diff --git a/library/bignum.c b/library/bignum.c
index d6f415c6f9..4536a3b862 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1542,12 +1542,15 @@ static void mpi_montg_init( mbedtls_mpi_uint *mm, const mbedtls_mpi *N )
 /*
  * Montgomery multiplication: A = A * B * R^-1 mod N  (HAC 14.36)
  */
-static void mpi_montmul( mbedtls_mpi *A, const mbedtls_mpi *B, const mbedtls_mpi *N, mbedtls_mpi_uint mm,
+static int mpi_montmul( mbedtls_mpi *A, const mbedtls_mpi *B, const mbedtls_mpi *N, mbedtls_mpi_uint mm,
                          const mbedtls_mpi *T )
 {
     size_t i, n, m;
     mbedtls_mpi_uint u0, u1, *d;
 
+    if( T->n < N->n + 1 || T->p == NULL )
+        return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
+
     memset( T->p, 0, T->n * ciL );
 
     d = T->p;
@@ -1575,12 +1578,14 @@ static void mpi_montmul( mbedtls_mpi *A, const mbedtls_mpi *B, const mbedtls_mpi
     else
         /* prevent timing attacks */
         mpi_sub_hlp( n, A->p, T->p );
+
+    return( 0 );
 }
 
 /*
  * Montgomery reduction: A = A * R^-1 mod N
  */
-static void mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N, mbedtls_mpi_uint mm, const mbedtls_mpi *T )
+static int mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N, mbedtls_mpi_uint mm, const mbedtls_mpi *T )
 {
     mbedtls_mpi_uint z = 1;
     mbedtls_mpi U;
@@ -1588,7 +1593,7 @@ static void mpi_montred( mbedtls_mpi *A, const mbedtls_mpi *N, mbedtls_mpi_uint
     U.n = U.s = (int) z;
     U.p = &z;
 
-    mpi_montmul( A, &U, N, mm, T );
+    return( mpi_montmul( A, &U, N, mm, T ) );
 }
 
 /*
@@ -1665,13 +1670,13 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
     else
         MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &W[1], A ) );
 
-    mpi_montmul( &W[1], &RR, N, mm, &T );
+    MBEDTLS_MPI_CHK( mpi_montmul( &W[1], &RR, N, mm, &T ) );
 
     /*
      * X = R^2 * R^-1 mod N = R mod N
      */
     MBEDTLS_MPI_CHK( mbedtls_mpi_copy( X, &RR ) );
-    mpi_montred( X, N, mm, &T );
+    MBEDTLS_MPI_CHK( mpi_montred( X, N, mm, &T ) );
 
     if( wsize > 1 )
     {
@@ -1684,7 +1689,7 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
         MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &W[j], &W[1]    ) );
 
         for( i = 0; i < wsize - 1; i++ )
-            mpi_montmul( &W[j], &W[j], N, mm, &T );
+            MBEDTLS_MPI_CHK( mpi_montmul( &W[j], &W[j], N, mm, &T ) );
 
         /*
          * W[i] = W[i - 1] * W[1]
@@ -1694,7 +1699,7 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
             MBEDTLS_MPI_CHK( mbedtls_mpi_grow( &W[i], N->n + 1 ) );
             MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &W[i], &W[i - 1] ) );
 
-            mpi_montmul( &W[i], &W[1], N, mm, &T );
+            MBEDTLS_MPI_CHK( mpi_montmul( &W[i], &W[1], N, mm, &T ) );
         }
     }
 
@@ -1731,7 +1736,7 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
             /*
              * out of window, square X
              */
-            mpi_montmul( X, X, N, mm, &T );
+            MBEDTLS_MPI_CHK( mpi_montmul( X, X, N, mm, &T ) );
             continue;
         }
 
@@ -1749,12 +1754,12 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
              * X = X^wsize R^-1 mod N
              */
             for( i = 0; i < wsize; i++ )
-                mpi_montmul( X, X, N, mm, &T );
+                MBEDTLS_MPI_CHK( mpi_montmul( X, X, N, mm, &T ) );
 
             /*
              * X = X * W[wbits] R^-1 mod N
              */
-            mpi_montmul( X, &W[wbits], N, mm, &T );
+            MBEDTLS_MPI_CHK( mpi_montmul( X, &W[wbits], N, mm, &T ) );
 
             state--;
             nbits = 0;
@@ -1767,18 +1772,18 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi
      */
     for( i = 0; i < nbits; i++ )
     {
-        mpi_montmul( X, X, N, mm, &T );
+        MBEDTLS_MPI_CHK( mpi_montmul( X, X, N, mm, &T ) );
 
         wbits <<= 1;
 
         if( ( wbits & ( one << wsize ) ) != 0 )
-            mpi_montmul( X, &W[1], N, mm, &T );
+            MBEDTLS_MPI_CHK( mpi_montmul( X, &W[1], N, mm, &T ) );
     }
 
     /*
      * X = A^E * R * R^-1 mod N = A^E mod N
      */
-    mpi_montred( X, N, mm, &T );
+    MBEDTLS_MPI_CHK( mpi_montred( X, N, mm, &T ) );
 
     if( neg )
     {
diff --git a/library/pkcs12.c b/library/pkcs12.c
index 7023b9dbc8..c603a13577 100644
--- a/library/pkcs12.c
+++ b/library/pkcs12.c
@@ -93,7 +93,7 @@ static int pkcs12_pbe_derive_key_iv( mbedtls_asn1_buf *pbe_params, mbedtls_md_ty
                                      unsigned char *key, size_t keylen,
                                      unsigned char *iv,  size_t ivlen )
 {
-    int ret, iterations;
+    int ret, iterations = 0;
     mbedtls_asn1_buf salt;
     size_t i;
     unsigned char unipwd[PKCS12_MAX_PWDLEN * 2 + 2];
diff --git a/library/rsa.c b/library/rsa.c
index 18fc702123..9386a762fe 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -804,7 +804,12 @@ int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
     int ret;
     size_t ilen, pad_count = 0, i;
     unsigned char *p, bad, pad_done = 0;
+#ifdef __clang_analyzer__
+    /* Shut up Clang, mbedtls_rsa_public/private writes to this */
+    unsigned char buf[MBEDTLS_MPI_MAX_SIZE] = { };
+#else
     unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+#endif
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -1182,13 +1187,18 @@ int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
     int ret;
     size_t siglen;
     unsigned char *p;
-    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
     unsigned char result[MBEDTLS_MD_MAX_SIZE];
     unsigned char zeros[8];
     unsigned int hlen;
     size_t slen, msb;
     const mbedtls_md_info_t *md_info;
     mbedtls_md_context_t md_ctx;
+#ifdef __clang_analyzer__
+    /* Shut up Clang, mbedtls_rsa_public/private writes to this */
+    unsigned char buf[MBEDTLS_MPI_MAX_SIZE] = { };
+#else
+    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+#endif
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -1327,10 +1337,15 @@ int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
     int ret;
     size_t len, siglen, asn1_len;
     unsigned char *p, *end;
-    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
     mbedtls_md_type_t msg_md_alg;
     const mbedtls_md_info_t *md_info;
     mbedtls_asn1_buf oid;
+#ifdef __clang_analyzer__
+    /* Shut up Clang, mbedtls_rsa_public/private writes to this */
+    unsigned char buf[MBEDTLS_MPI_MAX_SIZE] = { };
+#else
+    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+#endif
 
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index cd39db027e..509484e36a 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -267,7 +267,6 @@ static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
 #if defined(MBEDTLS_ECP_C)
     for( grp_id = ssl->conf->curve_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
     {
-        info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
 #else
     for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
     {
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 19cc357923..9208ec9c8e 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2709,7 +2709,7 @@ void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl )
  */
 int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl )
 {
-    int ret, done = 0;
+    int ret, done = 0, out_msg_type;
     size_t len = ssl->out_msglen;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) );
@@ -2725,7 +2725,9 @@ int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl )
 #endif
     if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
     {
-        if( ssl->out_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST &&
+        out_msg_type = ssl->out_msg[0];
+
+        if( out_msg_type != MBEDTLS_SSL_HS_HELLO_REQUEST &&
             ssl->handshake == NULL )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
@@ -2752,7 +2754,7 @@ int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl )
             len += 8;
 
             /* Write message_seq and update it, except for HelloRequest */
-            if( ssl->out_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST )
+            if( out_msg_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
             {
                 ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF;
                 ssl->out_msg[5] = ( ssl->handshake->out_msg_seq      ) & 0xFF;
@@ -2770,7 +2772,7 @@ int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl )
         }
 #endif /* MBEDTLS_SSL_PROTO_DTLS */
 
-        if( ssl->out_msg[0] != MBEDTLS_SSL_HS_HELLO_REQUEST )
+        if( out_msg_type != MBEDTLS_SSL_HS_HELLO_REQUEST )
             ssl->handshake->update_checksum( ssl, ssl->out_msg, len );
     }
 
diff --git a/library/x509_csr.c b/library/x509_csr.c
index f8c45f8d28..603d06b64f 100644
--- a/library/x509_csr.c
+++ b/library/x509_csr.c
@@ -104,7 +104,7 @@ int mbedtls_x509_csr_parse_der( mbedtls_x509_csr *csr,
     /*
      * Check for valid input
      */
-    if( csr == NULL || buf == NULL )
+    if( csr == NULL || buf == NULL || buflen == 0 )
         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
 
     mbedtls_x509_csr_init( csr );
@@ -274,14 +274,14 @@ int mbedtls_x509_csr_parse( mbedtls_x509_csr *csr, const unsigned char *buf, siz
     /*
      * Check for valid input
      */
-    if( csr == NULL || buf == NULL )
+    if( csr == NULL || buf == NULL || buflen == 0 )
         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_PEM_PARSE_C)
     mbedtls_pem_init( &pem );
 
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
-    if( buflen == 0 || buf[buflen - 1] != '\0' )
+    if( buf[buflen - 1] != '\0' )
         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
     else
         ret = mbedtls_pem_read_buffer( &pem,
diff --git a/programs/hash/generic_sum.c b/programs/hash/generic_sum.c
index f071d311e3..7805a79bcf 100644
--- a/programs/hash/generic_sum.c
+++ b/programs/hash/generic_sum.c
@@ -83,7 +83,7 @@ static int generic_check( const mbedtls_md_info_t *md_info, char *filename )
     int nb_err1, nb_err2;
     int nb_tot1, nb_tot2;
     unsigned char sum[MBEDTLS_MD_MAX_SIZE];
-    char buf[MBEDTLS_MD_MAX_SIZE * 2 + 1], line[1024];
+    char buf[MBEDTLS_MD_MAX_SIZE * 2 + 1] = { }, line[1024];
     char diff;
 
     if( ( f = fopen( filename, "rb" ) ) == NULL )