EVP_PKEY_CTX utility functions.

Utility functions to pass a string or hex string to EVP_PKEY_CTX_ctrl().
Reviewed-by: NRich Salz <rsalz@openssl.org>

crypto/evp/pmeth_lib.c

@@ -63,8 +63,10 @@
 # include <openssl/engine.h>
 #endif
 #include <openssl/evp.h>
+#include <openssl/x509v3.h>
 #include "internal/asn1_int.h"
 #include "internal/evp_int.h"
+#include "internal/numbers.h"
 
 typedef int sk_cmp_fn_type(const char *const *a, const char *const *b);
 
@@ -381,6 +383,33 @@ int EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx,
     return ctx->pmeth->ctrl_str(ctx, name, value);
 }
 
+/* Utility functions to send a string of hex string to a ctrl */
+
+int EVP_PKEY_CTX_str2ctrl(EVP_PKEY_CTX *ctx, int cmd, const char *str)
+{
+    size_t len;
+
+    len = strlen(str);
+    if (len > INT_MAX)
+        return -1;
+    return ctx->pmeth->ctrl(ctx, cmd, len, (void *)str);
+}
+
+int EVP_PKEY_CTX_hex2ctrl(EVP_PKEY_CTX *ctx, int cmd, const char *hex)
+{
+    unsigned char *bin;
+    long binlen;
+    int rv = -1;
+
+    bin = string_to_hex(hex, &binlen);
+    if (bin == NULL)
+        return 0;
+    if (binlen <= INT_MAX)
+        rv = ctx->pmeth->ctrl(ctx, cmd, binlen, bin);
+    OPENSSL_free(bin);
+    return rv;
+}
+
 int EVP_PKEY_CTX_get_operation(EVP_PKEY_CTX *ctx)
 {
     return ctx->operation;

include/openssl/evp.h

@@ -1224,6 +1224,9 @@ int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,
 int EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
                           const char *value);
 
+int EVP_PKEY_CTX_str2ctrl(EVP_PKEY_CTX *ctx, int cmd, const char *str);
+int EVP_PKEY_CTX_hex2ctrl(EVP_PKEY_CTX *ctx, int cmd, const char *hex);
+
 int EVP_PKEY_CTX_get_operation(EVP_PKEY_CTX *ctx);
 void EVP_PKEY_CTX_set0_keygen_info(EVP_PKEY_CTX *ctx, int *dat, int datlen);