[FFmpeg-cvslog] lavu: Add an API for calculating HMAC (RFC 2104)
Martin Storsjö
git at videolan.org
Tue Jan 15 16:03:57 CET 2013
ffmpeg | branch: master | Martin Storsjö <martin at martin.st> | Fri Oct 12 15:01:06 2012 +0300| [8ee288d2586f216aa698ef8e6d107f02c813ea06] | committer: Martin Storsjö
lavu: Add an API for calculating HMAC (RFC 2104)
This supports HMAC-MD5 and HMAC-SHA1 for now, other hashes are
simple to add.
Signed-off-by: Martin Storsjö <martin at martin.st>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8ee288d2586f216aa698ef8e6d107f02c813ea06
---
doc/APIchanges | 3 ++
libavutil/Makefile | 2 +
libavutil/hmac.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++
libavutil/hmac.h | 95 +++++++++++++++++++++++++++++++++++
libavutil/version.h | 2 +-
5 files changed, 239 insertions(+), 1 deletion(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 4b60253..3120f7e 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -13,6 +13,9 @@ libavutil: 2012-10-22
API changes, most recent first:
+2013-01-xx - xxxxxxx - lavu 52.5.0 - hmac.h
+ Add AVHMAC.
+
2013-01-13 - xxxxxxx - lavc 54.36.0 - vdpau.h
Add AVVDPAUContext struct for VDPAU hardware-accelerated decoding.
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 48a0e16..79e67b5 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -19,6 +19,7 @@ HEADERS = adler32.h \
eval.h \
fifo.h \
file.h \
+ hmac.h \
imgutils.h \
intfloat.h \
intfloat_readwrite.h \
@@ -66,6 +67,7 @@ OBJS = adler32.o \
fifo.o \
file.o \
float_dsp.o \
+ hmac.o \
imgutils.o \
intfloat_readwrite.o \
intmath.o \
diff --git a/libavutil/hmac.c b/libavutil/hmac.c
new file mode 100644
index 0000000..3308f1b
--- /dev/null
+++ b/libavutil/hmac.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2012 Martin Storsjo
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+
+#include "hmac.h"
+#include "md5.h"
+#include "sha.h"
+#include "mem.h"
+
+#define MAX_HASHLEN 20
+#define MAX_BLOCKLEN 64
+
+struct AVHMAC {
+ void *hash;
+ int blocklen, hashlen;
+ void (*final)(void*, uint8_t*);
+ void (*update)(void*, const uint8_t*, int len);
+ void (*init)(void*);
+ uint8_t key[MAX_BLOCKLEN];
+ int keylen;
+};
+
+static void sha1_init(void *ctx)
+{
+ av_sha_init(ctx, 160);
+}
+
+AVHMAC *av_hmac_alloc(enum AVHMACType type)
+{
+ AVHMAC *c = av_mallocz(sizeof(*c));
+ if (!c)
+ return NULL;
+ switch (type) {
+ case AV_HMAC_MD5:
+ c->blocklen = 64;
+ c->hashlen = 16;
+ c->init = av_md5_init;
+ c->update = av_md5_update;
+ c->final = av_md5_final;
+ c->hash = av_md5_alloc();
+ break;
+ case AV_HMAC_SHA1:
+ c->blocklen = 64;
+ c->hashlen = 20;
+ c->init = sha1_init;
+ c->update = av_sha_update;
+ c->final = av_sha_final;
+ c->hash = av_sha_alloc();
+ break;
+ default:
+ av_free(c);
+ return NULL;
+ }
+ if (!c->hash) {
+ av_free(c);
+ return NULL;
+ }
+ return c;
+}
+
+void av_hmac_free(AVHMAC *c)
+{
+ if (!c)
+ return;
+ av_free(c->hash);
+ av_free(c);
+}
+
+void av_hmac_init(AVHMAC *c, const uint8_t *key, unsigned int keylen)
+{
+ int i;
+ uint8_t block[MAX_BLOCKLEN];
+ if (keylen > c->blocklen) {
+ c->init(c->hash);
+ c->update(c->hash, key, keylen);
+ c->final(c->hash, c->key);
+ c->keylen = c->hashlen;
+ } else {
+ memcpy(c->key, key, keylen);
+ c->keylen = keylen;
+ }
+ c->init(c->hash);
+ for (i = 0; i < c->keylen; i++)
+ block[i] = c->key[i] ^ 0x36;
+ for (i = c->keylen; i < c->blocklen; i++)
+ block[i] = 0x36;
+ c->update(c->hash, block, c->blocklen);
+}
+
+void av_hmac_update(AVHMAC *c, const uint8_t *data, unsigned int len)
+{
+ c->update(c->hash, data, len);
+}
+
+int av_hmac_final(AVHMAC *c, uint8_t *out, unsigned int outlen)
+{
+ uint8_t block[MAX_BLOCKLEN];
+ int i;
+ if (outlen < c->hashlen)
+ return AVERROR(EINVAL);
+ c->final(c->hash, out);
+ c->init(c->hash);
+ for (i = 0; i < c->keylen; i++)
+ block[i] = c->key[i] ^ 0x5C;
+ for (i = c->keylen; i < c->blocklen; i++)
+ block[i] = 0x5C;
+ c->update(c->hash, block, c->blocklen);
+ c->update(c->hash, out, c->hashlen);
+ c->final(c->hash, out);
+ return c->hashlen;
+}
+
+int av_hmac_calc(AVHMAC *c, const uint8_t *data, unsigned int len,
+ const uint8_t *key, unsigned int keylen,
+ uint8_t *out, unsigned int outlen)
+{
+ av_hmac_init(c, key, keylen);
+ av_hmac_update(c, data, len);
+ return av_hmac_final(c, out, outlen);
+}
diff --git a/libavutil/hmac.h b/libavutil/hmac.h
new file mode 100644
index 0000000..28c2062
--- /dev/null
+++ b/libavutil/hmac.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2012 Martin Storsjo
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_HMAC_H
+#define AVUTIL_HMAC_H
+
+#include <stdint.h>
+
+/**
+ * @defgroup lavu_hmac HMAC
+ * @ingroup lavu_crypto
+ * @{
+ */
+
+enum AVHMACType {
+ AV_HMAC_MD5,
+ AV_HMAC_SHA1,
+};
+
+typedef struct AVHMAC AVHMAC;
+
+/**
+ * Allocate an AVHMAC context.
+ * @param type The hash function used for the HMAC.
+ */
+AVHMAC *av_hmac_alloc(enum AVHMACType type);
+
+/**
+ * Free an AVHMAC context.
+ * @param ctx The context to free, may be NULL
+ */
+void av_hmac_free(AVHMAC *ctx);
+
+/**
+ * Initialize an AVHMAC context with an authentication key.
+ * @param ctx The HMAC context
+ * @param key The authentication key
+ * @param keylen The length of the key, in bytes
+ */
+void av_hmac_init(AVHMAC *ctx, const uint8_t *key, unsigned int keylen);
+
+/**
+ * Hash data with the HMAC.
+ * @param ctx The HMAC context
+ * @param data The data to hash
+ * @param len The length of the data, in bytes
+ */
+void av_hmac_update(AVHMAC *ctx, const uint8_t *data, unsigned int len);
+
+/**
+ * Finish hashing and output the HMAC digest.
+ * @param ctx The HMAC context
+ * @param out The output buffer to write the digest into
+ * @param outlen The length of the out buffer, in bytes
+ * @return The number of bytes written to out, or a negative error code.
+ */
+int av_hmac_final(AVHMAC *ctx, uint8_t *out, unsigned int outlen);
+
+/**
+ * Hash an array of data with a key.
+ * @param ctx The HMAC context
+ * @param data The data to hash
+ * @param len The length of the data, in bytes
+ * @param key The authentication key
+ * @param keylen The length of the key, in bytes
+ * @param out The output buffer to write the digest into
+ * @param outlen The length of the out buffer, in bytes
+ * @return The number of bytes written to out, or a negative error code.
+ */
+int av_hmac_calc(AVHMAC *ctx, const uint8_t *data, unsigned int len,
+ const uint8_t *key, unsigned int keylen,
+ uint8_t *out, unsigned int outlen);
+
+/**
+ * @}
+ */
+
+#endif /* AVUTIL_HMAC_H */
diff --git a/libavutil/version.h b/libavutil/version.h
index 83a1f81..68f5752 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -37,7 +37,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 52
-#define LIBAVUTIL_VERSION_MINOR 4
+#define LIBAVUTIL_VERSION_MINOR 5
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
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