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| author | Roland Shoemaker <rolandshoemaker@gmail.com> | 2020-10-20 13:50:52 -0700 |
|---|---|---|
| committer | Roland Shoemaker <roland@golang.org> | 2020-10-21 17:13:25 +0000 |
| commit | b04eb73a6891e81e2e611ee93b3aa8c4769d5967 (patch) | |
| tree | 46d6a550f370493bd5e017711a30d1dea1dfeea1 /src/crypto | |
| parent | 6f45b39e4dbabf0b179a60ffacf434e55b2d5eab (diff) | |
| download | go-b04eb73a6891e81e2e611ee93b3aa8c4769d5967.tar.gz go-b04eb73a6891e81e2e611ee93b3aa8c4769d5967.zip | |
crypto/x509: bypass signature verification in CreateCertificate when using MD5WithRSA
Bypasses the signature verification check we previously added if the
signature algorithm is MD5WithRSA, as we only support this algorithm
for signing and not verification.
Change-Id: Idba6dbba8b365d6199d467526746b88a5f734af1
Reviewed-on: https://go-review.googlesource.com/c/go/+/264019
Run-TryBot: Roland Shoemaker <roland@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Trust: Roland Shoemaker <roland@golang.org>
Diffstat (limited to 'src/crypto')
| -rw-r--r-- | src/crypto/x509/x509.go | 8 | ||||
| -rw-r--r-- | src/crypto/x509/x509_test.go | 16 |
2 files changed, 22 insertions, 2 deletions
diff --git a/src/crypto/x509/x509.go b/src/crypto/x509/x509.go index bcef54ddb4..b421d75973 100644 --- a/src/crypto/x509/x509.go +++ b/src/crypto/x509/x509.go @@ -2156,8 +2156,12 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv } // Check the signature to ensure the crypto.Signer behaved correctly. - if err := checkSignature(getSignatureAlgorithmFromAI(signatureAlgorithm), c.Raw, signature, key.Public()); err != nil { - return nil, fmt.Errorf("x509: signature over certificate returned by signer is invalid: %w", err) + // We skip this check if the signature algorithm is MD5WithRSA as we + // only support this algorithm for signing, and not verification. + if sigAlg := getSignatureAlgorithmFromAI(signatureAlgorithm); sigAlg != MD5WithRSA { + if err := checkSignature(sigAlg, c.Raw, signature, key.Public()); err != nil { + return nil, fmt.Errorf("x509: signature over certificate returned by signer is invalid: %w", err) + } } return signedCert, nil diff --git a/src/crypto/x509/x509_test.go b/src/crypto/x509/x509_test.go index 5a39e61b3c..47d78cf02a 100644 --- a/src/crypto/x509/x509_test.go +++ b/src/crypto/x509/x509_test.go @@ -2896,3 +2896,19 @@ func TestCreateCertificateBrokenSigner(t *testing.T) { t.Fatalf("CreateCertificate returned an unexpected error: got %q, want %q", err, expectedErr) } } + +func TestCreateCertificateMD5(t *testing.T) { + template := &Certificate{ + SerialNumber: big.NewInt(10), + DNSNames: []string{"example.com"}, + SignatureAlgorithm: MD5WithRSA, + } + k, err := rsa.GenerateKey(rand.Reader, 1024) + if err != nil { + t.Fatalf("failed to generate test key: %s", err) + } + _, err = CreateCertificate(rand.Reader, template, template, k.Public(), &brokenSigner{k.Public()}) + if err != nil { + t.Fatalf("CreateCertificate failed when SignatureAlgorithm = MD5WithRSA: %s", err) + } +} |