Add a generic hash API.

Also use this API in framemd5.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

3 files changed, 233 insertions, 0 deletions

diff --git a/libavutil/Makefile b/libavutil/Makefile
index e6feccc5fe..f7852ee224 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -81,6 +81,7 @@ OBJS = adler32.o                                                        \
        file.o                                                           \
        float_dsp.o                                                      \
        frame.o                                                          \
+       hash.o                                                           \
        hmac.o                                                           \
        imgutils.o                                                       \
        intfloat_readwrite.o                                             \
diff --git a/libavutil/hash.c b/libavutil/hash.c
new file mode 100644
index 0000000000..481010dee8
--- /dev/null
+++ b/libavutil/hash.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2013 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <stdint.h>
+#include "hash.h"
+
+#include "adler32.h"
+#include "crc.h"
+#include "md5.h"
+#include "murmur3.h"
+#include "sha.h"
+
+#include "avstring.h"
+#include "error.h"
+#include "intreadwrite.h"
+#include "mem.h"
+
+enum hashtype {
+    MD5,
+    MURMUR3,
+    SHA160,
+    SHA224,
+    SHA256,
+    CRC32,
+    ADLER32,
+    NUM_HASHES
+};
+
+typedef struct AVHashContext {
+    void *ctx;
+    enum hashtype type;
+    const AVCRC *crctab;
+    uint32_t crc;
+} AVHashContext;
+
+struct {
+    const char *name;
+    int size;
+} hashdesc[] = {
+    [MD5]     = {"MD5",     16},
+    [MURMUR3] = {"murmur3", 16},
+    [SHA160]  = {"SHA160",  20},
+    [SHA224]  = {"SHA240",  28},
+    [SHA256]  = {"SHA256",  32},
+    [CRC32]   = {"CRC32",    4},
+    [ADLER32] = {"adler32",  4},
+};
+
+const char *av_hash_names(int i)
+{
+    if (i < 0 || i >= NUM_HASHES) return NULL;
+    return hashdesc[i].name;
+}
+
+const char *av_hash_get_name(const AVHashContext *ctx)
+{
+    return hashdesc[ctx->type].name;
+}
+
+int av_hash_get_size(const AVHashContext *ctx)
+{
+    return hashdesc[ctx->type].size;
+}
+
+int av_hash_alloc(AVHashContext **ctx, const char *name)
+{
+    AVHashContext *res;
+    int i;
+    *ctx = NULL;
+    for (i = 0; i < NUM_HASHES; i++)
+        if (av_strcasecmp(name, hashdesc[i].name) == 0)
+            break;
+    if (i >= NUM_HASHES) return AVERROR(EINVAL);
+    res = av_mallocz(sizeof(*res));
+    if (!res) return AVERROR(ENOMEM);
+    res->type = i;
+    switch (i) {
+    case MD5:     res->ctx = av_md5_alloc(); break;
+    case MURMUR3: res->ctx = av_murmur3_alloc(); break;
+    case SHA160:
+    case SHA224:
+    case SHA256:  res->ctx = av_sha_alloc(); break;
+    case CRC32:   res->crctab = av_crc_get_table(AV_CRC_32_IEEE); break;
+    case ADLER32: break;
+    }
+    if (i != ADLER32 && i != CRC32 && !res->ctx) {
+        av_free(res);
+        return AVERROR(ENOMEM);
+    }
+    *ctx = res;
+    return 0;
+}
+
+void av_hash_init(AVHashContext *ctx)
+{
+    switch (ctx->type) {
+    case MD5:     av_md5_init(ctx->ctx); break;
+    case MURMUR3: av_murmur3_init(ctx->ctx); break;
+    case SHA160:  av_sha_init(ctx->ctx, 160); break;
+    case SHA224:  av_sha_init(ctx->ctx, 224); break;
+    case SHA256:  av_sha_init(ctx->ctx, 256); break;
+    case CRC32:
+    case ADLER32: ctx->crc = 0; break;
+    }
+}
+
+void av_hash_update(AVHashContext *ctx, const uint8_t *src, int len)
+{
+    switch (ctx->type) {
+    case MD5:     av_md5_update(ctx->ctx, src, len); break;
+    case MURMUR3: av_murmur3_update(ctx->ctx, src, len); break;
+    case SHA160:
+    case SHA224:
+    case SHA256:  av_sha_update(ctx->ctx, src, len); break;
+    case CRC32:   ctx->crc = av_crc(ctx->crctab, ctx->crc, src, len); break;
+    case ADLER32: ctx->crc = av_adler32_update(ctx->crc, src, len); break;
+    }
+}
+
+void av_hash_final(AVHashContext *ctx, uint8_t *dst)
+{
+    switch (ctx->type) {
+    case MD5:     av_md5_final(ctx->ctx, dst); break;
+    case MURMUR3: av_murmur3_final(ctx->ctx, dst); break;
+    case SHA160:
+    case SHA224:
+    case SHA256:  av_sha_final(ctx->ctx, dst); break;
+    case CRC32:
+    case ADLER32: AV_WL32(dst, ctx->crc); break;
+    }
+}
+
+void av_hash_freep(AVHashContext **ctx)
+{
+    if (*ctx)
+        av_freep(&(*ctx)->ctx);
+    av_freep(ctx);
+}
diff --git a/libavutil/hash.h b/libavutil/hash.h
new file mode 100644
index 0000000000..7ecb3e72a9
--- /dev/null
+++ b/libavutil/hash.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2013 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_HASH_H
+#define AVUTIL_HASH_H
+
+#include <stdint.h>
+
+struct AVHashContext;
+
+/**
+ * Allocate a hash context for the algorithm specified by name.
+ *
+ * @return  >= 0 for success, a negative error code for failure
+ * @note  The context is not initialized, you must call av_hash_init().
+ */
+int av_hash_alloc(struct AVHashContext **ctx, const char *name);
+
+/**
+ * Get the names of available hash algorithms.
+ *
+ * This function can be used to enumerate the algorithms.
+ *
+ * @param i  index of the hash algorithm, starting from 0
+ * @return   a pointer to a static string or NULL if i is out of range
+ */
+const char *av_hash_names(int i);
+
+/**
+ * Get the name of the algorithm corresponding to the given hash context.
+ */
+const char *av_hash_get_name(const struct AVHashContext *ctx);
+
+/**
+ * Get the size of the resulting hash value in bytes.
+ *
+ * The pointer passed to av_hash_final have space for at least this many bytes.
+ */
+int av_hash_get_size(const struct AVHashContext *ctx);
+
+/**
+ * Initialize or reset a hash context.
+ */
+void av_hash_init(struct AVHashContext *ctx);
+
+/**
+ * Update a hash context with additional data.
+ */
+void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, int len);
+
+/**
+ * Finalize a hash context and compute the actual hash value.
+ */
+void av_hash_final(struct AVHashContext *ctx, uint8_t *dst);
+
+/**
+ * Free hash context.
+ */
+void av_hash_freep(struct AVHashContext **ctx);
+
+#endif /* AVUTIL_HASH_H */