45 lines
841 B
Go
45 lines
841 B
Go
package sha1
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import "encoding/binary"
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// Size of a SHA-1 checksum in bytes.
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const Size = 20
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// BlockSize is the block size of SHA-1 in bytes.
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const BlockSize = 64
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// Sum returns the SHA-1 checksum of data.
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func Sum(data []byte) [Size]byte {
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n := len(data)
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h := [5]uint32{0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0}
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// Consume full blocks.
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for len(data) >= BlockSize {
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block(&h, data)
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data = data[BlockSize:]
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}
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// Final block.
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tmp := make([]byte, BlockSize)
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copy(tmp, data)
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tmp[len(data)] = 0x80
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if len(data) >= 56 {
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block(&h, tmp)
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for i := 0; i < BlockSize; i++ {
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tmp[i] = 0
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}
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}
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binary.BigEndian.PutUint64(tmp[56:], uint64(8*n))
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block(&h, tmp)
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// Write into byte array.
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var digest [Size]byte
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for i := 0; i < 5; i++ {
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binary.BigEndian.PutUint32(digest[4*i:], h[i])
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}
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return digest
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}
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