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Remove doubled sha256 implementation
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Porting Adam's PR #9 to current master. Citing its description:
```
Fix doubled sha256 implementations and the resulting compilation error
 - sha256 implementation kept in atecc508a.c, deleted from u2f_atecc.c
 - sha256 functions delcared as extern
 - the above solution solves the SETUP config compilation error
originated from line 34 in u2f_atecc.c which messed up the scope of the
doubled sha256 implementations
```

Tested with current wkey/rkey setup on UB10 and https://u2f.bin.coffee/

Signed-off-by: Szczepan Zalega <szczepan@nitrokey.com>
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@szszszsz
szszszsz committed Jul 18, 2018
1 parent c4f3d6a commit 767ea15
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Showing 3 changed files with 75 additions and 133 deletions.
9 changes: 9 additions & 0 deletions firmware/inc/atecc508a.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,15 @@ struct atecc_key_config
uint8_t x509id : 2;
};

extern uint8_t SHA_FLAGS;
extern uint8_t SHA_HMAC_KEY;
extern struct atecc_response res_digest;

extern void u2f_sha256_start ();
extern void u2f_sha256_update (uint8_t * buf, uint8_t len);
extern void u2f_sha256_finish ();
extern void compute_key_hash (uint8_t * key, uint8_t * mask, int slot);

void atecc_idle();
void atecc_wake();
void atecc_sleep();
Expand Down
126 changes: 65 additions & 61 deletions firmware/src/atecc508a.c
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Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,12 @@
#include "bsp.h"


uint8_t shabuf[70];
uint8_t shaoffset = 0;
uint8_t SHA_FLAGS = 0;
uint8_t SHA_HMAC_KEY = 0;
struct atecc_response res_digest;


int8_t atecc_send(uint8_t cmd, uint8_t p1, uint16_t p2,
uint8_t * buf, uint8_t len)
Expand Down Expand Up @@ -176,46 +182,6 @@ int8_t atecc_send_recv(uint8_t cmd, uint8_t p1, uint16_t p2,
}


#ifdef ATECC_SETUP_DEVICE

int8_t atecc_write_eeprom(uint8_t base, uint8_t offset, uint8_t* srcbuf, uint8_t len)
{
uint8_t buf[7];
struct atecc_response res;

uint8_t * dstbuf = srcbuf;
if (offset + len > 4)
return -1;
if (len < 4)
{
atecc_send_recv(ATECC_CMD_READ,
ATECC_RW_CONFIG, base, NULL, 0,
buf, sizeof(buf), &res);

dstbuf = res.buf;
memmove(res.buf + offset, srcbuf, len);
}

atecc_send_recv(ATECC_CMD_WRITE,
ATECC_RW_CONFIG, base, dstbuf, 4,
buf, sizeof(buf), &res);

if (res.buf[0])
{
set_app_error(-res.buf[0]);
return -1;
}
return 0;
}



static uint8_t shabuf[70];
static uint8_t shaoffset = 0;
uint8_t SHA_FLAGS = 0;
uint8_t SHA_HMAC_KEY = 0;
static struct atecc_response res_digest;

void u2f_sha256_start()
{
shaoffset = 0;
Expand Down Expand Up @@ -253,6 +219,65 @@ void u2f_sha256_finish()
SHA_FLAGS = 0;
}

void compute_key_hash(uint8_t * key, uint8_t * mask, int slot)
{
// key must start with 4 zeros
memset(appdata.tmp,0,28);
memmove(appdata.tmp + 28, key, 36);

u2f_sha256_start();

u2f_sha256_update(mask,32);


appdata.tmp[0] = ATECC_CMD_PRIVWRITE;
appdata.tmp[1] = ATECC_PRIVWRITE_ENC;
appdata.tmp[2] = slot;
appdata.tmp[3] = 0;
appdata.tmp[4] = 0xee;
appdata.tmp[5] = 0x01;
appdata.tmp[6] = 0x23;

u2f_sha256_update(appdata.tmp,28 + 36);
u2f_sha256_finish();
}


#ifdef ATECC_SETUP_DEVICE

int8_t atecc_write_eeprom(uint8_t base, uint8_t offset, uint8_t* srcbuf, uint8_t len)
{
uint8_t buf[7];
struct atecc_response res;

uint8_t * dstbuf = srcbuf;
if (offset + len > 4)
return -1;
if (len < 4)
{
atecc_send_recv(ATECC_CMD_READ,
ATECC_RW_CONFIG, base, NULL, 0,
buf, sizeof(buf), &res);

dstbuf = res.buf;
memmove(res.buf + offset, srcbuf, len);
}

atecc_send_recv(ATECC_CMD_WRITE,
ATECC_RW_CONFIG, base, dstbuf, 4,
buf, sizeof(buf), &res);

if (res.buf[0])
{
set_app_error(-res.buf[0]);
return -1;
}
return 0;
}




static uint8_t get_signature_length(uint8_t * sig)
{
return 0x46 + ((sig[32] & 0x80) == 0x80) + ((sig[0] & 0x80) == 0x80);
Expand Down Expand Up @@ -489,28 +514,7 @@ int atecc_privwrite(uint16_t keyslot, uint8_t * key, uint8_t * mask, uint8_t * d
return 0;
}

static void compute_key_hash(uint8_t * key, uint8_t * mask, int slot)
{
// key must start with 4 zeros
memset(appdata.tmp,0,28);
memmove(appdata.tmp + 28, key, 36);

u2f_sha256_start();

u2f_sha256_update(mask,32);


appdata.tmp[0] = ATECC_CMD_PRIVWRITE;
appdata.tmp[1] = ATECC_PRIVWRITE_ENC;
appdata.tmp[2] = slot;
appdata.tmp[3] = 0;
appdata.tmp[4] = 0xee;
appdata.tmp[5] = 0x01;
appdata.tmp[6] = 0x23;

u2f_sha256_update(appdata.tmp,28 + 36);
u2f_sha256_finish();
}

void atecc_setup_init(uint8_t * buf)
{
Expand Down
73 changes: 1 addition & 72 deletions firmware/src/u2f_atecc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -98,55 +98,6 @@ int8_t u2f_get_user_feedback()
return 0;
}

#ifdef ATECC_SETUP_DEVICE
#define STATIC_IN_SETUP static
#else
#define STATIC_IN_SETUP
#endif


static uint8_t shabuf[70];
static uint8_t shaoffset = 0;
STATIC_IN_SETUP uint8_t SHA_FLAGS = 0;
STATIC_IN_SETUP uint8_t SHA_HMAC_KEY = 0;
static struct atecc_response res_digest;

STATIC_IN_SETUP void u2f_sha256_start()
{
shaoffset = 0;
atecc_send_recv(ATECC_CMD_SHA,
SHA_FLAGS, SHA_HMAC_KEY,NULL,0,
shabuf, sizeof(shabuf), NULL);
SHA_HMAC_KEY = 0;
}


STATIC_IN_SETUP void u2f_sha256_update(uint8_t * buf, uint8_t len)
{
uint8_t i = 0;
watchdog();
while(len--)
{
shabuf[shaoffset++] = *buf++;
if (shaoffset == 64)
{
atecc_send_recv(ATECC_CMD_SHA,
ATECC_SHA_UPDATE, 64,shabuf,64,
shabuf, sizeof(shabuf), NULL);
shaoffset = 0;
}
}
}


STATIC_IN_SETUP void u2f_sha256_finish()
{
if (SHA_FLAGS == ATECC_SHA_START) SHA_FLAGS = ATECC_SHA_END;
atecc_send_recv(ATECC_CMD_SHA,
SHA_FLAGS, shaoffset,shabuf,shaoffset,
shabuf, sizeof(shabuf), &res_digest);
SHA_FLAGS = ATECC_SHA_START;
}

static int atecc_prep_encryption()
{
Expand All @@ -170,28 +121,6 @@ static int atecc_prep_encryption()
return 0;
}

static void compute_key_hash(uint8_t * key, uint8_t * mask)
{
// key must start with 4 zeros
memset(appdata.tmp,0,28);
memmove(appdata.tmp + 28, key, 36);

u2f_sha256_start();

u2f_sha256_update(mask,32);


appdata.tmp[0] = ATECC_CMD_PRIVWRITE;
appdata.tmp[1] = ATECC_PRIVWRITE_ENC;
appdata.tmp[2] = 2;
appdata.tmp[3] = 0;
appdata.tmp[4] = 0xee;
appdata.tmp[5] = 0x01;
appdata.tmp[6] = 0x23;

u2f_sha256_update(appdata.tmp,28 + 36);
u2f_sha256_finish();
}

static int atecc_privwrite(int keyslot, uint8_t * key, uint8_t * mask, uint8_t * digest)
{
Expand Down Expand Up @@ -272,7 +201,7 @@ int8_t u2f_new_keypair(uint8_t * handle, uint8_t * appid, uint8_t * pubkey)
private_key[i] ^= RMASK[i];
}
watchdog();
compute_key_hash(private_key, WMASK);
compute_key_hash(private_key, WMASK, U2F_TEMP_KEY_SLOT);
memmove(handle+4, res_digest.buf, 32); // size of key handle must be 36+8


Expand Down

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