Commit fa013b65 authored by Péter Budai's avatar Péter Budai Committed by Rich Salz
Browse files

Fixed PKCS5_PBKDF2_HMAC() to adhere to the documentation. 



The documentation of this function states that the password parameter
can be NULL. However, the implementation returns an error in this case
due to the inner workings of the HMAC_Init_ex() function.
With this change, NULL password will be treated as an empty string and
PKCS5_PBKDF2_HMAC() no longer fails on this input.

I have also added two new test cases that tests the handling of the
special values NULL and -1 of the password and passlen parameters,
respectively.

Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1692)
parent 9998b32c

crypto/evp/p5_crpt2.c

+5 −2
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen, 
                      const unsigned char *salt, int saltlen, int iter,

                      const EVP_MD *digest, int keylen, unsigned char *out)

{

    const char *empty = "";

    unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];

    int cplen, j, k, tkeylen, mdlen;

    unsigned long i = 1;
@@ -47,10 +48,12 @@ int PKCS5_PBKDF2_HMAC(const char *pass, int passlen, 
        return 0;

    p = out;

    tkeylen = keylen;

    if (!pass)

    if (pass == NULL) {

        pass = empty;

        passlen = 0;

    else if (passlen == -1)

    } else if (passlen == -1) {

        passlen = strlen(pass);

    }

    if (!HMAC_Init_ex(hctx_tpl, pass, passlen, digest, NULL)) {

        HMAC_CTX_free(hctx_tpl);

        return 0;

test/evp_test.c

+12 −1
Original line number Diff line number Diff line
@@ -127,6 +127,8 @@ static int test_bin(const char *value, unsigned char **buf, size_t *buflen) 
    long len;



    *buflen = 0;



    /* Check for empty value */

    if (!*value) {

        /*

         * Don't return NULL for zero length buffer.
@@ -141,6 +143,14 @@ static int test_bin(const char *value, unsigned char **buf, size_t *buflen) 
        *buflen = 0;

        return 1;

    }



    /* Check for NULL literal */

    if (strcmp(value, "NULL") == 0) {

        *buf = NULL;

        *buflen = 0;

        return 1;

    }



    /* Check for string literal */

    if (value[0] == '"') {

        size_t vlen;
@@ -155,6 +165,7 @@ static int test_bin(const char *value, unsigned char **buf, size_t *buflen) 
        return 1;

    }



    /* Otherwise assume as hex literal and convert it to binary buffer */

    *buf = OPENSSL_hexstr2buf(value, &len);

    if (!*buf) {

        fprintf(stderr, "Value=%s\n", value);
@@ -640,7 +651,7 @@ int main(int argc, char **argv) 


    memset(&t, 0, sizeof(t));

    t.start_line = -1;

    in = BIO_new_file(argv[1], "r");

    in = BIO_new_file(argv[1], "rb");

    if (in == NULL) {

        fprintf(stderr, "Can't open %s for reading\n", argv[1]);

        return 1;

test/evptests.txt

+43 −0
Original line number Diff line number Diff line
@@ -3482,6 +3482,49 @@ iter = 4096 
MD = sha512

Key = 9d9e9c4cd21fe4be24d5b8244c759665



# PBKDF2 tests for empty and NULL inputs

PBE = pbkdf2

Password = ""

Salt = "salt"

iter = 1

MD = sha1

Key = a33dddc30478185515311f8752895d36ea4363a2



PBE = pbkdf2

Password = ""

Salt = "salt"

iter = 1

MD = sha256

Key = f135c27993baf98773c5cdb40a5706ce6a345cde



PBE = pbkdf2

Password = ""

Salt = "salt"

iter = 1

MD = sha512

Key = 00ef42cdbfc98d29db20976608e455567fdddf14



PBE = pbkdf2

Password = NULL

Salt = "salt"

iter = 1

MD = sha1

Key = a33dddc30478185515311f8752895d36ea4363a2



PBE = pbkdf2

Password = NULL

Salt = "salt"

iter = 1

MD = sha256

Key = f135c27993baf98773c5cdb40a5706ce6a345cde



PBE = pbkdf2

Password = NULL

Salt = "salt"

iter = 1

MD = sha512

Key = 00ef42cdbfc98d29db20976608e455567fdddf14



# Base64 tests



Encoding = canonical