crypto/rsa: improve error message for keys too short for PSS

FiloSottile · bradfitz · commit c0094338fb29 · 2018-02-14T15:31:22.000Z
Fixes #23736 Change-Id: I850d91a512394c4292927d51c475064bfa4e3053 Reviewed-on: https://go-review.googlesource.com/92815 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/crypto/rsa/pss.go b/src/crypto/rsa/pss.go
@@ -36,7 +36,7 @@ func emsaPSSEncode(mHash []byte, emBits int, salt []byte, hash hash.Hash) ([]byt
 	// 3.  If emLen < hLen + sLen + 2, output "encoding error" and stop.
 
 	if emLen < hLen+sLen+2 {
-		return nil, errors.New("crypto/rsa: encoding error")
+		return nil, errors.New("crypto/rsa: key size too small for PSS signature")
 	}
 
 	em := make([]byte, emLen)

Original file line number	Diff line number	Diff line change
`@@ -36,7 +36,7 @@ func emsaPSSEncode(mHash []byte, emBits int, salt []byte, hash hash.Hash) ([]byt`
`36`	`36`	`// 3. If emLen < hLen + sLen + 2, output "encoding error" and stop.`
`37`	`37`
`38`	`38`	`if emLen < hLen+sLen+2 {`
`39`		`- return nil, errors.New("crypto/rsa: encoding error")`
	`39`	`+ return nil, errors.New("crypto/rsa: key size too small for PSS signature")`
`40`	`40`	`}`
`41`	`41`
`42`	`42`	`em := make([]byte, emLen)`