PJ_DEF(void) pj_hmac_md5_final(pj_hmac_md5_context *hctx,
pj_uint8_t digest[16])
{
pj_md5_final(&hctx->context, digest);
/*
* perform outer MD5
*/
pj_md5_init(&hctx->context);
pj_md5_update(&hctx->context, hctx->k_opad, 64);
pj_md5_update(&hctx->context, digest, 16);
pj_md5_final(&hctx->context, digest);
}
/* Calculate HMAC-SHA1 key for long term credential, by getting
* MD5 digest of username, realm, and password.
*/
static void calc_md5_key(pj_uint8_t digest[16],
const pj_str_t *realm,
const pj_str_t *username,
const pj_str_t *passwd)
{
/* The 16-byte key for MESSAGE-INTEGRITY HMAC is formed by taking
* the MD5 hash of the result of concatenating the following five
* fields: (1) The username, with any quotes and trailing nulls
* removed, (2) A single colon, (3) The realm, with any quotes and
* trailing nulls removed, (4) A single colon, and (5) The
* password, with any trailing nulls removed.
*/
pj_md5_context ctx;
pj_str_t s;
pj_md5_init(&ctx);
#define REMOVE_QUOTE(s) if (s.slen && *s.ptr=='"') \
s.ptr++, s.slen--; \
if (s.slen && s.ptr[s.slen-1]=='"') \
s.slen--;
/* Add username */
s = *username;
REMOVE_QUOTE(s);
pj_md5_update(&ctx, (pj_uint8_t*)s.ptr, (unsigned)s.slen);
/* Add single colon */
pj_md5_update(&ctx, (pj_uint8_t*)":", 1);
/* Add realm */
s = *realm;
REMOVE_QUOTE(s);
pj_md5_update(&ctx, (pj_uint8_t*)s.ptr, (unsigned)s.slen);
#undef REMOVE_QUOTE
/* Another colon */
pj_md5_update(&ctx, (pj_uint8_t*)":", 1);
/* Add password */
pj_md5_update(&ctx, (pj_uint8_t*)passwd->ptr, (unsigned)passwd->slen);
/* Done */
pj_md5_final(&ctx, digest);
}
PJ_DEF(void) pj_hmac_md5_init(pj_hmac_md5_context *hctx,
const pj_uint8_t *key, unsigned key_len)
{
pj_uint8_t k_ipad[64];
pj_uint8_t tk[16];
int i;
/* if key is longer than 64 bytes reset it to key=MD5(key) */
if (key_len > 64) {
pj_md5_context tctx;
pj_md5_init(&tctx);
pj_md5_update(&tctx, key, key_len);
pj_md5_final(&tctx, tk);
key = tk;
key_len = 16;
}
/*
* HMAC = H(K XOR opad, H(K XOR ipad, text))
*/
/* start out by storing key in pads */
pj_bzero( k_ipad, sizeof(k_ipad));
pj_bzero( hctx->k_opad, sizeof(hctx->k_opad));
pj_memcpy( k_ipad, key, key_len);
pj_memcpy( hctx->k_opad, key, key_len);
/* XOR key with ipad and opad values */
for (i=0; i<64; i++) {
k_ipad[i] ^= 0x36;
hctx->k_opad[i] ^= 0x5c;
}
/*
* perform inner MD5
*/
pj_md5_init(&hctx->context);
pj_md5_update(&hctx->context, k_ipad, 64);
}
PJ_DEF(pj_str_t) pjsip_calculate_branch_id( pjsip_rx_data *rdata )
{
pj_md5_context ctx;
pj_uint8_t digest[16];
pj_str_t branch;
pj_str_t rfc3261_branch = {PJSIP_RFC3261_BRANCH_ID,
PJSIP_RFC3261_BRANCH_LEN};
/* If incoming request does not have RFC 3261 branch value, create
* a branch value from GUID .
*/
if (pj_strncmp(&rdata->msg_info.via->branch_param,
&rfc3261_branch, PJSIP_RFC3261_BRANCH_LEN) != 0 )
{
pj_str_t tmp;
branch.ptr = (char*)
pj_pool_alloc(rdata->tp_info.pool, PJSIP_MAX_BRANCH_LEN);
branch.slen = PJSIP_RFC3261_BRANCH_LEN;
pj_memcpy(branch.ptr, PJSIP_RFC3261_BRANCH_ID,
PJSIP_RFC3261_BRANCH_LEN);
tmp.ptr = branch.ptr + PJSIP_RFC3261_BRANCH_LEN + 2;
*(tmp.ptr-2) = (pj_int8_t)(branch.slen+73);
*(tmp.ptr-1) = (pj_int8_t)(branch.slen+99);
pj_generate_unique_string( &tmp );
branch.slen = PJSIP_MAX_BRANCH_LEN;
return branch;
}
/* Create branch ID for new request by calculating MD5 hash
* of the branch parameter in top-most Via header.
*/
pj_md5_init(&ctx);
pj_md5_update(&ctx, (pj_uint8_t*)rdata->msg_info.via->branch_param.ptr,
rdata->msg_info.via->branch_param.slen);
pj_md5_final(&ctx, digest);
branch.ptr = (char*)
pj_pool_alloc(rdata->tp_info.pool,
34 + PJSIP_RFC3261_BRANCH_LEN);
pj_memcpy(branch.ptr, PJSIP_RFC3261_BRANCH_ID, PJSIP_RFC3261_BRANCH_LEN);
branch.slen = PJSIP_RFC3261_BRANCH_LEN;
*(branch.ptr+PJSIP_RFC3261_BRANCH_LEN) = (pj_int8_t)(branch.slen+73);
*(branch.ptr+PJSIP_RFC3261_BRANCH_LEN+1) = (pj_int8_t)(branch.slen+99);
digest2str(digest, branch.ptr+PJSIP_RFC3261_BRANCH_LEN+2);
branch.slen = 34 + PJSIP_RFC3261_BRANCH_LEN;
return branch;
}
PJ_DEF(void) pj_hmac_md5_update(pj_hmac_md5_context *hctx,
const pj_uint8_t *input,
unsigned input_len)
{
pj_md5_update(&hctx->context, input, input_len);
}
