[mynewt-core] branch master updated: mbedtls; add a routine to add AAD data incrementally.

[ma...@apache.org]

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marko pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-core.git


The following commit(s) were added to refs/heads/master by this push:
     new f2ed758  mbedtls; add a routine to add AAD data incrementally.
     new ed4fa52  Merge pull request #1752 from mkiiskila/mbedtls_gcm_update_aad
f2ed758 is described below

commit f2ed758343651745404507f76c3022cf518fbf6f
Author: Marko Kiiskila <ma...@apache.org>
AuthorDate: Wed Apr 10 09:29:38 2019 +0300

    mbedtls; add a routine to add AAD data incrementally.
---
 crypto/mbedtls/include/mbedtls/gcm.h | 24 ++++++++++++++++++++++++
 crypto/mbedtls/src/gcm.c             | 35 ++++++++++++++++++++++++++++++++++-
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/crypto/mbedtls/include/mbedtls/gcm.h b/crypto/mbedtls/include/mbedtls/gcm.h
index af0017f..363496c 100644
--- a/crypto/mbedtls/include/mbedtls/gcm.h
+++ b/crypto/mbedtls/include/mbedtls/gcm.h
@@ -235,6 +235,30 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
 
 /**
  * \brief           This function feeds an input buffer into an ongoing GCM
+ *                  encryption or decryption operation as additional data.
+ *                  This needs to be called before starting enc/dec
+ *                  operations.
+ *
+ *    `             The function expects input to be a multiple of 16
+ *                  Bytes. Only the last call before mbedtls_gcm_update() or
+ *                  mbedtls_gcm_finish() can be less than 16 Bytes.
+ *
+ *
+ * \param ctx       The GCM context.
+ * \param length    The length of the input data. This must be a multiple of
+ *                  16 except in the last call before mbedtls_gcm_finish().
+ * \param input     The buffer holding the input ADD.
+ *
+ * \return         \c 0 on success.
+ * \return         #MBEDTLS_ERR_GCM_BAD_INPUT on failure.
+ */
+int mbedtls_gcm_update_add( mbedtls_gcm_context *ctx,
+                size_t length,
+                const unsigned char *input );
+
+
+/**
+ * \brief           This function feeds an input buffer into an ongoing GCM
  *                  encryption or decryption operation.
  *
  *    `             The function expects input to be a multiple of 16
diff --git a/crypto/mbedtls/src/gcm.c b/crypto/mbedtls/src/gcm.c
index 75e650f..e7adeac 100644
--- a/crypto/mbedtls/src/gcm.c
+++ b/crypto/mbedtls/src/gcm.c
@@ -360,7 +360,7 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
     {
         return( ret );
     }
-
+/*
     ctx->add_len = add_len;
     p = add;
     while( add_len > 0 )
@@ -377,6 +377,39 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
     }
 
     return( 0 );
+*/
+    return mbedtls_gcm_update_add( ctx, add_len, add );
+}
+
+int mbedtls_gcm_update_add( mbedtls_gcm_context *ctx,
+                size_t add_len,
+                const unsigned char *add )
+{
+    const unsigned char *p;
+    size_t i;
+    size_t use_len;
+
+    if ( ctx->add_len & 15 )
+    {
+        return( MBEDTLS_ERR_GCM_BAD_INPUT );
+    }
+    ctx->add_len += add_len;
+    p = add;
+
+    while (add_len > 0)
+    {
+        use_len = ( add_len < 16 ) ? add_len : 16;
+
+        for( i = 0; i < use_len; i++ ) {
+            ctx->buf[i] ^= p[i];
+        }
+        gcm_mult( ctx, ctx->buf, ctx->buf );
+
+        add_len -= use_len;
+        p += use_len;
+    }
+
+    return( 0 );
 }
 
 int mbedtls_gcm_update( mbedtls_gcm_context *ctx,