Fix hash buffer size in pkey programs

backport from 102a620
diff --git a/programs/pkey/dh_client.c b/programs/pkey/dh_client.c
index a5a137a..ea63ce7 100644
--- a/programs/pkey/dh_client.c
+++ b/programs/pkey/dh_client.c
@@ -75,7 +75,7 @@
 
     unsigned char *p, *end;
     unsigned char buf[2048];
-    unsigned char hash[20];
+    unsigned char hash[32];
     const char *pers = "dh_client";
 
     entropy_context entropy;
diff --git a/programs/pkey/dh_server.c b/programs/pkey/dh_server.c
index 0ac91a4..cc75ee8 100644
--- a/programs/pkey/dh_server.c
+++ b/programs/pkey/dh_server.c
@@ -75,7 +75,7 @@
     int client_fd = -1;
 
     unsigned char buf[2048];
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf2[2];
     const char *pers = "dh_server";
 
diff --git a/programs/pkey/pk_sign.c b/programs/pkey/pk_sign.c
index 7ccc70b..1423494 100644
--- a/programs/pkey/pk_sign.c
+++ b/programs/pkey/pk_sign.c
@@ -74,7 +74,7 @@
     pk_context pk;
     entropy_context entropy;
     ctr_drbg_context ctr_drbg;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];
     const char *pers = "pk_sign";
diff --git a/programs/pkey/pk_verify.c b/programs/pkey/pk_verify.c
index 3afa34a..1623708 100644
--- a/programs/pkey/pk_verify.c
+++ b/programs/pkey/pk_verify.c
@@ -68,7 +68,7 @@
     int ret = 1;
     size_t i;
     pk_context pk;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];
 
diff --git a/programs/pkey/rsa_sign.c b/programs/pkey/rsa_sign.c
index 63ef822..14b87ab 100644
--- a/programs/pkey/rsa_sign.c
+++ b/programs/pkey/rsa_sign.c
@@ -58,7 +58,7 @@
     int ret;
     size_t i;
     rsa_context rsa;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];
 
diff --git a/programs/pkey/rsa_sign_pss.c b/programs/pkey/rsa_sign_pss.c
index 7c0c7ca..e0dbcbc 100644
--- a/programs/pkey/rsa_sign_pss.c
+++ b/programs/pkey/rsa_sign_pss.c
@@ -74,7 +74,7 @@
     pk_context pk;
     entropy_context entropy;
     ctr_drbg_context ctr_drbg;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];
     const char *pers = "rsa_sign_pss";
diff --git a/programs/pkey/rsa_verify.c b/programs/pkey/rsa_verify.c
index 022ef33..cb42563 100644
--- a/programs/pkey/rsa_verify.c
+++ b/programs/pkey/rsa_verify.c
@@ -57,7 +57,7 @@
     int ret, c;
     size_t i;
     rsa_context rsa;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];
 
diff --git a/programs/pkey/rsa_verify_pss.c b/programs/pkey/rsa_verify_pss.c
index 217b713..3e73215 100644
--- a/programs/pkey/rsa_verify_pss.c
+++ b/programs/pkey/rsa_verify_pss.c
@@ -69,7 +69,7 @@
     int ret = 1;
     size_t i;
     pk_context pk;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];