diff --git a/sim/Cargo.lock b/sim/Cargo.lock
index 67d5c70..c16311d 100644
--- a/sim/Cargo.lock
+++ b/sim/Cargo.lock
@@ -7,11 +7,11 @@
  "enumflags_derive 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
- "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
- "rust-crypto 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ring 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "simflash 0.1.0",
 ]
 
@@ -25,33 +25,42 @@
 
 [[package]]
 name = "backtrace"
-version = "0.3.0"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace-sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "cfg-if 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace-sys 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "dbghelp-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-demangle 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-demangle 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "backtrace-sys"
-version = "0.1.5"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "cfg-if"
-version = "0.1.0"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "coco"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "either 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scopeguard 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "dbghelp-sys"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -65,13 +74,18 @@
 version = "0.6.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "lazy_static 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.1.80 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "strsim 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "either"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "enumflags"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -90,19 +104,24 @@
 version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.1.80 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "error-chain"
-version = "0.7.1"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "futures"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "gcc"
 version = "0.3.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -118,17 +137,17 @@
 
 [[package]]
 name = "lazy_static"
-version = "0.2.2"
+version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "libc"
-version = "0.2.17"
+version = "0.2.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "log"
-version = "0.3.6"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -136,7 +155,15 @@
 version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "num_cpus"
+version = "1.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -149,13 +176,29 @@
 version = "0.3.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
-name = "redox_syscall"
-version = "0.1.26"
+name = "rayon"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rayon-core 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "coco 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
+]
 
 [[package]]
 name = "regex"
@@ -175,32 +218,37 @@
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "rust-crypto"
-version = "0.2.36"
+name = "ring"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
- "time 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "untrusted 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rustc-demangle"
-version = "0.1.3"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "rustc-serialize"
-version = "0.3.22"
+version = "0.3.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "scopeguard"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "simflash"
 version = "0.1.0"
 dependencies = [
- "error-chain 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "error-chain 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -232,7 +280,7 @@
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -244,22 +292,16 @@
 ]
 
 [[package]]
-name = "time"
-version = "0.1.38"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
- "redox_syscall 0.1.26 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
 name = "unicode-xid"
 version = "0.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "untrusted"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "utf8-ranges"
 version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -276,36 +318,42 @@
 
 [metadata]
 "checksum aho-corasick 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ca972c2ea5f742bfce5687b9aef75506a764f61d37f8f649047846a9686ddb66"
-"checksum backtrace 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f551bc2ddd53aea015d453ef0b635af89444afa5ed2405dd0b2062ad5d600d80"
-"checksum backtrace-sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "3602e8d8c43336088a8505fa55cae2b3884a9be29440863a11528a42f46f6bb7"
-"checksum cfg-if 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de1e760d7b6535af4241fca8bd8adf68e2e7edacc6b29f5d399050c5e48cf88c"
+"checksum backtrace 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "72f9b4182546f4b04ebc4ab7f84948953a118bd6021a1b6a6c909e3e94f6be76"
+"checksum backtrace-sys 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3a0d842ea781ce92be2bf78a9b38883948542749640b8378b3b2f03d1fd9f1ff"
+"checksum cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c819a1287eb618df47cc647173c5c4c66ba19d888a6e50d605672aed3140de"
+"checksum coco 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c06169f5beb7e31c7c67ebf5540b8b472d23e3eade3b2ec7d1f5b504a85f91bd"
 "checksum dbghelp-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "97590ba53bcb8ac28279161ca943a924d1fd4a8fb3fa63302591647c4fc5b850"
 "checksum docopt 0.6.86 (registry+https://github.com/rust-lang/crates.io-index)" = "4a7ef30445607f6fc8720f0a0a2c7442284b629cf0d049286860fae23e71c4d9"
+"checksum either 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "18785c1ba806c258137c937e44ada9ee7e69a37e3c72077542cd2f069d78562a"
 "checksum enumflags 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b003f771fcd8df873645aa0142c86b50a9d5ce063ca0ce6057a4131f2b6ef3c2"
 "checksum enumflags_derive 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "46ac5d2e0ce7696d1b0c9fb0a1d1c388bc1b04a23b99d54520c15d43ec832466"
 "checksum env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "15abd780e45b3ea4f76b4e9a26ff4843258dd8a3eed2775a0e7368c2e7936c2f"
-"checksum error-chain 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1cd681735364a04cd5d69f01a4f6768e70473941f8d86d8c224faf6955a75799"
+"checksum error-chain 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "318cb3c71ee4cdea69fdc9e15c173b245ed6063e1709029e8fd32525a881120f"
+"checksum futures 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "4b63a4792d4f8f686defe3b39b92127fea6344de5d38202b2ee5a11bbbf29d6a"
 "checksum gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)" = "120d07f202dcc3f72859422563522b66fe6463a4c513df062874daad05f85f0a"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
-"checksum lazy_static 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6abe0ee2e758cd6bc8a2cd56726359007748fbf4128da998b65d0b70f881e19b"
-"checksum libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)" = "044d1360593a78f5c8e5e710beccdc24ab71d1f01bc19a29bcacdba22e8475d8"
-"checksum log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "ab83497bf8bf4ed2a74259c1c802351fcd67a65baa86394b6ba73c36f4838054"
+"checksum lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "3b37545ab726dd833ec6420aaba8231c5b320814b9029ad585555d2a03e94fbf"
+"checksum libc 0.2.26 (registry+https://github.com/rust-lang/crates.io-index)" = "30885bcb161cf67054244d10d4a7f4835ffd58773bc72e07d35fecf472295503"
+"checksum log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "880f77541efa6e5cc74e76910c9884d9859683118839d6a1dc3b11e63512565b"
 "checksum memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "d8b629fb514376c675b98c1421e80b151d3817ac42d7c667717d282761418d20"
+"checksum num_cpus 1.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "aec53c34f2d0247c5ca5d32cca1478762f301740468ee9ee6dcb7a0dd7a0c584"
 "checksum quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e920b65c65f10b2ae65c831a81a073a89edd28c7cce89475bff467ab4167a"
 "checksum rand 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)" = "022e0636ec2519ddae48154b028864bdce4eaf7d35226ab8e65c611be97b189d"
-"checksum redox_syscall 0.1.26 (registry+https://github.com/rust-lang/crates.io-index)" = "9df6a71a1e67be2104410736b2389fb8e383c1d7e9e792d629ff13c02867147a"
+"checksum rayon 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a77c51c07654ddd93f6cb543c7a849863b03abc7e82591afda6dc8ad4ac3ac4a"
+"checksum rayon-core 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7febc28567082c345f10cddc3612c6ea020fc3297a1977d472cf9fdb73e6e493"
 "checksum regex 0.1.80 (registry+https://github.com/rust-lang/crates.io-index)" = "4fd4ace6a8cf7860714a2c2280d6c1f7e6a413486c13298bbc86fd3da019402f"
 "checksum regex-syntax 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "f9ec002c35e86791825ed294b50008eea9ddfc8def4420124fbc6b08db834957"
-"checksum rust-crypto 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)" = "f76d05d3993fd5f4af9434e8e436db163a12a9d40e1a58a726f27a01dfd12a2a"
-"checksum rustc-demangle 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1430d286cadb237c17c885e25447c982c97113926bb579f4379c0eca8d9586dc"
-"checksum rustc-serialize 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)" = "237546c689f20bb44980270c73c3b9edd0891c1be49cc1274406134a66d3957b"
+"checksum ring 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1f2a6dc7fc06a05e6de183c5b97058582e9da2de0c136eafe49609769c507724"
+"checksum rustc-demangle 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "3058a43ada2c2d0b92b3ae38007a2d0fa5e9db971be260e0171408a4ff471c95"
+"checksum rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)" = "dcf128d1287d2ea9d80910b5f1120d0b8eede3fbf1abe91c40d39ea7d51e6fda"
+"checksum scopeguard 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c79eb2c3ac4bc2507cda80e7f3ac5b88bd8eae4c0914d5663e6a8933994be918"
 "checksum strsim 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "67f84c44fbb2f91db7fef94554e6b2ac05909c9c0b0bc23bb98d3a1aebfe7f7c"
 "checksum syn 0.11.11 (registry+https://github.com/rust-lang/crates.io-index)" = "d3b891b9015c88c576343b9b3e41c2c11a51c219ef067b264bd9c8aa9b441dad"
 "checksum synom 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a393066ed9010ebaed60b9eafa373d4b1baac186dd7e008555b0f702b51945b6"
 "checksum thread-id 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a9539db560102d1cef46b8b78ce737ff0bb64e7e18d35b2a5688f7d097d0ff03"
 "checksum thread_local 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "8576dbbfcaef9641452d5cf0df9b0e7eeab7694956dd33bb61515fb8f18cfdd5"
-"checksum time 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)" = "d5d788d3aa77bc0ef3e9621256885555368b47bd495c13dd2e7413c89f845520"
 "checksum unicode-xid 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f860d7d29cf02cb2f3f359fd35991af3d30bac52c57d265a3c461074cb4dc"
+"checksum untrusted 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6b65243989ef6aacd9c0d6bd2b822765c3361d8ed352185a6f3a41f3a718c673"
 "checksum utf8-ranges 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a1ca13c08c41c9c3e04224ed9ff80461d97e121589ff27c753a16cb10830ae0f"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
diff --git a/sim/Cargo.toml b/sim/Cargo.toml
index 2e9af87..1d294c0 100644
--- a/sim/Cargo.toml
+++ b/sim/Cargo.toml
@@ -17,7 +17,7 @@
 simflash = { path = "simflash" }
 enumflags = "0.1"
 enumflags_derive = "0.2"
-rust-crypto = "0.2"
+ring = "0.11"
 
 [profile.test]
 opt-level = 1
diff --git a/sim/src/main.rs b/sim/src/main.rs
index aa7c75d..614def3 100644
--- a/sim/src/main.rs
+++ b/sim/src/main.rs
@@ -1,5 +1,5 @@
 #[macro_use] extern crate log;
-extern crate crypto;
+extern crate ring;
 extern crate env_logger;
 extern crate enumflags;
 #[macro_use] extern crate enumflags_derive;
diff --git a/sim/src/tlv.rs b/sim/src/tlv.rs
index 071af0c..2df43cc 100644
--- a/sim/src/tlv.rs
+++ b/sim/src/tlv.rs
@@ -8,8 +8,7 @@
 //! Because of this header, we have to make two passes.  The first pass will compute the size of
 //! the TLV, and the second pass will build the data for the TLV.
 
-use crypto::digest::Digest;
-use crypto::sha2::Sha256;
+use ring::digest;
 
 #[derive(EnumFlags, Copy, Clone, Debug)]
 #[repr(u32)]
@@ -38,7 +37,7 @@
     flags: Flags,
     kinds: Vec<TlvKinds>,
     size: u16,
-    hasher: Sha256,
+    hasher: digest::Context,
 }
 
 impl TlvGen {
@@ -48,7 +47,7 @@
             flags: Flags::SHA256,
             kinds: vec![TlvKinds::SHA256],
             size: 4 + 32,
-            hasher: Sha256::new(),
+            hasher: digest::Context::new(&digest::SHA256),
         }
     }
 
@@ -64,26 +63,23 @@
 
     /// Add bytes to the covered hash.
     pub fn add_bytes(&mut self, bytes: &[u8]) {
-        self.hasher.input(bytes);
+        self.hasher.update(bytes);
     }
 
     /// Compute the TLV given the specified block of data.
-    pub fn make_tlv(mut self) -> Vec<u8> {
+    pub fn make_tlv(self) -> Vec<u8> {
         let mut result: Vec<u8> = vec![];
 
         if self.kinds.contains(&TlvKinds::SHA256) {
-            let hash_size = self.hasher.output_bytes();
-            assert!(hash_size == 32); // Assumption made.
+            let hash = self.hasher.finish();
+            let hash = hash.as_ref();
 
-            let mut hash = vec![0; hash_size];
-
-            self.hasher.result(&mut hash);
-
+            assert!(hash.len() == 32);
             result.push(TlvKinds::SHA256 as u8);
             result.push(0);
             result.push(32);
             result.push(0);
-            result.append(&mut hash);
+            result.extend_from_slice(hash);
         }
 
         result