Signature verification problems for ecdsa-with-SHA384 on Android 6

Question

I've problems verifying a certificate which is signed with ECDSA with SHA384 on Android 6.0 and up. However, it is working for Android 4.1 - 5.1. I tracked it down to an error in the Certificate class. An exception is thrown in the verify method:

java.lang.RuntimeException: error:0f092074:elliptic curve routines:ec_asn1_pkparameters2group:NON_NAMED_CURVE

Any idea why this is happening with Android 6.0 and how it can be fixed? I already tested it with Spongycastle as a security provider, but the verify function always throws that exception.

Thanks & Regards

Answer 1

Finally found the issue - not the verification of the signature itself was the problem, but loading of the intermediate certificate which holds the ec public key.

    Subject Public Key Info:
        Public Key Algorithm: id-ecPublicKey
        Unable to load Public Key
2536673920:error:0f092074:elliptic curve routines:ec_asn1_pkparameters2group:NON_NAMED_CURVE:external/boringssl/src/crypto/ec/ec_asn1.c:225:
2536673920:error:0f07f076:elliptic curve routines:d2i_ECPKParameters:PKPARAMETERS2GROUP_FAILURE:external/boringssl/src/crypto/ec/ec_asn1.c:253:
2536673920:error:0f08000f:elliptic curve routines:d2i_ECParameters:elliptic curve routines:external/boringssl/src/crypto/ec/ec_asn1.c:503:
2536673920:error:0608808f:public key routines:eckey_type2param:DECODE_ERROR:external/boringssl/src/crypto/evp/p_ec_asn1.c:140:
2536673920:error:0608600f:public key routines:eckey_pub_decode:elliptic curve routines:external/boringssl/src/crypto/evp/p_ec_asn1.c:180:
2536673920:error:0b07c07c:X.509 certificate routines:X509_PUBKEY_get:PUBLIC_KEY_DECODE_ERROR:external/boringssl/src/crypto/x509/x_pubkey.c:168:

This leads to the question - why does BoringSSL have problems decoding the public key in this certificate? And I guess this has to be a bug in BoringSSL. I checked the certificate with OpenSSL and had no problems there.

When the Spongycastle Provider is explicitly used when loading the intermediate certificate and later verifying the signature of the document signing certificate, everything works fine.