/*
* Make a new empty bigint. It may just use an old one if one is available.
* Otherwise get one off the heap.
*/
static bigint * ICACHE_FLASH_ATTR alloc(BI_CTX *ctx, int size)
{
bigint *biR;
/* Can we recycle an old bigint? */
if (ctx->free_list != NULL)
{
biR = ctx->free_list;
ctx->free_list = biR->next;
ctx->free_count--;
if (biR->refs != 0)
{
#ifdef CONFIG_SSL_FULL_MODE
ssl_printf("alloc: refs was not 0\n");
#endif
return biR; /* wujg : org ----> abort(); */
}
more_comps(biR, size);
}
else
{
/* No free bigints available - create a new one. */
biR = (bigint *)SSL_MALLOC(sizeof(bigint));
biR->comps = (comp*)SSL_MALLOC(size * COMP_BYTE_SIZE);
biR->max_comps = size; /* give some space to spare */
}
biR->size = size;
biR->refs = 1;
biR->next = NULL;
ctx->active_count++;
return biR;
}
/**
* @brief Use PKCS1.5 for decryption/verification.
* @param ctx [in] The context
* @param in_data [in] The data to decrypt (must be < modulus size-11)
* @param out_data [out] The decrypted data.
* @param out_len [int] The size of the decrypted buffer in bytes
* @param is_decryption [in] Decryption or verify operation.
* @return The number of bytes that were originally encrypted. -1 on error.
* @see http://www.rsasecurity.com/rsalabs/node.asp?id=2125
*/
int RSA_decrypt(const RSA_CTX *ctx, const uint8_t *in_data,
uint8_t *out_data, int out_len, int is_decryption)
{
const int byte_size = ctx->num_octets;
int i = 0, size;
bigint *decrypted_bi, *dat_bi;
uint8_t *block = (uint8_t *)SSL_MALLOC(byte_size);
int pad_count = 0;
if (out_len < byte_size) /* check output has enough size */
return -1;
memset(out_data, 0, out_len); /* initialise */
/* decrypt */
dat_bi = bi_import(ctx->bi_ctx, in_data, byte_size);
#ifdef CONFIG_SSL_CERT_VERIFICATION
decrypted_bi = is_decryption ? /* decrypt or verify? */
RSA_private(ctx, dat_bi) : RSA_public(ctx, dat_bi);
#else /* always a decryption */
decrypted_bi = RSA_private(ctx, dat_bi);
#endif
/* convert to a normal block */
bi_export(ctx->bi_ctx, decrypted_bi, block, byte_size);
if (block[i++] != 0) /* leading 0? */
return -1;
#ifdef CONFIG_SSL_CERT_VERIFICATION
if (is_decryption == 0) /* PKCS1.5 signing pads with "0xff"s */
{
if (block[i++] != 0x01) /* BT correct? */
return -1;
while (block[i++] == 0xff && i < byte_size)
pad_count++;
}
else /* PKCS1.5 encryption padding is random */
#endif
{
if (block[i++] != 0x02) /* BT correct? */
return -1;
while (block[i++] && i < byte_size)
pad_count++;
}
/* check separator byte 0x00 - and padding must be 8 or more bytes */
if (i == byte_size || pad_count < 8)
return -1;
size = byte_size - i;
/* get only the bit we want */
if (size > 0)
memcpy(out_data, &block[i], size);
SSL_FREE(block);
return size ? size : -1;
}
/**
* Obtain an ASN.1 printable string type.
*/
static int asn1_get_printable_str(const uint8_t *buf, int *offset, char **str)
{
int len = X509_NOT_OK;
int asn1_type = buf[*offset];
/* some certs have this awful crud in them for some reason */
if (asn1_type != ASN1_PRINTABLE_STR &&
asn1_type != ASN1_PRINTABLE_STR2 &&
asn1_type != ASN1_TELETEX_STR &&
asn1_type != ASN1_IA5_STR &&
asn1_type != ASN1_UNICODE_STR)
goto end_pnt_str;
(*offset)++;
len = get_asn1_length(buf, offset);
if (asn1_type == ASN1_UNICODE_STR)
{
int i;
*str = (char *)SSL_MALLOC(len/2+1); /* allow for null */
for (i = 0; i < len; i += 2)
(*str)[i/2] = buf[*offset + i + 1];
(*str)[len/2] = 0; /* null terminate */
}
else
{
*str = (char *)SSL_MALLOC(len+1); /* allow for null */
memcpy(*str, &buf[*offset], len);
(*str)[len] = 0; /* null terminate */
}
*offset += len;
end_pnt_str:
return len;
}
/**
* Read the signature of the certificate.
*/
int asn1_signature(const uint8_t *cert, int *offset, X509_CTX *x509_ctx)
{
int ret = X509_NOT_OK;
if (cert[(*offset)++] != ASN1_BIT_STRING)
goto end_sig;
x509_ctx->sig_len = get_asn1_length(cert, offset)-1;
(*offset)++; /* ignore bit string padding bits */
x509_ctx->signature = (uint8_t *)SSL_MALLOC(x509_ctx->sig_len);
memcpy(x509_ctx->signature, &cert[*offset], x509_ctx->sig_len);
*offset += x509_ctx->sig_len;
ret = X509_OK;
end_sig:
return ret;
}
/**
* Read an integer value for ASN.1 data
* Note: This function allocates memory which must be freed by the user.
*/
int asn1_get_int(const uint8_t *buf, int *offset, uint8_t **object)
{
int len;
if ((len = asn1_next_obj(buf, offset, ASN1_INTEGER)) < 0)
goto end_int_array;
if (len > 1 && buf[*offset] == 0x00) /* ignore the negative byte */
{
len--;
(*offset)++;
}
*object = (uint8_t *)SSL_MALLOC(len);
memcpy(*object, &buf[*offset], len);
*offset += len;
end_int_array:
return len;
}
/*
* Work out g1, g3, g5, g7... etc for the sliding-window algorithm
*/
static void ICACHE_FLASH_ATTR precompute_slide_window(BI_CTX *ctx, int window, bigint *g1)
{
int k = 1, i;
bigint *g2;
for (i = 0; i < window-1; i++) /* compute 2^(window-1) */
{
k <<= 1;
}
ctx->g = (bigint **)SSL_MALLOC(k*sizeof(bigint *));
ctx->g[0] = bi_clone(ctx, g1);
bi_permanent(ctx->g[0]);
g2 = bi_residue(ctx, bi_square(ctx, ctx->g[0])); /* g^2 */
for (i = 1; i < k; i++)
{
ctx->g[i] = bi_residue(ctx, bi_multiply(ctx, ctx->g[i-1], bi_copy(g2)));
bi_permanent(ctx->g[i]);
}
bi_free(ctx, g2);
ctx->window = k;
}
/**
* @brief Perform a modular exponentiation.
*
* This function requires bi_set_mod() to have been called previously. This is
* one of the optimisations used for performance.
* @param ctx [in] The bigint session context.
* @param bi [in] The bigint on which to perform the mod power operation.
* @param biexp [in] The bigint exponent.
* @return The result of the mod exponentiation operation
* @see bi_set_mod().
*/
bigint * ICACHE_FLASH_ATTR bi_mod_power(BI_CTX *ctx, bigint *bi, bigint *biexp)
{
int i = find_max_exp_index(biexp), j, window_size = 1;
bigint *biR = int_to_bi(ctx, 1);
#if defined(CONFIG_BIGINT_MONTGOMERY)
uint8_t mod_offset = ctx->mod_offset;
if (!ctx->use_classical)
{
/* preconvert */
bi = bi_mont(ctx,
bi_multiply(ctx, bi, ctx->bi_RR_mod_m[mod_offset])); /* x' */
bi_free(ctx, biR);
biR = ctx->bi_R_mod_m[mod_offset]; /* A */
}
#endif
check(bi);
check(biexp);
#ifdef CONFIG_BIGINT_SLIDING_WINDOW
for (j = i; j > 32; j /= 5) /* work out an optimum size */
window_size++;
/* work out the slide constants */
precompute_slide_window(ctx, window_size, bi);
#else /* just one constant */
ctx->g = (bigint **)SSL_MALLOC(sizeof(bigint *));
ctx->g[0] = bi_clone(ctx, bi);
ctx->window = 1;
bi_permanent(ctx->g[0]);
#endif
/* if sliding-window is off, then only one bit will be done at a time and
* will reduce to standard left-to-right exponentiation */
do
{
if (exp_bit_is_one(biexp, i))
{
int l = i-window_size+1;
int part_exp = 0;
if (l < 0) /* LSB of exponent will always be 1 */
l = 0;
else
{
while (exp_bit_is_one(biexp, l) == 0)
l++; /* go back up */
}
/* build up the section of the exponent */
for (j = i; j >= l; j--)
{
biR = bi_residue(ctx, bi_square(ctx, biR));
if (exp_bit_is_one(biexp, j))
part_exp++;
if (j != l)
part_exp <<= 1;
}
part_exp = (part_exp-1)/2; /* adjust for array */
biR = bi_residue(ctx, bi_multiply(ctx, biR, ctx->g[part_exp]));
i = l-1;
}
else /* square it */
{
biR = bi_residue(ctx, bi_square(ctx, biR));
i--;
}
} while (i >= 0);
/* cleanup */
for (i = 0; i < ctx->window; i++)
{
bi_depermanent(ctx->g[i]);
bi_free(ctx, ctx->g[i]);
}
SSL_FREE(ctx->g);
bi_free(ctx, bi);
bi_free(ctx, biexp);
#if defined CONFIG_BIGINT_MONTGOMERY
return ctx->use_classical ? biR : bi_mont(ctx, biR); /* convert back */
#else /* CONFIG_BIGINT_CLASSICAL or CONFIG_BIGINT_BARRETT */
return biR;
#endif
}
/**
* Set up AES with the key/iv and cipher size.
*/
void ICACHE_FLASH_ATTR AES_set_key(AES_CTX *ctx, const uint8_t *key,
const uint8_t *iv, AES_MODE mode)
{
int i, ii;
uint32_t *W, tmp, tmp2;
unsigned char *ip;
int words;
unsigned char *Rcon_ram = (unsigned char *)SSL_MALLOC(32);
switch (mode)
{
case AES_MODE_128:
i = 10;
words = 4;
break;
case AES_MODE_256:
i = 14;
words = 8;
break;
default: /* fail silently */
return;
}
ctx->rounds = i;
ctx->key_size = words;
W = ctx->ks;
for (i = 0; i < words; i+=2)
{
W[i+0]= ((uint32_t)key[ 0]<<24)|
((uint32_t)key[ 1]<<16)|
((uint32_t)key[ 2]<< 8)|
((uint32_t)key[ 3] );
W[i+1]= ((uint32_t)key[ 4]<<24)|
((uint32_t)key[ 5]<<16)|
((uint32_t)key[ 6]<< 8)|
((uint32_t)key[ 7] );
key += 8;
}
// ip = Rcon;
ip = Rcon_ram;
memcpy(ip, Rcon, 32); // align, copy two byte more
ii = 4 * (ctx->rounds+1);
for (i = words; i<ii; i++)
{
tmp = W[i-1];
if ((i % words) == 0)
{
tmp2 =(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp )&0xff)<< 8;
tmp2|=(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp>> 8)&0xff)<<16;
tmp2|=(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp>>16)&0xff)<<24;
tmp2|=(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp>>24) );
tmp=tmp2^(((unsigned int)*ip)<<24);
ip++;
}
if ((words == 8) && ((i % words) == 4))
{
tmp2 =(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp )&0xff) ;
tmp2|=(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp>> 8)&0xff)<< 8;
tmp2|=(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp>>16)&0xff)<<16;
tmp2|=(uint32_t)system_get_data_of_array_8(aes_sbox, (tmp>>24) )<<24;
tmp=tmp2;
}
