iv, len);
+               break;
+       case SSH_CIPHER_3DES:
+               ssh1_3des_iv(&cc->evp, 0, iv, 24);
+               break;
+       default:
+               fatal("%s: bad cipher %d", __func__, c->number);
+       }
+}
+
+void
+cipher_set_keyiv(CipherContext *cc, u_char *iv)
+{
+       Cipher *c = cc->cipher;
+       int evplen = 0;
+
+       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
+               if (c->evptype == evp_aes_128_ctr)
+                       ssh_aes_ctr_iv(&cc->evp, 1, iv, evplen);
+               else
+                       memcpy(cc->evp.iv, iv, evplen);
+               break;
+       case SSH_CIPHER_3DES:
+               ssh1_3des_iv(&cc->evp, 1, iv, 24);
+               break;
+       default:
+               fatal("%s: bad cipher %d", __func__, c->number);
+       }
+}
+
+#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
+
+int
+cipher_get_keycontext(CipherContext *cc, u_char *dat)
+{
+       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);
+}
+
+void
+cipher_set_keycontext(CipherContext *cc, u_char *dat)
+{
+       Cipher *c = cc->cipher;
+       int plen;
+
+       if (c->evptype == EVP_rc4) {
+               plen = EVP_X_STATE_LEN(cc->evp);
+               memcpy(EVP_X_STATE(cc->evp), dat, plen);
+       }
+}
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