Fixed counter overflow

Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Paul Dale <pauli@openssl.org> (Merged from #17607)
openssl · Feb 7, 2022 · 345c99b · 345c99b
1 parent b2f90e9
commit 345c99b
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Showing 3 changed files with 96 additions and 9 deletions.
diff --git a/crypto/modes/asm/aes-gcm-ppc.pl b/crypto/modes/asm/aes-gcm-ppc.pl
@@ -81,7 +81,6 @@
 
 $code=<<___;
 .machine        "any"
-.abiversion     2
 .text
 
 # 4x loops

diff --git a/include/crypto/aes_platform.h b/include/crypto/aes_platform.h
@@ -77,15 +77,23 @@ void AES_xts_decrypt(const unsigned char *inp, unsigned char *out, size_t len,
 #   define PPC_AES_GCM_CAPABLE (OPENSSL_ppccap_P & PPC_MADD300)
 #   define AES_GCM_ENC_BYTES 128
 #   define AES_GCM_DEC_BYTES 128
-size_t ppc_aes_gcm_encrypt(const unsigned char *in, unsigned char *out, size_t len,
-                         const void *key, unsigned char ivec[16], u64 *Xi);
-size_t ppc_aes_gcm_decrypt(const unsigned char *in, unsigned char *out, size_t len,
-                         const void *key, unsigned char ivec[16], u64 *Xi);
-void gcm_ghash_p8(u64 Xi[2],const u128 Htable[16],const u8 *inp, size_t len);
-#   define AES_gcm_encrypt ppc_aes_gcm_encrypt
-#   define AES_gcm_decrypt ppc_aes_gcm_decrypt
+size_t ppc_aes_gcm_encrypt(const unsigned char *in, unsigned char *out,
+                           size_t len, const void *key, unsigned char ivec[16],
+                           u64 *Xi);
+size_t ppc_aes_gcm_decrypt(const unsigned char *in, unsigned char *out,
+                           size_t len, const void *key, unsigned char ivec[16],
+                           u64 *Xi);
+size_t ppc_aes_gcm_encrypt_wrap(const unsigned char *in, unsigned char *out,
+                                size_t len, const void *key,
+                                unsigned char ivec[16], u64 *Xi);
+size_t ppc_aes_gcm_decrypt_wrap(const unsigned char *in, unsigned char *out,
+                                size_t len, const void *key,
+                                unsigned char ivec[16], u64 *Xi);
+#   define AES_gcm_encrypt ppc_aes_gcm_encrypt_wrap
+#   define AES_gcm_decrypt ppc_aes_gcm_decrypt_wrap
 #   define AES_GCM_ASM(gctx) ((gctx)->ctr==aes_p8_ctr32_encrypt_blocks && \
                               (gctx)->gcm.ghash==gcm_ghash_p8)
+void gcm_ghash_p8(u64 Xi[2],const u128 Htable[16],const u8 *inp, size_t len);
 #  endif /* PPC */
 
 #  if (defined(__arm__) || defined(__arm) || defined(__aarch64__))

diff --git a/providers/implementations/ciphers/cipher_aes_gcm_hw_ppc.inc b/providers/implementations/ciphers/cipher_aes_gcm_hw_ppc.inc
@@ -13,7 +13,7 @@
  */
 
 static int aes_ppc_gcm_initkey(PROV_GCM_CTX *ctx, const unsigned char *key,
-                             size_t keylen)
+                               size_t keylen)
 {
     PROV_AES_GCM_CTX *actx = (PROV_AES_GCM_CTX *)ctx;
     AES_KEY *ks = &actx->ks.ks;
@@ -23,6 +23,86 @@ static int aes_ppc_gcm_initkey(PROV_GCM_CTX *ctx, const unsigned char *key,
     return 1;
 }
 
+
+extern size_t ppc_aes_gcm_encrypt(const unsigned char *in, unsigned char *out, size_t len,
+                                  const void *key, unsigned char ivec[16], u64 *Xi);
+extern size_t ppc_aes_gcm_decrypt(const unsigned char *in, unsigned char *out, size_t len,
+                                  const void *key, unsigned char ivec[16], u64 *Xi);
+
+static inline u32 UTO32(unsigned char *buf)
+{
+    return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) | ((u32) buf[2] << 8) | ((u32) buf[3]);
+}
+
+static inline u32 add32TOU(unsigned char buf[4], u32 n)
+{
+    u32 r;
+
+    r = UTO32(buf);
+    r += n;
+    buf[0] = (unsigned char) (r >> 24) & 0xFF;
+    buf[1] = (unsigned char) (r >> 16) & 0xFF;
+    buf[2] = (unsigned char) (r >> 8) & 0xFF;
+    buf[3] = (unsigned char) r & 0xFF;
+    return r;
+}
+
+static size_t aes_p10_gcm_crypt(const unsigned char *in, unsigned char *out, size_t len,
+                                const void *key, unsigned char ivec[16], u64 *Xi, int encrypt)
+{
+    int s = 0;
+    int ndone = 0;
+    int ctr_reset = 0;
+    u64 blocks_unused;
+    u64 nb = len / 16;
+    u64 next_ctr = 0;
+    unsigned char ctr_saved[12];
+
+    memcpy(ctr_saved, ivec, 12);
+
+    while (nb) {
+        blocks_unused = (u64) 0xffffffffU + 1 - (u64) UTO32 (ivec + 12);
+        if (nb > blocks_unused) {
+            len = blocks_unused * 16;
+            nb -= blocks_unused;
+            next_ctr = blocks_unused;
+            ctr_reset = 1;
+        } else {
+            len = nb * 16;
+            next_ctr = nb;
+            nb = 0;
+        }
+
+        s = encrypt ? ppc_aes_gcm_encrypt(in, out, len, key, ivec, Xi)
+                    : ppc_aes_gcm_decrypt(in, out, len, key, ivec, Xi);
+
+        /* add counter to ivec */
+        add32TOU(ivec + 12, (u32) next_ctr);
+        if (ctr_reset) {
+            ctr_reset = 0;
+            in += len;
+            out += len;
+        }
+        memcpy(ivec, ctr_saved, 12);
+        ndone += s;
+    }
+
+    return ndone;
+}
+
+size_t ppc_aes_gcm_encrypt_wrap(const unsigned char *in, unsigned char *out, size_t len,
+                                const void *key, unsigned char ivec[16], u64 *Xi)
+{
+    return aes_p10_gcm_crypt(in, out, len, key, ivec, Xi, 1);
+}
+
+size_t ppc_aes_gcm_decrypt_wrap(const unsigned char *in, unsigned char *out, size_t len,
+                                const void *key, unsigned char ivec[16], u64 *Xi)
+{
+    return aes_p10_gcm_crypt(in, out, len, key, ivec, Xi, 0);
+}
+
+
 static const PROV_GCM_HW aes_ppc_gcm = {
     aes_ppc_gcm_initkey,
     ossl_gcm_setiv,