int
cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
int do_encrypt)
{
struct sshcipher_ctx *cc = NULL;
int ret = SSH_ERR_INTERNAL_ERROR;
#ifdef WITH_OPENSSL
const EVP_CIPHER *type;
int klen;
u_char *junk, *discard;
#endif
*ccp = NULL;
if ((cc = calloc(sizeof(*cc), 1)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if (cipher->number == SSH_CIPHER_DES) {
if (keylen > 8)
keylen = 8;
}
cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
cc->encrypt = do_encrypt;
if (keylen < cipher->key_len ||
(iv != NULL && ivlen < cipher_ivlen(cipher))) {
ret = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
cc->cipher = cipher;
if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
ret = chachapoly_init(&cc->cp_ctx, key, keylen);
goto out;
}
#ifndef WITH_OPENSSL
if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
aesctr_ivsetup(&cc->ac_ctx, iv);
ret = 0;
goto out;
}
if ((cc->cipher->flags & CFLAG_NONE) != 0) {
ret = 0;
goto out;
}
ret = SSH_ERR_INVALID_ARGUMENT;
goto out;
#else /* WITH_OPENSSL */
type = (*cipher->evptype)();
if ((cc->evp = EVP_CIPHER_CTX_new()) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (EVP_CipherInit(cc->evp, type, NULL, (const u_char *)iv,
(do_encrypt == CIPHER_ENCRYPT)) == 0) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if (cipher_authlen(cipher) &&
!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
-1, __UNCONST(iv))) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
klen = EVP_CIPHER_CTX_key_length(cc->evp);
if (klen > 0 && keylen != (u_int)klen) {
if (EVP_CIPHER_CTX_set_key_length(cc->evp, keylen) == 0) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
}
if (EVP_CipherInit(cc->evp, NULL, __UNCONST(key), NULL, -1) == 0) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if (cipher->discard_len > 0) {
if ((junk = malloc(cipher->discard_len)) == NULL ||
(discard = malloc(cipher->discard_len)) == NULL) {
free(junk);
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
ret = EVP_Cipher(cc->evp, discard, junk, cipher->discard_len);
explicit_bzero(discard, cipher->discard_len);
free(junk);
free(discard);
if (ret != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
}
ret = 0;
#endif /* WITH_OPENSSL */
out:
if (ret == 0) {
/* success */
*ccp = cc;
} else {
if (cc != NULL) {
#ifdef WITH_OPENSSL
if (cc->evp != NULL)
EVP_CIPHER_CTX_free(cc->evp);
#endif /* WITH_OPENSSL */
explicit_bzero(cc, sizeof(*cc));
free(cc);
}
}
return ret;
}
int
cipher_init(struct sshcipher_ctx *cc, const struct sshcipher *cipher,
const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
int do_encrypt)
{
#ifdef WITH_OPENSSL
int ret = SSH_ERR_INTERNAL_ERROR;
const EVP_CIPHER *type;
int klen;
u_char *junk, *discard;
if (cipher->number == SSH_CIPHER_DES) {
if (keylen > 8)
keylen = 8;
}
#endif
cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
cc->encrypt = do_encrypt;
if (keylen < cipher->key_len ||
(iv != NULL && ivlen < cipher_ivlen(cipher)))
return SSH_ERR_INVALID_ARGUMENT;
cc->cipher = cipher;
if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
return chachapoly_init(&cc->cp_ctx, key, keylen);
}
#ifndef WITH_OPENSSL
if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
aesctr_ivsetup(&cc->ac_ctx, iv);
return 0;
}
if ((cc->cipher->flags & CFLAG_NONE) != 0)
return 0;
return SSH_ERR_INVALID_ARGUMENT;
#else
type = (*cipher->evptype)();
EVP_CIPHER_CTX_init(&cc->evp);
if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
(do_encrypt == CIPHER_ENCRYPT)) == 0) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto bad;
}
if (cipher_authlen(cipher) &&
!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
-1, (u_char *)iv)) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto bad;
}
klen = EVP_CIPHER_CTX_key_length(&cc->evp);
if (klen > 0 && keylen != (u_int)klen) {
if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto bad;
}
}
if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto bad;
}
if (cipher->discard_len > 0) {
if ((junk = malloc(cipher->discard_len)) == NULL ||
(discard = malloc(cipher->discard_len)) == NULL) {
if (junk != NULL)
free(junk);
ret = SSH_ERR_ALLOC_FAIL;
goto bad;
}
ret = EVP_Cipher(&cc->evp, discard, junk, cipher->discard_len);
explicit_bzero(discard, cipher->discard_len);
free(junk);
free(discard);
if (ret != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
bad:
EVP_CIPHER_CTX_cleanup(&cc->evp);
return ret;
}
}
#endif
return 0;
}
