Fix incomplete checks for EVP_CIPHER_asn1_to_param

EVP_CIPHER_asn1_to_param() returns a value <= 0 in case of an error, and
a value greater than 0 in case of success. Two callsites only check for
< 0 instead of <= 0. The other callsites perform this check correctly.
Change the two callsites to <= 0. Additionally correctly handle a zero
return value from EVP_CIPHER_get_asn1_iv as success.

Fixes: #20116

CLA: trivial

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/201213)

crypto/evp/evp_lib.c

@@ -209,7 +209,7 @@ int evp_cipher_asn1_to_param_ex(EVP_CIPHER_CTX *c, ASN1_TYPE *type,
             break;
 
         default:
-            ret = EVP_CIPHER_get_asn1_iv(c, type);
+            ret = EVP_CIPHER_get_asn1_iv(c, type) >= 0 ? 1 : -1;
         }
     } else if (cipher->prov != NULL) {
         OSSL_PARAM params[3], *p = params;

crypto/evp/p5_crpt2.c

@@ -159,7 +159,7 @@ int PKCS5_v2_PBE_keyivgen_ex(EVP_CIPHER_CTX *ctx, const char *pass, int passlen,
     /* Fixup cipher based on AlgorithmIdentifier */
     if (!EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, en_de))
         goto err;
-    if (EVP_CIPHER_asn1_to_param(ctx, pbe2->encryption->parameter) < 0) {
+    if (EVP_CIPHER_asn1_to_param(ctx, pbe2->encryption->parameter) <= 0) {
         ERR_raise(ERR_LIB_EVP, EVP_R_CIPHER_PARAMETER_ERROR);
         goto err;
     }

crypto/pkcs7/pk7_doit.c

@@ -589,7 +589,7 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
         BIO_get_cipher_ctx(etmp, &evp_ctx);
         if (EVP_CipherInit_ex(evp_ctx, cipher, NULL, NULL, NULL, 0) <= 0)
             goto err;
-        if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) < 0)
+        if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) <= 0)
             goto err;
         /* Generate random key as MMA defence */
         len = EVP_CIPHER_CTX_get_key_length(evp_ctx);