aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/hash.cpp10
-rw-r--r--src/hash.h9
2 files changed, 19 insertions, 0 deletions
diff --git a/src/hash.cpp b/src/hash.cpp
index 83b90ae063..3657b38639 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -6,6 +6,7 @@
#include <crypto/common.h>
#include <crypto/hmac_sha512.h>
+#include <string>
inline uint32_t ROTL32(uint32_t x, int8_t r)
{
@@ -84,3 +85,12 @@ uint256 SHA256Uint256(const uint256& input)
CSHA256().Write(input.begin(), 32).Finalize(result.begin());
return result;
}
+
+CHashWriter TaggedHash(const std::string& tag)
+{
+ CHashWriter writer(SER_GETHASH, 0);
+ uint256 taghash;
+ CSHA256().Write((const unsigned char*)tag.data(), tag.size()).Finalize(taghash.begin());
+ writer << taghash << taghash;
+ return writer;
+}
diff --git a/src/hash.h b/src/hash.h
index c16bbb48ce..6d876076ee 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -15,6 +15,7 @@
#include <uint256.h>
#include <version.h>
+#include <string>
#include <vector>
typedef uint256 ChainCode;
@@ -202,4 +203,12 @@ unsigned int MurmurHash3(unsigned int nHashSeed, Span<const unsigned char> vData
void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]);
+/** Return a CHashWriter primed for tagged hashes (as specified in BIP 340).
+ *
+ * The returned object will have SHA256(tag) written to it twice (= 64 bytes).
+ * A tagged hash can be computed by feeding the message into this object, and
+ * then calling CHashWriter::GetSHA256().
+ */
+CHashWriter TaggedHash(const std::string& tag);
+
#endif // BITCOIN_HASH_H