diff options
Diffstat (limited to 'fs/cifs/smb2pdu.c')
| -rw-r--r-- | fs/cifs/smb2pdu.c | 53 |
1 files changed, 44 insertions, 9 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 96c172d94fba..445e80862865 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -449,10 +449,22 @@ static void build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt) { pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES; - pneg_ctxt->DataLength = cpu_to_le16(6); /* Cipher Count + two ciphers */ - pneg_ctxt->CipherCount = cpu_to_le16(2); - pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM; - pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM; + if (require_gcm_256) { + pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + 1 cipher */ + pneg_ctxt->CipherCount = cpu_to_le16(1); + pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES256_GCM; + } else if (enable_gcm_256) { + pneg_ctxt->DataLength = cpu_to_le16(8); /* Cipher Count + 3 ciphers */ + pneg_ctxt->CipherCount = cpu_to_le16(3); + pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM; + pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES256_GCM; + pneg_ctxt->Ciphers[2] = SMB2_ENCRYPTION_AES128_CCM; + } else { + pneg_ctxt->DataLength = cpu_to_le16(6); /* Cipher Count + 2 ciphers */ + pneg_ctxt->CipherCount = cpu_to_le16(2); + pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM; + pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM; + } } static unsigned int @@ -598,8 +610,29 @@ static int decode_encrypt_ctx(struct TCP_Server_Info *server, return -EINVAL; } cifs_dbg(FYI, "SMB311 cipher type:%d\n", le16_to_cpu(ctxt->Ciphers[0])); - if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) && - (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM)) { + if (require_gcm_256) { + if (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM) { + cifs_dbg(VFS, "Server does not support requested encryption type (AES256 GCM)\n"); + return -EOPNOTSUPP; + } + } else if (ctxt->Ciphers[0] == 0) { + /* + * e.g. if server only supported AES256_CCM (very unlikely) + * or server supported no encryption types or had all disabled. + * Since GLOBAL_CAP_ENCRYPTION will be not set, in the case + * in which mount requested encryption ("seal") checks later + * on during tree connection will return proper rc, but if + * seal not requested by client, since server is allowed to + * return 0 to indicate no supported cipher, we can't fail here + */ + server->cipher_type = 0; + server->capabilities &= ~SMB2_GLOBAL_CAP_ENCRYPTION; + pr_warn_once("Server does not support requested encryption types\n"); + return 0; + } else if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) && + (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM) && + (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM)) { + /* server returned a cipher we didn't ask for */ pr_warn_once("Invalid SMB3.11 cipher returned\n"); return -EINVAL; } @@ -1948,9 +1981,11 @@ smb2_parse_contexts(struct TCP_Server_Info *server, unsigned int next; unsigned int remaining; char *name; - const char smb3_create_tag_posix[] = {0x93, 0xAD, 0x25, 0x50, 0x9C, - 0xB4, 0x11, 0xE7, 0xB4, 0x23, 0x83, - 0xDE, 0x96, 0x8B, 0xCD, 0x7C}; + static const char smb3_create_tag_posix[] = { + 0x93, 0xAD, 0x25, 0x50, 0x9C, + 0xB4, 0x11, 0xE7, 0xB4, 0x23, 0x83, + 0xDE, 0x96, 0x8B, 0xCD, 0x7C + }; *oplock = 0; data_offset = (char *)rsp + le32_to_cpu(rsp->CreateContextsOffset); |