diff --git a/ChangeLog.d/zeroizations_of_sensitive_data_in_PKCS5_and_SHA.txt b/ChangeLog.d/zeroizations_of_sensitive_data_in_PKCS5_and_SHA.txt
new file mode 100644
index 0000000..320bb0e
--- /dev/null
+++ b/ChangeLog.d/zeroizations_of_sensitive_data_in_PKCS5_and_SHA.txt
@@ -0,0 +1,6 @@
+Security
+   * Zeroising of local buffers and variables which are used for calculations
+     in mbedtls_pkcs5_pbkdf2_hmac(), mbedtls_internal_sha*_process(),
+     mbedtls_internal_md*_process() and mbedtls_internal_ripemd160_process()
+     functions to erase sensitive data from memory. Reported by
+     Johan Malmgren and Johan Uppman Bruce from Sectra.
diff --git a/library/md2.c b/library/md2.c
index cbdaaab..fdcb630 100644
--- a/library/md2.c
+++ b/library/md2.c
@@ -177,6 +177,9 @@
         t  = ctx->cksum[i];
     }
 
+    /* Zeroise variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &t, sizeof( t ) );
+
     return( 0 );
 }
 
diff --git a/library/md4.c b/library/md4.c
index cb16dce..95e893e 100644
--- a/library/md4.c
+++ b/library/md4.c
@@ -143,31 +143,34 @@
 int mbedtls_internal_md4_process( mbedtls_md4_context *ctx,
                                   const unsigned char data[64] )
 {
-    uint32_t X[16], A, B, C, D;
+    struct
+    {
+        uint32_t X[16], A, B, C, D;
+    } local;
 
-    GET_UINT32_LE( X[ 0], data,  0 );
-    GET_UINT32_LE( X[ 1], data,  4 );
-    GET_UINT32_LE( X[ 2], data,  8 );
-    GET_UINT32_LE( X[ 3], data, 12 );
-    GET_UINT32_LE( X[ 4], data, 16 );
-    GET_UINT32_LE( X[ 5], data, 20 );
-    GET_UINT32_LE( X[ 6], data, 24 );
-    GET_UINT32_LE( X[ 7], data, 28 );
-    GET_UINT32_LE( X[ 8], data, 32 );
-    GET_UINT32_LE( X[ 9], data, 36 );
-    GET_UINT32_LE( X[10], data, 40 );
-    GET_UINT32_LE( X[11], data, 44 );
-    GET_UINT32_LE( X[12], data, 48 );
-    GET_UINT32_LE( X[13], data, 52 );
-    GET_UINT32_LE( X[14], data, 56 );
-    GET_UINT32_LE( X[15], data, 60 );
+    GET_UINT32_LE( local.X[ 0], data,  0 );
+    GET_UINT32_LE( local.X[ 1], data,  4 );
+    GET_UINT32_LE( local.X[ 2], data,  8 );
+    GET_UINT32_LE( local.X[ 3], data, 12 );
+    GET_UINT32_LE( local.X[ 4], data, 16 );
+    GET_UINT32_LE( local.X[ 5], data, 20 );
+    GET_UINT32_LE( local.X[ 6], data, 24 );
+    GET_UINT32_LE( local.X[ 7], data, 28 );
+    GET_UINT32_LE( local.X[ 8], data, 32 );
+    GET_UINT32_LE( local.X[ 9], data, 36 );
+    GET_UINT32_LE( local.X[10], data, 40 );
+    GET_UINT32_LE( local.X[11], data, 44 );
+    GET_UINT32_LE( local.X[12], data, 48 );
+    GET_UINT32_LE( local.X[13], data, 52 );
+    GET_UINT32_LE( local.X[14], data, 56 );
+    GET_UINT32_LE( local.X[15], data, 60 );
 
 #define S(x,n) (((x) << (n)) | (((x) & 0xFFFFFFFF) >> (32 - (n))))
 
-    A = ctx->state[0];
-    B = ctx->state[1];
-    C = ctx->state[2];
-    D = ctx->state[3];
+    local.A = ctx->state[0];
+    local.B = ctx->state[1];
+    local.C = ctx->state[2];
+    local.D = ctx->state[3];
 
 #define F(x, y, z) (((x) & (y)) | ((~(x)) & (z)))
 #define P(a,b,c,d,x,s)                           \
@@ -178,22 +181,22 @@
     } while( 0 )
 
 
-    P( A, B, C, D, X[ 0],  3 );
-    P( D, A, B, C, X[ 1],  7 );
-    P( C, D, A, B, X[ 2], 11 );
-    P( B, C, D, A, X[ 3], 19 );
-    P( A, B, C, D, X[ 4],  3 );
-    P( D, A, B, C, X[ 5],  7 );
-    P( C, D, A, B, X[ 6], 11 );
-    P( B, C, D, A, X[ 7], 19 );
-    P( A, B, C, D, X[ 8],  3 );
-    P( D, A, B, C, X[ 9],  7 );
-    P( C, D, A, B, X[10], 11 );
-    P( B, C, D, A, X[11], 19 );
-    P( A, B, C, D, X[12],  3 );
-    P( D, A, B, C, X[13],  7 );
-    P( C, D, A, B, X[14], 11 );
-    P( B, C, D, A, X[15], 19 );
+    P( local.A, local.B, local.C, local.D, local.X[ 0],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 1],  7 );
+    P( local.C, local.D, local.A, local.B, local.X[ 2], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[ 3], 19 );
+    P( local.A, local.B, local.C, local.D, local.X[ 4],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 5],  7 );
+    P( local.C, local.D, local.A, local.B, local.X[ 6], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[ 7], 19 );
+    P( local.A, local.B, local.C, local.D, local.X[ 8],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 9],  7 );
+    P( local.C, local.D, local.A, local.B, local.X[10], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[11], 19 );
+    P( local.A, local.B, local.C, local.D, local.X[12],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[13],  7 );
+    P( local.C, local.D, local.A, local.B, local.X[14], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[15], 19 );
 
 #undef P
 #undef F
@@ -206,22 +209,22 @@
         (a) = S((a),(s));                               \
     } while( 0 )
 
-    P( A, B, C, D, X[ 0],  3 );
-    P( D, A, B, C, X[ 4],  5 );
-    P( C, D, A, B, X[ 8],  9 );
-    P( B, C, D, A, X[12], 13 );
-    P( A, B, C, D, X[ 1],  3 );
-    P( D, A, B, C, X[ 5],  5 );
-    P( C, D, A, B, X[ 9],  9 );
-    P( B, C, D, A, X[13], 13 );
-    P( A, B, C, D, X[ 2],  3 );
-    P( D, A, B, C, X[ 6],  5 );
-    P( C, D, A, B, X[10],  9 );
-    P( B, C, D, A, X[14], 13 );
-    P( A, B, C, D, X[ 3],  3 );
-    P( D, A, B, C, X[ 7],  5 );
-    P( C, D, A, B, X[11],  9 );
-    P( B, C, D, A, X[15], 13 );
+    P( local.A, local.B, local.C, local.D, local.X[ 0],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 4],  5 );
+    P( local.C, local.D, local.A, local.B, local.X[ 8],  9 );
+    P( local.B, local.C, local.D, local.A, local.X[12], 13 );
+    P( local.A, local.B, local.C, local.D, local.X[ 1],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 5],  5 );
+    P( local.C, local.D, local.A, local.B, local.X[ 9],  9 );
+    P( local.B, local.C, local.D, local.A, local.X[13], 13 );
+    P( local.A, local.B, local.C, local.D, local.X[ 2],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 6],  5 );
+    P( local.C, local.D, local.A, local.B, local.X[10],  9 );
+    P( local.B, local.C, local.D, local.A, local.X[14], 13 );
+    P( local.A, local.B, local.C, local.D, local.X[ 3],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 7],  5 );
+    P( local.C, local.D, local.A, local.B, local.X[11],  9 );
+    P( local.B, local.C, local.D, local.A, local.X[15], 13 );
 
 #undef P
 #undef F
@@ -234,30 +237,33 @@
         (a) = S((a),(s));                               \
     } while( 0 )
 
-    P( A, B, C, D, X[ 0],  3 );
-    P( D, A, B, C, X[ 8],  9 );
-    P( C, D, A, B, X[ 4], 11 );
-    P( B, C, D, A, X[12], 15 );
-    P( A, B, C, D, X[ 2],  3 );
-    P( D, A, B, C, X[10],  9 );
-    P( C, D, A, B, X[ 6], 11 );
-    P( B, C, D, A, X[14], 15 );
-    P( A, B, C, D, X[ 1],  3 );
-    P( D, A, B, C, X[ 9],  9 );
-    P( C, D, A, B, X[ 5], 11 );
-    P( B, C, D, A, X[13], 15 );
-    P( A, B, C, D, X[ 3],  3 );
-    P( D, A, B, C, X[11],  9 );
-    P( C, D, A, B, X[ 7], 11 );
-    P( B, C, D, A, X[15], 15 );
+    P( local.A, local.B, local.C, local.D, local.X[ 0],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 8],  9 );
+    P( local.C, local.D, local.A, local.B, local.X[ 4], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[12], 15 );
+    P( local.A, local.B, local.C, local.D, local.X[ 2],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[10],  9 );
+    P( local.C, local.D, local.A, local.B, local.X[ 6], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[14], 15 );
+    P( local.A, local.B, local.C, local.D, local.X[ 1],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[ 9],  9 );
+    P( local.C, local.D, local.A, local.B, local.X[ 5], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[13], 15 );
+    P( local.A, local.B, local.C, local.D, local.X[ 3],  3 );
+    P( local.D, local.A, local.B, local.C, local.X[11],  9 );
+    P( local.C, local.D, local.A, local.B, local.X[ 7], 11 );
+    P( local.B, local.C, local.D, local.A, local.X[15], 15 );
 
 #undef F
 #undef P
 
-    ctx->state[0] += A;
-    ctx->state[1] += B;
-    ctx->state[2] += C;
-    ctx->state[3] += D;
+    ctx->state[0] += local.A;
+    ctx->state[1] += local.B;
+    ctx->state[2] += local.C;
+    ctx->state[3] += local.D;
+
+    /* Zeroise variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &local, sizeof( local ) );
 
     return( 0 );
 }
diff --git a/library/md5.c b/library/md5.c
index fe25925..d2b634f 100644
--- a/library/md5.c
+++ b/library/md5.c
@@ -142,128 +142,134 @@
 int mbedtls_internal_md5_process( mbedtls_md5_context *ctx,
                                   const unsigned char data[64] )
 {
-    uint32_t X[16], A, B, C, D;
+    struct
+    {
+        uint32_t X[16], A, B, C, D;
+    } local;
 
-    GET_UINT32_LE( X[ 0], data,  0 );
-    GET_UINT32_LE( X[ 1], data,  4 );
-    GET_UINT32_LE( X[ 2], data,  8 );
-    GET_UINT32_LE( X[ 3], data, 12 );
-    GET_UINT32_LE( X[ 4], data, 16 );
-    GET_UINT32_LE( X[ 5], data, 20 );
-    GET_UINT32_LE( X[ 6], data, 24 );
-    GET_UINT32_LE( X[ 7], data, 28 );
-    GET_UINT32_LE( X[ 8], data, 32 );
-    GET_UINT32_LE( X[ 9], data, 36 );
-    GET_UINT32_LE( X[10], data, 40 );
-    GET_UINT32_LE( X[11], data, 44 );
-    GET_UINT32_LE( X[12], data, 48 );
-    GET_UINT32_LE( X[13], data, 52 );
-    GET_UINT32_LE( X[14], data, 56 );
-    GET_UINT32_LE( X[15], data, 60 );
+    GET_UINT32_LE( local.X[ 0], data,  0 );
+    GET_UINT32_LE( local.X[ 1], data,  4 );
+    GET_UINT32_LE( local.X[ 2], data,  8 );
+    GET_UINT32_LE( local.X[ 3], data, 12 );
+    GET_UINT32_LE( local.X[ 4], data, 16 );
+    GET_UINT32_LE( local.X[ 5], data, 20 );
+    GET_UINT32_LE( local.X[ 6], data, 24 );
+    GET_UINT32_LE( local.X[ 7], data, 28 );
+    GET_UINT32_LE( local.X[ 8], data, 32 );
+    GET_UINT32_LE( local.X[ 9], data, 36 );
+    GET_UINT32_LE( local.X[10], data, 40 );
+    GET_UINT32_LE( local.X[11], data, 44 );
+    GET_UINT32_LE( local.X[12], data, 48 );
+    GET_UINT32_LE( local.X[13], data, 52 );
+    GET_UINT32_LE( local.X[14], data, 56 );
+    GET_UINT32_LE( local.X[15], data, 60 );
 
 #define S(x,n)                                                          \
     ( ( (x) << (n) ) | ( ( (x) & 0xFFFFFFFF) >> ( 32 - (n) ) ) )
 
-#define P(a,b,c,d,k,s,t)                                        \
-    do                                                          \
-    {                                                           \
-        (a) += F((b),(c),(d)) + X[(k)] + (t);                   \
-        (a) = S((a),(s)) + (b);                                 \
+#define P(a,b,c,d,k,s,t)                                                \
+    do                                                                  \
+    {                                                                   \
+        (a) += F((b),(c),(d)) + local.X[(k)] + (t);                     \
+        (a) = S((a),(s)) + (b);                                         \
     } while( 0 )
 
-    A = ctx->state[0];
-    B = ctx->state[1];
-    C = ctx->state[2];
-    D = ctx->state[3];
+    local.A = ctx->state[0];
+    local.B = ctx->state[1];
+    local.C = ctx->state[2];
+    local.D = ctx->state[3];
 
 #define F(x,y,z) ((z) ^ ((x) & ((y) ^ (z))))
 
-    P( A, B, C, D,  0,  7, 0xD76AA478 );
-    P( D, A, B, C,  1, 12, 0xE8C7B756 );
-    P( C, D, A, B,  2, 17, 0x242070DB );
-    P( B, C, D, A,  3, 22, 0xC1BDCEEE );
-    P( A, B, C, D,  4,  7, 0xF57C0FAF );
-    P( D, A, B, C,  5, 12, 0x4787C62A );
-    P( C, D, A, B,  6, 17, 0xA8304613 );
-    P( B, C, D, A,  7, 22, 0xFD469501 );
-    P( A, B, C, D,  8,  7, 0x698098D8 );
-    P( D, A, B, C,  9, 12, 0x8B44F7AF );
-    P( C, D, A, B, 10, 17, 0xFFFF5BB1 );
-    P( B, C, D, A, 11, 22, 0x895CD7BE );
-    P( A, B, C, D, 12,  7, 0x6B901122 );
-    P( D, A, B, C, 13, 12, 0xFD987193 );
-    P( C, D, A, B, 14, 17, 0xA679438E );
-    P( B, C, D, A, 15, 22, 0x49B40821 );
+    P( local.A, local.B, local.C, local.D,  0,  7, 0xD76AA478 );
+    P( local.D, local.A, local.B, local.C,  1, 12, 0xE8C7B756 );
+    P( local.C, local.D, local.A, local.B,  2, 17, 0x242070DB );
+    P( local.B, local.C, local.D, local.A,  3, 22, 0xC1BDCEEE );
+    P( local.A, local.B, local.C, local.D,  4,  7, 0xF57C0FAF );
+    P( local.D, local.A, local.B, local.C,  5, 12, 0x4787C62A );
+    P( local.C, local.D, local.A, local.B,  6, 17, 0xA8304613 );
+    P( local.B, local.C, local.D, local.A,  7, 22, 0xFD469501 );
+    P( local.A, local.B, local.C, local.D,  8,  7, 0x698098D8 );
+    P( local.D, local.A, local.B, local.C,  9, 12, 0x8B44F7AF );
+    P( local.C, local.D, local.A, local.B, 10, 17, 0xFFFF5BB1 );
+    P( local.B, local.C, local.D, local.A, 11, 22, 0x895CD7BE );
+    P( local.A, local.B, local.C, local.D, 12,  7, 0x6B901122 );
+    P( local.D, local.A, local.B, local.C, 13, 12, 0xFD987193 );
+    P( local.C, local.D, local.A, local.B, 14, 17, 0xA679438E );
+    P( local.B, local.C, local.D, local.A, 15, 22, 0x49B40821 );
 
 #undef F
 
 #define F(x,y,z) ((y) ^ ((z) & ((x) ^ (y))))
 
-    P( A, B, C, D,  1,  5, 0xF61E2562 );
-    P( D, A, B, C,  6,  9, 0xC040B340 );
-    P( C, D, A, B, 11, 14, 0x265E5A51 );
-    P( B, C, D, A,  0, 20, 0xE9B6C7AA );
-    P( A, B, C, D,  5,  5, 0xD62F105D );
-    P( D, A, B, C, 10,  9, 0x02441453 );
-    P( C, D, A, B, 15, 14, 0xD8A1E681 );
-    P( B, C, D, A,  4, 20, 0xE7D3FBC8 );
-    P( A, B, C, D,  9,  5, 0x21E1CDE6 );
-    P( D, A, B, C, 14,  9, 0xC33707D6 );
-    P( C, D, A, B,  3, 14, 0xF4D50D87 );
-    P( B, C, D, A,  8, 20, 0x455A14ED );
-    P( A, B, C, D, 13,  5, 0xA9E3E905 );
-    P( D, A, B, C,  2,  9, 0xFCEFA3F8 );
-    P( C, D, A, B,  7, 14, 0x676F02D9 );
-    P( B, C, D, A, 12, 20, 0x8D2A4C8A );
+    P( local.A, local.B, local.C, local.D,  1,  5, 0xF61E2562 );
+    P( local.D, local.A, local.B, local.C,  6,  9, 0xC040B340 );
+    P( local.C, local.D, local.A, local.B, 11, 14, 0x265E5A51 );
+    P( local.B, local.C, local.D, local.A,  0, 20, 0xE9B6C7AA );
+    P( local.A, local.B, local.C, local.D,  5,  5, 0xD62F105D );
+    P( local.D, local.A, local.B, local.C, 10,  9, 0x02441453 );
+    P( local.C, local.D, local.A, local.B, 15, 14, 0xD8A1E681 );
+    P( local.B, local.C, local.D, local.A,  4, 20, 0xE7D3FBC8 );
+    P( local.A, local.B, local.C, local.D,  9,  5, 0x21E1CDE6 );
+    P( local.D, local.A, local.B, local.C, 14,  9, 0xC33707D6 );
+    P( local.C, local.D, local.A, local.B,  3, 14, 0xF4D50D87 );
+    P( local.B, local.C, local.D, local.A,  8, 20, 0x455A14ED );
+    P( local.A, local.B, local.C, local.D, 13,  5, 0xA9E3E905 );
+    P( local.D, local.A, local.B, local.C,  2,  9, 0xFCEFA3F8 );
+    P( local.C, local.D, local.A, local.B,  7, 14, 0x676F02D9 );
+    P( local.B, local.C, local.D, local.A, 12, 20, 0x8D2A4C8A );
 
 #undef F
 
 #define F(x,y,z) ((x) ^ (y) ^ (z))
 
-    P( A, B, C, D,  5,  4, 0xFFFA3942 );
-    P( D, A, B, C,  8, 11, 0x8771F681 );
-    P( C, D, A, B, 11, 16, 0x6D9D6122 );
-    P( B, C, D, A, 14, 23, 0xFDE5380C );
-    P( A, B, C, D,  1,  4, 0xA4BEEA44 );
-    P( D, A, B, C,  4, 11, 0x4BDECFA9 );
-    P( C, D, A, B,  7, 16, 0xF6BB4B60 );
-    P( B, C, D, A, 10, 23, 0xBEBFBC70 );
-    P( A, B, C, D, 13,  4, 0x289B7EC6 );
-    P( D, A, B, C,  0, 11, 0xEAA127FA );
-    P( C, D, A, B,  3, 16, 0xD4EF3085 );
-    P( B, C, D, A,  6, 23, 0x04881D05 );
-    P( A, B, C, D,  9,  4, 0xD9D4D039 );
-    P( D, A, B, C, 12, 11, 0xE6DB99E5 );
-    P( C, D, A, B, 15, 16, 0x1FA27CF8 );
-    P( B, C, D, A,  2, 23, 0xC4AC5665 );
+    P( local.A, local.B, local.C, local.D,  5,  4, 0xFFFA3942 );
+    P( local.D, local.A, local.B, local.C,  8, 11, 0x8771F681 );
+    P( local.C, local.D, local.A, local.B, 11, 16, 0x6D9D6122 );
+    P( local.B, local.C, local.D, local.A, 14, 23, 0xFDE5380C );
+    P( local.A, local.B, local.C, local.D,  1,  4, 0xA4BEEA44 );
+    P( local.D, local.A, local.B, local.C,  4, 11, 0x4BDECFA9 );
+    P( local.C, local.D, local.A, local.B,  7, 16, 0xF6BB4B60 );
+    P( local.B, local.C, local.D, local.A, 10, 23, 0xBEBFBC70 );
+    P( local.A, local.B, local.C, local.D, 13,  4, 0x289B7EC6 );
+    P( local.D, local.A, local.B, local.C,  0, 11, 0xEAA127FA );
+    P( local.C, local.D, local.A, local.B,  3, 16, 0xD4EF3085 );
+    P( local.B, local.C, local.D, local.A,  6, 23, 0x04881D05 );
+    P( local.A, local.B, local.C, local.D,  9,  4, 0xD9D4D039 );
+    P( local.D, local.A, local.B, local.C, 12, 11, 0xE6DB99E5 );
+    P( local.C, local.D, local.A, local.B, 15, 16, 0x1FA27CF8 );
+    P( local.B, local.C, local.D, local.A,  2, 23, 0xC4AC5665 );
 
 #undef F
 
 #define F(x,y,z) ((y) ^ ((x) | ~(z)))
 
-    P( A, B, C, D,  0,  6, 0xF4292244 );
-    P( D, A, B, C,  7, 10, 0x432AFF97 );
-    P( C, D, A, B, 14, 15, 0xAB9423A7 );
-    P( B, C, D, A,  5, 21, 0xFC93A039 );
-    P( A, B, C, D, 12,  6, 0x655B59C3 );
-    P( D, A, B, C,  3, 10, 0x8F0CCC92 );
-    P( C, D, A, B, 10, 15, 0xFFEFF47D );
-    P( B, C, D, A,  1, 21, 0x85845DD1 );
-    P( A, B, C, D,  8,  6, 0x6FA87E4F );
-    P( D, A, B, C, 15, 10, 0xFE2CE6E0 );
-    P( C, D, A, B,  6, 15, 0xA3014314 );
-    P( B, C, D, A, 13, 21, 0x4E0811A1 );
-    P( A, B, C, D,  4,  6, 0xF7537E82 );
-    P( D, A, B, C, 11, 10, 0xBD3AF235 );
-    P( C, D, A, B,  2, 15, 0x2AD7D2BB );
-    P( B, C, D, A,  9, 21, 0xEB86D391 );
+    P( local.A, local.B, local.C, local.D,  0,  6, 0xF4292244 );
+    P( local.D, local.A, local.B, local.C,  7, 10, 0x432AFF97 );
+    P( local.C, local.D, local.A, local.B, 14, 15, 0xAB9423A7 );
+    P( local.B, local.C, local.D, local.A,  5, 21, 0xFC93A039 );
+    P( local.A, local.B, local.C, local.D, 12,  6, 0x655B59C3 );
+    P( local.D, local.A, local.B, local.C,  3, 10, 0x8F0CCC92 );
+    P( local.C, local.D, local.A, local.B, 10, 15, 0xFFEFF47D );
+    P( local.B, local.C, local.D, local.A,  1, 21, 0x85845DD1 );
+    P( local.A, local.B, local.C, local.D,  8,  6, 0x6FA87E4F );
+    P( local.D, local.A, local.B, local.C, 15, 10, 0xFE2CE6E0 );
+    P( local.C, local.D, local.A, local.B,  6, 15, 0xA3014314 );
+    P( local.B, local.C, local.D, local.A, 13, 21, 0x4E0811A1 );
+    P( local.A, local.B, local.C, local.D,  4,  6, 0xF7537E82 );
+    P( local.D, local.A, local.B, local.C, 11, 10, 0xBD3AF235 );
+    P( local.C, local.D, local.A, local.B,  2, 15, 0x2AD7D2BB );
+    P( local.B, local.C, local.D, local.A,  9, 21, 0xEB86D391 );
 
 #undef F
 
-    ctx->state[0] += A;
-    ctx->state[1] += B;
-    ctx->state[2] += C;
-    ctx->state[3] += D;
+    ctx->state[0] += local.A;
+    ctx->state[1] += local.B;
+    ctx->state[2] += local.C;
+    ctx->state[3] += local.D;
+
+    /* Zeroise variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &local, sizeof( local ) );
 
     return( 0 );
 }
diff --git a/library/pkcs5.c b/library/pkcs5.c
index 8a80aa5..c4447f1 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -247,7 +247,7 @@
                        unsigned int iteration_count,
                        uint32_t key_length, unsigned char *output )
 {
-    int ret, j;
+    int ret = 0, j;
     unsigned int i;
     unsigned char md1[MBEDTLS_MD_MAX_SIZE];
     unsigned char work[MBEDTLS_MD_MAX_SIZE];
@@ -269,16 +269,16 @@
         // U1 ends up in work
         //
         if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         if( ( ret = mbedtls_md_hmac_update( ctx, salt, slen ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         if( ( ret = mbedtls_md_hmac_update( ctx, counter, 4 ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         if( ( ret = mbedtls_md_hmac_finish( ctx, work ) ) != 0 )
-            return( ret );
+            goto cleanup;
 
         memcpy( md1, work, md_size );
 
@@ -287,13 +287,13 @@
             // U2 ends up in md1
             //
             if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             if( ( ret = mbedtls_md_hmac_update( ctx, md1, md_size ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             if( ( ret = mbedtls_md_hmac_finish( ctx, md1 ) ) != 0 )
-                return( ret );
+                goto cleanup;
 
             // U1 xor U2
             //
@@ -312,7 +312,12 @@
                 break;
     }
 
-    return( 0 );
+cleanup:
+    /* Zeroise buffers to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( work, MBEDTLS_MD_MAX_SIZE );
+    mbedtls_platform_zeroize( md1, MBEDTLS_MD_MAX_SIZE );
+
+    return( ret );
 }
 
 #if defined(MBEDTLS_SELF_TEST)
diff --git a/library/ripemd160.c b/library/ripemd160.c
index 0b6efcb..d6ee933 100644
--- a/library/ripemd160.c
+++ b/library/ripemd160.c
@@ -147,30 +147,33 @@
 int mbedtls_internal_ripemd160_process( mbedtls_ripemd160_context *ctx,
                                         const unsigned char data[64] )
 {
-    uint32_t A, B, C, D, E, Ap, Bp, Cp, Dp, Ep, X[16];
+    struct
+    {
+        uint32_t A, B, C, D, E, Ap, Bp, Cp, Dp, Ep, X[16];
+    } local;
 
-    GET_UINT32_LE( X[ 0], data,  0 );
-    GET_UINT32_LE( X[ 1], data,  4 );
-    GET_UINT32_LE( X[ 2], data,  8 );
-    GET_UINT32_LE( X[ 3], data, 12 );
-    GET_UINT32_LE( X[ 4], data, 16 );
-    GET_UINT32_LE( X[ 5], data, 20 );
-    GET_UINT32_LE( X[ 6], data, 24 );
-    GET_UINT32_LE( X[ 7], data, 28 );
-    GET_UINT32_LE( X[ 8], data, 32 );
-    GET_UINT32_LE( X[ 9], data, 36 );
-    GET_UINT32_LE( X[10], data, 40 );
-    GET_UINT32_LE( X[11], data, 44 );
-    GET_UINT32_LE( X[12], data, 48 );
-    GET_UINT32_LE( X[13], data, 52 );
-    GET_UINT32_LE( X[14], data, 56 );
-    GET_UINT32_LE( X[15], data, 60 );
+    GET_UINT32_LE( local.X[ 0], data,  0 );
+    GET_UINT32_LE( local.X[ 1], data,  4 );
+    GET_UINT32_LE( local.X[ 2], data,  8 );
+    GET_UINT32_LE( local.X[ 3], data, 12 );
+    GET_UINT32_LE( local.X[ 4], data, 16 );
+    GET_UINT32_LE( local.X[ 5], data, 20 );
+    GET_UINT32_LE( local.X[ 6], data, 24 );
+    GET_UINT32_LE( local.X[ 7], data, 28 );
+    GET_UINT32_LE( local.X[ 8], data, 32 );
+    GET_UINT32_LE( local.X[ 9], data, 36 );
+    GET_UINT32_LE( local.X[10], data, 40 );
+    GET_UINT32_LE( local.X[11], data, 44 );
+    GET_UINT32_LE( local.X[12], data, 48 );
+    GET_UINT32_LE( local.X[13], data, 52 );
+    GET_UINT32_LE( local.X[14], data, 56 );
+    GET_UINT32_LE( local.X[15], data, 60 );
 
-    A = Ap = ctx->state[0];
-    B = Bp = ctx->state[1];
-    C = Cp = ctx->state[2];
-    D = Dp = ctx->state[3];
-    E = Ep = ctx->state[4];
+    local.A = local.Ap = ctx->state[0];
+    local.B = local.Bp = ctx->state[1];
+    local.C = local.Cp = ctx->state[2];
+    local.D = local.Dp = ctx->state[3];
+    local.E = local.Ep = ctx->state[4];
 
 #define F1( x, y, z )   ( (x) ^ (y) ^ (z) )
 #define F2( x, y, z )   ( ( (x) & (y) ) | ( ~(x) & (z) ) )
@@ -180,12 +183,12 @@
 
 #define S( x, n ) ( ( (x) << (n) ) | ( (x) >> (32 - (n)) ) )
 
-#define P( a, b, c, d, e, r, s, f, k )                \
-    do                                                \
-    {                                                 \
-        (a) += f( (b), (c), (d) ) + X[r] + (k);       \
-        (a) = S( (a), (s) ) + (e);                    \
-        (c) = S( (c), 10 );                           \
+#define P( a, b, c, d, e, r, s, f, k )                      \
+    do                                                      \
+    {                                                       \
+        (a) += f( (b), (c), (d) ) + local.X[r] + (k);       \
+        (a) = S( (a), (s) ) + (e);                          \
+        (c) = S( (c), 10 );                                 \
     } while( 0 )
 
 #define P2( a, b, c, d, e, r, s, rp, sp )                               \
@@ -200,22 +203,22 @@
 #define K   0x00000000
 #define Fp  F5
 #define Kp  0x50A28BE6
-    P2( A, B, C, D, E,  0, 11,  5,  8 );
-    P2( E, A, B, C, D,  1, 14, 14,  9 );
-    P2( D, E, A, B, C,  2, 15,  7,  9 );
-    P2( C, D, E, A, B,  3, 12,  0, 11 );
-    P2( B, C, D, E, A,  4,  5,  9, 13 );
-    P2( A, B, C, D, E,  5,  8,  2, 15 );
-    P2( E, A, B, C, D,  6,  7, 11, 15 );
-    P2( D, E, A, B, C,  7,  9,  4,  5 );
-    P2( C, D, E, A, B,  8, 11, 13,  7 );
-    P2( B, C, D, E, A,  9, 13,  6,  7 );
-    P2( A, B, C, D, E, 10, 14, 15,  8 );
-    P2( E, A, B, C, D, 11, 15,  8, 11 );
-    P2( D, E, A, B, C, 12,  6,  1, 14 );
-    P2( C, D, E, A, B, 13,  7, 10, 14 );
-    P2( B, C, D, E, A, 14,  9,  3, 12 );
-    P2( A, B, C, D, E, 15,  8, 12,  6 );
+    P2( local.A, local.B, local.C, local.D, local.E,  0, 11,  5,  8 );
+    P2( local.E, local.A, local.B, local.C, local.D,  1, 14, 14,  9 );
+    P2( local.D, local.E, local.A, local.B, local.C,  2, 15,  7,  9 );
+    P2( local.C, local.D, local.E, local.A, local.B,  3, 12,  0, 11 );
+    P2( local.B, local.C, local.D, local.E, local.A,  4,  5,  9, 13 );
+    P2( local.A, local.B, local.C, local.D, local.E,  5,  8,  2, 15 );
+    P2( local.E, local.A, local.B, local.C, local.D,  6,  7, 11, 15 );
+    P2( local.D, local.E, local.A, local.B, local.C,  7,  9,  4,  5 );
+    P2( local.C, local.D, local.E, local.A, local.B,  8, 11, 13,  7 );
+    P2( local.B, local.C, local.D, local.E, local.A,  9, 13,  6,  7 );
+    P2( local.A, local.B, local.C, local.D, local.E, 10, 14, 15,  8 );
+    P2( local.E, local.A, local.B, local.C, local.D, 11, 15,  8, 11 );
+    P2( local.D, local.E, local.A, local.B, local.C, 12,  6,  1, 14 );
+    P2( local.C, local.D, local.E, local.A, local.B, 13,  7, 10, 14 );
+    P2( local.B, local.C, local.D, local.E, local.A, 14,  9,  3, 12 );
+    P2( local.A, local.B, local.C, local.D, local.E, 15,  8, 12,  6 );
 #undef F
 #undef K
 #undef Fp
@@ -225,22 +228,22 @@
 #define K   0x5A827999
 #define Fp  F4
 #define Kp  0x5C4DD124
-    P2( E, A, B, C, D,  7,  7,  6,  9 );
-    P2( D, E, A, B, C,  4,  6, 11, 13 );
-    P2( C, D, E, A, B, 13,  8,  3, 15 );
-    P2( B, C, D, E, A,  1, 13,  7,  7 );
-    P2( A, B, C, D, E, 10, 11,  0, 12 );
-    P2( E, A, B, C, D,  6,  9, 13,  8 );
-    P2( D, E, A, B, C, 15,  7,  5,  9 );
-    P2( C, D, E, A, B,  3, 15, 10, 11 );
-    P2( B, C, D, E, A, 12,  7, 14,  7 );
-    P2( A, B, C, D, E,  0, 12, 15,  7 );
-    P2( E, A, B, C, D,  9, 15,  8, 12 );
-    P2( D, E, A, B, C,  5,  9, 12,  7 );
-    P2( C, D, E, A, B,  2, 11,  4,  6 );
-    P2( B, C, D, E, A, 14,  7,  9, 15 );
-    P2( A, B, C, D, E, 11, 13,  1, 13 );
-    P2( E, A, B, C, D,  8, 12,  2, 11 );
+    P2( local.E, local.A, local.B, local.C, local.D,  7,  7,  6,  9 );
+    P2( local.D, local.E, local.A, local.B, local.C,  4,  6, 11, 13 );
+    P2( local.C, local.D, local.E, local.A, local.B, 13,  8,  3, 15 );
+    P2( local.B, local.C, local.D, local.E, local.A,  1, 13,  7,  7 );
+    P2( local.A, local.B, local.C, local.D, local.E, 10, 11,  0, 12 );
+    P2( local.E, local.A, local.B, local.C, local.D,  6,  9, 13,  8 );
+    P2( local.D, local.E, local.A, local.B, local.C, 15,  7,  5,  9 );
+    P2( local.C, local.D, local.E, local.A, local.B,  3, 15, 10, 11 );
+    P2( local.B, local.C, local.D, local.E, local.A, 12,  7, 14,  7 );
+    P2( local.A, local.B, local.C, local.D, local.E,  0, 12, 15,  7 );
+    P2( local.E, local.A, local.B, local.C, local.D,  9, 15,  8, 12 );
+    P2( local.D, local.E, local.A, local.B, local.C,  5,  9, 12,  7 );
+    P2( local.C, local.D, local.E, local.A, local.B,  2, 11,  4,  6 );
+    P2( local.B, local.C, local.D, local.E, local.A, 14,  7,  9, 15 );
+    P2( local.A, local.B, local.C, local.D, local.E, 11, 13,  1, 13 );
+    P2( local.E, local.A, local.B, local.C, local.D,  8, 12,  2, 11 );
 #undef F
 #undef K
 #undef Fp
@@ -250,22 +253,22 @@
 #define K   0x6ED9EBA1
 #define Fp  F3
 #define Kp  0x6D703EF3
-    P2( D, E, A, B, C,  3, 11, 15,  9 );
-    P2( C, D, E, A, B, 10, 13,  5,  7 );
-    P2( B, C, D, E, A, 14,  6,  1, 15 );
-    P2( A, B, C, D, E,  4,  7,  3, 11 );
-    P2( E, A, B, C, D,  9, 14,  7,  8 );
-    P2( D, E, A, B, C, 15,  9, 14,  6 );
-    P2( C, D, E, A, B,  8, 13,  6,  6 );
-    P2( B, C, D, E, A,  1, 15,  9, 14 );
-    P2( A, B, C, D, E,  2, 14, 11, 12 );
-    P2( E, A, B, C, D,  7,  8,  8, 13 );
-    P2( D, E, A, B, C,  0, 13, 12,  5 );
-    P2( C, D, E, A, B,  6,  6,  2, 14 );
-    P2( B, C, D, E, A, 13,  5, 10, 13 );
-    P2( A, B, C, D, E, 11, 12,  0, 13 );
-    P2( E, A, B, C, D,  5,  7,  4,  7 );
-    P2( D, E, A, B, C, 12,  5, 13,  5 );
+    P2( local.D, local.E, local.A, local.B, local.C,  3, 11, 15,  9 );
+    P2( local.C, local.D, local.E, local.A, local.B, 10, 13,  5,  7 );
+    P2( local.B, local.C, local.D, local.E, local.A, 14,  6,  1, 15 );
+    P2( local.A, local.B, local.C, local.D, local.E,  4,  7,  3, 11 );
+    P2( local.E, local.A, local.B, local.C, local.D,  9, 14,  7,  8 );
+    P2( local.D, local.E, local.A, local.B, local.C, 15,  9, 14,  6 );
+    P2( local.C, local.D, local.E, local.A, local.B,  8, 13,  6,  6 );
+    P2( local.B, local.C, local.D, local.E, local.A,  1, 15,  9, 14 );
+    P2( local.A, local.B, local.C, local.D, local.E,  2, 14, 11, 12 );
+    P2( local.E, local.A, local.B, local.C, local.D,  7,  8,  8, 13 );
+    P2( local.D, local.E, local.A, local.B, local.C,  0, 13, 12,  5 );
+    P2( local.C, local.D, local.E, local.A, local.B,  6,  6,  2, 14 );
+    P2( local.B, local.C, local.D, local.E, local.A, 13,  5, 10, 13 );
+    P2( local.A, local.B, local.C, local.D, local.E, 11, 12,  0, 13 );
+    P2( local.E, local.A, local.B, local.C, local.D,  5,  7,  4,  7 );
+    P2( local.D, local.E, local.A, local.B, local.C, 12,  5, 13,  5 );
 #undef F
 #undef K
 #undef Fp
@@ -275,22 +278,22 @@
 #define K   0x8F1BBCDC
 #define Fp  F2
 #define Kp  0x7A6D76E9
-    P2( C, D, E, A, B,  1, 11,  8, 15 );
-    P2( B, C, D, E, A,  9, 12,  6,  5 );
-    P2( A, B, C, D, E, 11, 14,  4,  8 );
-    P2( E, A, B, C, D, 10, 15,  1, 11 );
-    P2( D, E, A, B, C,  0, 14,  3, 14 );
-    P2( C, D, E, A, B,  8, 15, 11, 14 );
-    P2( B, C, D, E, A, 12,  9, 15,  6 );
-    P2( A, B, C, D, E,  4,  8,  0, 14 );
-    P2( E, A, B, C, D, 13,  9,  5,  6 );
-    P2( D, E, A, B, C,  3, 14, 12,  9 );
-    P2( C, D, E, A, B,  7,  5,  2, 12 );
-    P2( B, C, D, E, A, 15,  6, 13,  9 );
-    P2( A, B, C, D, E, 14,  8,  9, 12 );
-    P2( E, A, B, C, D,  5,  6,  7,  5 );
-    P2( D, E, A, B, C,  6,  5, 10, 15 );
-    P2( C, D, E, A, B,  2, 12, 14,  8 );
+    P2( local.C, local.D, local.E, local.A, local.B,  1, 11,  8, 15 );
+    P2( local.B, local.C, local.D, local.E, local.A,  9, 12,  6,  5 );
+    P2( local.A, local.B, local.C, local.D, local.E, 11, 14,  4,  8 );
+    P2( local.E, local.A, local.B, local.C, local.D, 10, 15,  1, 11 );
+    P2( local.D, local.E, local.A, local.B, local.C,  0, 14,  3, 14 );
+    P2( local.C, local.D, local.E, local.A, local.B,  8, 15, 11, 14 );
+    P2( local.B, local.C, local.D, local.E, local.A, 12,  9, 15,  6 );
+    P2( local.A, local.B, local.C, local.D, local.E,  4,  8,  0, 14 );
+    P2( local.E, local.A, local.B, local.C, local.D, 13,  9,  5,  6 );
+    P2( local.D, local.E, local.A, local.B, local.C,  3, 14, 12,  9 );
+    P2( local.C, local.D, local.E, local.A, local.B,  7,  5,  2, 12 );
+    P2( local.B, local.C, local.D, local.E, local.A, 15,  6, 13,  9 );
+    P2( local.A, local.B, local.C, local.D, local.E, 14,  8,  9, 12 );
+    P2( local.E, local.A, local.B, local.C, local.D,  5,  6,  7,  5 );
+    P2( local.D, local.E, local.A, local.B, local.C,  6,  5, 10, 15 );
+    P2( local.C, local.D, local.E, local.A, local.B,  2, 12, 14,  8 );
 #undef F
 #undef K
 #undef Fp
@@ -300,33 +303,36 @@
 #define K   0xA953FD4E
 #define Fp  F1
 #define Kp  0x00000000
-    P2( B, C, D, E, A,  4,  9, 12,  8 );
-    P2( A, B, C, D, E,  0, 15, 15,  5 );
-    P2( E, A, B, C, D,  5,  5, 10, 12 );
-    P2( D, E, A, B, C,  9, 11,  4,  9 );
-    P2( C, D, E, A, B,  7,  6,  1, 12 );
-    P2( B, C, D, E, A, 12,  8,  5,  5 );
-    P2( A, B, C, D, E,  2, 13,  8, 14 );
-    P2( E, A, B, C, D, 10, 12,  7,  6 );
-    P2( D, E, A, B, C, 14,  5,  6,  8 );
-    P2( C, D, E, A, B,  1, 12,  2, 13 );
-    P2( B, C, D, E, A,  3, 13, 13,  6 );
-    P2( A, B, C, D, E,  8, 14, 14,  5 );
-    P2( E, A, B, C, D, 11, 11,  0, 15 );
-    P2( D, E, A, B, C,  6,  8,  3, 13 );
-    P2( C, D, E, A, B, 15,  5,  9, 11 );
-    P2( B, C, D, E, A, 13,  6, 11, 11 );
+    P2( local.B, local.C, local.D, local.E, local.A,  4,  9, 12,  8 );
+    P2( local.A, local.B, local.C, local.D, local.E,  0, 15, 15,  5 );
+    P2( local.E, local.A, local.B, local.C, local.D,  5,  5, 10, 12 );
+    P2( local.D, local.E, local.A, local.B, local.C,  9, 11,  4,  9 );
+    P2( local.C, local.D, local.E, local.A, local.B,  7,  6,  1, 12 );
+    P2( local.B, local.C, local.D, local.E, local.A, 12,  8,  5,  5 );
+    P2( local.A, local.B, local.C, local.D, local.E,  2, 13,  8, 14 );
+    P2( local.E, local.A, local.B, local.C, local.D, 10, 12,  7,  6 );
+    P2( local.D, local.E, local.A, local.B, local.C, 14,  5,  6,  8 );
+    P2( local.C, local.D, local.E, local.A, local.B,  1, 12,  2, 13 );
+    P2( local.B, local.C, local.D, local.E, local.A,  3, 13, 13,  6 );
+    P2( local.A, local.B, local.C, local.D, local.E,  8, 14, 14,  5 );
+    P2( local.E, local.A, local.B, local.C, local.D, 11, 11,  0, 15 );
+    P2( local.D, local.E, local.A, local.B, local.C,  6,  8,  3, 13 );
+    P2( local.C, local.D, local.E, local.A, local.B, 15,  5,  9, 11 );
+    P2( local.B, local.C, local.D, local.E, local.A, 13,  6, 11, 11 );
 #undef F
 #undef K
 #undef Fp
 #undef Kp
 
-    C             = ctx->state[1] + C + Dp;
-    ctx->state[1] = ctx->state[2] + D + Ep;
-    ctx->state[2] = ctx->state[3] + E + Ap;
-    ctx->state[3] = ctx->state[4] + A + Bp;
-    ctx->state[4] = ctx->state[0] + B + Cp;
-    ctx->state[0] = C;
+    local.C       = ctx->state[1] + local.C + local.Dp;
+    ctx->state[1] = ctx->state[2] + local.D + local.Ep;
+    ctx->state[2] = ctx->state[3] + local.E + local.Ap;
+    ctx->state[3] = ctx->state[4] + local.A + local.Bp;
+    ctx->state[4] = ctx->state[0] + local.B + local.Cp;
+    ctx->state[0] = local.C;
+
+    /* Zeroise variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &local, sizeof( local ) );
 
     return( 0 );
 }
diff --git a/library/sha1.c b/library/sha1.c
index 8682abd..e99a5e8 100644
--- a/library/sha1.c
+++ b/library/sha1.c
@@ -155,35 +155,40 @@
 int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
                                    const unsigned char data[64] )
 {
-    uint32_t temp, W[16], A, B, C, D, E;
+    struct
+    {
+        uint32_t temp, W[16], A, B, C, D, E;
+    } local;
 
     SHA1_VALIDATE_RET( ctx != NULL );
     SHA1_VALIDATE_RET( (const unsigned char *)data != NULL );
 
-    GET_UINT32_BE( W[ 0], data,  0 );
-    GET_UINT32_BE( W[ 1], data,  4 );
-    GET_UINT32_BE( W[ 2], data,  8 );
-    GET_UINT32_BE( W[ 3], data, 12 );
-    GET_UINT32_BE( W[ 4], data, 16 );
-    GET_UINT32_BE( W[ 5], data, 20 );
-    GET_UINT32_BE( W[ 6], data, 24 );
-    GET_UINT32_BE( W[ 7], data, 28 );
-    GET_UINT32_BE( W[ 8], data, 32 );
-    GET_UINT32_BE( W[ 9], data, 36 );
-    GET_UINT32_BE( W[10], data, 40 );
-    GET_UINT32_BE( W[11], data, 44 );
-    GET_UINT32_BE( W[12], data, 48 );
-    GET_UINT32_BE( W[13], data, 52 );
-    GET_UINT32_BE( W[14], data, 56 );
-    GET_UINT32_BE( W[15], data, 60 );
+    GET_UINT32_BE( local.W[ 0], data,  0 );
+    GET_UINT32_BE( local.W[ 1], data,  4 );
+    GET_UINT32_BE( local.W[ 2], data,  8 );
+    GET_UINT32_BE( local.W[ 3], data, 12 );
+    GET_UINT32_BE( local.W[ 4], data, 16 );
+    GET_UINT32_BE( local.W[ 5], data, 20 );
+    GET_UINT32_BE( local.W[ 6], data, 24 );
+    GET_UINT32_BE( local.W[ 7], data, 28 );
+    GET_UINT32_BE( local.W[ 8], data, 32 );
+    GET_UINT32_BE( local.W[ 9], data, 36 );
+    GET_UINT32_BE( local.W[10], data, 40 );
+    GET_UINT32_BE( local.W[11], data, 44 );
+    GET_UINT32_BE( local.W[12], data, 48 );
+    GET_UINT32_BE( local.W[13], data, 52 );
+    GET_UINT32_BE( local.W[14], data, 56 );
+    GET_UINT32_BE( local.W[15], data, 60 );
 
 #define S(x,n) (((x) << (n)) | (((x) & 0xFFFFFFFF) >> (32 - (n))))
 
 #define R(t)                                                    \
     (                                                           \
-        temp = W[( (t) -  3 ) & 0x0F] ^ W[( (t) - 8 ) & 0x0F] ^ \
-               W[( (t) - 14 ) & 0x0F] ^ W[  (t)       & 0x0F],  \
-        ( W[(t) & 0x0F] = S(temp,1) )                           \
+        local.temp = local.W[( (t) -  3 ) & 0x0F] ^             \
+                     local.W[( (t) -  8 ) & 0x0F] ^             \
+                     local.W[( (t) - 14 ) & 0x0F] ^             \
+                     local.W[  (t)        & 0x0F],              \
+        ( local.W[(t) & 0x0F] = S(local.temp,1) )               \
     )
 
 #define P(a,b,c,d,e,x)                                          \
@@ -193,35 +198,35 @@
         (b) = S((b),30);                                        \
     } while( 0 )
 
-    A = ctx->state[0];
-    B = ctx->state[1];
-    C = ctx->state[2];
-    D = ctx->state[3];
-    E = ctx->state[4];
+    local.A = ctx->state[0];
+    local.B = ctx->state[1];
+    local.C = ctx->state[2];
+    local.D = ctx->state[3];
+    local.E = ctx->state[4];
 
 #define F(x,y,z) ((z) ^ ((x) & ((y) ^ (z))))
 #define K 0x5A827999
 
-    P( A, B, C, D, E, W[0]  );
-    P( E, A, B, C, D, W[1]  );
-    P( D, E, A, B, C, W[2]  );
-    P( C, D, E, A, B, W[3]  );
-    P( B, C, D, E, A, W[4]  );
-    P( A, B, C, D, E, W[5]  );
-    P( E, A, B, C, D, W[6]  );
-    P( D, E, A, B, C, W[7]  );
-    P( C, D, E, A, B, W[8]  );
-    P( B, C, D, E, A, W[9]  );
-    P( A, B, C, D, E, W[10] );
-    P( E, A, B, C, D, W[11] );
-    P( D, E, A, B, C, W[12] );
-    P( C, D, E, A, B, W[13] );
-    P( B, C, D, E, A, W[14] );
-    P( A, B, C, D, E, W[15] );
-    P( E, A, B, C, D, R(16) );
-    P( D, E, A, B, C, R(17) );
-    P( C, D, E, A, B, R(18) );
-    P( B, C, D, E, A, R(19) );
+    P( local.A, local.B, local.C, local.D, local.E, local.W[0]  );
+    P( local.E, local.A, local.B, local.C, local.D, local.W[1]  );
+    P( local.D, local.E, local.A, local.B, local.C, local.W[2]  );
+    P( local.C, local.D, local.E, local.A, local.B, local.W[3]  );
+    P( local.B, local.C, local.D, local.E, local.A, local.W[4]  );
+    P( local.A, local.B, local.C, local.D, local.E, local.W[5]  );
+    P( local.E, local.A, local.B, local.C, local.D, local.W[6]  );
+    P( local.D, local.E, local.A, local.B, local.C, local.W[7]  );
+    P( local.C, local.D, local.E, local.A, local.B, local.W[8]  );
+    P( local.B, local.C, local.D, local.E, local.A, local.W[9]  );
+    P( local.A, local.B, local.C, local.D, local.E, local.W[10] );
+    P( local.E, local.A, local.B, local.C, local.D, local.W[11] );
+    P( local.D, local.E, local.A, local.B, local.C, local.W[12] );
+    P( local.C, local.D, local.E, local.A, local.B, local.W[13] );
+    P( local.B, local.C, local.D, local.E, local.A, local.W[14] );
+    P( local.A, local.B, local.C, local.D, local.E, local.W[15] );
+    P( local.E, local.A, local.B, local.C, local.D, R(16) );
+    P( local.D, local.E, local.A, local.B, local.C, R(17) );
+    P( local.C, local.D, local.E, local.A, local.B, R(18) );
+    P( local.B, local.C, local.D, local.E, local.A, R(19) );
 
 #undef K
 #undef F
@@ -229,26 +234,26 @@
 #define F(x,y,z) ((x) ^ (y) ^ (z))
 #define K 0x6ED9EBA1
 
-    P( A, B, C, D, E, R(20) );
-    P( E, A, B, C, D, R(21) );
-    P( D, E, A, B, C, R(22) );
-    P( C, D, E, A, B, R(23) );
-    P( B, C, D, E, A, R(24) );
-    P( A, B, C, D, E, R(25) );
-    P( E, A, B, C, D, R(26) );
-    P( D, E, A, B, C, R(27) );
-    P( C, D, E, A, B, R(28) );
-    P( B, C, D, E, A, R(29) );
-    P( A, B, C, D, E, R(30) );
-    P( E, A, B, C, D, R(31) );
-    P( D, E, A, B, C, R(32) );
-    P( C, D, E, A, B, R(33) );
-    P( B, C, D, E, A, R(34) );
-    P( A, B, C, D, E, R(35) );
-    P( E, A, B, C, D, R(36) );
-    P( D, E, A, B, C, R(37) );
-    P( C, D, E, A, B, R(38) );
-    P( B, C, D, E, A, R(39) );
+    P( local.A, local.B, local.C, local.D, local.E, R(20) );
+    P( local.E, local.A, local.B, local.C, local.D, R(21) );
+    P( local.D, local.E, local.A, local.B, local.C, R(22) );
+    P( local.C, local.D, local.E, local.A, local.B, R(23) );
+    P( local.B, local.C, local.D, local.E, local.A, R(24) );
+    P( local.A, local.B, local.C, local.D, local.E, R(25) );
+    P( local.E, local.A, local.B, local.C, local.D, R(26) );
+    P( local.D, local.E, local.A, local.B, local.C, R(27) );
+    P( local.C, local.D, local.E, local.A, local.B, R(28) );
+    P( local.B, local.C, local.D, local.E, local.A, R(29) );
+    P( local.A, local.B, local.C, local.D, local.E, R(30) );
+    P( local.E, local.A, local.B, local.C, local.D, R(31) );
+    P( local.D, local.E, local.A, local.B, local.C, R(32) );
+    P( local.C, local.D, local.E, local.A, local.B, R(33) );
+    P( local.B, local.C, local.D, local.E, local.A, R(34) );
+    P( local.A, local.B, local.C, local.D, local.E, R(35) );
+    P( local.E, local.A, local.B, local.C, local.D, R(36) );
+    P( local.D, local.E, local.A, local.B, local.C, R(37) );
+    P( local.C, local.D, local.E, local.A, local.B, R(38) );
+    P( local.B, local.C, local.D, local.E, local.A, R(39) );
 
 #undef K
 #undef F
@@ -256,26 +261,26 @@
 #define F(x,y,z) (((x) & (y)) | ((z) & ((x) | (y))))
 #define K 0x8F1BBCDC
 
-    P( A, B, C, D, E, R(40) );
-    P( E, A, B, C, D, R(41) );
-    P( D, E, A, B, C, R(42) );
-    P( C, D, E, A, B, R(43) );
-    P( B, C, D, E, A, R(44) );
-    P( A, B, C, D, E, R(45) );
-    P( E, A, B, C, D, R(46) );
-    P( D, E, A, B, C, R(47) );
-    P( C, D, E, A, B, R(48) );
-    P( B, C, D, E, A, R(49) );
-    P( A, B, C, D, E, R(50) );
-    P( E, A, B, C, D, R(51) );
-    P( D, E, A, B, C, R(52) );
-    P( C, D, E, A, B, R(53) );
-    P( B, C, D, E, A, R(54) );
-    P( A, B, C, D, E, R(55) );
-    P( E, A, B, C, D, R(56) );
-    P( D, E, A, B, C, R(57) );
-    P( C, D, E, A, B, R(58) );
-    P( B, C, D, E, A, R(59) );
+    P( local.A, local.B, local.C, local.D, local.E, R(40) );
+    P( local.E, local.A, local.B, local.C, local.D, R(41) );
+    P( local.D, local.E, local.A, local.B, local.C, R(42) );
+    P( local.C, local.D, local.E, local.A, local.B, R(43) );
+    P( local.B, local.C, local.D, local.E, local.A, R(44) );
+    P( local.A, local.B, local.C, local.D, local.E, R(45) );
+    P( local.E, local.A, local.B, local.C, local.D, R(46) );
+    P( local.D, local.E, local.A, local.B, local.C, R(47) );
+    P( local.C, local.D, local.E, local.A, local.B, R(48) );
+    P( local.B, local.C, local.D, local.E, local.A, R(49) );
+    P( local.A, local.B, local.C, local.D, local.E, R(50) );
+    P( local.E, local.A, local.B, local.C, local.D, R(51) );
+    P( local.D, local.E, local.A, local.B, local.C, R(52) );
+    P( local.C, local.D, local.E, local.A, local.B, R(53) );
+    P( local.B, local.C, local.D, local.E, local.A, R(54) );
+    P( local.A, local.B, local.C, local.D, local.E, R(55) );
+    P( local.E, local.A, local.B, local.C, local.D, R(56) );
+    P( local.D, local.E, local.A, local.B, local.C, R(57) );
+    P( local.C, local.D, local.E, local.A, local.B, R(58) );
+    P( local.B, local.C, local.D, local.E, local.A, R(59) );
 
 #undef K
 #undef F
@@ -283,35 +288,38 @@
 #define F(x,y,z) ((x) ^ (y) ^ (z))
 #define K 0xCA62C1D6
 
-    P( A, B, C, D, E, R(60) );
-    P( E, A, B, C, D, R(61) );
-    P( D, E, A, B, C, R(62) );
-    P( C, D, E, A, B, R(63) );
-    P( B, C, D, E, A, R(64) );
-    P( A, B, C, D, E, R(65) );
-    P( E, A, B, C, D, R(66) );
-    P( D, E, A, B, C, R(67) );
-    P( C, D, E, A, B, R(68) );
-    P( B, C, D, E, A, R(69) );
-    P( A, B, C, D, E, R(70) );
-    P( E, A, B, C, D, R(71) );
-    P( D, E, A, B, C, R(72) );
-    P( C, D, E, A, B, R(73) );
-    P( B, C, D, E, A, R(74) );
-    P( A, B, C, D, E, R(75) );
-    P( E, A, B, C, D, R(76) );
-    P( D, E, A, B, C, R(77) );
-    P( C, D, E, A, B, R(78) );
-    P( B, C, D, E, A, R(79) );
+    P( local.A, local.B, local.C, local.D, local.E, R(60) );
+    P( local.E, local.A, local.B, local.C, local.D, R(61) );
+    P( local.D, local.E, local.A, local.B, local.C, R(62) );
+    P( local.C, local.D, local.E, local.A, local.B, R(63) );
+    P( local.B, local.C, local.D, local.E, local.A, R(64) );
+    P( local.A, local.B, local.C, local.D, local.E, R(65) );
+    P( local.E, local.A, local.B, local.C, local.D, R(66) );
+    P( local.D, local.E, local.A, local.B, local.C, R(67) );
+    P( local.C, local.D, local.E, local.A, local.B, R(68) );
+    P( local.B, local.C, local.D, local.E, local.A, R(69) );
+    P( local.A, local.B, local.C, local.D, local.E, R(70) );
+    P( local.E, local.A, local.B, local.C, local.D, R(71) );
+    P( local.D, local.E, local.A, local.B, local.C, R(72) );
+    P( local.C, local.D, local.E, local.A, local.B, R(73) );
+    P( local.B, local.C, local.D, local.E, local.A, R(74) );
+    P( local.A, local.B, local.C, local.D, local.E, R(75) );
+    P( local.E, local.A, local.B, local.C, local.D, R(76) );
+    P( local.D, local.E, local.A, local.B, local.C, R(77) );
+    P( local.C, local.D, local.E, local.A, local.B, R(78) );
+    P( local.B, local.C, local.D, local.E, local.A, R(79) );
 
 #undef K
 #undef F
 
-    ctx->state[0] += A;
-    ctx->state[1] += B;
-    ctx->state[2] += C;
-    ctx->state[3] += D;
-    ctx->state[4] += E;
+    ctx->state[0] += local.A;
+    ctx->state[1] += local.B;
+    ctx->state[2] += local.C;
+    ctx->state[3] += local.D;
+    ctx->state[4] += local.E;
+
+    /* Zeroise buffers and variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &local, sizeof( local ) );
 
     return( 0 );
 }
diff --git a/library/sha256.c b/library/sha256.c
index 5169584..75a8f8a 100644
--- a/library/sha256.c
+++ b/library/sha256.c
@@ -209,77 +209,104 @@
 #define F0(x,y,z) (((x) & (y)) | ((z) & ((x) | (y))))
 #define F1(x,y,z) ((z) ^ ((x) & ((y) ^ (z))))
 
-#define R(t)                                    \
-    (                                           \
-        W[t] = S1(W[(t) -  2]) + W[(t) -  7] +  \
-               S0(W[(t) - 15]) + W[(t) - 16]    \
+#define R(t)                                                        \
+    (                                                               \
+        local.W[t] = S1(local.W[(t) -  2]) + local.W[(t) -  7] +    \
+                     S0(local.W[(t) - 15]) + local.W[(t) - 16]      \
     )
 
-#define P(a,b,c,d,e,f,g,h,x,K)                          \
-    do                                                  \
-    {                                                   \
-        temp1 = (h) + S3(e) + F1((e),(f),(g)) + (K) + (x);      \
-        temp2 = S2(a) + F0((a),(b),(c));                        \
-        (d) += temp1; (h) = temp1 + temp2;              \
+#define P(a,b,c,d,e,f,g,h,x,K)                                      \
+    do                                                              \
+    {                                                               \
+        local.temp1 = (h) + S3(e) + F1((e),(f),(g)) + (K) + (x);    \
+        local.temp2 = S2(a) + F0((a),(b),(c));                      \
+        (d) += local.temp1; (h) = local.temp1 + local.temp2;        \
     } while( 0 )
 
 int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
                                 const unsigned char data[64] )
 {
-    uint32_t temp1, temp2, W[64];
-    uint32_t A[8];
+    struct
+    {
+        uint32_t temp1, temp2, W[64];
+        uint32_t A[8];
+    } local;
+
     unsigned int i;
 
     SHA256_VALIDATE_RET( ctx != NULL );
     SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );
 
     for( i = 0; i < 8; i++ )
-        A[i] = ctx->state[i];
+        local.A[i] = ctx->state[i];
 
 #if defined(MBEDTLS_SHA256_SMALLER)
     for( i = 0; i < 64; i++ )
     {
         if( i < 16 )
-            GET_UINT32_BE( W[i], data, 4 * i );
+            GET_UINT32_BE( local.W[i], data, 4 * i );
         else
             R( i );
 
-        P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i], K[i] );
+        P( local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
+           local.A[5], local.A[6], local.A[7], local.W[i], K[i] );
 
-        temp1 = A[7]; A[7] = A[6]; A[6] = A[5]; A[5] = A[4]; A[4] = A[3];
-        A[3] = A[2]; A[2] = A[1]; A[1] = A[0]; A[0] = temp1;
+        local.temp1 = local.A[7]; local.A[7] = local.A[6];
+        local.A[6] = local.A[5]; local.A[5] = local.A[4];
+        local.A[4] = local.A[3]; local.A[3] = local.A[2];
+        local.A[2] = local.A[1]; local.A[1] = local.A[0];
+        local.A[0] = local.temp1;
     }
 #else /* MBEDTLS_SHA256_SMALLER */
     for( i = 0; i < 16; i++ )
-        GET_UINT32_BE( W[i], data, 4 * i );
+        GET_UINT32_BE( local.W[i], data, 4 * i );
 
     for( i = 0; i < 16; i += 8 )
     {
-        P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i+0], K[i+0] );
-        P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], W[i+1], K[i+1] );
-        P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], W[i+2], K[i+2] );
-        P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], W[i+3], K[i+3] );
-        P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], W[i+4], K[i+4] );
-        P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], W[i+5], K[i+5] );
-        P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], W[i+6], K[i+6] );
-        P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], W[i+7], K[i+7] );
+        P( local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
+           local.A[5], local.A[6], local.A[7], local.W[i+0], K[i+0] );
+        P( local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
+           local.A[4], local.A[5], local.A[6], local.W[i+1], K[i+1] );
+        P( local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
+           local.A[3], local.A[4], local.A[5], local.W[i+2], K[i+2] );
+        P( local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
+           local.A[2], local.A[3], local.A[4], local.W[i+3], K[i+3] );
+        P( local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
+           local.A[1], local.A[2], local.A[3], local.W[i+4], K[i+4] );
+        P( local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
+           local.A[0], local.A[1], local.A[2], local.W[i+5], K[i+5] );
+        P( local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
+           local.A[7], local.A[0], local.A[1], local.W[i+6], K[i+6] );
+        P( local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
+           local.A[6], local.A[7], local.A[0], local.W[i+7], K[i+7] );
     }
 
     for( i = 16; i < 64; i += 8 )
     {
-        P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], R(i+0), K[i+0] );
-        P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], R(i+1), K[i+1] );
-        P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], R(i+2), K[i+2] );
-        P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], R(i+3), K[i+3] );
-        P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], R(i+4), K[i+4] );
-        P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], R(i+5), K[i+5] );
-        P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], R(i+6), K[i+6] );
-        P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], R(i+7), K[i+7] );
+        P( local.A[0], local.A[1], local.A[2], local.A[3], local.A[4],
+           local.A[5], local.A[6], local.A[7], R(i+0), K[i+0] );
+        P( local.A[7], local.A[0], local.A[1], local.A[2], local.A[3],
+           local.A[4], local.A[5], local.A[6], R(i+1), K[i+1] );
+        P( local.A[6], local.A[7], local.A[0], local.A[1], local.A[2],
+           local.A[3], local.A[4], local.A[5], R(i+2), K[i+2] );
+        P( local.A[5], local.A[6], local.A[7], local.A[0], local.A[1],
+           local.A[2], local.A[3], local.A[4], R(i+3), K[i+3] );
+        P( local.A[4], local.A[5], local.A[6], local.A[7], local.A[0],
+           local.A[1], local.A[2], local.A[3], R(i+4), K[i+4] );
+        P( local.A[3], local.A[4], local.A[5], local.A[6], local.A[7],
+           local.A[0], local.A[1], local.A[2], R(i+5), K[i+5] );
+        P( local.A[2], local.A[3], local.A[4], local.A[5], local.A[6],
+           local.A[7], local.A[0], local.A[1], R(i+6), K[i+6] );
+        P( local.A[1], local.A[2], local.A[3], local.A[4], local.A[5],
+           local.A[6], local.A[7], local.A[0], R(i+7), K[i+7] );
     }
 #endif /* MBEDTLS_SHA256_SMALLER */
 
     for( i = 0; i < 8; i++ )
-        ctx->state[i] += A[i];
+        ctx->state[i] += local.A[i];
+
+    /* Zeroise buffers and variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &local, sizeof( local ) );
 
     return( 0 );
 }
diff --git a/library/sha512.c b/library/sha512.c
index 36d5d96..986037a 100644
--- a/library/sha512.c
+++ b/library/sha512.c
@@ -243,8 +243,11 @@
                                      const unsigned char data[128] )
 {
     int i;
-    uint64_t temp1, temp2, W[80];
-    uint64_t A, B, C, D, E, F, G, H;
+    struct
+    {
+        uint64_t temp1, temp2, W[80];
+        uint64_t A, B, C, D, E, F, G, H;
+    } local;
 
     SHA512_VALIDATE_RET( ctx != NULL );
     SHA512_VALIDATE_RET( (const unsigned char *)data != NULL );
@@ -261,56 +264,67 @@
 #define F0(x,y,z) (((x) & (y)) | ((z) & ((x) | (y))))
 #define F1(x,y,z) ((z) ^ ((x) & ((y) ^ (z))))
 
-#define P(a,b,c,d,e,f,g,h,x,K)                                  \
-    do                                                          \
-    {                                                           \
-        temp1 = (h) + S3(e) + F1((e),(f),(g)) + (K) + (x);      \
-        temp2 = S2(a) + F0((a),(b),(c));                        \
-        (d) += temp1; (h) = temp1 + temp2;                      \
+#define P(a,b,c,d,e,f,g,h,x,K)                                      \
+    do                                                              \
+    {                                                               \
+        local.temp1 = (h) + S3(e) + F1((e),(f),(g)) + (K) + (x);    \
+        local.temp2 = S2(a) + F0((a),(b),(c));                      \
+        (d) += local.temp1; (h) = local.temp1 + local.temp2;        \
     } while( 0 )
 
     for( i = 0; i < 16; i++ )
     {
-        GET_UINT64_BE( W[i], data, i << 3 );
+        GET_UINT64_BE( local.W[i], data, i << 3 );
     }
 
     for( ; i < 80; i++ )
     {
-        W[i] = S1(W[i -  2]) + W[i -  7] +
-               S0(W[i - 15]) + W[i - 16];
+        local.W[i] = S1(local.W[i -  2]) + local.W[i -  7] +
+                     S0(local.W[i - 15]) + local.W[i - 16];
     }
 
-    A = ctx->state[0];
-    B = ctx->state[1];
-    C = ctx->state[2];
-    D = ctx->state[3];
-    E = ctx->state[4];
-    F = ctx->state[5];
-    G = ctx->state[6];
-    H = ctx->state[7];
+    local.A = ctx->state[0];
+    local.B = ctx->state[1];
+    local.C = ctx->state[2];
+    local.D = ctx->state[3];
+    local.E = ctx->state[4];
+    local.F = ctx->state[5];
+    local.G = ctx->state[6];
+    local.H = ctx->state[7];
     i = 0;
 
     do
     {
-        P( A, B, C, D, E, F, G, H, W[i], K[i] ); i++;
-        P( H, A, B, C, D, E, F, G, W[i], K[i] ); i++;
-        P( G, H, A, B, C, D, E, F, W[i], K[i] ); i++;
-        P( F, G, H, A, B, C, D, E, W[i], K[i] ); i++;
-        P( E, F, G, H, A, B, C, D, W[i], K[i] ); i++;
-        P( D, E, F, G, H, A, B, C, W[i], K[i] ); i++;
-        P( C, D, E, F, G, H, A, B, W[i], K[i] ); i++;
-        P( B, C, D, E, F, G, H, A, W[i], K[i] ); i++;
+        P( local.A, local.B, local.C, local.D, local.E,
+           local.F, local.G, local.H, local.W[i], K[i] ); i++;
+        P( local.H, local.A, local.B, local.C, local.D,
+           local.E, local.F, local.G, local.W[i], K[i] ); i++;
+        P( local.G, local.H, local.A, local.B, local.C,
+           local.D, local.E, local.F, local.W[i], K[i] ); i++;
+        P( local.F, local.G, local.H, local.A, local.B,
+           local.C, local.D, local.E, local.W[i], K[i] ); i++;
+        P( local.E, local.F, local.G, local.H, local.A,
+           local.B, local.C, local.D, local.W[i], K[i] ); i++;
+        P( local.D, local.E, local.F, local.G, local.H,
+           local.A, local.B, local.C, local.W[i], K[i] ); i++;
+        P( local.C, local.D, local.E, local.F, local.G,
+           local.H, local.A, local.B, local.W[i], K[i] ); i++;
+        P( local.B, local.C, local.D, local.E, local.F,
+           local.G, local.H, local.A, local.W[i], K[i] ); i++;
     }
     while( i < 80 );
 
-    ctx->state[0] += A;
-    ctx->state[1] += B;
-    ctx->state[2] += C;
-    ctx->state[3] += D;
-    ctx->state[4] += E;
-    ctx->state[5] += F;
-    ctx->state[6] += G;
-    ctx->state[7] += H;
+    ctx->state[0] += local.A;
+    ctx->state[1] += local.B;
+    ctx->state[2] += local.C;
+    ctx->state[3] += local.D;
+    ctx->state[4] += local.E;
+    ctx->state[5] += local.F;
+    ctx->state[6] += local.G;
+    ctx->state[7] += local.H;
+
+    /* Zeroise buffers and variables to clear sensitive data from memory. */
+    mbedtls_platform_zeroize( &local, sizeof( local ) );
 
     return( 0 );
 }