1 files changed, 118 insertions, 0 deletions
diff --git a/lib/sha256.h b/lib/sha256.h
new file mode 100644
index 0000000..dc9d87e
--- /dev/null
+++ b/lib/sha256.h
@@ -0,0 +1,118 @@
+/* Declarations of functions and data types used for SHA256 and SHA224 sum
+   library functions.
+   Copyright (C) 2005-2006, 2008-2022 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef SHA256_H
+# define SHA256_H 1
+
+# include <stdio.h>
+# include <stdint.h>
+
+# if HAVE_OPENSSL_SHA256
+#  include <openssl/sha.h>
+# endif
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+enum { SHA224_DIGEST_SIZE = 224 / 8 };
+enum { SHA256_DIGEST_SIZE = 256 / 8 };
+
+# if HAVE_OPENSSL_SHA256
+#  define GL_OPENSSL_NAME 224
+#  include "gl_openssl.h"
+#  define GL_OPENSSL_NAME 256
+#  include "gl_openssl.h"
+# else
+/* Structure to save state of computation between the single steps.  */
+struct sha256_ctx
+{
+  uint32_t state[8];
+
+  uint32_t total[2];
+  size_t buflen;       /* ≥ 0, ≤ 128 */
+  uint32_t buffer[32]; /* 128 bytes; the first buflen bytes are in use */
+};
+
+/* Initialize structure containing state of computation. */
+extern void sha256_init_ctx (struct sha256_ctx *ctx);
+extern void sha224_init_ctx (struct sha256_ctx *ctx);
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is necessary that LEN is a multiple of 64!!! */
+extern void sha256_process_block (const void *buffer, size_t len,
+                                  struct sha256_ctx *ctx);
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is NOT required that LEN is a multiple of 64.  */
+extern void sha256_process_bytes (const void *buffer, size_t len,
+                                  struct sha256_ctx *ctx);
+
+/* Process the remaining bytes in the buffer and put result from CTX
+   in first 32 (28) bytes following RESBUF.  The result is always in little
+   endian byte order, so that a byte-wise output yields to the wanted
+   ASCII representation of the message digest.  */
+extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
+extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
+
+
+/* Put result from CTX in first 32 (28) bytes following RESBUF.  The result is
+   always in little endian byte order, so that a byte-wise output yields
+   to the wanted ASCII representation of the message digest.  */
+extern void *sha256_read_ctx (const struct sha256_ctx *ctx,
+                              void *restrict resbuf);
+extern void *sha224_read_ctx (const struct sha256_ctx *ctx,
+                              void *restrict resbuf);
+
+
+/* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER.
+   The result is always in little endian byte order, so that a byte-wise
+   output yields to the wanted ASCII representation of the message
+   digest.  */
+extern void *sha256_buffer (const char *buffer, size_t len,
+                            void *restrict resblock);
+extern void *sha224_buffer (const char *buffer, size_t len,
+                            void *restrict resblock);
+
+# endif
+
+/* Compute SHA256 (SHA224) message digest for bytes read from STREAM.
+   STREAM is an open file stream.  Regular files are handled more efficiently.
+   The contents of STREAM from its current position to its end will be read.
+   The case that the last operation on STREAM was an 'ungetc' is not supported.
+   The resulting message digest number will be written into the 32 (28) bytes
+   beginning at RESBLOCK.  */
+extern int sha256_stream (FILE *stream, void *resblock);
+extern int sha224_stream (FILE *stream, void *resblock);
+
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif
+
+/*
+ * Hey Emacs!
+ * Local Variables:
+ * coding: utf-8
+ * End:
+ */