问题描述
我想创建一个完美散列alogrithim的散列一个字符串作为一个64位的int
I am trying to create a universal hashing alogrithim that hashes a string as a 64 bit int.
我能够正确地散列字符串:
SQL:
I am able to hash the strings correctly:sql:
select
convert
(
varchar(64),
HASHBYTES
(
'SHA1',
'google.com'
),
2
)
收益 BAEA954B95731C68AE6E45BD1E252EB4560CDC45
C#
System.Security.Cryptography.SHA1 c = System.Security.Cryptography.SHA1.Create();
System.Text.StringBuilder sb = new StringBuilder();
byte[] b = c.ComputeHash(Encoding.UTF8.GetBytes("google.com"));
for (int i = 0; i < b.Length;i++ )
{
byte by = b[i];
sb.Append(by.ToString("x2").ToUpper());
}
return sb.ToString();
retruns BAEA954B95731C68AE6E45BD1E252EB4560CDC45
然而,当我转换为一个BIGINT /长值不匹配:
SQL:
However when I convert to a bigint/long the values do not match:sql:
select
convert
(
bigint,
HASHBYTES
(
'SHA1',
'google.com'
)
)
收益 2172193747348806725
C#:
System.Security.Cryptography.SHA1 c = System.Security.Cryptography.SHA1.Create();
byte[] b = c.ComputeHash(Encoding.UTF8.GetBytes("google.com"));
return BitConverter.ToInt64(b, 0);
收益 7501998164347841210
这是如何得到这些数字的任何想法,以匹配?
Any ideas on how to get these numbers to match?
推荐答案
您SQL BIGINT取最后8个字节,而C#实现取前8个字节(并逆转他们,因为其小端运行)。
Your SQL bigint takes the last 8 bytes while the c# implementation takes the first 8 bytes (and reverses them because its running on little endian).
以数组的适当范围在C#和反向它。然后你应该罚款
Take the proper Range of the array in C# and reverse it. Then you should be fine.
做了一些代码:
System.Security.Cryptography.SHA1 c = System.Security.Cryptography.SHA1.Create();
byte[] b = c.ComputeHash(Encoding.UTF8.GetBytes("google.com"));
long value = BitConverter.ToInt64(b, 12);
value = IPAddress.HostToNetworkOrder(value);
Debug.WriteLine(value);
// writes 2172193747348806725
这篇关于SQL BIGINT哈希匹配C#的Int64哈希的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!