- void (*setkey)(CipherContext *, const u_char *, u_int);
- void (*setiv)(CipherContext *, const u_char *, u_int);
- void (*encrypt)(CipherContext *, u_char *, const u_char *, u_int);
- void (*decrypt)(CipherContext *, u_char *, const u_char *, u_int);
-};
-
-/* 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];
- }
-}
-
-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);
-}
-
-/* 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)
-{
- CAST_cbc_encrypt(src, dest, len, &cc->u.cast.key, cc->u.cast.iv,
- CAST_DECRYPT);
-}
-
-/* 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, (char *)key, 8*keylen, 1);
- rijndael_set_key(&cc->u.rijndael.dec, (char *)key, 8*keylen, 0);
-}
-static void
-rijndael_setiv(CipherContext *cc, const u_char *iv, u_int ivlen)
-{
- if (iv == NULL || ivlen != RIJNDAEL_BLOCKSIZE)
- fatal("bad/no IV for %s.", cc->cipher->name);
- memcpy(cc->u.rijndael.iv, iv, RIJNDAEL_BLOCKSIZE);
-}
-static void
-rijndael_cbc_encrypt(CipherContext *cc, u_char *dest, const u_char *src,
- u_int len)
-{
- rijndael_ctx *ctx = &cc->u.rijndael.enc;
- u_char *iv = cc->u.rijndael.iv;
- u_char in[RIJNDAEL_BLOCKSIZE];
- u_char *cprev, *cnow, *plain;
- int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
-
- if (len == 0)
- return;
- if (len % RIJNDAEL_BLOCKSIZE)
- fatal("rijndael_cbc_encrypt: bad len %d", len);
- cnow = dest;
- plain = (u_char *)src;
- cprev = iv;
- for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
- cnow+=RIJNDAEL_BLOCKSIZE) {
- for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
- in[j] = plain[j] ^ cprev[j];
- rijndael_encrypt(ctx, in, cnow);
- cprev = cnow;
- }
- memcpy(iv, cprev, RIJNDAEL_BLOCKSIZE);
-}
-static void
-rijndael_cbc_decrypt(CipherContext *cc, u_char *dest, const u_char *src,
- u_int len)
-{
- rijndael_ctx *ctx = &cc->u.rijndael.dec;
- u_char *iv = cc->u.rijndael.iv;
- u_char ivsaved[RIJNDAEL_BLOCKSIZE];
- u_char *cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
- u_char *plain = dest+len-RIJNDAEL_BLOCKSIZE;
- u_char *ivp;
- int i, j, 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-=RIJNDAEL_BLOCKSIZE,
- plain-=RIJNDAEL_BLOCKSIZE) {
- rijndael_decrypt(ctx, cnow, plain);
- ivp = (i == 1) ? iv : cnow-RIJNDAEL_BLOCKSIZE;
- for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
- plain[j] ^= ivp[j];
- }
- 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 },
- { NULL, SSH_CIPHER_ILLEGAL, 0, 0, NULL, NULL, NULL, NULL }