Remove the embedded sha1 code, and use one of botan or gcrypt

This adds a hard dependency on one of Botan or gcrypt. Botan is already a
recommended dependency, and gcrypt is probably packaged almost everywhere,
so this should not be a big deal.

ref #3241

louloulibs/utils/sha1.hpp

@@ -1,33 +1,5 @@
-/* This code is public-domain - it is based on libcrypt
- * placed in the public domain by Wei Dai and other contributors.
- */
+#pragma once
 
-#include <stdint.h>
-#include <string.h>
+#include <string>
 
-#define HASH_LENGTH 20
-#define BLOCK_LENGTH 64
-
-union _buffer {
-	uint8_t b[BLOCK_LENGTH];
-	uint32_t w[BLOCK_LENGTH/4];
-};
-
-union _state {
-	uint8_t b[HASH_LENGTH];
-	uint32_t w[HASH_LENGTH/4];
-};
-
-typedef struct sha1nfo {
-	union _buffer buffer;
-	uint8_t bufferOffset;
-	union _state state;
-	uint32_t byteCount;
-	uint8_t keyBuffer[BLOCK_LENGTH];
-	uint8_t innerHash[HASH_LENGTH];
-} sha1nfo;
-
-void sha1_init(sha1nfo *s);
-void sha1_writebyte(sha1nfo *s, uint8_t data);
-void sha1_write(sha1nfo *s, const char *data, size_t len);
-uint8_t* sha1_result(sha1nfo *s);
+std::string sha1(const std::string& input);