39 lines
1.2 KiB
Go
39 lines
1.2 KiB
Go
// [SHA1 hashes](http://en.wikipedia.org/wiki/SHA-1) are
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// frequently used to compute short identities for binary
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// or text blobs. For example, the [git revision control
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// system](http://git-scm.com/) uses SHA1s extensively to
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// identify versioned files and directories. Here's how to
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// compute SHA1 hashes in Go.
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package main
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// Go implements several hash functions in various
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// `crtypo/*` packages.
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import "crypto/sha1"
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import "encoding/hex"
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import "fmt"
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func main() {
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s := "sha1 this string"
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// The pattern for generating a hash is `sha1.New()`,
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// `sha1.Write(bytes)`, then `sha1.Sum([]byte{}).
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// Here we start with a new hash.
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h := sha1.New()
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// `Write` expects bytes. If you have a string `s`,
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// use `[]byte(s)` to coerce it to bytes.
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h.Write([]byte(s))
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// This gets the finalized hash result as a byte
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// slice. The argument to `Sum` can be used to append
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// to an existing byte slice: it usually isn't needed.
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bs := h.Sum(nil)
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// SHA1 values are often printed in hex, for example
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// in git commits. Use `hex.EncodeToString` to convert
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// a hash results to a hex string.
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fmt.Println(s)
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fmt.Println(hex.EncodeToString(bs))
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}
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