Add appropriate NULL checks in EVP_CIPHER api

apps/enc.c

@@ -593,6 +593,7 @@ int enc_main(int argc, char **argv)
         }
         if (hiv != NULL) {
             int siz = EVP_CIPHER_get_iv_length(cipher);
+
             if (siz == 0) {
                 BIO_printf(bio_err, "warning: iv not used by this cipher\n");
             } else if (!set_hex(hiv, iv, siz)) {

crypto/cmac/cmac.c

@@ -95,7 +95,7 @@ int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in)
 
     if (in->nlast_block == -1)
         return 0;
-    if ((bl = EVP_CIPHER_CTX_get_block_size(in->cctx)) < 0)
+    if ((bl = EVP_CIPHER_CTX_get_block_size(in->cctx)) == 0)
         return 0;
     if (!EVP_CIPHER_CTX_copy(out->cctx, in->cctx))
         return 0;
@@ -111,6 +111,7 @@ int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,
               const EVP_CIPHER *cipher, ENGINE *impl)
 {
     static const unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH] = { 0 };
+    int block_len;
 
     /* All zeros means restart */
     if (!key && !cipher && !impl && keylen == 0) {
@@ -119,7 +120,10 @@ int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,
             return 0;
         if (!EVP_EncryptInit_ex(ctx->cctx, NULL, NULL, NULL, zero_iv))
             return 0;
-        memset(ctx->tbl, 0, EVP_CIPHER_CTX_get_block_size(ctx->cctx));
+        block_len = EVP_CIPHER_CTX_get_block_size(ctx->cctx);
+        if (block_len == 0)
+            return 0;
+        memset(ctx->tbl, 0, block_len);
         ctx->nlast_block = 0;
         return 1;
     }
@@ -170,7 +174,7 @@ int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen)
         return 0;
     if (dlen == 0)
         return 1;
-    if ((bl = EVP_CIPHER_CTX_get_block_size(ctx->cctx)) < 0)
+    if ((bl = EVP_CIPHER_CTX_get_block_size(ctx->cctx)) == 0)
         return 0;
     /* Copy into partial block if we need to */
     if (ctx->nlast_block > 0) {
@@ -234,7 +238,7 @@ int CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen)
 
     if (ctx->nlast_block == -1)
         return 0;
-    if ((bl = EVP_CIPHER_CTX_get_block_size(ctx->cctx)) < 0)
+    if ((bl = EVP_CIPHER_CTX_get_block_size(ctx->cctx)) == 0)
         return 0;
     if (poutlen != NULL)
         *poutlen = (size_t)bl;

crypto/cms/cms_pwri.c

@@ -204,6 +204,10 @@ static int kek_unwrap_key(unsigned char *out, size_t *outlen,
     size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
     unsigned char *tmp;
     int outl, rv = 0;
+
+    if (blocklen == 0)
+        return 0;
+
     if (inlen < 2 * blocklen) {
         /* too small */
         return 0;
@@ -257,6 +261,10 @@ static int kek_wrap_key(unsigned char *out, size_t *outlen,
     size_t blocklen = EVP_CIPHER_CTX_get_block_size(ctx);
     size_t olen;
     int dummy;
+
+    if (blocklen == 0)
+        return 0;
+
     /*
      * First decide length of output buffer: need header and round up to
      * multiple of block length.

crypto/evp/bio_enc.c

@@ -132,6 +132,10 @@ static int enc_read(BIO *b, char *out, int outl)
     }
 
     blocksize = EVP_CIPHER_CTX_get_block_size(ctx->cipher);
+
+    if (blocksize == 0)
+        return 0;
+
     if (blocksize == 1)
         blocksize = 0;
 

crypto/evp/evp_key.c

@@ -88,7 +88,7 @@ int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
     nkey = EVP_CIPHER_get_key_length(type);
     niv = EVP_CIPHER_get_iv_length(type);
     OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
-    OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
+    OPENSSL_assert(niv >= 0 && niv <= EVP_MAX_IV_LENGTH);
 
     if (data == NULL)
         return nkey;

crypto/evp/evp_lib.c

@@ -81,8 +81,12 @@ int evp_cipher_param_to_asn1_ex(EVP_CIPHER_CTX *c, ASN1_TYPE *type,
                                 evp_cipher_aead_asn1_params *asn1_params)
 {
     int ret = -1;                /* Assume the worst */
-    const EVP_CIPHER *cipher = c->cipher;
+    const EVP_CIPHER *cipher;
 
+    if (c == NULL || c->cipher == NULL)
+        goto err;
+
+    cipher = c->cipher;
     /*
      * For legacy implementations, we detect custom AlgorithmIdentifier
      * parameter handling by checking if the function pointer
@@ -172,8 +176,12 @@ int evp_cipher_asn1_to_param_ex(EVP_CIPHER_CTX *c, ASN1_TYPE *type,
                                 evp_cipher_aead_asn1_params *asn1_params)
 {
     int ret = -1;                /* Assume the worst */
-    const EVP_CIPHER *cipher = c->cipher;
+    const EVP_CIPHER *cipher;
+
+    if (c == NULL || c->cipher == NULL)
+        goto err;
 
+    cipher = c->cipher;
     /*
      * For legacy implementations, we detect custom AlgorithmIdentifier
      * parameter handling by checking if there the function pointer
@@ -230,6 +238,7 @@ int evp_cipher_asn1_to_param_ex(EVP_CIPHER_CTX *c, ASN1_TYPE *type,
         ret = -2;
     }
 
+err:
     if (ret == -2)
         ERR_raise(ERR_LIB_EVP, EVP_R_UNSUPPORTED_CIPHER);
     else if (ret <= 0)
@@ -387,7 +396,7 @@ int evp_cipher_cache_constants(EVP_CIPHER *cipher)
 
 int EVP_CIPHER_get_block_size(const EVP_CIPHER *cipher)
 {
-    return cipher->block_size;
+    return (cipher == NULL) ? 0 : cipher->block_size;
 }
 
 int EVP_CIPHER_CTX_get_block_size(const EVP_CIPHER_CTX *ctx)
@@ -403,6 +412,9 @@ int EVP_CIPHER_impl_ctx_size(const EVP_CIPHER *e)
 int EVP_Cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
                const unsigned char *in, unsigned int inl)
 {
+    if (ctx == NULL || ctx->cipher == NULL)
+        return 0;
+
     if (ctx->cipher->prov != NULL) {
         /*
          * If the provided implementation has a ccipher function, we use it,
@@ -415,6 +427,9 @@ int EVP_Cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
         size_t outl = 0;
         size_t blocksize = EVP_CIPHER_CTX_get_block_size(ctx);
 
+        if (blocksize == 0)
+            return 0;
+
         if (ctx->cipher->ccipher != NULL)
             ret =  ctx->cipher->ccipher(ctx->algctx, out, &outl,
                                         inl + (blocksize == 1 ? 0 : blocksize),
@@ -454,7 +469,7 @@ EVP_CIPHER *EVP_CIPHER_CTX_get1_cipher(EVP_CIPHER_CTX *ctx)
 {
     EVP_CIPHER *cipher;
 
-    if (ctx == NULL)
+    if (ctx == NULL || ctx->cipher == NULL)
         return NULL;
     cipher = (EVP_CIPHER *)ctx->cipher;
     if (!EVP_CIPHER_up_ref(cipher))
@@ -469,7 +484,7 @@ int EVP_CIPHER_CTX_is_encrypting(const EVP_CIPHER_CTX *ctx)
 
 unsigned long EVP_CIPHER_get_flags(const EVP_CIPHER *cipher)
 {
-    return cipher->flags;
+    return cipher == NULL ? 0 : cipher->flags;
 }
 
 void *EVP_CIPHER_CTX_get_app_data(const EVP_CIPHER_CTX *ctx)
@@ -499,11 +514,14 @@ void *EVP_CIPHER_CTX_set_cipher_data(EVP_CIPHER_CTX *ctx, void *cipher_data)
 
 int EVP_CIPHER_get_iv_length(const EVP_CIPHER *cipher)
 {
-    return cipher->iv_len;
+    return (cipher == NULL) ? 0 : cipher->iv_len;
 }
 
 int EVP_CIPHER_CTX_get_iv_length(const EVP_CIPHER_CTX *ctx)
 {
+    if (ctx->cipher == NULL)
+        return 0;
+
     if (ctx->iv_len < 0) {
         int rv, len = EVP_CIPHER_get_iv_length(ctx->cipher);
         size_t v = len;
@@ -678,12 +696,12 @@ int EVP_CIPHER_CTX_get_key_length(const EVP_CIPHER_CTX *ctx)
 
 int EVP_CIPHER_get_nid(const EVP_CIPHER *cipher)
 {
-    return cipher->nid;
+    return (cipher == NULL) ? NID_undef : cipher->nid;
 }
 
 int EVP_CIPHER_CTX_get_nid(const EVP_CIPHER_CTX *ctx)
 {
-    return ctx->cipher->nid;
+    return EVP_CIPHER_get_nid(ctx->cipher);
 }
 
 int EVP_CIPHER_is_a(const EVP_CIPHER *cipher, const char *name)

crypto/pkcs12/p12_decr.c

@@ -26,6 +26,7 @@ unsigned char *PKCS12_pbe_crypt_ex(const X509_ALGOR *algor,
     int outlen, i;
     EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
     int max_out_len, mac_len = 0;
+    int block_size;
 
     if (ctx == NULL) {
         ERR_raise(ERR_LIB_PKCS12, ERR_R_EVP_LIB);
@@ -43,7 +44,14 @@ unsigned char *PKCS12_pbe_crypt_ex(const X509_ALGOR *algor,
      * It's appended to encrypted text on encrypting
      * MAC should be processed on decrypting separately from plain text
      */
-    max_out_len = inlen + EVP_CIPHER_CTX_get_block_size(ctx);
+    block_size = EVP_CIPHER_CTX_get_block_size(ctx);
+
+    if (block_size == 0) {
+        ERR_raise(ERR_LIB_PKCS12, ERR_R_PASSED_NULL_PARAMETER);
+        goto err;
+    }
+
+    max_out_len = inlen + block_size;
     if ((EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(ctx))
                 & EVP_CIPH_FLAG_CIPHER_WITH_MAC) != 0) {
         if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_TLS1_AAD, 0, &mac_len) < 0) {

doc/man3/EVP_EncryptInit.pod

@@ -484,7 +484,9 @@ EVP_CIPHER_free().
 
 Return the NID of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX>
 structure.  The actual NID value is an internal value which may not have a
-corresponding OBJECT IDENTIFIER.
+corresponding OBJECT IDENTIFIER.  NID_undef is returned in the event that the
+nid is unknown or if the cipher has not been properly initalized via a call to
+B<EVP_CipherInit>.
 
 =item EVP_CIPHER_CTX_set_flags(), EVP_CIPHER_CTX_clear_flags() and EVP_CIPHER_CTX_test_flags()
 
@@ -521,8 +523,10 @@ length to any value other than the fixed value is an error.
 =item EVP_CIPHER_get_iv_length() and EVP_CIPHER_CTX_get_iv_length()
 
 Return the IV length of a cipher when passed an B<EVP_CIPHER> or
-B<EVP_CIPHER_CTX>. It will return zero if the cipher does not use an IV.
-The constant B<EVP_MAX_IV_LENGTH> is the maximum IV length for all ciphers.
+B<EVP_CIPHER_CTX>. It will return zero if the cipher does not use an IV, if
+the cipher has not yet been initalized within the B<EVP_CIPHER_CTX>, or if the
+passed cipher is NULL.  The constant B<EVP_MAX_IV_LENGTH> is the maximum IV
+length for all ciphers.
 
 =item EVP_CIPHER_CTX_get_tag_length()
 
@@ -534,7 +538,8 @@ the tag length has not been set.
 
 Return the block size of a cipher when passed an B<EVP_CIPHER> or
 B<EVP_CIPHER_CTX> structure. The constant B<EVP_MAX_BLOCK_LENGTH> is also the
-maximum block length for all ciphers.
+maximum block length for all ciphers. A value of 0 is returned if the cipher
+has not been properly initalized with a call to B<EVP_CipherInit>.
 
 =item EVP_CIPHER_get_type() and EVP_CIPHER_CTX_get_type()
 
@@ -576,7 +581,7 @@ B<EVP_CIPHER>.
 
 Returns the B<EVP_CIPHER> structure when passed an B<EVP_CIPHER_CTX> structure.
 EVP_CIPHER_CTX_get1_cipher() is the same except the ownership is passed to
-the caller.
+the caller. Both functions return NULL on error.
 
 =item EVP_CIPHER_get_mode() and EVP_CIPHER_CTX_get_mode()
 
@@ -612,7 +617,8 @@ Sets the AlgorithmIdentifier "parameter" based on the passed cipher. This will
 typically include any parameters and an IV. The cipher IV (if any) must be set
 when this call is made. This call should be made before the cipher is actually
 "used" (before any EVP_EncryptUpdate(), EVP_DecryptUpdate() calls for example).
-This function may fail if the cipher does not have any ASN1 support.
+This function may fail if the cipher does not have any ASN1 support, or if an
+uninitialized cipher is passed to it.
 
 =item EVP_CIPHER_asn1_to_param()
 
@@ -1244,8 +1250,9 @@ EVP_DecryptFinal_ex() returns 0 if the decrypt failed or 1 for success.
 EVP_CipherInit_ex2() and EVP_CipherUpdate() return 1 for success and 0 for failure.
 EVP_CipherFinal_ex() returns 0 for a decryption failure or 1 for success.
 
-EVP_Cipher() returns 1 on success or 0 on failure, if the flag
-B<EVP_CIPH_FLAG_CUSTOM_CIPHER> is not set for the cipher.
+EVP_Cipher() returns 1 on success and <= 0 on failure, if the flag
+B<EVP_CIPH_FLAG_CUSTOM_CIPHER> is not set for the cipher, or if the cipher has
+not been initalized via a call to B<EVP_CipherInit_ex2>.
 EVP_Cipher() returns the number of bytes written to I<out> for encryption / decryption, or
 the number of bytes authenticated in a call specifying AAD for an AEAD cipher, if the flag
 B<EVP_CIPH_FLAG_CUSTOM_CIPHER> is set for the cipher.
@@ -1258,7 +1265,7 @@ return an B<EVP_CIPHER> structure or NULL on error.
 EVP_CIPHER_get_nid() and EVP_CIPHER_CTX_get_nid() return a NID.
 
 EVP_CIPHER_get_block_size() and EVP_CIPHER_CTX_get_block_size() return the
-block size.
+block size, or 0 on error.
 
 EVP_CIPHER_get_key_length() and EVP_CIPHER_CTX_get_key_length() return the key
 length.

providers/implementations/kdfs/krb5kdf.c

@@ -416,6 +416,12 @@ static int KRB5KDF(const EVP_CIPHER *cipher, ENGINE *engine,
     /* Initialize input block */
     blocksize = EVP_CIPHER_CTX_get_block_size(ctx);
 
+    if (blocksize == 0) {
+        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CIPHER);
+        ret = 0;
+        goto out;
+    }
+
     if (constant_len > blocksize) {
         ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CONSTANT_LENGTH);
         ret = 0;

ssl/record/methods/ssl3_meth.c

@@ -115,6 +115,9 @@ static int ssl3_cipher(OSSL_RECORD_LAYER *rl, TLS_RL_RECORD *inrecs,
     l = rec->length;
     bs = EVP_CIPHER_CTX_get_block_size(ds);
 
+    if (bs == 0)
+        return 0;
+
     /* COMPRESS */
 
     if ((bs != 1) && sending && !provided) {

ssl/record/methods/tls1_meth.c

@@ -222,6 +222,11 @@ static int tls1_cipher(OSSL_RECORD_LAYER *rl, TLS_RL_RECORD *recs,
 
     bs = EVP_CIPHER_get_block_size(EVP_CIPHER_CTX_get0_cipher(ds));
 
+    if (bs == 0) {
+        RLAYERfatal(rl, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_CIPHER);
+        return 0;
+    }
+
     if (n_recs > 1) {
         if ((EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(ds))
                  & EVP_CIPH_FLAG_PIPELINE) == 0) {

ssl/s3_enc.c

@@ -120,6 +120,7 @@ int ssl3_change_cipher_state(SSL_CONNECTION *s, int which)
     md_len = (size_t)mdi;
     key_len = EVP_CIPHER_get_key_length(ciph);
     iv_len = EVP_CIPHER_get_iv_length(ciph);
+
     if ((which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||
         (which == SSL3_CHANGE_CIPHER_SERVER_READ)) {
         mac_secret = &(p[0]);

ssl/ssl_ciph.c

@@ -2221,6 +2221,8 @@ int ssl_cipher_get_overhead(const SSL_CIPHER *c, size_t *mac_overhead,
             in = 1; /* padding length byte */
             out = EVP_CIPHER_get_iv_length(e_ciph);
             blk = EVP_CIPHER_get_block_size(e_ciph);
+            if (blk == 0)
+                return 0;
         }
     }
 

test/evp_extra_test.c

@@ -3490,6 +3490,10 @@ static int test_evp_iv_aes(int idx)
             || !TEST_true(EVP_EncryptFinal_ex(ctx, ciphertext, &len)))
         goto err;
     ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
+
+    if (!TEST_int_gt(ivlen, 0))
+        goto err;
+
     if (!TEST_mem_eq(init_iv, ivlen, oiv, ivlen)
             || !TEST_mem_eq(ref_iv, ref_len, iv, ivlen))
         goto err;
@@ -3601,6 +3605,10 @@ static int test_evp_iv_des(int idx)
             || !TEST_true(EVP_EncryptFinal_ex(ctx, ciphertext, &len)))
         goto err;
     ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
+
+    if (!TEST_int_gt(ivlen, 0))
+        goto err;
+
     if (!TEST_mem_eq(init_iv, ivlen, oiv, ivlen)
             || !TEST_mem_eq(ref_iv, ref_len, iv, ivlen))
         goto err;
@@ -4153,7 +4161,8 @@ static int test_evp_updated_iv(int idx)
         errmsg = "CIPHER_CTX_GET_UPDATED_IV";
         goto err;
     }
-    if (!TEST_true(iv_len = EVP_CIPHER_CTX_get_iv_length(ctx))) {
+    iv_len = EVP_CIPHER_CTX_get_iv_length(ctx);
+    if (!TEST_int_ge(iv_len,0)) {
         errmsg = "CIPHER_CTX_GET_IV_LEN";
         goto err;
     }