Allow oversized buffers for provider cipher IV fetch

When we're fetching an IV, there's no need to enforce that the
provided buffer is exactly the same size as the IV we want to
write into it.  This might happen, for example, when
EVP_CIPHER_CTX_iv_noconst() passes sizeof(ctx->iv) (that is,
EVP_MAX_IV_LENGTH) for an AES-GCM cipher that uses a shorter IV.
AES-OCB and CCM were also affected.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/12039)

diff --git a/providers/implementations/ciphers/cipher_aes_ocb.c b/providers/implementations/ciphers/cipher_aes_ocb.c
index 681eb9ee707d52c84b6ae829c063a2e7131eb1cd..84ba062d6b7e3cd110c2ab84e579162328b6807a 100644 (file)
--- a/providers/implementations/ciphers/cipher_aes_ocb.c
+++ b/providers/implementations/ciphers/cipher_aes_ocb.c
@@ -401,7 +401,7 @@ static int aes_ocb_get_ctx_params(void *vctx, OSSL_PARAM params[])
 
     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV);
     if (p != NULL) {
-        if (ctx->base.ivlen != p->data_size) {
+        if (ctx->base.ivlen > p->data_size) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
             return 0;
         }

diff --git a/providers/implementations/ciphers/ciphercommon_ccm.c b/providers/implementations/ciphers/ciphercommon_ccm.c
index 3825a0741c864db0f4c217c1f2f485342200d77b..2b9a0687e3c947008762b93cd1200cb58dd0cd81 100644 (file)
--- a/providers/implementations/ciphers/ciphercommon_ccm.c
+++ b/providers/implementations/ciphers/ciphercommon_ccm.c
@@ -160,7 +160,7 @@ int ccm_get_ctx_params(void *vctx, OSSL_PARAM params[])
 
     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV);
     if (p != NULL) {
-        if (ccm_get_ivlen(ctx) != p->data_size) {
+        if (ccm_get_ivlen(ctx) > p->data_size) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
             return 0;
         }

diff --git a/providers/implementations/ciphers/ciphercommon_gcm.c b/providers/implementations/ciphers/ciphercommon_gcm.c
index 06fbbd07aaf6b68a744c6bb676b3f8e00dd8fe44..7daa8dce5b1a004c3f9c099c3e776448acb2018f 100644 (file)
--- a/providers/implementations/ciphers/ciphercommon_gcm.c
+++ b/providers/implementations/ciphers/ciphercommon_gcm.c
@@ -156,7 +156,7 @@ int gcm_get_ctx_params(void *vctx, OSSL_PARAM params[])
     if (p != NULL) {
         if (ctx->iv_gen != 1 && ctx->iv_gen_rand != 1)
             return 0;
-        if (ctx->ivlen != p->data_size) {
+        if (ctx->ivlen > p->data_size) {
             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
             return 0;
         }