libcli/smb: add smb2_signing_[en|e]crypt_pdu()

metze

diff --git a/libcli/smb/smb2_signing.c b/libcli/smb/smb2_signing.c
index 43c9ba5c1c00a85092a8ef8534efc29efc90e9a3..bb621fd27e5fc145eb4178cc7a7839c9e5e71e63 100644 (file)
--- a/libcli/smb/smb2_signing.c
+++ b/libcli/smb/smb2_signing.c
@@ -207,3 +207,135 @@ void smb2_key_derivation(const uint8_t *KI, size_t KI_len,
 
        memcpy(KO, digest, 16);
 }
+
+NTSTATUS smb2_signing_encrypt_pdu(DATA_BLOB encryption_key,
+                                 enum protocol_types protocol,
+                                 struct iovec *vector,
+                                 int count)
+{
+       uint8_t *tf;
+       uint16_t alg;
+       uint8_t sig[16];
+       int i;
+       size_t a_total;
+       size_t m_total = 0;
+       struct aes_ccm_128_context ctx;
+       uint8_t key[AES_BLOCK_SIZE];
+
+       if (count < 1) {
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       if (vector[0].iov_len != SMB2_TF_HDR_SIZE) {
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       tf = (uint8_t *)vector[0].iov_base;
+
+       if (encryption_key.length == 0) {
+               DEBUG(2,("Wrong encryption key length %u for SMB2 signing\n",
+                        (unsigned)encryption_key.length));
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       alg = SMB2_ENCRYPTION_AES128_CCM;
+       SSVAL(tf, SMB2_TF_ALGORITHM, alg);
+
+       a_total = SMB2_TF_HDR_SIZE - SMB2_TF_NONCE;
+       for (i=1; i < count; i++) {
+               m_total += vector[i].iov_len;
+       }
+       ZERO_STRUCT(key);
+       memcpy(key, encryption_key.data,
+              MIN(encryption_key.length, AES_BLOCK_SIZE));
+       aes_ccm_128_init(&ctx, key,
+                        tf + SMB2_TF_NONCE,
+                        a_total, m_total);
+       aes_ccm_128_update(&ctx, tf + SMB2_TF_NONCE, a_total);
+       for (i=1; i < count; i++) {
+               aes_ccm_128_update(&ctx,
+                               (const uint8_t *)vector[i].iov_base,
+                               vector[i].iov_len);
+       }
+       for (i=1; i < count; i++) {
+               aes_ccm_128_crypt(&ctx,
+                               (uint8_t *)vector[i].iov_base,
+                               vector[i].iov_len);
+       }
+       aes_ccm_128_digest(&ctx, sig);
+
+       memcpy(tf + SMB2_TF_SIGNATURE, sig, 16);
+
+       DEBUG(5,("encrypt SMB2 message\n"));
+
+       return NT_STATUS_OK;
+}
+
+NTSTATUS smb2_signing_decrypt_pdu(DATA_BLOB decryption_key,
+                                 enum protocol_types protocol,
+                                 struct iovec *vector,
+                                 int count)
+{
+       uint8_t *tf;
+       uint16_t alg;
+       uint8_t *sig_ptr = NULL;
+       uint8_t sig[16];
+       int i;
+       size_t a_total;
+       size_t m_total = 0;
+       struct aes_ccm_128_context ctx;
+       uint8_t key[AES_BLOCK_SIZE];
+
+       if (count < 1) {
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       if (vector[0].iov_len != SMB2_TF_HDR_SIZE) {
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       tf = (uint8_t *)vector[0].iov_base;
+
+       if (decryption_key.length == 0) {
+               DEBUG(2,("Wrong decryption key length %u for SMB2 signing\n",
+                        (unsigned)decryption_key.length));
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       alg = SVAL(tf, SMB2_TF_ALGORITHM);
+       if (alg != SMB2_ENCRYPTION_AES128_CCM) {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       a_total = SMB2_TF_HDR_SIZE - SMB2_TF_NONCE;
+       for (i=1; i < count; i++) {
+               m_total += vector[i].iov_len;
+       }
+       ZERO_STRUCT(key);
+       memcpy(key, decryption_key.data,
+              MIN(decryption_key.length, AES_BLOCK_SIZE));
+       aes_ccm_128_init(&ctx, key,
+                        tf + SMB2_TF_NONCE,
+                        a_total, m_total);
+       for (i=1; i < count; i++) {
+               aes_ccm_128_crypt(&ctx,
+                               (uint8_t *)vector[i].iov_base,
+                               vector[i].iov_len);
+       }
+       aes_ccm_128_update(&ctx, tf + SMB2_TF_NONCE, a_total);
+       for (i=1; i < count; i++) {
+               aes_ccm_128_update(&ctx,
+                               ( uint8_t *)vector[i].iov_base,
+                               vector[i].iov_len);
+       }
+       aes_ccm_128_digest(&ctx, sig);
+
+       sig_ptr = tf + SMB2_TF_SIGNATURE;
+       if (memcmp(sig_ptr, sig, 16) != 0) {
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       DEBUG(5,("decrypt SMB2 message\n"));
+
+       return NT_STATUS_OK;
+}

diff --git a/libcli/smb/smb2_signing.h b/libcli/smb/smb2_signing.h
index 200274ba6d3049c61be31e1dddbdc481c5d0a578..e8e2e6a718189364fe219ebf7d73a66f9831acc9 100644 (file)
--- a/libcli/smb/smb2_signing.h
+++ b/libcli/smb/smb2_signing.h
@@ -38,4 +38,13 @@ void smb2_key_derivation(const uint8_t *KI, size_t KI_len,
                         const uint8_t *Context, size_t Context_len,
                         uint8_t KO[16]);
 
+NTSTATUS smb2_signing_encrypt_pdu(DATA_BLOB encryption_key,
+                                 enum protocol_types protocol,
+                                 struct iovec *vector,
+                                 int count);
+NTSTATUS smb2_signing_decrypt_pdu(DATA_BLOB decryption_key,
+                                 enum protocol_types protocol,
+                                 struct iovec *vector,
+                                 int count);
+
 #endif /* _LIBCLI_SMB_SMB2_SIGNING_H_ */