hmac: Fixed crashes on CPUs that don't allow unaligned memory access.

dovecot · Sep 8, 2013 · d8361cc · d8361cc
1 parent 1c1ded8
commit d8361cc
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Showing 3 changed files with 20 additions and 6 deletions.
diff --git a/src/lib/hmac-cram-md5.c b/src/lib/hmac-cram-md5.c
@@ -9,9 +9,10 @@
 #include "md5.h"
 #include "hmac-cram-md5.h"
 
-void hmac_md5_get_cram_context(struct hmac_context *hmac_ctx,
+void hmac_md5_get_cram_context(struct hmac_context *_hmac_ctx,
 			unsigned char context_digest[CRAM_MD5_CONTEXTLEN])
 {
+	struct hmac_context_priv *hmac_ctx = &_hmac_ctx->u.priv;
 	unsigned char *cdp;
 
 	struct md5_context *ctx = (void*)hmac_ctx->ctx;
@@ -34,9 +35,10 @@ void hmac_md5_get_cram_context(struct hmac_context *hmac_ctx,
 	CDPUT(cdp, ctx->d);
 }
 
-void hmac_md5_set_cram_context(struct hmac_context *hmac_ctx,
+void hmac_md5_set_cram_context(struct hmac_context *_hmac_ctx,
 			const unsigned char context_digest[CRAM_MD5_CONTEXTLEN])
 {
+	struct hmac_context_priv *hmac_ctx = &_hmac_ctx->u.priv;
 	const unsigned char *cdp;
 
 	struct md5_context *ctx = (void*)hmac_ctx->ctx;

diff --git a/src/lib/hmac.c b/src/lib/hmac.c
@@ -11,9 +11,10 @@
 #include "hmac.h"
 #include "safe-memset.h"
 
-void hmac_init(struct hmac_context *ctx, const unsigned char *key,
+void hmac_init(struct hmac_context *_ctx, const unsigned char *key,
 		size_t key_len, const struct hash_method *meth)
 {
+	struct hmac_context_priv *ctx = &_ctx->u.priv;
 	int i;
 	unsigned char k_ipad[64];
 	unsigned char k_opad[64];
@@ -49,8 +50,10 @@ void hmac_init(struct hmac_context *ctx, const unsigned char *key,
 	safe_memset(k_opad, 0, 64);
 }
 
-void hmac_final(struct hmac_context *ctx, unsigned char *digest)
+void hmac_final(struct hmac_context *_ctx, unsigned char *digest)
 {
+	struct hmac_context_priv *ctx = &_ctx->u.priv;
+
 	ctx->hash->result(ctx->ctx, digest);
 
 	ctx->hash->loop(ctx->ctxo, digest, ctx->hash->digest_size);

diff --git a/src/lib/hmac.h b/src/lib/hmac.h
@@ -6,20 +6,29 @@
 
 #define HMAC_MAX_CONTEXT_SIZE 256
 
-struct hmac_context {
+struct hmac_context_priv {
 	char ctx[HMAC_MAX_CONTEXT_SIZE];
 	char ctxo[HMAC_MAX_CONTEXT_SIZE];
 	const struct hash_method *hash;
 };
 
+struct hmac_context {
+	union {
+		struct hmac_context_priv priv;
+		uint64_t padding_requirement;
+	} u;
+};
+
 void hmac_init(struct hmac_context *ctx, const unsigned char *key,
 		size_t key_len, const struct hash_method *meth);
 void hmac_final(struct hmac_context *ctx, unsigned char *digest);
 
 
 static inline void
-hmac_update(struct hmac_context *ctx, const void *data, size_t size)
+hmac_update(struct hmac_context *_ctx, const void *data, size_t size)
 {
+	struct hmac_context_priv *ctx = &_ctx->u.priv;
+
 	ctx->hash->loop(ctx->ctx, data, size);
 }