/* Public key static functions. */
static void SecECPublicKeyDestroy(SecKeyRef key) {
/* Zero out the public key */
ccec_pub_ctx_t pubkey;
pubkey.pub = key->key;
if (ccec_ctx_cp(pubkey).zp)
cc_zero(ccec_pub_ctx_size(ccn_sizeof_n(ccec_ctx_n(pubkey))), pubkey.pub);
}
/* Private key static functions. */
static void SecECPrivateKeyDestroy(SecKeyRef key) {
/* Zero out the public key */
ccec_full_ctx_t fullkey;
fullkey.hdr = key->key;
if (ccec_ctx_cp(fullkey).zp)
cc_zero(ccec_full_ctx_size(ccn_sizeof_n(ccec_ctx_n(fullkey))), fullkey.hdr);
}
static OSStatus SecECPublicKeyInit(SecKeyRef key,
const uint8_t *keyData, CFIndex keyDataLength, SecKeyEncoding encoding) {
ccec_pub_ctx_t pubkey;
pubkey.pub = key->key;
OSStatus err = errSecParam;
switch (encoding) {
case kSecDERKeyEncoding:
{
const SecDERKey *derKey = (const SecDERKey *)keyData;
if (keyDataLength != sizeof(SecDERKey)) {
err = errSecDecode;
break;
}
ccec_const_cp_t cp = getCPForPublicSize(derKey->keyLength);
/* TODO: Parse and use real params from passed in derKey->algId.params */
err = (ccec_import_pub(cp, derKey->keyLength, derKey->key, pubkey)
? errSecDecode : errSecSuccess);
break;
}
case kSecKeyEncodingBytes:
{
ccec_const_cp_t cp = getCPForPublicSize(keyDataLength);
err = (ccec_import_pub(cp, keyDataLength, keyData, pubkey)
? errSecDecode : errSecSuccess);
break;
}
case kSecExtractPublicFromPrivate:
{
ccec_full_ctx_t fullKey;
fullKey._full = (ccec_full_ctx *) keyData;
cc_size fullKeyN = ccec_ctx_n(fullKey);
require(fullKeyN <= ccn_nof(kMaximumECKeySize), errOut);
memcpy(pubkey._pub, fullKey.pub, ccec_pub_ctx_size(ccn_sizeof_n(fullKeyN)));
err = errSecSuccess;
break;
}
case kSecKeyEncodingApplePkcs1:
default:
err = errSecParam;
break;
}
errOut:
return err;
}
static CFDataRef SecECPPrivateKeyExport(CFAllocatorRef allocator,
ccec_full_ctx_t fullkey) {
size_t prime_size = ccec_cp_prime_size(ccec_ctx_cp(fullkey));
size_t key_size = ccec_export_pub_size(fullkey) + prime_size;
CFMutableDataRef blob = CFDataCreateMutable(allocator, key_size);
if (blob) {
CFDataSetLength(blob, key_size);
ccec_export_pub(fullkey, CFDataGetMutableBytePtr(blob));
UInt8 *dest = CFDataGetMutableBytePtr(blob) + ccec_export_pub_size(fullkey);
const cc_unit *k = ccec_ctx_k(fullkey);
ccn_write_uint_padded(ccec_ctx_n(fullkey), k, prime_size, dest);
}
return blob;
}
int
ccec_get_fullkey_components(ccec_full_ctx_t key, size_t *nbits,
uint8_t *x, size_t *xsize,
uint8_t *y, size_t *ysize,
uint8_t *d, size_t *dsize)
{
cc_size n = ccec_ctx_n(key);
size_t len;
if(ccec_get_pubkey_components(key, nbits, x, xsize, y, ysize)) return -1;
if((len = ccn_write_uint_size(n, ccec_ctx_k(key))) > *dsize) return -1;
*dsize = len;
ccn_write_uint(n, ccec_ctx_k(key), *dsize, d);
return 0;
}
static OSStatus SecECPrivateKeyInit(SecKeyRef key,
const uint8_t *keyData, CFIndex keyDataLength, SecKeyEncoding encoding) {
ccec_full_ctx_t fullkey;
fullkey.hdr = key->key;
OSStatus err = errSecParam;
switch (encoding) {
case kSecKeyEncodingPkcs1:
{
/* TODO: DER import size (and thus cp), pub.x, pub.y and k. */
//err = ecc_import(keyData, keyDataLength, fullkey);
/* DER != PKCS#1, but we'll go along with it */
ccoid_t oid;
size_t n;
ccec_const_cp_t cp;
require_noerr(ccec_der_import_priv_keytype(keyDataLength, keyData, &oid, &n), abort);
cp = ccec_cp_for_oid(oid);
if (cp.zp == NULL) {
cp = ccec_curve_for_length_lookup(n * 8 /* bytes -> bits */,
ccec_cp_192(), ccec_cp_224(), ccec_cp_256(), ccec_cp_384(), ccec_cp_521(), NULL);
}
require_action(cp.zp != NULL, abort, err = errSecDecode);
ccec_ctx_init(cp, fullkey);
require_noerr(ccec_der_import_priv(cp, keyDataLength, keyData, fullkey), abort);
err = errSecSuccess;
break;
}
case kSecKeyEncodingBytes:
{
ccec_const_cp_t cp = getCPForPrivateSize(keyDataLength);
require(cp.zp != NULL, abort);
ccec_ctx_init(cp, fullkey);
size_t pubSize = ccec_export_pub_size(fullkey);
require(pubSize < (size_t) keyDataLength, abort);
require_noerr_action(ccec_import_pub(cp, pubSize, keyData, fullkey),
abort,
err = errSecDecode);
keyData += pubSize;
keyDataLength -= pubSize;
cc_unit *k = ccec_ctx_k(fullkey);
require_noerr_action(ccn_read_uint(ccec_ctx_n(fullkey), k, keyDataLength, keyData),
abort,
err = errSecDecode);
err = errSecSuccess;
break;
}
case kSecGenerateKey:
{
CFDictionaryRef parameters = (CFDictionaryRef) keyData;
CFTypeRef ksize = CFDictionaryGetValue(parameters, kSecAttrKeySizeInBits);
CFIndex keyLengthInBits = getIntValue(ksize);
ccec_const_cp_t cp = ccec_get_cp(keyLengthInBits);
if (!cp.zp) {
secwarning("Invalid or missing key size in: %@", parameters);
return errSecKeySizeNotAllowed;
}
if (!ccec_generate_key(cp, ccrng_seckey, fullkey))
err = errSecSuccess;
break;
}
default:
break;
}
abort:
return err;
}