gcm128.c: add boundary condition checks.
authorAndy Polyakov <appro@openssl.org>
Mon, 7 Feb 2011 19:11:13 +0000 (19:11 +0000)
committerAndy Polyakov <appro@openssl.org>
Mon, 7 Feb 2011 19:11:13 +0000 (19:11 +0000)
crypto/modes/gcm128.c
crypto/modes/modes.h

index a9e9a34..3f6b70d 100644 (file)
@@ -809,14 +809,20 @@ void CRYPTO_gcm128_setiv(GCM128_CONTEXT *ctx,const unsigned char *iv,size_t len)
                ctx->Yi.d[3] = ctr;
 }
 
-void CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx,const unsigned char *aad,size_t len)
+int CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx,const unsigned char *aad,size_t len)
 {
        size_t i;
-       int n;
+       unsigned int n;
+       u64 alen = ctx->len.u[0];
 
-       ctx->len.u[0] += len;
-       n = ctx->ares;
+       if (ctx->len.u[1]) return -2;
+
+       alen += len;
+       if (alen>(U64(1)<<61) || (sizeof(len)==8 && alen<len))
+               return -1;
+       ctx->len.u[0] = alen;
 
+       n = ctx->ares;
        if (n) {
                while (n && len) {
                        ctx->Xi.c[n] ^= *(aad++);
@@ -826,7 +832,7 @@ void CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx,const unsigned char *aad,size_t len)
                if (n==0) GCM_MUL(ctx,Xi);
                else {
                        ctx->ares = n;
-                       return;
+                       return 0;
                }
        }
 
@@ -845,20 +851,30 @@ void CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx,const unsigned char *aad,size_t len)
        }
 #endif
        if (len) {
-               n = (int)len;
+               n = (unsigned int)len;
                for (i=0; i<len; ++i) ctx->Xi.c[i] ^= aad[i];
        }
 
        ctx->ares = n;
+       return 0;
 }
 
-void CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
                const unsigned char *in, unsigned char *out,
                size_t len)
 {
        const union { long one; char little; } is_endian = {1};
        unsigned int n, ctr;
        size_t i;
+       u64 mlen = ctx->len.u[1];
+
+#if 0
+       n = (unsigned int)mlen%16; /* alternative to ctx->mres */
+#endif
+       mlen += len;
+       if (mlen>((U64(1)<<36)-32) || (sizeof(len)==8 && mlen<len))
+               return -1;
+       ctx->len.u[1] = mlen;
 
        if (ctx->ares) {
                /* First call to encrypt finalizes GHASH(AAD) */
@@ -866,13 +882,12 @@ void CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
                ctx->ares = 0;
        }
 
-       ctx->len.u[1] += len;
-       n   = ctx->mres;
        if (is_endian.little)
                ctr = GETU32(ctx->Yi.c+12);
        else
                ctr = ctx->Yi.d[3];
 
+       n = ctx->mres;
 #if !defined(OPENSSL_SMALL_FOOTPRINT)
        if (16%sizeof(size_t) == 0) do {        /* always true actually */
                if (n) {
@@ -884,7 +899,7 @@ void CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
                        if (n==0) GCM_MUL(ctx,Xi);
                        else {
                                ctx->mres = n;
-                               return;
+                               return 0;
                        }
                }
 #if defined(STRICT_ALIGNMENT)
@@ -963,7 +978,7 @@ void CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
                }
 
                ctx->mres = n;
-               return;
+               return 0;
        } while(0);
 #endif
        for (i=0;i<len;++i) {
@@ -982,15 +997,22 @@ void CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
        }
 
        ctx->mres = n;
+       return 0;
 }
 
-void CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
                const unsigned char *in, unsigned char *out,
                size_t len)
 {
        const union { long one; char little; } is_endian = {1};
        unsigned int n, ctr;
        size_t i;
+       u64 mlen = ctx->len.u[1];
+
+       mlen += len;
+       if (mlen>((U64(1)<<36)-32) || (sizeof(len)==8 && mlen<len))
+               return -1;
+       ctx->len.u[1] = mlen;
 
        if (ctx->ares) {
                /* First call to decrypt finalizes GHASH(AAD) */
@@ -998,13 +1020,12 @@ void CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
                ctx->ares = 0;
        }
 
-       ctx->len.u[1] += len;
-       n   = ctx->mres;
        if (is_endian.little)
                ctr = GETU32(ctx->Yi.c+12);
        else
                ctr = ctx->Yi.d[3];
 
+       n = ctx->mres;
 #if !defined(OPENSSL_SMALL_FOOTPRINT)
        if (16%sizeof(size_t) == 0) do {        /* always true actually */
                if (n) {
@@ -1018,7 +1039,7 @@ void CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
                        if (n==0) GCM_MUL (ctx,Xi);
                        else {
                                ctx->mres = n;
-                               return;
+                               return 0;
                        }
                }
 #if defined(STRICT_ALIGNMENT)
@@ -1098,7 +1119,7 @@ void CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
                }
 
                ctx->mres = n;
-               return;
+               return 0;
        } while(0);
 #endif
        for (i=0;i<len;++i) {
@@ -1120,15 +1141,22 @@ void CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
        }
 
        ctx->mres = n;
+       return 0;
 }
 
-void CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
                const unsigned char *in, unsigned char *out,
                size_t len, ctr128_f stream)
 {
        const union { long one; char little; } is_endian = {1};
        unsigned int n, ctr;
        size_t i;
+       u64 mlen = ctx->len.u[1];
+
+       mlen += len;
+       if (mlen>((U64(1)<<36)-32) || (sizeof(len)==8 && mlen<len))
+               return -1;
+       ctx->len.u[1] = mlen;
 
        if (ctx->ares) {
                /* First call to encrypt finalizes GHASH(AAD) */
@@ -1136,13 +1164,12 @@ void CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
                ctx->ares = 0;
        }
 
-       ctx->len.u[1] += len;
-       n   = ctx->mres;
        if (is_endian.little)
                ctr = GETU32(ctx->Yi.c+12);
        else
                ctr = ctx->Yi.d[3];
 
+       n = ctx->mres;
        if (n) {
                while (n && len) {
                        ctx->Xi.c[n] ^= *(out++) = *(in++)^ctx->EKi.c[n];
@@ -1152,7 +1179,7 @@ void CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
                if (n==0) GCM_MUL(ctx,Xi);
                else {
                        ctx->mres = n;
-                       return;
+                       return 0;
                }
        }
 #if defined(GHASH) && !defined(OPENSSL_SMALL_FOOTPRINT)
@@ -1205,15 +1232,22 @@ void CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
        }
 
        ctx->mres = n;
+       return 0;
 }
 
-void CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
                const unsigned char *in, unsigned char *out,
                size_t len,ctr128_f stream)
 {
        const union { long one; char little; } is_endian = {1};
        unsigned int n, ctr;
        size_t i;
+       u64 mlen = ctx->len.u[1];
+
+       mlen += len;
+       if (mlen>((U64(1)<<36)-32) || (sizeof(len)==8 && mlen<len))
+               return -1;
+       ctx->len.u[1] = mlen;
 
        if (ctx->ares) {
                /* First call to decrypt finalizes GHASH(AAD) */
@@ -1221,13 +1255,12 @@ void CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
                ctx->ares = 0;
        }
 
-       ctx->len.u[1] += len;
-       n   = ctx->mres;
        if (is_endian.little)
                ctr = GETU32(ctx->Yi.c+12);
        else
                ctr = ctx->Yi.d[3];
 
+       n = ctx->mres;
        if (n) {
                while (n && len) {
                        u8 c = *(in++);
@@ -1239,7 +1272,7 @@ void CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
                if (n==0) GCM_MUL (ctx,Xi);
                else {
                        ctx->mres = n;
-                       return;
+                       return 0;
                }
        }
 #if defined(GHASH) && !defined(OPENSSL_SMALL_FOOTPRINT)
@@ -1297,6 +1330,7 @@ void CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
        }
 
        ctx->mres = n;
+       return 0;
 }
 
 int CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx,const unsigned char *tag,
@@ -1340,7 +1374,7 @@ int CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx,const unsigned char *tag,
 void CRYPTO_gcm128_tag(GCM128_CONTEXT *ctx, unsigned char *tag, size_t len)
 {
        CRYPTO_gcm128_finish(ctx, NULL, 0);
-       memcpy(tag, ctx->Xi.c, len);
+       memcpy(tag, ctx->Xi.c, len<=sizeof(ctx->Xi.c)?len:sizeof(ctx->Xi.c));
 }
 
 GCM128_CONTEXT *CRYPTO_gcm128_new(void *key, block128_f block)
index 1af06ef..0a41b23 100644 (file)
@@ -86,18 +86,18 @@ GCM128_CONTEXT *CRYPTO_gcm128_new(void *key, block128_f block);
 void CRYPTO_gcm128_init(GCM128_CONTEXT *ctx,void *key,block128_f block);
 void CRYPTO_gcm128_setiv(GCM128_CONTEXT *ctx, const unsigned char *iv,
                        size_t len);
-void CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx, const unsigned char *aad,
+int CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx, const unsigned char *aad,
                        size_t len);
-void CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,
                        const unsigned char *in, unsigned char *out,
                        size_t len);
-void CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx,
                        const unsigned char *in, unsigned char *out,
                        size_t len);
-void CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
                        const unsigned char *in, unsigned char *out,
                        size_t len, ctr128_f stream);
-void CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
+int CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
                        const unsigned char *in, unsigned char *out,
                        size_t len, ctr128_f stream);
 int  CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx,const unsigned char *tag,