42 lines
1.2 KiB
Go
42 lines
1.2 KiB
Go
package libnmdc
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import (
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"encoding/base32"
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"errors"
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"strings"
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"github.com/cxmcc/tiger"
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)
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// Base32 encodes the input slice in BASE32 string format without any trailing
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// padding equals characters.
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func Base32(input []byte) string {
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return strings.TrimRight(base32.StdEncoding.EncodeToString(input), "=")
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}
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// TTH returns the TTH hash of a string in raw byte format. Use the Base32()
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// function to convert it to normal string format.
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// This is a basic implementation that only supports content up to 1024 bytes in length.
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func TTH(input string) ([]byte, error) {
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// Short segments do not need to be padded.
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// Content above 1024 bytes needs tree handling (0x00 prefix for leaf nodes,
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// 0x01 prefix for hash nodes) but for content less than 1024 bytes, just
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// return the leaf hash
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// @ref http://adc.sourceforge.net/draft-jchapweske-thex-02.html
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if len(input) > 1024 {
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return nil, errors.New("TTH content exceeded 1024 bytes")
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}
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// Single leaf hash only
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leafHash := tiger.New()
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leafHash.Write([]byte("\x00" + input))
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return leafHash.Sum(nil), nil
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}
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func Tiger(input string) []byte {
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leafHash := tiger.New()
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leafHash.Write([]byte(input))
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return leafHash.Sum(nil)
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}
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