diff --git a/u2f.h b/u2f.h
new file mode 100644
index 0000000..a499dba
--- /dev/null
+++ b/u2f.h
@@ -0,0 +1,106 @@
+// Common U2F raw message format header - Review Draft
+// 2014-10-08
+// Editor: Jakob Ehrensvard, Yubico, jakob@yubico.com
+
+#ifndef __U2F_H_INCLUDED__
+#define __U2F_H_INCLUDED__
+
+#ifdef _MSC_VER  // Windows
+typedef unsigned char     uint8_t;
+typedef unsigned short    uint16_t;
+typedef unsigned int      uint32_t;
+typedef unsigned long int uint64_t;
+#else
+#include <stdint.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// General constants
+
+#define U2F_EC_KEY_SIZE         32      // EC key size in bytes
+#define U2F_EC_POINT_SIZE       ((U2F_EC_KEY_SIZE * 2) + 1) // Size of EC point
+#define U2F_MAX_KH_SIZE         128     // Max size of key handle
+#define U2F_MAX_ATT_CERT_SIZE   2048    // Max size of attestation certificate
+#define U2F_MAX_EC_SIG_SIZE     72      // Max size of DER coded EC signature
+#define U2F_CTR_SIZE            4       // Size of counter field
+#define U2F_APPID_SIZE          32      // Size of application id
+#define U2F_CHAL_SIZE           32      // Size of challenge
+
+#define ENC_SIZE(x)             ((x + 7) & 0xfff8)
+
+// EC (uncompressed) point
+
+#define U2F_POINT_UNCOMPRESSED  0x04    // Uncompressed point format
+
+typedef struct {
+    uint8_t pointFormat;                // Point type
+    uint8_t x[U2F_EC_KEY_SIZE];         // X-value
+    uint8_t y[U2F_EC_KEY_SIZE];         // Y-value
+} __attribute__((packed)) U2F_EC_POINT;
+
+// U2F native commands
+
+#define U2F_REGISTER            0x01    // Registration command
+#define U2F_AUTHENTICATE        0x02    // Authenticate/sign command
+#define U2F_VERSION             0x03    // Read version string command
+
+#define U2F_VENDOR_FIRST        0x40    // First vendor defined command
+#define U2F_VENDOR_LAST         0xbf    // Last vendor defined command
+
+// U2F_CMD_REGISTER command defines
+
+#define U2F_REGISTER_ID         0x05    // Version 2 registration identifier
+#define U2F_REGISTER_HASH_ID    0x00    // Version 2 hash identintifier
+
+typedef struct {
+    uint8_t chal[U2F_CHAL_SIZE];        // Challenge
+    uint8_t appId[U2F_APPID_SIZE];      // Application id
+} __attribute__((packed)) U2F_REGISTER_REQ;
+
+typedef struct {
+    uint8_t registerId;                 // Registration identifier (U2F_REGISTER_ID_V2)
+    U2F_EC_POINT pubKey;                // Generated public key
+    uint8_t keyHandleLen;               // Length of key handle
+    uint8_t keyHandleCertSig[
+        U2F_MAX_KH_SIZE +               // Key handle
+        U2F_MAX_ATT_CERT_SIZE +         // Attestation certificate
+        U2F_MAX_EC_SIG_SIZE];           // Registration signature
+} __attribute__((packed)) U2F_REGISTER_RESP;
+
+// U2F_CMD_AUTHENTICATE command defines
+
+// Authentication control byte
+
+#define U2F_AUTH_ENFORCE        0x03    // Enforce user presence and sign
+#define U2F_AUTH_CHECK_ONLY     0x07    // Check only
+#define U2F_AUTH_FLAG_TUP       0x01    // Test of user presence set
+
+typedef struct {
+    uint8_t chal[U2F_CHAL_SIZE];        // Challenge
+    uint8_t appId[U2F_APPID_SIZE];      // Application id
+    uint8_t keyHandleLen;               // Length of key handle
+    uint8_t keyHandle[U2F_MAX_KH_SIZE]; // Key handle
+} __attribute__((packed)) U2F_AUTHENTICATE_REQ;
+
+typedef struct {
+    uint8_t flags;                      // U2F_AUTH_FLAG_ values
+    uint8_t ctr[U2F_CTR_SIZE];          // Counter field (big-endian)
+    uint8_t sig[U2F_MAX_EC_SIG_SIZE];   // Signature
+} __attribute__((packed)) U2F_AUTHENTICATE_RESP;
+
+// Command status responses
+
+#define U2F_SW_NO_ERROR                 0x9000 // SW_NO_ERROR
+#define U2F_SW_WRONG_DATA               0x6A80 // SW_WRONG_DATA
+#define U2F_SW_CONDITIONS_NOT_SATISFIED 0x6985 // SW_CONDITIONS_NOT_SATISFIED
+#define U2F_SW_COMMAND_NOT_ALLOWED      0x6986 // SW_COMMAND_NOT_ALLOWED
+#define U2F_SW_INS_NOT_SUPPORTED        0x6D00 // SW_INS_NOT_SUPPORTED
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // __U2F_H_INCLUDED__
diff --git a/u2f_hid.h b/u2f_hid.h
new file mode 100644
index 0000000..0b168f2
--- /dev/null
+++ b/u2f_hid.h
@@ -0,0 +1,126 @@
+// Common U2F HID transport header - Review Draft
+// 2014-10-08
+// Editor: Jakob Ehrensvard, Yubico, jakob@yubico.com
+
+#ifndef __U2FHID_H_INCLUDED__
+#define __U2FHID_H_INCLUDED__
+
+#ifdef _MSC_VER  // Windows
+typedef unsigned char     uint8_t;
+typedef unsigned short    uint16_t;
+typedef unsigned int      uint32_t;
+typedef unsigned long int uint64_t;
+#else
+#include <stdint.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Size of HID reports 
+
+#define HID_RPT_SIZE            64      // Default size of raw HID report
+    
+// Frame layout - command- and continuation frames
+
+#define CID_BROADCAST           0xffffffff // Broadcast channel id
+
+#define TYPE_MASK               0x80    // Frame type mask 
+#define TYPE_INIT               0x80    // Initial frame identifier
+#define TYPE_CONT               0x00    // Continuation frame identifier
+
+typedef struct {
+  uint32_t cid;                        // Channel identifier
+  union {
+    uint8_t type;                      // Frame type - b7 defines type
+    struct {
+      uint8_t cmd;                     // Command - b7 set
+      uint8_t bcnth;                   // Message byte count - high part
+      uint8_t bcntl;                   // Message byte count - low part
+      uint8_t data[HID_RPT_SIZE - 7];  // Data payload
+    } init;
+    struct {
+      uint8_t seq;                     // Sequence number - b7 cleared
+      uint8_t data[HID_RPT_SIZE - 5];  // Data payload
+    } cont;
+  };
+} __attribute__((packed)) U2FHID_FRAME;
+
+#define FRAME_TYPE(f) ((f).type & TYPE_MASK)
+#define FRAME_CMD(f)  ((f).init.cmd & ~TYPE_MASK)
+#define MSG_LEN(f)    ((f).init.bcnth*256 + (f).init.bcntl)
+#define FRAME_SEQ(f)  ((f).cont.seq & ~TYPE_MASK)
+
+// HID usage- and usage-page definitions
+
+#define FIDO_USAGE_PAGE         0xf1d0  // FIDO alliance HID usage page
+#define FIDO_USAGE_U2FHID       0x01    // U2FHID usage for top-level collection
+#define FIDO_USAGE_DATA_IN      0x20    // Raw IN data report
+#define FIDO_USAGE_DATA_OUT     0x21    // Raw OUT data report
+        
+// General constants    
+
+#define U2FHID_IF_VERSION       2       // Current interface implementation version
+#define U2FHID_TRANS_TIMEOUT    3000    // Default message timeout in ms
+
+// U2FHID native commands
+
+#define U2FHID_PING         (TYPE_INIT | 0x01)  // Echo data through local processor only
+#define U2FHID_MSG          (TYPE_INIT | 0x03)  // Send U2F message frame
+#define U2FHID_LOCK         (TYPE_INIT | 0x04)  // Send lock channel command
+#define U2FHID_INIT         (TYPE_INIT | 0x06)  // Channel initialization
+#define U2FHID_WINK         (TYPE_INIT | 0x08)  // Send device identification wink
+#define U2FHID_SYNC         (TYPE_INIT | 0x3c)  // Protocol resync command
+#define U2FHID_ERROR        (TYPE_INIT | 0x3f)  // Error response
+
+#define U2FHID_VENDOR_FIRST (TYPE_INIT | 0x40)  // First vendor defined command
+#define U2FHID_VENDOR_LAST  (TYPE_INIT | 0x7f)  // Last vendor defined command
+    
+// U2FHID_INIT command defines
+
+#define INIT_NONCE_SIZE         8       // Size of channel initialization challenge
+#define CAPFLAG_WINK            0x01    // Device supports WINK command
+
+typedef struct {
+  uint8_t nonce[INIT_NONCE_SIZE];       // Client application nonce
+} __attribute__((packed)) U2FHID_INIT_REQ;
+
+typedef struct {
+  uint8_t nonce[INIT_NONCE_SIZE];       // Client application nonce
+  uint32_t cid;                         // Channel identifier  
+  uint8_t versionInterface;             // Interface version
+  uint8_t versionMajor;                 // Major version number
+  uint8_t versionMinor;                 // Minor version number
+  uint8_t versionBuild;                 // Build version number
+  uint8_t capFlags;                     // Capabilities flags  
+}  __attribute__((packed)) U2FHID_INIT_RESP;
+
+// U2FHID_SYNC command defines
+
+typedef struct {
+  uint8_t nonce;                        // Client application nonce
+} __attribute__((packed)) U2FHID_SYNC_REQ;
+
+typedef struct {
+  uint8_t nonce;                        // Client application nonce
+} __attribute__((packed)) U2FHID_SYNC_RESP;
+
+// Low-level error codes. Return as negatives.
+
+#define ERR_NONE                0x00    // No error
+#define ERR_INVALID_CMD         0x01    // Invalid command
+#define ERR_INVALID_PAR         0x02    // Invalid parameter
+#define ERR_INVALID_LEN         0x03    // Invalid message length
+#define ERR_INVALID_SEQ         0x04    // Invalid message sequencing
+#define ERR_MSG_TIMEOUT         0x05    // Message has timed out
+#define ERR_CHANNEL_BUSY        0x06    // Channel busy
+#define ERR_LOCK_REQUIRED       0x0a    // Command requires channel lock
+#define ERR_SYNC_FAIL           0x0b    // SYNC command failed
+#define ERR_OTHER               0x7f    // Other unspecified error
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // __U2FHID_H_INCLUDED__