我正在尝试对BigInteger/BigNum进行哈希,但在Android/iOS中得到了不同的结果。我需要获得相同的哈希结果,以便两个应用程序根据SRP协议正常工作。经过仔细检查,对于正数它能正常工作,但对于负数(第一个字节大于7),则不能正常工作。不确定哪个是正确的,哪个需要调整以与另一个匹配。
Android:
void hashBigInteger(String s) {
try {
BigInteger a = new BigInteger(s, 16);
MessageDigest sha = MessageDigest.getInstance("SHA-256");
byte[] b = a.toByteArray();
sha.update(b, 0, b.length);
byte[] digest = sha.digest();
BigInteger d = new BigInteger(digest);
Log.d("HASH", "H = " + d.toString(16));
} catch (NoSuchAlgorithmException e) {
throw new UnsupportedOperationException(e);
}
}
iOS:
void hashBigNum(unsigned char *c) {
BIGNUM *n = BN_new();
BN_hex2bn(&n, c);
unsigned char buff[ SHA256_DIGEST_LENGTH ];
int len = BN_num_bytes(n);
unsigned char * bin = (unsigned char *) malloc( len );
BN_bn2bin(n, bin);
hash( SRP_SHA256, bin, len, buff );
fprintf(stderr, "H: ");
for (int z = 0; z < SHA256_DIGEST_LENGTH; z++)
fprintf(stderr, "%2x", buff[z]);
fprintf(stderr, "\n");
free(bin);
}
结果:
Source String = "6F"
Android Hash = 65c74c15a686187bb6bbf9958f494fc6b80068034a659a9ad44991b08c58f2d2
iOS Hash = 65c74c15a686187bb6bbf9958f494fc6b80068034a659a9ad44991b08c58f2d2
Source String = "FF"
Android Hash = 06eb7d6a69ee19e5fbdf749018d3d2abfa04bcbd1365db312eb86dc7169389b8
iOS Hash = a8100ae6aa1940d0b663bb31cd466142ebbdbd5187131b92d93818987832eb89