Shawn Willden | 0a4df7e | 2014-08-28 16:09:05 -0600 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include <openssl/bn.h> |
| 18 | |
| 19 | #include "dsa_operation.h" |
| 20 | #include "openssl_utils.h" |
| 21 | |
| 22 | namespace keymaster { |
| 23 | |
| 24 | DsaOperation::~DsaOperation() { |
| 25 | if (dsa_key_ != NULL) |
| 26 | DSA_free(dsa_key_); |
| 27 | } |
| 28 | |
| 29 | keymaster_error_t DsaOperation::Update(const Buffer& input, Buffer* /* output */) { |
| 30 | switch (purpose()) { |
| 31 | default: |
| 32 | return KM_ERROR_UNIMPLEMENTED; |
| 33 | case KM_PURPOSE_SIGN: |
| 34 | case KM_PURPOSE_VERIFY: |
| 35 | return StoreData(input); |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | keymaster_error_t DsaOperation::StoreData(const Buffer& input) { |
| 40 | if (!data_.reserve(data_.available_read() + input.available_read()) || |
| 41 | !data_.write(input.peek_read(), input.available_read())) |
| 42 | return KM_ERROR_INVALID_INPUT_LENGTH; |
| 43 | return KM_ERROR_OK; |
| 44 | } |
| 45 | |
| 46 | keymaster_error_t DsaSignOperation::Finish(const Buffer& /* signature */, Buffer* output) { |
| 47 | output->Reinitialize(DSA_size(dsa_key_)); |
Shawn Willden | 0a4df7e | 2014-08-28 16:09:05 -0600 | [diff] [blame] | 48 | unsigned int siglen; |
| 49 | if (!DSA_sign(0 /* type -- ignored */, data_.peek_read(), data_.available_read(), |
| 50 | output->peek_write(), &siglen, dsa_key_)) |
| 51 | return KM_ERROR_UNKNOWN_ERROR; |
| 52 | output->advance_write(siglen); |
| 53 | return KM_ERROR_OK; |
| 54 | } |
| 55 | |
| 56 | keymaster_error_t DsaVerifyOperation::Finish(const Buffer& signature, Buffer* /* output */) { |
| 57 | if ((int)data_.available_read() != DSA_size(dsa_key_)) |
| 58 | return KM_ERROR_INVALID_INPUT_LENGTH; |
| 59 | |
| 60 | int result = DSA_verify(0 /* type -- ignored */, data_.peek_read(), data_.available_read(), |
| 61 | signature.peek_read(), signature.available_read(), dsa_key_); |
| 62 | if (result < 0) |
| 63 | return KM_ERROR_UNKNOWN_ERROR; |
| 64 | else if (result == 0) |
| 65 | return KM_ERROR_VERIFICATION_FAILED; |
| 66 | else |
| 67 | return KM_ERROR_OK; |
| 68 | } |
| 69 | |
| 70 | } // namespace keymaster |