X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/089fbbd27c6b5d2665402bf1bb7bfe1385f961f2..23aa123701299d88160cdd67e871a2244082afa6:/cipher.c diff --git a/cipher.c b/cipher.c index a44e51d9..86d92340 100644 --- a/cipher.c +++ b/cipher.c @@ -1,194 +1,156 @@ /* - * - * cipher.c - * * Author: Tatu Ylonen - * * Copyright (c) 1995 Tatu Ylonen , 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". * - */ - -#include "includes.h" -RCSID("$OpenBSD: cipher.c,v 1.29 2000/07/10 16:30:25 ho Exp $"); - -#include "ssh.h" -#include "cipher.h" -#include "xmalloc.h" - -#include - -/* - * This is used by SSH1: * - * What kind of triple DES are these 2 routines? + * Copyright (c) 1999 Niels Provos. All rights reserved. + * Copyright (c) 1999, 2000 Markus Friedl. All rights reserved. * - * Why is there a redundant initialization vector? + * 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. * - * 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. + * 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. */ -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) -{ - des_cblock iv1; - memcpy(&iv1, iv2, 8); +#include "includes.h" +RCSID("$OpenBSD: cipher.c,v 1.55 2002/04/03 09:26:11 markus Exp $"); - des_cbc_encrypt(src, dest, len, ks1, &iv1, DES_ENCRYPT); - memcpy(&iv1, dest + len - 8, 8); +#include "xmalloc.h" +#include "log.h" +#include "cipher.h" - des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_DECRYPT); - memcpy(iv2, &iv1, 8); /* Note how iv1 == iv2 on entry and exit. */ +#include +#include "rijndael.h" + +#if OPENSSL_VERSION_NUMBER < 0x00906000L +#define SSH_OLD_EVP +#define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data) +#endif + +static EVP_CIPHER *evp_ssh1_3des(void); +static EVP_CIPHER *evp_ssh1_bf(void); +static EVP_CIPHER *evp_rijndael(void); + +struct Cipher { + char *name; + int number; /* for ssh1 only */ + u_int block_size; + u_int key_len; + 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 }, + { "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 }, + + { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } +}; - des_cbc_encrypt(dest, dest, len, ks3, iv3, DES_ENCRYPT); - memcpy(iv3, dest + len - 8, 8); -} +/*--*/ -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) +u_int +cipher_blocksize(Cipher *c) { - des_cblock iv1; - - memcpy(&iv1, iv2, 8); - - des_cbc_encrypt(src, dest, len, ks3, iv3, DES_DECRYPT); - memcpy(iv3, src + len - 8, 8); - - des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_ENCRYPT); - memcpy(iv2, dest + len - 8, 8); - - des_cbc_encrypt(dest, dest, len, ks1, &iv1, DES_DECRYPT); - /* memcpy(&iv1, iv2, 8); */ - /* Note how iv1 == iv2 on entry and exit. */ + return (c->block_size); } - -/* - * 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) +u_int +cipher_keylen(Cipher *c) { - /* 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; - } + return (c->key_len); } - -/* - * Names of all encryption algorithms. - * These must match the numbers defined in cipher.h. - */ -static char *cipher_names[] = +u_int +cipher_get_number(Cipher *c) { - "none", - "idea", - "des", - "3des", - "tss", - "rc4", - "blowfish", - "reserved", - "blowfish-cbc", - "3des-cbc", - "arcfour", - "cast128-cbc" -}; - -/* - * Returns a bit mask indicating which ciphers are supported by this - * implementation. The bit mask has the corresponding bit set of each - * supported cipher. - */ + return (c->number); +} -unsigned int -cipher_mask1() +u_int +cipher_mask_ssh1(int client) { - unsigned int mask = 0; + u_int mask = 0; mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ mask |= 1 << SSH_CIPHER_BLOWFISH; + if (client) { + mask |= 1 << SSH_CIPHER_DES; + } return mask; } -unsigned int -cipher_mask2() -{ - unsigned int mask = 0; - mask |= 1 << SSH_CIPHER_BLOWFISH_CBC; - mask |= 1 << SSH_CIPHER_3DES_CBC; - mask |= 1 << SSH_CIPHER_ARCFOUR; - mask |= 1 << SSH_CIPHER_CAST128_CBC; - return mask; -} -unsigned int -cipher_mask() + +Cipher * +cipher_by_name(const char *name) { - return cipher_mask1() | cipher_mask2(); + Cipher *c; + for (c = ciphers; c->name != NULL; c++) + if (strcasecmp(c->name, name) == 0) + return c; + return NULL; } -/* Returns the name of the cipher. */ - -const char * -cipher_name(int cipher) +Cipher * +cipher_by_number(int id) { - if (cipher < 0 || cipher >= sizeof(cipher_names) / sizeof(cipher_names[0]) || - cipher_names[cipher] == NULL) - fatal("cipher_name: bad cipher name: %d", cipher); - return cipher_names[cipher]; + Cipher *c; + for (c = ciphers; c->name != NULL; c++) + if (c->number == id) + return c; + return NULL; } -/* Returns 1 if the name of the ciphers are valid. */ - #define CIPHER_SEP "," int ciphers_valid(const char *names) { + Cipher *c; char *ciphers, *cp; char *p; - int i; 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))) { - i = cipher_number(p); - if (i == -1 || !(cipher_mask2() & (1 << i))) { + 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; } @@ -201,14 +163,103 @@ ciphers_valid(const char *names) int cipher_number(const char *name) { - int i; + Cipher *c; if (name == NULL) return -1; - 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; + 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) ? "" : 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 + 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) { + debug("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 } /* @@ -217,248 +268,451 @@ cipher_number(const char *name) */ void -cipher_set_key_string(CipherContext *context, int cipher, const char *passphrase) +cipher_set_key_string(CipherContext *cc, Cipher *cipher, + const char *passphrase, int encrypt) { MD5_CTX md; - unsigned char digest[16]; + u_char digest[16]; MD5_Init(&md); - MD5_Update(&md, (const unsigned char *) passphrase, strlen(passphrase)); + MD5_Update(&md, (const u_char *)passphrase, strlen(passphrase)); MD5_Final(digest, &md); - cipher_set_key(context, cipher, digest, 16); + cipher_init(cc, cipher, digest, 16, NULL, 0, encrypt); memset(digest, 0, sizeof(digest)); memset(&md, 0, sizeof(md)); } -/* Selects the cipher to use and sets the key. */ +/* Implementations for other non-EVP ciphers */ -void -cipher_set_key(CipherContext *context, int cipher, const unsigned char *key, - int keylen) +/* + * 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. + */ +struct ssh1_3des_ctx { - unsigned char padded[32]; - - /* 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; + EVP_CIPHER_CTX k1, k2, k3; +}; +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; - 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); + 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 - 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)); - break; - - case SSH_CIPHER_BLOWFISH: - if (keylen < 16) - error("Key length %d is insufficient for blowfish.", keylen); - BF_set_key(&context->u.bf.key, keylen, padded); - memset(context->u.bf.iv, 0, 8); - break; - - case SSH_CIPHER_3DES_CBC: - case SSH_CIPHER_BLOWFISH_CBC: - case SSH_CIPHER_ARCFOUR: - case SSH_CIPHER_CAST128_CBC: - fatal("cipher_set_key: illegal cipher: %s", cipher_name(cipher)); - break; - - default: - fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher)); + 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); } - memset(padded, 0, sizeof(padded)); +#endif + return (1); } +static int +ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) +{ + struct ssh1_3des_ctx *c; -void -cipher_set_key_iv(CipherContext * context, int cipher, - const unsigned char *key, int keylen, - const unsigned char *iv, int ivlen) + 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); +} +static int +ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) { - /* Set cipher type. */ - context->type = cipher; + struct ssh1_3des_ctx *c; - /* Initialize the initialization vector. */ - switch (cipher) { - case SSH_CIPHER_NONE: - break; + 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); +} +static 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); +} - case SSH_CIPHER_3DES: - case SSH_CIPHER_BLOWFISH: - fatal("cipher_set_key_iv: illegal cipher: %s", cipher_name(cipher)); - break; +/* + * 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) +{ + 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]; + } +} +static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; +static int +bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) +{ + int ret; - case SSH_CIPHER_3DES_CBC: - if (keylen < 24) - error("Key length %d is insufficient for 3des-cbc.", keylen); - des_set_key((void *) key, context->u.des3.key1); - des_set_key((void *) (key+8), context->u.des3.key2); - des_set_key((void *) (key+16), context->u.des3.key3); - if (ivlen < 8) - error("IV length %d is insufficient for 3des-cbc.", ivlen); - memcpy(context->u.des3.iv3, (char *)iv, 8); - break; + swap_bytes(in, out, len); + ret = (*orig_bf)(ctx, out, out, len); + swap_bytes(out, out, len); + return (ret); +} +static EVP_CIPHER * +evp_ssh1_bf(void) +{ + static EVP_CIPHER ssh1_bf; + + memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); + orig_bf = ssh1_bf.do_cipher; + ssh1_bf.nid = NID_undef; + ssh1_bf.do_cipher = bf_ssh1_cipher; + ssh1_bf.key_len = 32; + return (&ssh1_bf); +} - case SSH_CIPHER_BLOWFISH_CBC: - if (keylen < 16) - error("Key length %d is insufficient for blowfish.", keylen); - if (ivlen < 8) - error("IV length %d is insufficient for blowfish.", ivlen); - BF_set_key(&context->u.bf.key, keylen, (unsigned char *)key); - memcpy(context->u.bf.iv, (char *)iv, 8); - break; +/* RIJNDAEL */ +#define RIJNDAEL_BLOCKSIZE 16 +struct ssh_rijndael_ctx +{ + rijndael_ctx r_ctx; + u_char r_iv[RIJNDAEL_BLOCKSIZE]; +}; - case SSH_CIPHER_ARCFOUR: - if (keylen < 16) - error("Key length %d is insufficient for arcfour.", keylen); - RC4_set_key(&context->u.rc4, keylen, (unsigned char *)key); - break; +static int +ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, + int enc) +{ + struct ssh_rijndael_ctx *c; - case SSH_CIPHER_CAST128_CBC: - if (keylen < 16) - error("Key length %d is insufficient for cast128.", keylen); - if (ivlen < 8) - error("IV length %d is insufficient for cast128.", ivlen); - CAST_set_key(&context->u.cast.key, keylen, (unsigned char *) key); - memcpy(context->u.cast.iv, (char *)iv, 8); - break; + 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); +} +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); +} +static int +ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) +{ + struct ssh_rijndael_ctx *c; - default: - fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher)); + 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); +} +static EVP_CIPHER * +evp_rijndael(void) +{ + 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; +#endif + return (&rijndal_cbc); } -/* Encrypts data using the cipher. */ +/* + * Exports an IV from the CipherContext required to export the key + * state back from the unprivileged child to the privileged parent + * process. + */ -void -cipher_encrypt(CipherContext *context, unsigned char *dest, - const unsigned char *src, unsigned int len) +int +cipher_get_keyiv_len(CipherContext *cc) { - if ((len & 7) != 0) - fatal("cipher_encrypt: bad plaintext length %d", len); - - switch (context->type) { - case SSH_CIPHER_NONE: - memcpy(dest, src, len); - break; + 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); +} - 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); - break; +void +cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len) +{ + Cipher *c = cc->cipher; + u_char *civ = NULL; + int evplen; + switch (c->number) { + case SSH_CIPHER_SSH2: + case SSH_CIPHER_DES: 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; - - case SSH_CIPHER_BLOWFISH_CBC: - BF_cbc_encrypt((void *)src, dest, len, - &context->u.bf.key, context->u.bf.iv, - BF_ENCRYPT); - break; - - case SSH_CIPHER_3DES_CBC: - des_ede3_cbc_encrypt(src, dest, len, - context->u.des3.key1, context->u.des3.key2, - context->u.des3.key3, &context->u.des3.iv3, DES_ENCRYPT); - break; - - case SSH_CIPHER_ARCFOUR: - RC4(&context->u.rc4, len, (unsigned char *)src, dest); - break; - - case SSH_CIPHER_CAST128_CBC: - CAST_cbc_encrypt(src, dest, len, - &context->u.cast.key, context->u.cast.iv, CAST_ENCRYPT); + evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); + if (evplen == 0) + return; + if (evplen != len) + fatal("%s: wrong iv length %d != %d", __FUNCTION__, + evplen, len); + + if (c->evptype == evp_rijndael) { + struct ssh_rijndael_ctx *aesc; + + aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (aesc == NULL) + fatal("%s: no rijndael context", __FUNCTION__); + civ = aesc->r_iv; + } else { + civ = cc->evp.iv; + } break; - + case SSH_CIPHER_3DES: { + struct ssh1_3des_ctx *desc; + if (len != 24) + fatal("%s: bad 3des iv length: %d", __FUNCTION__, len); + desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (desc == NULL) + fatal("%s: no 3des context", __FUNCTION__); + debug3("%s: Copying 3DES IV", __FUNCTION__); + memcpy(iv, desc->k1.iv, 8); + memcpy(iv + 8, desc->k2.iv, 8); + memcpy(iv + 16, desc->k3.iv, 8); + return; + } default: - fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type)); + fatal("%s: bad cipher %d", __FUNCTION__, c->number); } + memcpy(iv, civ, len); } -/* Decrypts data using the cipher. */ - void -cipher_decrypt(CipherContext *context, unsigned char *dest, - const unsigned char *src, unsigned int len) +cipher_set_keyiv(CipherContext *cc, u_char *iv) { - 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: - 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; + u_char *div = NULL; + int evplen = 0; + switch (c->number) { + case SSH_CIPHER_SSH2: + case SSH_CIPHER_DES: case SSH_CIPHER_BLOWFISH: - 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); + evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); + if (evplen == 0) + return; + + if (c->evptype == evp_rijndael) { + struct ssh_rijndael_ctx *aesc; + + aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (aesc == NULL) + fatal("%s: no rijndael context", __FUNCTION__); + div = aesc->r_iv; + }else { + div = cc->evp.iv; + } break; + case SSH_CIPHER_3DES: { + struct ssh1_3des_ctx *desc; + desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (desc == NULL) + fatal("%s: no 3des context", __FUNCTION__); + debug3("%s: Installed 3DES IV", __FUNCTION__); + memcpy(desc->k1.iv, iv, 8); + memcpy(desc->k2.iv, iv + 8, 8); + memcpy(desc->k3.iv, iv + 16, 8); + return; + } + default: + fatal("%s: bad cipher %d", __FUNCTION__, c->number); + } + memcpy(div, iv, evplen); +} - case SSH_CIPHER_BLOWFISH_CBC: - BF_cbc_encrypt((void *) src, dest, len, - &context->u.bf.key, context->u.bf.iv, - BF_DECRYPT); - break; +#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 - case SSH_CIPHER_3DES_CBC: - des_ede3_cbc_encrypt(src, dest, len, - context->u.des3.key1, context->u.des3.key2, - context->u.des3.key3, &context->u.des3.iv3, DES_DECRYPT); - break; +int +cipher_get_keycontext(CipherContext *cc, u_char *dat) +{ + Cipher *c = cc->cipher; + int plen; + + if (c->number == SSH_CIPHER_3DES) { + struct ssh1_3des_ctx *desc; + desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (desc == NULL) + fatal("%s: no 3des context", __FUNCTION__); + plen = EVP_X_STATE_LEN(desc->k1); + if (dat == NULL) + return (3*plen); + memcpy(dat, EVP_X_STATE(desc->k1), plen); + memcpy(dat + plen, EVP_X_STATE(desc->k2), plen); + memcpy(dat + 2*plen, EVP_X_STATE(desc->k3), plen); + return (3*plen); + } - case SSH_CIPHER_ARCFOUR: - RC4(&context->u.rc4, len, (unsigned char *)src, dest); - break; + /* Generic EVP */ + plen = EVP_X_STATE_LEN(cc->evp); + if (dat == NULL) + return (plen); - case SSH_CIPHER_CAST128_CBC: - CAST_cbc_encrypt(src, dest, len, - &context->u.cast.key, context->u.cast.iv, CAST_DECRYPT); - break; + memcpy(dat, EVP_X_STATE(cc->evp), plen); + return (plen); +} - default: - fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type)); +void +cipher_set_keycontext(CipherContext *cc, u_char *dat) +{ + Cipher *c = cc->cipher; + int plen; + + if (c->number == SSH_CIPHER_3DES) { + struct ssh1_3des_ctx *desc; + desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (desc == NULL) + fatal("%s: no 3des context", __FUNCTION__); + plen = EVP_X_STATE_LEN(desc->k1); + memcpy(EVP_X_STATE(desc->k1), dat, plen); + memcpy(EVP_X_STATE(desc->k2), dat + plen, plen); + memcpy(EVP_X_STATE(desc->k3), dat + 2*plen, plen); + } else { + plen = EVP_X_STATE_LEN(cc->evp); + memcpy(EVP_X_STATE(cc->evp), dat, plen); } }