| // Copyright 2012 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifdef UNSAFE_BUFFERS_BUILD |
| // TODO(crbug.com/390223051): Remove C-library calls to fix the errors. |
| #pragma allow_unsafe_libc_calls |
| #endif |
| |
| #ifndef CRYPTO_OPENSSL_UTIL_H_ |
| #define CRYPTO_OPENSSL_UTIL_H_ |
| |
| #include<stddef.h> |
| #include<string.h> |
| |
| #include"base/location.h" |
| #include"base/memory/raw_ptr.h" |
| #include"crypto/crypto_export.h" |
| |
| namespace crypto{ |
| |
| // Provides a buffer of at least MIN_SIZE bytes, for use when calling OpenSSL's |
| // SHA256, HMAC, etc functions, adapting the buffer sizing rules to meet those |
| // of our base wrapper APIs. |
| // This allows the library to write directly to the caller's buffer if it is of |
| // sufficient size, but if not it will write to temporary |min_sized_buffer_| |
| // of required size and then its content is automatically copied out on |
| // destruction, with truncation as appropriate. |
| template<int MIN_SIZE> |
| classScopedOpenSSLSafeSizeBuffer{ |
| public: |
| ScopedOpenSSLSafeSizeBuffer(unsignedchar* output,size_t output_len) |
| : output_(output), |
| output_len_(output_len){ |
| } |
| |
| ScopedOpenSSLSafeSizeBuffer(constScopedOpenSSLSafeSizeBuffer&)=delete; |
| ScopedOpenSSLSafeSizeBuffer&operator=(constScopedOpenSSLSafeSizeBuffer&)= |
| delete; |
| |
| ~ScopedOpenSSLSafeSizeBuffer(){ |
| if(output_len_< MIN_SIZE){ |
| // Copy the temporary buffer out, truncating as needed. |
| memcpy(output_, min_sized_buffer_, output_len_); |
| } |
| // else... any writing already happened directly into |output_|. |
| } |
| |
| unsignedchar* safe_buffer(){ |
| return output_len_< MIN_SIZE? min_sized_buffer_: output_.get(); |
| } |
| |
| private: |
| // Pointer to the caller's data area and its associated size, where data |
| // written via safe_buffer() will [eventually] end up. |
| raw_ptr<unsignedchar> output_; |
| size_t output_len_; |
| |
| // Temporary buffer writen into in the case where the caller's |
| // buffer is not of sufficient size. |
| unsignedchar min_sized_buffer_[MIN_SIZE]; |
| }; |
| |
| // Drains the OpenSSL ERR_get_error stack. On a debug build the error codes |
| // are send to VLOG(1), on a release build they are disregarded. In most |
| // cases you should pass FROM_HERE as the |location|. |
| CRYPTO_EXPORTvoidClearOpenSSLERRStack(constbase::Location& location); |
| |
| // Place an instance of this class on the call stack to automatically clear |
| // the OpenSSL error stack on function exit. |
| classOpenSSLErrStackTracer{ |
| public: |
| OpenSSLErrStackTracer()=delete; |
| |
| // Pass FROM_HERE as |location|, to help track the source of OpenSSL error |
| // messages. Note any diagnostic emitted will be tagged with the location of |
| // the constructor call as it's not possible to trace a destructor's callsite. |
| explicitOpenSSLErrStackTracer(constbase::Location& location) |
| : location_(location){} |
| |
| OpenSSLErrStackTracer(constOpenSSLErrStackTracer&)=delete; |
| OpenSSLErrStackTracer&operator=(constOpenSSLErrStackTracer&)=delete; |
| |
| ~OpenSSLErrStackTracer(){ |
| ClearOpenSSLERRStack(location_); |
| } |
| |
| private: |
| constbase::Location location_; |
| }; |
| |
| }// namespace crypto |
| |
| #endif// CRYPTO_OPENSSL_UTIL_H_ |
