crypto/cipher: panic on s390x when len(src) == 0 #17435
Description
What version of Go are you using (go version)?
go version go1.7.1 linux/s390x
What did you do?
Encrypt an empty plaintext using AES in CBC mode.
c := cipher.NewCBCEncrypter(b, iv[:])
pt := make([]byte, 0)
c.CryptBlocks(pt, pt)
fmt.Println("ok!")
https://play.golang.org/p/InSmIcI_MT
What did you expect to see?
ok!
What did you see instead?
panic: runtime error: index out of range
goroutine 1 [running]:
panic(0xb2c00, 0x1245f0)
/localbox/munday/go/src/runtime/panic.go:527 +0x190
crypto/aes.(*cbc).CryptBlocks(0xc42000e220, 0x14fad8, 0x0, 0x0, 0x14fad8, 0x0, 0x0)
/localbox/munday/go/src/crypto/aes/cbc_s390x.go:51 +0xd8
main.main()
/localbox/munday/main.go:18 +0x122
exit status 2
Will send a CL to fix (I'm working on a test now). If there is still time I'd like to get this fix into 1.7.2.