This test specified a valid RSA PKCS#1 v.1.5 signature and RSA key (the same as rsa-pkcs1-sha256.pem). The problem however is the signature algorithm is indicated as being ECDSA. Signature verification consequently should fail. -----BEGIN PUBLIC KEY----- MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqR+B2Mj1irNp1JnY2zQIQRQPz7ybs6mUjHT3 hf5APyaig2u6fBPThqxssgg0YviqIj/70hVK/JXcqP1zgR5AhsA0agnwAjfB/ow4EH+3HEYV52q pxN98pUxC+1l2hgVtn8xCS/JGyjK+6dv+lZw3ixJoX2RjVtdJ4/cn318EhhQIDAQAB -----END PUBLIC KEY----- $ openssl asn1parse -i < [PUBLIC KEY] 0:d=0 hl=3 l= 159 cons: SEQUENCE 3:d=1 hl=2 l= 13 cons: SEQUENCE 5:d=2 hl=2 l= 9 prim: OBJECT :rsaEncryption 16:d=2 hl=2 l= 0 prim: NULL 18:d=1 hl=3 l= 141 prim: BIT STRING -----BEGIN ALGORITHM----- MAoGCCqGSM49BAMC -----END ALGORITHM----- $ openssl asn1parse -i < [ALGORITHM] 0:d=0 hl=2 l= 10 cons: SEQUENCE 2:d=1 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256 -----BEGIN DATA----- MIIB46ADAgECAgkA3l4tFOVii0UwDQYJKoZIhvcNAQELBQAwVjELMAkGA1UEBhMCQVUxEzARBgN VBAgMClNvbWUtU3RhdGUxITAfBgNVBAoMGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1 UEAwwGTXkga2V5MB4XDTE1MDcwMjE3MDYzOVoXDTE2MDcwMTE3MDYzOVowVjELMAkGA1UEBhMCQ VUxEzARBgNVBAgMClNvbWUtU3RhdGUxITAfBgNVBAoMGEludGVybmV0IFdpZGdpdHMgUHR5IEx0 ZDEPMA0GA1UEAwwGTXkga2V5MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqR+B2Mj1irNp 1JnY2zQIQRQPz7ybs6mUjHT3hf5APyaig2u6fBPThqxssgg0YviqIj/70hVK/JXcqP1zgR5AhsA 0agnwAjfB/ow4EH+3HEYV52qpxN98pUxC+1l2hgVtn8xCS/JGyjK+6dv+lZw3ixJoX2RjVtdJ4/ cn318EhhQIDAQABo1AwTjAdBgNVHQ4EFgQUzQBVKTEknyLndWd2HTsBdTKvyikwHwYDVR0jBBgw FoAUzQBVKTEknyLndWd2HTsBdTKvyikwDAYDVR0TBAUwAwEB/w== -----END DATA----- -----BEGIN SIGNATURE----- A4GBADrHSmFSJw/Gv7hs5PNzpaJwAri/sitarIZfzN/SjR+n8L8yeTEoiDb1+BkxlFvXvPHTaOK oO3WlslNNOxh1W5/JkYYGOUkCcyIjnln6qS560imcr3VNjomT/M8M2Iss+rJiKau1TRuaP7H8i6 +Gqf3saGdr8/LnvFAdNQvkalQt -----END SIGNATURE----- $ openssl asn1parse -i < [SIGNATURE] 0:d=0 hl=3 l= 129 prim: BIT STRING