github.com/geraldss/go/src@v0.0.0-20210511222824-ac7d0ebfc235/crypto/ecdsa/ecdsa_s390x.s (about)

     1  // Copyright 2020 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "textflag.h"
     6  
     7  // func kdsa(fc uint64, params *[4096]byte) (errn uint64)
     8  TEXT ·kdsa(SB), NOSPLIT|NOFRAME, $0-24
     9  	MOVD fc+0(FP), R0     // function code
    10  	MOVD params+8(FP), R1 // address parameter block
    11  
    12  loop:
    13  	WORD $0xB93A0008 // compute digital signature authentication
    14  	BVS  loop        // branch back if interrupted
    15  	BGT  retry       // signing unsuccessful, but retry with new CSPRN
    16  	BLT  error       // condition code of 1 indicates a failure
    17  
    18  success:
    19  	MOVD $0, errn+16(FP) // return 0 - sign/verify was successful
    20  	RET
    21  
    22  error:
    23  	MOVD $1, errn+16(FP) // return 1 - sign/verify failed
    24  	RET
    25  
    26  retry:
    27  	MOVD $2, errn+16(FP) // return 2 - sign/verify was unsuccessful -- if sign, retry with new RN
    28  	RET