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			50 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			50 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright 2018 The Go Authors. All rights reserved.
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| // Use of this source code is governed by a BSD-style
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| // license that can be found in the LICENSE file.
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| 
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| // +build s390x,go1.11,!gccgo,!appengine
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| 
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| package poly1305
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| 
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| // hasVectorFacility reports whether the machine supports
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| // the vector facility (vx).
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| func hasVectorFacility() bool
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| 
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| // hasVMSLFacility reports whether the machine supports
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| // Vector Multiply Sum Logical (VMSL).
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| func hasVMSLFacility() bool
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| 
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| var hasVX = hasVectorFacility()
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| var hasVMSL = hasVMSLFacility()
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| 
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| // poly1305vx is an assembly implementation of Poly1305 that uses vector
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| // instructions. It must only be called if the vector facility (vx) is
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| // available.
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| //go:noescape
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| func poly1305vx(out *[16]byte, m *byte, mlen uint64, key *[32]byte)
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| 
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| // poly1305vmsl is an assembly implementation of Poly1305 that uses vector
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| // instructions, including VMSL. It must only be called if the vector facility (vx) is
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| // available and if VMSL is supported.
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| //go:noescape
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| func poly1305vmsl(out *[16]byte, m *byte, mlen uint64, key *[32]byte)
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| 
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| // Sum generates an authenticator for m using a one-time key and puts the
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| // 16-byte result into out. Authenticating two different messages with the same
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| // key allows an attacker to forge messages at will.
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| func Sum(out *[16]byte, m []byte, key *[32]byte) {
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| 	if hasVX {
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| 		var mPtr *byte
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| 		if len(m) > 0 {
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| 			mPtr = &m[0]
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| 		}
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| 		if hasVMSL && len(m) > 256 {
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| 			poly1305vmsl(out, mPtr, uint64(len(m)), key)
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| 		} else {
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| 			poly1305vx(out, mPtr, uint64(len(m)), key)
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| 		}
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| 	} else {
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| 		sumGeneric(out, m, key)
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| 	}
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| }
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