Add PK_Signer::signature_length

7 files changed, 29 insertions, 11 deletions

diff --git a/src/lib/prov/bearssl/bearssl_ec.cpp b/src/lib/prov/bearssl/bearssl_ec.cpp
index 23f566043..89f7773aa 100644
--- a/src/lib/prov/bearssl/bearssl_ec.cpp
+++ b/src/lib/prov/bearssl/bearssl_ec.cpp
@@ -77,7 +77,7 @@ class BearSSL_ECDSA_Verification_Operation final : public PK_Ops::Verification
    {
    public:
       BearSSL_ECDSA_Verification_Operation(const ECDSA_PublicKey& ecdsa, const std::string& emsa) :
-         m_order_bits(ecdsa.domain().get_order().bits())
+         m_order_bits(ecdsa.domain().get_order_bits())
          {
          const int curve = BearSSL_EC_curve_for(ecdsa.domain().get_oid());
          if (curve < 0)
@@ -132,7 +132,8 @@ class BearSSL_ECDSA_Signing_Operation final : public PK_Ops::Signature
    {
    public:
       BearSSL_ECDSA_Signing_Operation(const ECDSA_PrivateKey& ecdsa, const std::string& emsa) :
-         m_order_bits(ecdsa.domain().get_order().bits())
+         m_order_bits(ecdsa.domain().get_order_bits()),
+         m_order_bytes(ecdsa.domain().get_order_bytes())
          {
          const int curve = BearSSL_EC_curve_for(ecdsa.domain().get_oid());
          if(curve < 0)
@@ -175,12 +176,15 @@ class BearSSL_ECDSA_Signing_Operation final : public PK_Ops::Signature
 
       size_t max_input_bits() const { return m_order_bits; }
 
+      size_t signature_length() const override { return 2*m_order_bytes; }
+
    private:
       br_ec_private_key m_key;
       std::unique_ptr<HashFunction> m_hf;
       secure_vector<uint8_t> m_x_buf;
       const br_hash_class *m_hash;
       size_t m_order_bits;
+      size_t m_order_bytes;
    };
 
 }
diff --git a/src/lib/prov/openssl/openssl_ec.cpp b/src/lib/prov/openssl/openssl_ec.cpp
index b9e53b6fd..33f277d5a 100644
--- a/src/lib/prov/openssl/openssl_ec.cpp
+++ b/src/lib/prov/openssl/openssl_ec.cpp
@@ -229,8 +229,11 @@ class OpenSSL_ECDSA_Signing_Operation final : public PK_Ops::Signature_with_EMSA
 
          const EC_GROUP* group = ::EC_KEY_get0_group(m_ossl_ec.get());
          m_order_bits = ::EC_GROUP_get_degree(group);
+         m_order_bytes = (m_order_bits + 7) / 8;
          }
 
+      size_t signature_length() const { return 2*m_order_bytes; }
+
       secure_vector<uint8_t> raw_sign(const uint8_t msg[], size_t msg_len,
                                    RandomNumberGenerator&) override
          {
@@ -240,8 +243,6 @@ class OpenSSL_ECDSA_Signing_Operation final : public PK_Ops::Signature_with_EMSA
          if(!sig)
             throw OpenSSL_Error("ECDSA_do_sign");
 
-         const size_t order_bytes = (m_order_bits + 7) / 8;
-
 #if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
          const BIGNUM* r = sig->r;
          const BIGNUM* s = sig->s;
@@ -253,9 +254,9 @@ class OpenSSL_ECDSA_Signing_Operation final : public PK_Ops::Signature_with_EMSA
 
          const size_t r_bytes = BN_num_bytes(r);
          const size_t s_bytes = BN_num_bytes(s);
-         secure_vector<uint8_t> sigval(2*order_bytes);
-         BN_bn2bin(r, &sigval[order_bytes - r_bytes]);
-         BN_bn2bin(s, &sigval[2*order_bytes - s_bytes]);
+         secure_vector<uint8_t> sigval(2*m_order_bytes);
+         BN_bn2bin(r, &sigval[m_order_bytes - r_bytes]);
+         BN_bn2bin(s, &sigval[2*m_order_bytes - s_bytes]);
          return sigval;
          }
 
@@ -263,7 +264,8 @@ class OpenSSL_ECDSA_Signing_Operation final : public PK_Ops::Signature_with_EMSA
 
    private:
       std::unique_ptr<EC_KEY, std::function<void (EC_KEY*)>> m_ossl_ec;
-      size_t m_order_bits = 0;
+      size_t m_order_bits;
+      size_t m_order_bytes;
    };
 
 }
diff --git a/src/lib/prov/openssl/openssl_rsa.cpp b/src/lib/prov/openssl/openssl_rsa.cpp
index 6385bcbb3..cf9c2b52b 100644
--- a/src/lib/prov/openssl/openssl_rsa.cpp
+++ b/src/lib/prov/openssl/openssl_rsa.cpp
@@ -205,6 +205,8 @@ class OpenSSL_RSA_Signing_Operation final : public PK_Ops::Signature_with_EMSA
             throw OpenSSL_Error("d2i_RSAPrivateKey");
          }
 
+      size_t signature_length() const override { return ::RSA_size(m_openssl_rsa.get()); }
+
       secure_vector<uint8_t> raw_sign(const uint8_t msg[], size_t msg_len,
                                    RandomNumberGenerator&) override
          {
diff --git a/src/lib/prov/pkcs11/p11_ecdsa.cpp b/src/lib/prov/pkcs11/p11_ecdsa.cpp
index a93e761b1..bdea2c1fa 100644
--- a/src/lib/prov/pkcs11/p11_ecdsa.cpp
+++ b/src/lib/prov/pkcs11/p11_ecdsa.cpp
@@ -100,6 +100,8 @@ class PKCS11_ECDSA_Signature_Operation final : public PK_Ops::Signature
          return signature;
          }
 
+      size_t signature_length() const override { return 2*m_order.bytes(); }
+
    private:
       const PKCS11_EC_PrivateKey& m_key;
       const BigInt& m_order;
diff --git a/src/lib/prov/pkcs11/p11_rsa.cpp b/src/lib/prov/pkcs11/p11_rsa.cpp
index e62c038ec..65bcd2d22 100644
--- a/src/lib/prov/pkcs11/p11_rsa.cpp
+++ b/src/lib/prov/pkcs11/p11_rsa.cpp
@@ -206,6 +206,8 @@ class PKCS11_RSA_Signature_Operation final : public PK_Ops::Signature
          : m_key(key), m_mechanism(MechanismWrapper::create_rsa_sign_mechanism(padding))
          {}
 
+      size_t signature_length() const override { return m_key.get_n().bytes(); }
+
       void update(const uint8_t msg[], size_t msg_len) override
          {
          if(!m_initialized)
diff --git a/src/lib/prov/tpm/tpm.cpp b/src/lib/prov/tpm/tpm.cpp
index ccc6e9958..4847b0df6 100644
--- a/src/lib/prov/tpm/tpm.cpp
+++ b/src/lib/prov/tpm/tpm.cpp
@@ -394,6 +394,11 @@ class TPM_Signing_Operation final : public PK_Ops::Signature
          {
          }
 
+      size_t signature_length() const override
+         {
+         return m_key.get_n().bytes();
+         }
+
       void update(const uint8_t msg[], size_t msg_len) override
          {
          m_hash->update(msg, msg_len);
diff --git a/src/lib/prov/tpm/tpm.h b/src/lib/prov/tpm/tpm.h
index bb215a476..b6e220935 100644
--- a/src/lib/prov/tpm/tpm.h
+++ b/src/lib/prov/tpm/tpm.h
@@ -159,6 +159,10 @@ class BOTAN_PUBLIC_API(2,0) TPM_PrivateKey final : public Private_Key
 
       bool check_key(RandomNumberGenerator& rng, bool) const override;
 
+      BigInt get_n() const;
+
+      BigInt get_e() const;
+
       std::string algo_name() const override { return "RSA"; } // ???
 
       std::unique_ptr<PK_Ops::Signature>
@@ -167,9 +171,6 @@ class BOTAN_PUBLIC_API(2,0) TPM_PrivateKey final : public Private_Key
                              const std::string& provider) const override;
 
    private:
-      BigInt get_n() const;
-      BigInt get_e() const;
-
       TPM_Context& m_ctx;
       TSS_HKEY m_key;