From ec3a85730742497b29782c0b545911eb78d3c65e Mon Sep 17 00:00:00 2001 From: John Ericson Date: Tue, 23 Jun 2020 18:19:40 +0000 Subject: [PATCH] Fix and clean up hash parser --- src/libutil/hash.cc | 62 ++++++++++++++++++++++----------------------- 1 file changed, 30 insertions(+), 32 deletions(-) diff --git a/src/libutil/hash.cc b/src/libutil/hash.cc index f44210737..70a18f9a0 100644 --- a/src/libutil/hash.cc +++ b/src/libutil/hash.cc @@ -133,68 +133,66 @@ std::string Hash::to_string(Base base, bool includeType) const Hash::Hash(std::string_view s, HashType type) : Hash(s, std::optional { type }) { } Hash::Hash(std::string_view s) : Hash(s, std::optional{}) { } -Hash::Hash(std::string_view s, std::optional optType) +Hash::Hash(std::string_view original, std::optional optType) { + auto rest = original; + size_t pos = 0; bool isSRI = false; - // Find the : or - separater, and set `isSRI` to the correct value - auto sep = s.find(':'); - if (sep == std::string_view::npos) { - sep = s.find('-'); - if (sep != std::string_view::npos) - isSRI = true; - } - // Parse the has type before the separater, if there was one. std::optional optParsedType; - if (sep != std::string_view::npos) { - auto hts = s.substr(0, sep); - auto optParsedType = parseHashTypeOpt(hts); - if (!optParsedType) - throw BadHash("unknown hash type '%s'", hts); - pos = sep + 1; + { + auto sep = rest.find(':'); + if (sep == std::string_view::npos) { + sep = rest.find('-'); + if (sep != std::string_view::npos) + isSRI = true; + } + if (sep != std::string_view::npos) { + auto hashRaw = rest.substr(0, sep); + optParsedType = parseHashType(hashRaw); + rest = rest.substr(sep + 1); + } } // Either the string or user must provide the type, if they both do they // must agree. if (!optParsedType && !optType) { - throw BadHash("hash '%s' does not include a type, nor is the type otherwise known from context.", s); + throw BadHash("hash '%s' does not include a type, nor is the type otherwise known from context.", rest); } else { this->type = optParsedType ? *optParsedType : *optType; if (optParsedType && optType && *optParsedType != *optType) - throw BadHash("hash '%s' should have type '%s'", s, printHashType(*optType)); + throw BadHash("hash '%s' should have type '%s'", original, printHashType(*optType)); } init(); - size_t size = s.size() - pos; - - if (!isSRI && size == base16Len()) { + if (!isSRI && rest.size() == base16Len()) { auto parseHexDigit = [&](char c) { if (c >= '0' && c <= '9') return c - '0'; if (c >= 'A' && c <= 'F') return c - 'A' + 10; if (c >= 'a' && c <= 'f') return c - 'a' + 10; - throw BadHash("invalid base-16 hash '%s'", s); + throw BadHash("invalid base-16 hash '%s'", original); }; for (unsigned int i = 0; i < hashSize; i++) { hash[i] = - parseHexDigit(s[pos + i * 2]) << 4 - | parseHexDigit(s[pos + i * 2 + 1]); + parseHexDigit(rest[pos + i * 2]) << 4 + | parseHexDigit(rest[pos + i * 2 + 1]); } } - else if (!isSRI && size == base32Len()) { + else if (!isSRI && rest.size() == base32Len()) { - for (unsigned int n = 0; n < size; ++n) { - char c = s[pos + size - n - 1]; + for (unsigned int n = 0; n < rest.size(); ++n) { + char c = rest[rest.size() - n - 1]; unsigned char digit; for (digit = 0; digit < base32Chars.size(); ++digit) /* !!! slow */ if (base32Chars[digit] == c) break; if (digit >= 32) - throw BadHash("invalid base-32 hash '%s'", s); + throw BadHash("invalid base-32 hash '%s'", original); unsigned int b = n * 5; unsigned int i = b / 8; unsigned int j = b % 8; @@ -204,21 +202,21 @@ Hash::Hash(std::string_view s, std::optional optType) hash[i + 1] |= digit >> (8 - j); } else { if (digit >> (8 - j)) - throw BadHash("invalid base-32 hash '%s'", s); + throw BadHash("invalid base-32 hash '%s'", original); } } } - else if (isSRI || size == base64Len()) { - auto d = base64Decode(s.substr(pos)); + else if (isSRI || rest.size() == base64Len()) { + auto d = base64Decode(rest); if (d.size() != hashSize) - throw BadHash("invalid %s hash '%s'", isSRI ? "SRI" : "base-64", s); + throw BadHash("invalid %s hash '%s'", isSRI ? "SRI" : "base-64", original); assert(hashSize); memcpy(hash, d.data(), hashSize); } else - throw BadHash("hash '%s' has wrong length for hash type '%s'", s, printHashType(type)); + throw BadHash("hash '%s' has wrong length for hash type '%s'", rest, printHashType(this->type)); } Hash newHashAllowEmpty(std::string hashStr, std::optional ht)