Add test for DSA signatures of raw digests of various sizes

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6749)

3 files changed, 252 insertions, 2 deletions

diff --git a/test/build.info b/test/build.info
index 8dbe0c2f76..04014e7286 100644
--- a/test/build.info
+++ b/test/build.info
@@ -33,7 +33,7 @@ INCLUDE_MAIN___test_libtestutil_OLB = /INCLUDE=MAIN
           rc2test rc4test rc5test \
           destest mdc2test \
           dhtest enginetest casttest \
-          bftest ssltest_old dsatest exptest rsa_test \
+          bftest ssltest_old dsatest dsa_no_digest_size_test exptest rsa_test \
           evp_test evp_extra_test igetest v3nametest v3ext \
           crltest danetest bad_dtls_test lhash_test \
           conf_include_test \
@@ -152,6 +152,10 @@ INCLUDE_MAIN___test_libtestutil_OLB = /INCLUDE=MAIN
   INCLUDE[dsatest]=../include
   DEPEND[dsatest]=../libcrypto libtestutil.a
 
+  SOURCE[dsa_no_digest_size_test]=dsa_no_digest_size_test.c
+  INCLUDE[dsa_no_digest_size_test]=../include
+  DEPEND[dsa_no_digest_size_test]=../libcrypto libtestutil.a
+
   SOURCE[exptest]=exptest.c
   INCLUDE[exptest]=../include
   DEPEND[exptest]=../libcrypto libtestutil.a
diff --git a/test/dsa_no_digest_size_test.c b/test/dsa_no_digest_size_test.c
new file mode 100644
index 0000000000..88c6036f53
--- /dev/null
+++ b/test/dsa_no_digest_size_test.c
@@ -0,0 +1,245 @@
+/*
+ * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "testutil.h"
+
+#include <openssl/evp.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+#ifndef OPENSSL_NO_DSA
+#include <openssl/dsa.h>
+
+static DSA *dsakey;
+
+/*
+ * These parameters are from test/recipes/04-test_pem_data/dsaparam.pem,
+ * converted using dsaparam -C
+ */
+static DSA *load_dsa_params(void)
+{
+    static unsigned char dsap_2048[] = {
+        0xAE, 0x35, 0x7D, 0x4E, 0x1D, 0x96, 0xE2, 0x9F, 0x00, 0x96,
+        0x60, 0x5A, 0x6E, 0x4D, 0x07, 0x8D, 0xA5, 0x7C, 0xBC, 0xF9,
+        0xAD, 0xD7, 0x9F, 0xD5, 0xE9, 0xEE, 0xA6, 0x33, 0x51, 0xDE,
+        0x7B, 0x72, 0xD2, 0x75, 0xAA, 0x71, 0x77, 0xF1, 0x63, 0xFB,
+        0xB6, 0xEC, 0x5A, 0xBA, 0x0D, 0x72, 0xA2, 0x1A, 0x1C, 0x64,
+        0xB8, 0xE5, 0x89, 0x09, 0x6D, 0xC9, 0x6F, 0x0B, 0x7F, 0xD2,
+        0xCE, 0x9F, 0xEF, 0x87, 0x5A, 0xB6, 0x67, 0x2F, 0xEF, 0xEE,
+        0xEB, 0x59, 0xF5, 0x5E, 0xFF, 0xA8, 0x28, 0x84, 0x9E, 0x5B,
+        0x37, 0x09, 0x11, 0x80, 0x7C, 0x08, 0x5C, 0xD5, 0xE1, 0x48,
+        0x4B, 0xD2, 0x68, 0xFB, 0x3F, 0x9F, 0x2B, 0x6B, 0x6C, 0x0D,
+        0x48, 0x1B, 0x1A, 0x80, 0xC2, 0xEB, 0x11, 0x1B, 0x37, 0x79,
+        0xD6, 0x8C, 0x8B, 0x72, 0x3E, 0x67, 0xA5, 0x05, 0x0E, 0x41,
+        0x8A, 0x9E, 0x35, 0x50, 0xB4, 0xD2, 0x40, 0x27, 0x6B, 0xFD,
+        0xE0, 0x64, 0x6B, 0x5B, 0x38, 0x42, 0x94, 0xB5, 0x49, 0xDA,
+        0xEF, 0x6E, 0x78, 0x37, 0xCD, 0x30, 0x89, 0xC3, 0x45, 0x50,
+        0x7B, 0x9C, 0x8C, 0xE7, 0x1C, 0x98, 0x70, 0x71, 0x5D, 0x79,
+        0x5F, 0xEF, 0xE8, 0x94, 0x85, 0x53, 0x3E, 0xEF, 0xA3, 0x2C,
+        0xCE, 0x1A, 0xAB, 0x7D, 0xD6, 0x5E, 0x14, 0xCD, 0x51, 0x54,
+        0x89, 0x9D, 0x77, 0xE4, 0xF8, 0x22, 0xF0, 0x35, 0x10, 0x75,
+        0x05, 0x71, 0x51, 0x4F, 0x8C, 0x4C, 0x5C, 0x0D, 0x2C, 0x2C,
+        0xBE, 0x6C, 0x34, 0xEE, 0x12, 0x82, 0x87, 0x03, 0x19, 0x06,
+        0x12, 0xA8, 0xAA, 0xF4, 0x0D, 0x3C, 0x49, 0xCC, 0x70, 0x5A,
+        0xD8, 0x32, 0xEE, 0x32, 0x50, 0x85, 0x70, 0xE8, 0x18, 0xFD,
+        0x74, 0x80, 0x53, 0x32, 0x57, 0xEE, 0x50, 0xC9, 0xAE, 0xEB,
+        0xAE, 0xB6, 0x22, 0x32, 0x16, 0x6B, 0x8C, 0x59, 0xDA, 0xEE,
+        0x1D, 0x33, 0xDF, 0x4C, 0xA2, 0x3D
+    };
+    static unsigned char dsaq_2048[] = {
+        0xAD, 0x2D, 0x6E, 0x17, 0xB0, 0xF3, 0xEB, 0xC7, 0xB8, 0xEE,
+        0x95, 0x78, 0xF2, 0x17, 0xF5, 0x33, 0x01, 0x67, 0xBC, 0xDE,
+        0x93, 0xFF, 0xEE, 0x40, 0xE8, 0x7F, 0xF1, 0x93, 0x6D, 0x4B,
+        0x87, 0x13
+    };
+    static unsigned char dsag_2048[] = {
+        0x66, 0x6F, 0xDA, 0x63, 0xA5, 0x8E, 0xD2, 0x4C, 0xD5, 0x45,
+        0x2D, 0x76, 0x5D, 0x5F, 0xCD, 0x4A, 0xB4, 0x1A, 0x42, 0x35,
+        0x86, 0x3A, 0x6F, 0xA9, 0xFA, 0x27, 0xAB, 0xDE, 0x03, 0x21,
+        0x36, 0x0A, 0x07, 0x29, 0xC9, 0x2F, 0x6D, 0x49, 0xA8, 0xF7,
+        0xC6, 0xF4, 0x92, 0xD7, 0x73, 0xC1, 0xD8, 0x76, 0x0E, 0x61,
+        0xA7, 0x0B, 0x6E, 0x96, 0xB8, 0xC8, 0xCB, 0x38, 0x35, 0x12,
+        0x20, 0x79, 0xA5, 0x08, 0x28, 0x35, 0x5C, 0xBC, 0x52, 0x16,
+        0xAF, 0x52, 0xBA, 0x0F, 0xC3, 0xB1, 0x63, 0x12, 0x27, 0x0B,
+        0x74, 0xA4, 0x47, 0x43, 0xD6, 0x30, 0xB8, 0x9C, 0x2E, 0x40,
+        0x14, 0xCD, 0x99, 0x7F, 0xE8, 0x8E, 0x37, 0xB0, 0xA9, 0x3F,
+        0x54, 0xE9, 0x66, 0x22, 0x61, 0x4C, 0xF8, 0x49, 0x03, 0x57,
+        0x14, 0x32, 0x1D, 0x37, 0x3D, 0xE2, 0x92, 0xF8, 0x8E, 0xA0,
+        0x6A, 0x66, 0x63, 0xF0, 0xB0, 0x6E, 0x07, 0x2B, 0x3D, 0xBF,
+        0xD0, 0x84, 0x6A, 0xAA, 0x1F, 0x30, 0x77, 0x65, 0xE5, 0xFC,
+        0xF5, 0xEC, 0x55, 0xCE, 0x73, 0xDB, 0xBE, 0xA7, 0x8D, 0x3A,
+        0x9F, 0x7A, 0xED, 0x4F, 0xAF, 0xA2, 0x80, 0x4C, 0x30, 0x9E,
+        0x28, 0x49, 0x65, 0x40, 0xF0, 0x03, 0x45, 0x56, 0x99, 0xA2,
+        0x93, 0x1B, 0x9C, 0x46, 0xDE, 0xBD, 0xA8, 0xAB, 0x5F, 0x90,
+        0x3F, 0xB7, 0x3F, 0xD4, 0x6F, 0x8D, 0x5A, 0x30, 0xE1, 0xD4,
+        0x63, 0x3A, 0x6A, 0x7C, 0x8F, 0x24, 0xFC, 0xD9, 0x14, 0x28,
+        0x09, 0xE4, 0x84, 0x4E, 0x17, 0x43, 0x56, 0xB8, 0xD4, 0x4B,
+        0xA2, 0x29, 0x45, 0xD3, 0x13, 0xF0, 0xC2, 0x76, 0x9B, 0x01,
+        0xA0, 0x80, 0x6E, 0x93, 0x63, 0x5E, 0x87, 0x24, 0x20, 0x2A,
+        0xFF, 0xBB, 0x9F, 0xA8, 0x99, 0x6C, 0xA7, 0x9A, 0x00, 0xB9,
+        0x7D, 0xDA, 0x66, 0xC9, 0xC0, 0x72, 0x72, 0x22, 0x0F, 0x1A,
+        0xCC, 0x23, 0xD9, 0xB7, 0x5F, 0x1B
+    };
+    DSA *dsa = DSA_new();
+    BIGNUM *p, *q, *g;
+
+    if (dsa == NULL)
+        return NULL;
+    if (!DSA_set0_pqg(dsa, p = BN_bin2bn(dsap_2048, sizeof(dsap_2048), NULL),
+                           q = BN_bin2bn(dsaq_2048, sizeof(dsaq_2048), NULL),
+                           g = BN_bin2bn(dsag_2048, sizeof(dsag_2048), NULL))) {
+        DSA_free(dsa);
+        BN_free(p);
+        BN_free(q);
+        BN_free(g);
+        return NULL;
+    }
+    return dsa;
+}
+
+static int genkeys(void)
+{
+    if (!TEST_ptr(dsakey = load_dsa_params()))
+        return 0;
+
+    if (!TEST_int_eq(DSA_generate_key(dsakey), 1))
+        return 0;
+
+    return 1;
+}
+
+static int sign_and_verify(int len)
+{
+    /*
+     * Per FIPS 186-4, the hash is recommended to be the same length as q.
+     * If the hash is longer than q, the leftmost N bits are used; if the hash
+     * is shorter, then we left-pad (see appendix C.2.1).
+     */
+    size_t sigLength;
+    int digestlen = BN_num_bytes(DSA_get0_q(dsakey));
+    int ok = 0;
+
+    unsigned char *dataToSign = OPENSSL_malloc(len);
+    unsigned char *paddedData = OPENSSL_malloc(digestlen);
+    unsigned char *signature = NULL;
+    EVP_PKEY_CTX *ctx = NULL;
+    EVP_PKEY *pkey = NULL;
+
+    if (!TEST_ptr(dataToSign) ||
+        !TEST_ptr(paddedData) ||
+        !TEST_int_eq(RAND_bytes(dataToSign, len), 1))
+        goto end;
+
+    memset(paddedData, 0, digestlen);
+    if (len > digestlen)
+        memcpy(paddedData, dataToSign, digestlen);
+    else
+        memcpy(paddedData + digestlen - len, dataToSign, len);
+
+    if (!TEST_ptr(pkey = EVP_PKEY_new()))
+        goto end;
+    EVP_PKEY_set1_DSA(pkey, dsakey);
+
+    if (!TEST_ptr(ctx = EVP_PKEY_CTX_new(pkey, NULL)))
+        goto end;
+    if (!TEST_int_eq(EVP_PKEY_sign_init(ctx), 1))
+        goto end;
+
+    if (EVP_PKEY_sign(ctx, NULL, &sigLength, dataToSign, len) != 1) {
+        TEST_error("Failed to get signature length, len=%d", len);
+        goto end;
+    }
+
+    if (!TEST_ptr(signature = OPENSSL_malloc(sigLength)))
+        goto end;
+
+    if (EVP_PKEY_sign(ctx, signature, &sigLength, dataToSign, len) != 1) {
+        TEST_error("Failed to sign, len=%d", len);
+        goto end;
+    }
+
+    /* Check that the signature is okay via the EVP interface */
+    if (!TEST_int_eq(EVP_PKEY_verify_init(ctx), 1))
+        goto end;
+
+    /* ... using the same data we just signed */
+    if (EVP_PKEY_verify(ctx, signature, sigLength, dataToSign, len) != 1) {
+        TEST_error("EVP verify with unpadded length %d failed\n", len);
+        goto end;
+    }
+
+    /* ... padding/truncating the data to the appropriate digest size */
+    if (EVP_PKEY_verify(ctx, signature, sigLength, paddedData, digestlen) != 1) {
+        TEST_error("EVP verify with length %d failed\n", len);
+        goto end;
+    }
+
+    /* Verify again using the raw DSA interface */
+    if (DSA_verify(0, dataToSign, len, signature, sigLength, dsakey) != 1) {
+        TEST_error("Verification with unpadded data failed, len=%d", len);
+        goto end;
+    }
+
+    if (DSA_verify(0, paddedData, digestlen, signature, sigLength, dsakey) != 1) {
+        TEST_error("verify with length %d failed\n", len);
+        goto end;
+    }
+
+    ok = 1;
+end:
+    EVP_PKEY_CTX_free(ctx);
+    EVP_PKEY_free(pkey);
+
+    OPENSSL_free(signature);
+    OPENSSL_free(paddedData);
+    OPENSSL_free(dataToSign);
+
+    return ok;
+}
+
+static int dsa_exact_size_test(void) {
+    /*
+     * For a 2048-bit p, q should be either 224 or 256 bits per the table in
+     * FIPS 186-4 4.2.
+     */
+
+    return sign_and_verify(224 / 8) && sign_and_verify(256 / 8);
+}
+
+static int dsa_small_digest_test(void) {
+    return sign_and_verify(16) && sign_and_verify(1);
+}
+
+static int dsa_large_digest_test(void) {
+    return sign_and_verify(33) && sign_and_verify(64);
+}
+
+void cleanup_tests(void)
+{
+    DSA_free(dsakey);
+}
+
+#endif /* OPENSSL_NO_DSA */
+
+int setup_tests(void)
+{
+#ifndef OPENSSL_NO_DSA
+    if (!genkeys())
+        return 0;
+
+    ADD_TEST(dsa_exact_size_test);
+    ADD_TEST(dsa_small_digest_test);
+    ADD_TEST(dsa_large_digest_test);
+#endif
+    return 1;
+}
+
diff --git a/test/recipes/15-test_dsa.t b/test/recipes/15-test_dsa.t
index 311b9b3e0a..c8f61cca21 100644
--- a/test/recipes/15-test_dsa.t
+++ b/test/recipes/15-test_dsa.t
@@ -16,11 +16,12 @@ use OpenSSL::Test::Utils;
 
 setup("test_dsa");
 
-plan tests => 5;
+plan tests => 6;
 
 require_ok(srctop_file('test','recipes','tconversion.pl'));
 
 ok(run(test(["dsatest"])), "running dsatest");
+ok(run(test(["dsa_no_digest_size_test"])), "running dsa_no_digest_size_test");
 
  SKIP: {
      skip "Skipping dsa conversion test", 3