X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/6b523bae5ef58330194993a03c5b11b6fee0d34c..9300be60be71b56cfa3ee5bf6bb2e9239abb1ae2:/cipher.c diff --git a/cipher.c b/cipher.c index 788028c1..b5d38747 100644 --- 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 @@ -35,395 +35,84 @@ */ #include "includes.h" -RCSID("$OpenBSD: cipher.c,v 1.40 2000/12/09 13:41:52 markus Exp $"); +RCSID("$OpenBSD: cipher.c,v 1.62 2002/11/21 22:45:31 markus Exp $"); -#include "ssh.h" #include "xmalloc.h" +#include "log.h" +#include "cipher.h" #include +#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 -/* no encryption */ -void -none_setkey(CipherContext *cc, const u_char *key, u_int keylen) -{ -} -void -none_setiv(CipherContext *cc, const u_char *iv, u_int ivlen) -{ -} -void -none_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) -{ - memcpy(dest, src, len); -} - -/* DES */ -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); -} -void -des_ssh1_setiv(CipherContext *cc, const u_char *iv, u_int ivlen) -{ - memset(cc->u.des.iv, 0, sizeof(cc->u.des.iv)); -} -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); -} -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 */ -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); -} -void -des3_setiv(CipherContext *cc, const u_char *iv, u_int ivlen) -{ - 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); -} -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); -} -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. - */ -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); -} -void -des3_ssh1_encrypt(CipherContext *cc, u_char *dest, const u_char *src, - u_int len) -{ - des_cblock iv1; - des_cblock *iv2 = &cc->u.des3.iv2; - des_cblock *iv3 = &cc->u.des3.iv3; - - memcpy(&iv1, iv2, 8); - - des_ncbc_encrypt(src, dest, len, cc->u.des3.key1, &iv1, DES_ENCRYPT); - des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_DECRYPT); - des_ncbc_encrypt(dest, dest, len, cc->u.des3.key3, iv3, DES_ENCRYPT); -} -void -des3_ssh1_decrypt(CipherContext *cc, u_char *dest, const u_char *src, - u_int len) -{ - des_cblock iv1; - des_cblock *iv2 = &cc->u.des3.iv2; - des_cblock *iv3 = &cc->u.des3.iv3; - - memcpy(&iv1, iv2, 8); - - des_ncbc_encrypt(src, dest, len, cc->u.des3.key3, iv3, DES_DECRYPT); - des_ncbc_encrypt(dest, dest, len, cc->u.des3.key2, iv2, DES_ENCRYPT); - des_ncbc_encrypt(dest, dest, len, cc->u.des3.key1, &iv1, DES_DECRYPT); -} - -/* Blowfish */ -void -blowfish_setkey(CipherContext *cc, const u_char *key, u_int keylen) -{ - BF_set_key(&cc->u.bf.key, keylen, (unsigned char *)key); -} -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); -} -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); -} -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 unsigned char *src, unsigned 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]; - } -} + { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL } +}; -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); -} -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); -} +/*--*/ -/* alleged rc4 */ -void -arcfour_setkey(CipherContext *cc, const u_char *key, u_int keylen) -{ - RC4_set_key(&cc->u.rc4, keylen, (u_char *)key); -} -void -arcfour_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len) +u_int +cipher_blocksize(Cipher *c) { - RC4(&cc->u.rc4, len, (u_char *)src, dest); + return (c->block_size); } -/* CAST */ -void -cast_setkey(CipherContext *cc, const u_char *key, u_int keylen) -{ - CAST_set_key(&cc->u.cast.key, keylen, (unsigned char *) key); -} -void -cast_setiv(CipherContext *cc, const u_char *iv, u_int ivlen) +u_int +cipher_keylen(Cipher *c) { - if (iv == NULL) - fatal("no IV for %s.", cc->cipher->name); - memcpy(cc->u.cast.iv, (char *)iv, 8); + return (c->key_len); } -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); -} -void -cast_cbc_decrypt(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_DECRYPT); -} - -/* RIJNDAEL */ -#define RIJNDAEL_BLOCKSIZE 16 -void -rijndael_setkey(CipherContext *cc, const u_char *key, u_int keylen) +u_int +cipher_get_number(Cipher *c) { - rijndael_set_key(&cc->u.rijndael.enc, (u4byte *)key, 8*keylen, 1); - rijndael_set_key(&cc->u.rijndael.dec, (u4byte *)key, 8*keylen, 0); -} -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); -} -void -rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src, - u_int len) -{ - 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->number); } -void -rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src, - u_int len) -{ - 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); -} - -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 } -}; - -/*--*/ - -unsigned int +u_int cipher_mask_ssh1(int client) { - unsigned int mask = 0; - mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ + u_int mask = 0; + mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */ mask |= 1 << SSH_CIPHER_BLOWFISH; if (client) { mask |= 1 << SSH_CIPHER_DES; @@ -463,7 +152,7 @@ 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); @@ -502,8 +191,28 @@ 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); @@ -511,24 +220,58 @@ 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 } /* @@ -538,17 +281,460 @@ 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; - unsigned char digest[16]; + 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); + 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 */ + +/* + * 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 +{ + 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; + + 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); +} + +static int +ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len) +{ + struct ssh1_3des_ctx *c; + + 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) +{ + struct ssh1_3des_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); +} + +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); +} + +/* + * 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]; + } +} + +#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 int +bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) +{ + int ret; + + swap_bytes(in, out, len); + ret = (*orig_bf)(ctx, out, out, len); + swap_bytes(out, out, len); + return (ret); +} + +static const 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; +#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); +} + +#if OPENSSL_VERSION_NUMBER < 0x00907000L +/* RIJNDAEL */ +#define RIJNDAEL_BLOCKSIZE 16 +struct ssh_rijndael_ctx +{ + 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); +} + +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; + + 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 const 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 | EVP_CIPH_CUSTOM_IV; +#endif + return (&rijndal_cbc); +} +#endif + +/* + * 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; + u_char *civ = NULL; + 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) { + struct ssh_rijndael_ctx *aesc; + + aesc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (aesc == NULL) + fatal("%s: no rijndael context", __func__); + civ = aesc->r_iv; + } else +#endif + { + civ = cc->evp.iv; + } + break; + case SSH_CIPHER_3DES: { + struct ssh1_3des_ctx *desc; + if (len != 24) + fatal("%s: bad 3des iv length: %d", __func__, len); + desc = EVP_CIPHER_CTX_get_app_data(&cc->evp); + if (desc == NULL) + fatal("%s: no 3des context", __func__); + debug3("%s: Copying 3DES IV", __func__); + memcpy(iv, desc->k1.iv, 8); + memcpy(iv + 8, desc->k2.iv, 8); + memcpy(iv + 16, desc->k3.iv, 8); + return; + } + default: + fatal("%s: bad cipher %d", __func__, c->number); + } + memcpy(iv, civ, len); +} + +void +cipher_set_keyiv(CipherContext *cc, u_char *iv) +{ + 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: + evplen = EVP_CIPHER_CTX_iv_length(&cc->evp); + if (evplen == 0) + return; + +#if OPENSSL_VERSION_NUMBER < 0x00907000L + 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", __func__); + div = aesc->r_iv; + } else +#endif + { + 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", __func__); + debug3("%s: Installed 3DES IV", __func__); + 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", __func__, c->number); + } + memcpy(div, iv, evplen); +} + +#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); + } +}