diff options
Diffstat (limited to 'libqpdf/Pl_SHA2.cc')
-rw-r--r-- | libqpdf/Pl_SHA2.cc | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/libqpdf/Pl_SHA2.cc b/libqpdf/Pl_SHA2.cc new file mode 100644 index 00000000..018f411f --- /dev/null +++ b/libqpdf/Pl_SHA2.cc @@ -0,0 +1,164 @@ +#include <qpdf/Pl_SHA2.hh> +#include <stdexcept> +#include <cstdio> +#include <qpdf/PointerHolder.hh> + +Pl_SHA2::Pl_SHA2(int bits, Pipeline* next) : + Pipeline("sha2", next), + in_progress(false), + bits(0) +{ + if (bits) + { + resetBits(bits); + } +} + +Pl_SHA2::~Pl_SHA2() +{ +} + +void +Pl_SHA2::badBits() +{ + throw std::logic_error("Pl_SHA2 has unexpected value for bits"); +} + +void +Pl_SHA2::write(unsigned char* buf, size_t len) +{ + if (! this->in_progress) + { + switch (bits) + { + case 256: + sph_sha256_init(&this->ctx256); + break; + case 384: + sph_sha384_init(&this->ctx384); + break; + case 512: + sph_sha512_init(&this->ctx512); + break; + default: + badBits(); + break; + } + this->in_progress = true; + } + + // Write in chunks in case len is too big to fit in an int. + // Assume int is at least 32 bits. + static size_t const max_bytes = 1 << 30; + size_t bytes_left = len; + unsigned char* data = buf; + while (bytes_left > 0) + { + size_t bytes = (bytes_left >= max_bytes ? max_bytes : bytes_left); + switch (bits) + { + case 256: + sph_sha256(&this->ctx256, data, bytes); + break; + case 384: + sph_sha384(&this->ctx384, data, bytes); + break; + case 512: + sph_sha512(&this->ctx512, data, bytes); + break; + default: + badBits(); + break; + } + bytes_left -= bytes; + data += bytes; + } + + if (this->getNext(true)) + { + this->getNext()->write(buf, len); + } +} + +void +Pl_SHA2::finish() +{ + if (this->getNext(true)) + { + this->getNext()->finish(); + } + switch (bits) + { + case 256: + sph_sha256_close(&this->ctx256, sha256sum); + break; + case 384: + sph_sha384_close(&this->ctx384, sha384sum); + break; + case 512: + sph_sha512_close(&this->ctx512, sha512sum); + break; + default: + badBits(); + break; + } + this->in_progress = false; +} + +void +Pl_SHA2::resetBits(int bits) +{ + if (this->in_progress) + { + throw std::logic_error( + "bit reset requested for in-progress SHA2 Pipeline"); + } + if (! ((bits == 256) || (bits == 384) || (bits == 512))) + { + throw std::logic_error("Pl_SHA2 called with bits != 256, 384, or 512"); + } + this->bits = bits; +} + +std::string +Pl_SHA2::getRawDigest() +{ + std::string result; + switch (bits) + { + case 256: + result = std::string((char*)this->sha256sum, sizeof(this->sha256sum)); + break; + case 384: + result = std::string((char*)this->sha384sum, sizeof(this->sha384sum)); + break; + case 512: + result = std::string((char*)this->sha512sum, sizeof(this->sha512sum)); + break; + default: + badBits(); + break; + } + return result; +} + +std::string +Pl_SHA2::getHexDigest() +{ + if (this->in_progress) + { + throw std::logic_error( + "digest requested for in-progress SHA2 Pipeline"); + } + std::string raw = getRawDigest(); + size_t raw_size = raw.length(); + size_t hex_size = 1 + (2 * raw_size); + PointerHolder<char> bufp(true, new char[hex_size]); + char* buf = bufp.getPointer(); + buf[hex_size - 1] = '\0'; + for (unsigned int i = 0; i < raw_size; ++i) + { + std::sprintf(buf + i * 2, "%02x", (unsigned char)raw[i]); + } + return buf; +} |