diff --git a/library/rsa.c b/library/rsa.c
index 7615e1e..af1a878 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -71,6 +71,12 @@
 
 #if !defined(MBEDTLS_RSA_ALT)
 
+/* Parameter validation macros */
+#define RSA_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
+#define RSA_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_PKCS1_V15)
 /* constant-time buffer comparison */
 static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
@@ -93,6 +99,7 @@
                         const mbedtls_mpi *D, const mbedtls_mpi *E )
 {
     int ret;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     if( ( N != NULL && ( ret = mbedtls_mpi_copy( &ctx->N, N ) ) != 0 ) ||
         ( P != NULL && ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ) ||
@@ -117,6 +124,7 @@
                             unsigned char const *E, size_t E_len )
 {
     int ret = 0;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     if( N != NULL )
     {
@@ -240,12 +248,16 @@
 int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
 {
     int ret = 0;
+    int have_N, have_P, have_Q, have_D, have_E;
+    int n_missing, pq_missing, d_missing, is_pub, is_priv;
 
-    const int have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
-    const int have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
-    const int have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
-    const int have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
-    const int have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
+    RSA_VALIDATE_RET( ctx != NULL );
+
+    have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
+    have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
+    have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
+    have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
+    have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
 
     /*
      * Check whether provided parameters are enough
@@ -257,13 +269,13 @@
      *
      */
 
-    const int n_missing  =              have_P &&  have_Q &&  have_D && have_E;
-    const int pq_missing =   have_N && !have_P && !have_Q &&  have_D && have_E;
-    const int d_missing  =              have_P &&  have_Q && !have_D && have_E;
-    const int is_pub     =   have_N && !have_P && !have_Q && !have_D && have_E;
+    n_missing  =              have_P &&  have_Q &&  have_D && have_E;
+    pq_missing =   have_N && !have_P && !have_Q &&  have_D && have_E;
+    d_missing  =              have_P &&  have_Q && !have_D && have_E;
+    is_pub     =   have_N && !have_P && !have_Q && !have_D && have_E;
 
     /* These three alternatives are mutually exclusive */
-    const int is_priv = n_missing || pq_missing || d_missing;
+    is_priv = n_missing || pq_missing || d_missing;
 
     if( !is_priv && !is_pub )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -336,9 +348,11 @@
                             unsigned char *E, size_t E_len )
 {
     int ret = 0;
+    int is_priv;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     /* Check if key is private or public */
-    const int is_priv =
+    is_priv =
         mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
@@ -379,9 +393,11 @@
                         mbedtls_mpi *D, mbedtls_mpi *E )
 {
     int ret;
+    int is_priv;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     /* Check if key is private or public */
-    int is_priv =
+    is_priv =
         mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
@@ -421,9 +437,11 @@
                             mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP )
 {
     int ret;
+    int is_priv;
+    RSA_VALIDATE_RET( ctx != NULL );
 
     /* Check if key is private or public */
-    int is_priv =
+    is_priv =
         mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
         mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
@@ -459,6 +477,10 @@
                int padding,
                int hash_id )
 {
+    RSA_VALIDATE( ctx != NULL );
+    RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
+                  padding == MBEDTLS_RSA_PKCS_V21 );
+
     memset( ctx, 0, sizeof( mbedtls_rsa_context ) );
 
     mbedtls_rsa_set_padding( ctx, padding, hash_id );
@@ -471,8 +493,13 @@
 /*
  * Set padding for an existing RSA context
  */
-void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding, int hash_id )
+void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding,
+                              int hash_id )
 {
+    RSA_VALIDATE( ctx != NULL );
+    RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
+                  padding == MBEDTLS_RSA_PKCS_V21 );
+
     ctx->padding = padding;
     ctx->hash_id = hash_id;
 }
@@ -503,11 +530,10 @@
     int ret;
     mbedtls_mpi H, G, L;
     int prime_quality = 0;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( f_rng != NULL );
 
-    if( f_rng == NULL || nbits < 128 || exponent < 3 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    if( nbits % 2 )
+    if( nbits < 128 || exponent < 3 || nbits % 2 != 0 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
     /*
@@ -612,6 +638,8 @@
  */
 int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+
     if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) != 0 )
         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
 
@@ -635,6 +663,8 @@
  */
 int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+
     if( mbedtls_rsa_check_pubkey( ctx ) != 0 ||
         rsa_check_context( ctx, 1 /* private */, 1 /* blinding */ ) != 0 )
     {
@@ -664,6 +694,9 @@
 int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub,
                                 const mbedtls_rsa_context *prv )
 {
+    RSA_VALIDATE_RET( pub != NULL );
+    RSA_VALIDATE_RET( prv != NULL );
+
     if( mbedtls_rsa_check_pubkey( pub )  != 0 ||
         mbedtls_rsa_check_privkey( prv ) != 0 )
     {
@@ -689,6 +722,9 @@
     int ret;
     size_t olen;
     mbedtls_mpi T;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( output != NULL );
 
     if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -831,6 +867,10 @@
      * checked result; should be the same in the end. */
     mbedtls_mpi I, C;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( input  != NULL );
+    RSA_VALIDATE_RET( output != NULL );
+
     if( rsa_check_context( ctx, 1             /* private key checks */,
                                 f_rng != NULL /* blinding y/n       */ ) != 0 )
     {
@@ -1091,6 +1131,13 @@
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( label_len == 0 || label != NULL );
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -1167,11 +1214,13 @@
     int ret;
     unsigned char *p = output;
 
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
 
-    // We don't check p_rng because it won't be dereferenced here
-    if( f_rng == NULL || input == NULL || output == NULL )
+    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
     olen = ctx->len;
@@ -1185,6 +1234,9 @@
     *p++ = 0;
     if( mode == MBEDTLS_RSA_PUBLIC )
     {
+        if( f_rng == NULL )
+            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
         *p++ = MBEDTLS_RSA_CRYPT;
 
         while( nb_pad-- > 0 )
@@ -1229,6 +1281,12 @@
                        const unsigned char *input,
                        unsigned char *output )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -1271,6 +1329,14 @@
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+    RSA_VALIDATE_RET( label_len == 0 || label != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( olen != NULL );
+
     /*
      * Parameters sanity checks
      */
@@ -1387,6 +1453,97 @@
 #endif /* MBEDTLS_PKCS1_V21 */
 
 #if defined(MBEDTLS_PKCS1_V15)
+/** Turn zero-or-nonzero into zero-or-all-bits-one, without branches.
+ *
+ * \param value     The value to analyze.
+ * \return          Zero if \p value is zero, otherwise all-bits-one.
+ */
+static unsigned all_or_nothing_int( unsigned value )
+{
+    /* MSVC has a warning about unary minus on unsigned, but this is
+     * well-defined and precisely what we want to do here */
+#if defined(_MSC_VER)
+#pragma warning( push )
+#pragma warning( disable : 4146 )
+#endif
+    return( - ( ( value | - value ) >> ( sizeof( value ) * 8 - 1 ) ) );
+#if defined(_MSC_VER)
+#pragma warning( pop )
+#endif
+}
+
+/** Check whether a size is out of bounds, without branches.
+ *
+ * This is equivalent to `size > max`, but is likely to be compiled to
+ * to code using bitwise operation rather than a branch.
+ *
+ * \param size      Size to check.
+ * \param max       Maximum desired value for \p size.
+ * \return          \c 0 if `size <= max`.
+ * \return          \c 1 if `size > max`.
+ */
+static unsigned size_greater_than( size_t size, size_t max )
+{
+    /* Return the sign bit (1 for negative) of (max - size). */
+    return( ( max - size ) >> ( sizeof( size_t ) * 8 - 1 ) );
+}
+
+/** Choose between two integer values, without branches.
+ *
+ * This is equivalent to `cond ? if1 : if0`, but is likely to be compiled
+ * to code using bitwise operation rather than a branch.
+ *
+ * \param cond      Condition to test.
+ * \param if1       Value to use if \p cond is nonzero.
+ * \param if0       Value to use if \p cond is zero.
+ * \return          \c if1 if \p cond is nonzero, otherwise \c if0.
+ */
+static unsigned if_int( unsigned cond, unsigned if1, unsigned if0 )
+{
+    unsigned mask = all_or_nothing_int( cond );
+    return( ( mask & if1 ) | (~mask & if0 ) );
+}
+
+/** Shift some data towards the left inside a buffer without leaking
+ * the length of the data through side channels.
+ *
+ * `mem_move_to_left(start, total, offset)` is functionally equivalent to
+ * ```
+ * memmove(start, start + offset, total - offset);
+ * memset(start + offset, 0, total - offset);
+ * ```
+ * but it strives to use a memory access pattern (and thus total timing)
+ * that does not depend on \p offset. This timing independence comes at
+ * the expense of performance.
+ *
+ * \param start     Pointer to the start of the buffer.
+ * \param total     Total size of the buffer.
+ * \param offset    Offset from which to copy \p total - \p offset bytes.
+ */
+static void mem_move_to_left( void *start,
+                              size_t total,
+                              size_t offset )
+{
+    volatile unsigned char *buf = start;
+    size_t i, n;
+    if( total == 0 )
+        return;
+    for( i = 0; i < total; i++ )
+    {
+        unsigned no_op = size_greater_than( total - offset, i );
+        /* The first `total - offset` passes are a no-op. The last
+         * `offset` passes shift the data one byte to the left and
+         * zero out the last byte. */
+        for( n = 0; n < total - 1; n++ )
+        {
+            unsigned char current = buf[n];
+            unsigned char next = buf[n+1];
+            buf[n] = if_int( no_op, current, next );
+        }
+        buf[total-1] = if_int( no_op, buf[total-1], 0 );
+    }
+}
+
 /*
  * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
  */
@@ -1396,18 +1553,42 @@
                                  int mode, size_t *olen,
                                  const unsigned char *input,
                                  unsigned char *output,
-                                 size_t output_max_len)
+                                 size_t output_max_len )
 {
     int ret;
-    size_t ilen, pad_count = 0, i;
-    unsigned char *p, bad, pad_done = 0;
+    size_t ilen, i, plaintext_max_size;
     unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+    /* The following variables take sensitive values: their value must
+     * not leak into the observable behavior of the function other than
+     * the designated outputs (output, olen, return value). Otherwise
+     * this would open the execution of the function to
+     * side-channel-based variants of the Bleichenbacher padding oracle
+     * attack. Potential side channels include overall timing, memory
+     * access patterns (especially visible to an adversary who has access
+     * to a shared memory cache), and branches (especially visible to
+     * an adversary who has access to a shared code cache or to a shared
+     * branch predictor). */
+    size_t pad_count = 0;
+    unsigned bad = 0;
+    unsigned char pad_done = 0;
+    size_t plaintext_size = 0;
+    unsigned output_too_large;
+
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( olen != NULL );
+
+    ilen = ctx->len;
+    plaintext_max_size = ( output_max_len > ilen - 11 ?
+                           ilen - 11 :
+                           output_max_len );
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
-    ilen = ctx->len;
-
     if( ilen < 16 || ilen > sizeof( buf ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -1418,63 +1599,109 @@
     if( ret != 0 )
         goto cleanup;
 
-    p = buf;
-    bad = 0;
+    /* Check and get padding length in constant time and constant
+     * memory trace. The first byte must be 0. */
+    bad |= buf[0];
 
-    /*
-     * Check and get padding len in "constant-time"
-     */
-    bad |= *p++; /* First byte must be 0 */
-
-    /* This test does not depend on secret data */
     if( mode == MBEDTLS_RSA_PRIVATE )
     {
-        bad |= *p++ ^ MBEDTLS_RSA_CRYPT;
+        /* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
+         * where PS must be at least 8 nonzero bytes. */
+        bad |= buf[1] ^ MBEDTLS_RSA_CRYPT;
 
-        /* Get padding len, but always read till end of buffer
-         * (minus one, for the 00 byte) */
-        for( i = 0; i < ilen - 3; i++ )
+        /* Read the whole buffer. Set pad_done to nonzero if we find
+         * the 0x00 byte and remember the padding length in pad_count. */
+        for( i = 2; i < ilen; i++ )
         {
-            pad_done  |= ((p[i] | (unsigned char)-p[i]) >> 7) ^ 1;
+            pad_done  |= ((buf[i] | (unsigned char)-buf[i]) >> 7) ^ 1;
             pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
         }
-
-        p += pad_count;
-        bad |= *p++; /* Must be zero */
     }
     else
     {
-        bad |= *p++ ^ MBEDTLS_RSA_SIGN;
+        /* Decode EMSA-PKCS1-v1_5 padding: 0x00 || 0x01 || PS || 0x00
+         * where PS must be at least 8 bytes with the value 0xFF. */
+        bad |= buf[1] ^ MBEDTLS_RSA_SIGN;
 
-        /* Get padding len, but always read till end of buffer
-         * (minus one, for the 00 byte) */
-        for( i = 0; i < ilen - 3; i++ )
+        /* Read the whole buffer. Set pad_done to nonzero if we find
+         * the 0x00 byte and remember the padding length in pad_count.
+         * If there's a non-0xff byte in the padding, the padding is bad. */
+        for( i = 2; i < ilen; i++ )
         {
-            pad_done |= ( p[i] != 0xFF );
-            pad_count += ( pad_done == 0 );
+            pad_done |= if_int( buf[i], 0, 1 );
+            pad_count += if_int( pad_done, 0, 1 );
+            bad |= if_int( pad_done, 0, buf[i] ^ 0xFF );
         }
-
-        p += pad_count;
-        bad |= *p++; /* Must be zero */
     }
 
-    bad |= ( pad_count < 8 );
+    /* If pad_done is still zero, there's no data, only unfinished padding. */
+    bad |= if_int( pad_done, 0, 1 );
 
-    if( bad )
-    {
-        ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
-        goto cleanup;
-    }
+    /* There must be at least 8 bytes of padding. */
+    bad |= size_greater_than( 8, pad_count );
 
-    if( ilen - ( p - buf ) > output_max_len )
-    {
-        ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
-        goto cleanup;
-    }
+    /* If the padding is valid, set plaintext_size to the number of
+     * remaining bytes after stripping the padding. If the padding
+     * is invalid, avoid leaking this fact through the size of the
+     * output: use the maximum message size that fits in the output
+     * buffer. Do it without branches to avoid leaking the padding
+     * validity through timing. RSA keys are small enough that all the
+     * size_t values involved fit in unsigned int. */
+    plaintext_size = if_int( bad,
+                             (unsigned) plaintext_max_size,
+                             (unsigned) ( ilen - pad_count - 3 ) );
 
-    *olen = ilen - (p - buf);
-    memcpy( output, p, *olen );
-    ret = 0;
+    /* Set output_too_large to 0 if the plaintext fits in the output
+     * buffer and to 1 otherwise. */
+    output_too_large = size_greater_than( plaintext_size,
+                                          plaintext_max_size );
+
+    /* Set ret without branches to avoid timing attacks. Return:
+     * - INVALID_PADDING if the padding is bad (bad != 0).
+     * - OUTPUT_TOO_LARGE if the padding is good but the decrypted
+     *   plaintext does not fit in the output buffer.
+     * - 0 if the padding is correct. */
+    ret = - (int) if_int( bad, - MBEDTLS_ERR_RSA_INVALID_PADDING,
+                  if_int( output_too_large, - MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE,
+                          0 ) );
+
+    /* If the padding is bad or the plaintext is too large, zero the
+     * data that we're about to copy to the output buffer.
+     * We need to copy the same amount of data
+     * from the same buffer whether the padding is good or not to
+     * avoid leaking the padding validity through overall timing or
+     * through memory or cache access patterns. */
+    bad = all_or_nothing_int( bad | output_too_large );
+    for( i = 11; i < ilen; i++ )
+        buf[i] &= ~bad;
+
+    /* If the plaintext is too large, truncate it to the buffer size.
+     * Copy anyway to avoid revealing the length through timing, because
+     * revealing the length is as bad as revealing the padding validity
+     * for a Bleichenbacher attack. */
+    plaintext_size = if_int( output_too_large,
+                             (unsigned) plaintext_max_size,
+                             (unsigned) plaintext_size );
+
+    /* Move the plaintext to the leftmost position where it can start in
+     * the working buffer, i.e. make it start plaintext_max_size from
+     * the end of the buffer. Do this with a memory access trace that
+     * does not depend on the plaintext size. After this move, the
+     * starting location of the plaintext is no longer sensitive
+     * information. */
+    mem_move_to_left( buf + ilen - plaintext_max_size,
+                      plaintext_max_size,
+                      plaintext_max_size - plaintext_size );
+
+    /* Finally copy the decrypted plaintext plus trailing zeros
+     * into the output buffer. */
+    memcpy( output, buf + ilen - plaintext_max_size, plaintext_max_size );
+
+    /* Report the amount of data we copied to the output buffer. In case
+     * of errors (bad padding or output too large), the value of *olen
+     * when this function returns is not specified. Making it equivalent
+     * to the good case limits the risks of leaking the padding validity. */
+    *olen = plaintext_size;
 
 cleanup:
     mbedtls_platform_zeroize( buf, sizeof( buf ) );
@@ -1494,6 +1721,13 @@
                        unsigned char *output,
                        size_t output_max_len)
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+    RSA_VALIDATE_RET( input != NULL );
+    RSA_VALIDATE_RET( olen != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -1535,6 +1769,13 @@
     size_t msb;
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+    RSA_VALIDATE_RET( sig != NULL );
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -1782,6 +2023,14 @@
     int ret;
     unsigned char *sig_try = NULL, *verif = NULL;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+    RSA_VALIDATE_RET( sig != NULL );
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -1851,6 +2100,14 @@
                     const unsigned char *hash,
                     unsigned char *sig )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+    RSA_VALIDATE_RET( sig != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -1897,6 +2154,14 @@
     mbedtls_md_context_t md_ctx;
     unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -2025,7 +2290,16 @@
                            const unsigned char *hash,
                            const unsigned char *sig )
 {
-    mbedtls_md_type_t mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
+    mbedtls_md_type_t mgf1_hash_id;
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
+    mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
                              ? (mbedtls_md_type_t) ctx->hash_id
                              : md_alg;
 
@@ -2051,9 +2325,19 @@
                                  const unsigned char *sig )
 {
     int ret = 0;
-    const size_t sig_len = ctx->len;
+    size_t sig_len;
     unsigned char *encoded = NULL, *encoded_expected = NULL;
 
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
+    sig_len = ctx->len;
+
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
@@ -2123,6 +2407,14 @@
                       const unsigned char *hash,
                       const unsigned char *sig )
 {
+    RSA_VALIDATE_RET( ctx != NULL );
+    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+                      mode == MBEDTLS_RSA_PUBLIC );
+    RSA_VALIDATE_RET( sig != NULL );
+    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
+                        hashlen == 0 ) ||
+                      hash != NULL );
+
     switch( ctx->padding )
     {
 #if defined(MBEDTLS_PKCS1_V15)
@@ -2148,6 +2440,8 @@
 int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
 {
     int ret;
+    RSA_VALIDATE_RET( dst != NULL );
+    RSA_VALIDATE_RET( src != NULL );
 
     dst->ver = src->ver;
     dst->len = src->len;
@@ -2187,14 +2481,23 @@
  */
 void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
 {
-    mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->Vf );
-    mbedtls_mpi_free( &ctx->RN ); mbedtls_mpi_free( &ctx->D  );
-    mbedtls_mpi_free( &ctx->Q  ); mbedtls_mpi_free( &ctx->P  );
-    mbedtls_mpi_free( &ctx->E  ); mbedtls_mpi_free( &ctx->N  );
+    if( ctx == NULL )
+        return;
+
+    mbedtls_mpi_free( &ctx->Vi );
+    mbedtls_mpi_free( &ctx->Vf );
+    mbedtls_mpi_free( &ctx->RN );
+    mbedtls_mpi_free( &ctx->D  );
+    mbedtls_mpi_free( &ctx->Q  );
+    mbedtls_mpi_free( &ctx->P  );
+    mbedtls_mpi_free( &ctx->E  );
+    mbedtls_mpi_free( &ctx->N  );
 
 #if !defined(MBEDTLS_RSA_NO_CRT)
-    mbedtls_mpi_free( &ctx->RQ ); mbedtls_mpi_free( &ctx->RP );
-    mbedtls_mpi_free( &ctx->QP ); mbedtls_mpi_free( &ctx->DQ );
+    mbedtls_mpi_free( &ctx->RQ );
+    mbedtls_mpi_free( &ctx->RP );
+    mbedtls_mpi_free( &ctx->QP );
+    mbedtls_mpi_free( &ctx->DQ );
     mbedtls_mpi_free( &ctx->DP );
 #endif /* MBEDTLS_RSA_NO_CRT */