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Diffstat (limited to 'libcli/auth/session.c')
| -rw-r--r-- | libcli/auth/session.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/libcli/auth/session.c b/libcli/auth/session.c new file mode 100644 index 0000000..43ce9d5 --- /dev/null +++ b/libcli/auth/session.c @@ -0,0 +1,243 @@ +/* + Unix SMB/CIFS implementation. + + code to encrypt/decrypt data using the user session key + + Copyright (C) Andrew Tridgell 2004 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "libcli/auth/libcli_auth.h" + +/* + encrypt or decrypt a blob of data using the user session key + as used in lsa_SetSecret + + before calling, the out blob must be initialised to be the same size + as the in blob +*/ +int sess_crypt_blob(DATA_BLOB *out, const DATA_BLOB *in, const DATA_BLOB *session_key, + enum samba_gnutls_direction encrypt) +{ + int i, k, rc; + + if (in->length % 8 != 0) { + return GNUTLS_E_INVALID_REQUEST; + } + + for (i=0,k=0; + i<in->length; + i += 8, k += 7) { + uint8_t bin[8], bout[8], key[7]; + + memcpy(bin, &in->data[i], 8); + + if (k + 7 > session_key->length) { + k = (session_key->length - k); + } + memcpy(key, &session_key->data[k], 7); + + rc = des_crypt56_gnutls(bout, bin, key, encrypt); + if (rc != 0) { + return rc; + } + + memcpy(&out->data[i], bout, 8); + } + return 0; +} + + +/* + a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention + + note that we round the length to a multiple of 8. This seems to be needed for + compatibility with windows + + caller should free using data_blob_free() +*/ +DATA_BLOB sess_encrypt_string(const char *str, const DATA_BLOB *session_key) +{ + DATA_BLOB ret, src; + int slen = strlen(str); + int dlen = (slen+7) & ~7; + int rc; + + src = data_blob(NULL, 8+dlen); + if (!src.data) { + return data_blob(NULL, 0); + } + + ret = data_blob(NULL, 8+dlen); + if (!ret.data) { + data_blob_free(&src); + return data_blob(NULL, 0); + } + + SIVAL(src.data, 0, slen); + SIVAL(src.data, 4, 1); + memset(src.data+8, 0, dlen); + memcpy(src.data+8, str, slen); + + rc = sess_crypt_blob(&ret, &src, session_key, SAMBA_GNUTLS_ENCRYPT); + + data_blob_free(&src); + if (rc != 0) { + data_blob_free(&ret); + return data_blob(NULL, 0); + } + + return ret; +} + +/* + a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention + + caller should free the returned string +*/ +char *sess_decrypt_string(TALLOC_CTX *mem_ctx, + DATA_BLOB *blob, const DATA_BLOB *session_key) +{ + DATA_BLOB out; + int rc, slen; + char *ret; + + if (blob->length < 8) { + return NULL; + } + + out = data_blob_talloc(mem_ctx, NULL, blob->length); + if (!out.data) { + return NULL; + } + + rc = sess_crypt_blob(&out, blob, session_key, SAMBA_GNUTLS_DECRYPT); + if (rc != 0) { + data_blob_free(&out); + return NULL; + } + + if (IVAL(out.data, 4) != 1) { + DEBUG(0,("Unexpected revision number %d in session crypted string\n", + IVAL(out.data, 4))); + data_blob_free(&out); + return NULL; + } + + slen = IVAL(out.data, 0); + if (slen > blob->length - 8) { + DEBUG(0,("Invalid crypt length %d\n", slen)); + data_blob_free(&out); + return NULL; + } + + ret = talloc_strndup(mem_ctx, (const char *)(out.data+8), slen); + + data_blob_free(&out); + + DEBUG(0,("decrypted string '%s' of length %d\n", ret, slen)); + + return ret; +} + +/* + a convenient wrapper around sess_crypt_blob() for DATA_BLOBs, using the LSA convention + + note that we round the length to a multiple of 8. This seems to be needed for + compatibility with windows + + caller should free using data_blob_free() +*/ +DATA_BLOB sess_encrypt_blob(TALLOC_CTX *mem_ctx, DATA_BLOB *blob_in, const DATA_BLOB *session_key) +{ + DATA_BLOB ret, src; + int dlen = (blob_in->length+7) & ~7; + int rc; + + src = data_blob_talloc(mem_ctx, NULL, 8+dlen); + if (!src.data) { + return data_blob(NULL, 0); + } + + ret = data_blob_talloc(mem_ctx, NULL, 8+dlen); + if (!ret.data) { + data_blob_free(&src); + return data_blob(NULL, 0); + } + + SIVAL(src.data, 0, blob_in->length); + SIVAL(src.data, 4, 1); + memset(src.data+8, 0, dlen); + memcpy(src.data+8, blob_in->data, blob_in->length); + + rc = sess_crypt_blob(&ret, &src, session_key, SAMBA_GNUTLS_ENCRYPT); + + data_blob_free(&src); + if (rc != 0) { + data_blob_free(&ret); + return data_blob(NULL, 0); + } + + return ret; +} + +/* + Decrypt a DATA_BLOB using the LSA convention +*/ +NTSTATUS sess_decrypt_blob(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob, const DATA_BLOB *session_key, + DATA_BLOB *ret) +{ + DATA_BLOB out; + int rc, slen; + + if (blob->length < 8) { + DEBUG(0, ("Unexpected length %d in session crypted secret (BLOB)\n", + (int)blob->length)); + return NT_STATUS_INVALID_PARAMETER; + } + + out = data_blob_talloc(mem_ctx, NULL, blob->length); + if (!out.data) { + return NT_STATUS_NO_MEMORY; + } + + rc = sess_crypt_blob(&out, blob, session_key, SAMBA_GNUTLS_DECRYPT); + if (rc != 0) { + data_blob_free(&out); + return gnutls_error_to_ntstatus(rc, NT_STATUS_ACCESS_DISABLED_BY_POLICY_OTHER); + } + + if (IVAL(out.data, 4) != 1) { + DEBUG(2,("Unexpected revision number %d in session crypted secret (BLOB)\n", + IVAL(out.data, 4))); + return NT_STATUS_UNKNOWN_REVISION; + } + + slen = IVAL(out.data, 0); + if (slen > blob->length - 8) { + DEBUG(0,("Invalid crypt length %d in session crypted secret (BLOB)\n", slen)); + return NT_STATUS_WRONG_PASSWORD; + } + + *ret = data_blob_talloc(mem_ctx, out.data+8, slen); + if (slen && !ret->data) { + return NT_STATUS_NO_MEMORY; + } + + data_blob_free(&out); + + return NT_STATUS_OK; +} |