crypto/rsa: revert minimum GenerateKey size to 32 bits

No point in causing breakage even with GODEBUG=rsa1024min=0.

Change-Id: I923254a8c8afaca77be551b19e3555c44ebdbb67
Reviewed-on: https://go-review.googlesource.com/c/go/+/636557
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>

diff --git a/src/crypto/internal/fips140/rsa/keygen.go b/src/crypto/internal/fips140/rsa/keygen.go
index df76772ef5878d7443f792c68c8e73e2ce742ca2..d8a282bcd44634548a931646e3cdacd978cab61e 100644 (file)
--- a/src/crypto/internal/fips140/rsa/keygen.go
+++ b/src/crypto/internal/fips140/rsa/keygen.go
@@ -13,9 +13,9 @@ import (
 )
 
 // GenerateKey generates a new RSA key pair of the given bit size.
-// bits must be at least 128.
+// bits must be at least 32.
 func GenerateKey(rand io.Reader, bits int) (*PrivateKey, error) {
-       if bits < 128 {
+       if bits < 32 {
                return nil, errors.New("rsa: key too small")
        }
        fips140.RecordApproved()
@@ -93,8 +93,8 @@ func GenerateKey(rand io.Reader, bits int) (*PrivateKey, error) {
 // randomPrime returns a random prime number of the given bit size following
 // the process in FIPS 186-5, Appendix A.1.3.
 func randomPrime(rand io.Reader, bits int) ([]byte, error) {
-       if bits < 64 {
-               return nil, errors.New("rsa: prime size must be at least 32-bit")
+       if bits < 16 {
+               return nil, errors.New("rsa: prime size must be at least 16 bits")
        }
 
        b := make([]byte, (bits+7)/8)

diff --git a/src/crypto/rsa/rsa_test.go b/src/crypto/rsa/rsa_test.go
index 2474ab82dfa207eca2a77fdad664c2e841d90cb2..2535661040273a73bdad1ea1857044f45ae2616e 100644 (file)
--- a/src/crypto/rsa/rsa_test.go
+++ b/src/crypto/rsa/rsa_test.go
@@ -101,7 +101,7 @@ func TestImpossibleKeyGeneration(t *testing.T) {
        // This test ensures that trying to generate or validate toy RSA keys
        // doesn't enter an infinite loop or panic.
        t.Setenv("GODEBUG", "rsa1024min=0")
-       for i := 0; i < 128; i++ {
+       for i := 0; i < 32; i++ {
                GenerateKey(rand.Reader, i)
                GenerateMultiPrimeKey(rand.Reader, 3, i)
                GenerateMultiPrimeKey(rand.Reader, 4, i)
@@ -184,7 +184,7 @@ func TestEverything(t *testing.T) {
        }
 
        t.Setenv("GODEBUG", "rsa1024min=0")
-       min := 128
+       min := 32
        max := 560 // any smaller than this and not all tests will run
        if *allFlag {
                max = 2048