57 lines
1.5 KiB
Go
57 lines
1.5 KiB
Go
package timestamp
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import (
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"crypto"
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"encoding/asn1"
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)
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// TODO(vanbroup): taken from "golang.org/x/crypto/ocsp"
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// use directly from crypto/x509 when exported as suggested below.
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var hashOIDs = map[crypto.Hash]asn1.ObjectIdentifier{
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crypto.SHA1: asn1.ObjectIdentifier([]int{1, 3, 14, 3, 2, 26}),
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crypto.SHA256: asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 1}),
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crypto.SHA384: asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 2}),
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crypto.SHA512: asn1.ObjectIdentifier([]int{2, 16, 840, 1, 101, 3, 4, 2, 3}),
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}
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// TODO(rlb): This is not taken from crypto/x509, but it's of the same general form.
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func getHashAlgorithmFromOID(target asn1.ObjectIdentifier) crypto.Hash {
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for hash, oid := range hashOIDs {
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if oid.Equal(target) {
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return hash
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}
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}
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return crypto.Hash(0)
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}
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func getOIDFromHashAlgorithm(target crypto.Hash) asn1.ObjectIdentifier {
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for hash, oid := range hashOIDs {
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if hash == target {
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return oid
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}
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}
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return nil
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}
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// TODO(vanbroup): taken from golang.org/x/crypto/x509
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// asn1BitLength returns the bit-length of bitString by considering the
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// most-significant bit in a byte to be the "first" bit. This convention
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// matches ASN.1, but differs from almost everything else.
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func asn1BitLength(bitString []byte) int {
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bitLen := len(bitString) * 8
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for i := range bitString {
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b := bitString[len(bitString)-i-1]
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for bit := uint(0); bit < 8; bit++ {
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if (b>>bit)&1 == 1 {
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return bitLen
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}
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bitLen--
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}
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}
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return 0
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}
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