From a82fdf2fcec9f44c7ea06b8d903e57041ae3e873 Mon Sep 17 00:00:00 2001 From: Daniel Wyatt Date: Sun, 26 May 2019 18:58:58 -0400 Subject: Fix PKCS#11 C_Decrypt buffer output size. Section 5.2 of the spec states that there are two ways to call functions that return a variable-length buffer: 1. When the output buffer is NULL, an estimated size is returned (which may be larger than required). 2. When the output buffer is not NULL, the exact size must be returned. So only after the second call to C_Decrypt has the final output size been determined, and we must resize the output buffer. --- src/lib/prov/pkcs11/p11.h | 15 ++++++++++----- src/tests/test_pkcs11_high_level.cpp | 3 --- 2 files changed, 10 insertions(+), 8 deletions(-) (limited to 'src') diff --git a/src/lib/prov/pkcs11/p11.h b/src/lib/prov/pkcs11/p11.h index 043b1795a..9afedb8c6 100644 --- a/src/lib/prov/pkcs11/p11.h +++ b/src/lib/prov/pkcs11/p11.h @@ -1950,11 +1950,16 @@ class BOTAN_PUBLIC_API(2,0) LowLevel } decrypted_data.resize(decrypted_size); - return C_Decrypt(session, - const_cast(encrypted_data.data()), - static_cast(encrypted_data.size()), - decrypted_data.data(), - &decrypted_size, return_value); + if(!C_Decrypt(session, + const_cast(encrypted_data.data()), + static_cast(encrypted_data.size()), + decrypted_data.data(), + &decrypted_size, return_value)) + { + return false; + } + decrypted_data.resize(decrypted_size); + return true; } /** diff --git a/src/tests/test_pkcs11_high_level.cpp b/src/tests/test_pkcs11_high_level.cpp index c9c34a28b..077e0240f 100644 --- a/src/tests/test_pkcs11_high_level.cpp +++ b/src/tests/test_pkcs11_high_level.cpp @@ -831,9 +831,6 @@ Test::Result test_rsa_encrypt_decrypt() Botan::PK_Decryptor_EME decryptor(keypair.second, Test::rng(), padding); auto decrypted = decryptor.decrypt(encrypted); - // some token / middlewares do not remove the padding bytes - decrypted.resize(plaintext.size()); - result.test_eq("RSA PKCS11 encrypt and decrypt: " + padding, decrypted, plaintext); }; -- cgit v1.2.3