Add test to verify TLS depadding works correctly

Signed-off-by: Simo Sorce <[email protected]>

tests/tlsctx.c

@@ -5,6 +5,10 @@
 #include <stdbool.h>
 #include <openssl/ssl.h>
 #include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+#include <openssl/store.h>
+#include <openssl/core_names.h>
 
 static void ossl_err_print(void)
 {
@@ -33,6 +37,161 @@ static void ossl_err_print(void)
     }
 }
 
+static EVP_PKEY *load_key(const char *uri)
+{
+    OSSL_STORE_CTX *store;
+    OSSL_STORE_INFO *info;
+    EVP_PKEY *key = NULL;
+
+    if (!uri) {
+        fprintf(stderr, "Invalid NULL uri");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    store = OSSL_STORE_open(uri, NULL, NULL, NULL, NULL);
+    if (store == NULL) {
+        fprintf(stderr, "Failed to open store: %s\n", uri);
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    if (strncmp(uri, "pkcs11:", 7) && strstr(uri, "type=private") == NULL) {
+        /* This is a workaround for OpenSSL < 3.2.0 where the code fails
+         * to correctly source public keys unless explicitly requested
+         * via an expect hint */
+        if (OSSL_STORE_expect(store, OSSL_STORE_INFO_PUBKEY) != 1) {
+            fprintf(stderr, "Failed to expect Public Key File\n");
+            exit(EXIT_FAILURE);
+        }
+    }
+
+    for (info = OSSL_STORE_load(store); info != NULL;
+         info = OSSL_STORE_load(store)) {
+        int type = OSSL_STORE_INFO_get_type(info);
+
+        if (key != NULL) {
+            fprintf(stderr, "Multiple keys matching URI: %s\n", uri);
+            exit(EXIT_FAILURE);
+        }
+
+        switch (type) {
+        case OSSL_STORE_INFO_PUBKEY:
+            key = OSSL_STORE_INFO_get1_PUBKEY(info);
+            break;
+        case OSSL_STORE_INFO_PKEY:
+            key = OSSL_STORE_INFO_get1_PKEY(info);
+            break;
+        }
+        OSSL_STORE_INFO_free(info);
+    }
+
+    if (key == NULL) {
+        fprintf(stderr, "Failed to load key from URI: %s\n", uri);
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+    OSSL_STORE_close(store);
+
+    return key;
+}
+
+static void test_pkcs1_with_tls_padding(void)
+{
+    EVP_PKEY_CTX *ctx;
+    EVP_PKEY *prikey;
+    EVP_PKEY *pubkey;
+    unsigned char plain[SSL_MAX_MASTER_KEY_LENGTH + 2] = { 0x03, 0x03, 0x01 };
+    unsigned char enc[1024];
+    unsigned char dec[1024];
+    size_t enclen;
+    size_t declen;
+    unsigned int ver = 0x0303;
+    const OSSL_PARAM ver_params[] = {
+        OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, &ver),
+        OSSL_PARAM_END
+    };
+    int err;
+
+    pubkey = load_key(getenv("PUBURI"));
+
+    ctx = EVP_PKEY_CTX_new_from_pkey(NULL, pubkey, NULL);
+    if (!ctx) {
+        fprintf(stderr, "Failed to init pkey ctx for puburi\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+    err = EVP_PKEY_encrypt_init(ctx);
+    if (err != 1) {
+        fprintf(stderr, "Failed to init encrypt ctx\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+    err = EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING);
+    if (err != 1) {
+        fprintf(stderr, "Failed to set padding on encrypt ctx\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    enclen = sizeof(enc);
+    err = EVP_PKEY_encrypt(ctx, enc, &enclen, plain, sizeof(plain));
+    if (err != 1) {
+        fprintf(stderr, "Failed to encrypt TLS master key\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    EVP_PKEY_CTX_free(ctx);
+    EVP_PKEY_free(pubkey);
+
+    prikey = load_key(getenv("PRIURI"));
+
+    ctx = EVP_PKEY_CTX_new_from_pkey(NULL, prikey, NULL);
+    if (!ctx) {
+        fprintf(stderr, "Failed to init pkey ctx for priuri\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+    err = EVP_PKEY_decrypt_init(ctx);
+    if (err != 1) {
+        fprintf(stderr, "Failed to init decrypt ctx\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+    err = EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_WITH_TLS_PADDING);
+    if (err != 1) {
+        fprintf(stderr, "Failed to set padding on decrypt ctx\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    err = EVP_PKEY_CTX_set_params(ctx, ver_params);
+    if (err != 1) {
+        fprintf(stderr, "Failed to set version params\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    declen = sizeof(dec);
+    err = EVP_PKEY_decrypt(ctx, dec, &declen, enc, enclen);
+    if (err != 1) {
+        fprintf(stderr, "Failed to decrypt TLS master key\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+
+    EVP_PKEY_CTX_free(ctx);
+    EVP_PKEY_free(prikey);
+
+    if ((declen != sizeof(plain) - 2)
+        || (memcmp(plain + 2, dec, declen) != 0)) {
+        fprintf(stderr, "Fail, decrypted master secret differs from input\n");
+        ossl_err_print();
+        exit(EXIT_FAILURE);
+    }
+}
+
 int main(int argc, char *argv[])
 {
     SSL_CTX *ctx;
@@ -48,5 +207,7 @@ int main(int argc, char *argv[])
 
     SSL_CTX_free(ctx);
 
+    test_pkcs1_with_tls_padding();
+
     exit(EXIT_SUCCESS);
 }