diff --git a/fastboot/engine.cpp b/fastboot/engine.cpp
index d80bc06..a43e7a6 100644
--- a/fastboot/engine.cpp
+++ b/fastboot/engine.cpp
@@ -136,69 +136,6 @@
     RUN_COMMAND(fb->RawCommand(FB_CMD_RESIZE_PARTITION ":" + partition + ":" + size));
 }
 
-static int match(const char* str, const char** value, unsigned count) {
-    unsigned n;
-
-    for (n = 0; n < count; n++) {
-        const char *val = value[n];
-        int len = strlen(val);
-        int match;
-
-        if ((len > 1) && (val[len-1] == '*')) {
-            len--;
-            match = !strncmp(val, str, len);
-        } else {
-            match = !strcmp(val, str);
-        }
-
-        if (match) return 1;
-    }
-
-    return 0;
-}
-
-void fb_require(const std::string& product, const std::string& var, bool invert, size_t count,
-                const char** values) {
-    Status("Checking '" + var + "'");
-
-    double start = now();
-
-    std::string var_value;
-    auto status = fb->GetVar(var, &var_value);
-
-    if (status) {
-        fprintf(stderr, "getvar:%s FAILED (%s)\n", var.c_str(), fb->Error().c_str());
-        die("requirements not met!");
-    }
-
-    if (!product.empty()) {
-        if (product != cur_product) {
-            double split = now();
-            fprintf(stderr, "IGNORE, product is %s required only for %s [%7.3fs]\n", cur_product,
-                    product.c_str(), (split - start));
-            return;
-        }
-    }
-
-    int yes = match(var_value.c_str(), values, count);
-    if (invert) yes = !yes;
-
-    if (yes) {
-        double split = now();
-        fprintf(stderr, "OKAY [%7.3fs]\n", (split - start));
-        return;
-    }
-
-    fprintf(stderr, "FAILED\n\n");
-    fprintf(stderr, "Device %s is '%s'.\n", var.c_str(), var_value.c_str());
-    fprintf(stderr, "Update %s '%s'", invert ? "rejects" : "requires", values[0]);
-    for (size_t n = 1; n < count; n++) {
-        fprintf(stderr, " or '%s'", values[n]);
-    }
-    fprintf(stderr, ".\n\n");
-    die("requirements not met!");
-}
-
 void fb_display(const std::string& label, const std::string& var) {
     std::string value;
     auto status = fb->GetVar(var, &value);
@@ -210,18 +147,6 @@
     fprintf(stderr, "%s: %s\n", label.c_str(), value.c_str());
 }
 
-void fb_query_save(const std::string& var, char* dest, uint32_t dest_size) {
-    std::string value;
-    auto status = fb->GetVar(var, &value);
-
-    if (status) {
-        fprintf(stderr, "getvar:%s FAILED (%s)\n", var.c_str(), fb->Error().c_str());
-        return;
-    }
-
-    strncpy(dest, value.c_str(), dest_size);
-}
-
 void fb_reboot() {
     fprintf(stderr, "Rebooting");
     fb->Reboot();
diff --git a/fastboot/engine.h b/fastboot/engine.h
index 6b0bdca..b681f5a 100644
--- a/fastboot/engine.h
+++ b/fastboot/engine.h
@@ -53,10 +53,7 @@
 void fb_flash_sparse(const std::string& partition, struct sparse_file* s, uint32_t sz,
                      size_t current, size_t total);
 void fb_erase(const std::string& partition);
-void fb_require(const std::string& prod, const std::string& var, bool invert, size_t nvalues,
-                const char** values);
 void fb_display(const std::string& label, const std::string& var);
-void fb_query_save(const std::string& var, char* dest, uint32_t dest_size);
 void fb_reboot();
 void fb_command(const std::string& cmd, const std::string& msg);
 void fb_download(const std::string& name, const std::vector<char>& data);
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index fd7b233..5173bab 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -43,6 +43,7 @@
 
 #include <chrono>
 #include <functional>
+#include <regex>
 #include <thread>
 #include <utility>
 #include <vector>
@@ -70,14 +71,14 @@
 #include "usb.h"
 
 using android::base::ReadFully;
+using android::base::Split;
+using android::base::Trim;
 using android::base::unique_fd;
 
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
 
-char cur_product[FB_RESPONSE_SZ + 1];
-
 static const char* serial = nullptr;
 
 static bool g_long_listing = false;
@@ -588,109 +589,145 @@
     return fd.release();
 }
 
-static char* strip(char* s) {
-    while (*s && isspace(*s)) s++;
+static void CheckRequirement(const std::string& cur_product, const std::string& var,
+                             const std::string& product, bool invert,
+                             const std::vector<std::string>& options) {
+    Status("Checking '" + var + "'");
 
-    int n = strlen(s);
-    while (n-- > 0) {
-        if (!isspace(s[n])) break;
-        s[n] = 0;
+    double start = now();
+
+    if (!product.empty()) {
+        if (product != cur_product) {
+            double split = now();
+            fprintf(stderr, "IGNORE, product is %s required only for %s [%7.3fs]\n",
+                    cur_product.c_str(), product.c_str(), (split - start));
+            return;
+        }
     }
-    return s;
+
+    std::string var_value;
+    if (!fb_getvar(var, &var_value)) {
+        fprintf(stderr, "FAILED\n\n");
+        fprintf(stderr, "Could not getvar for '%s' (%s)\n\n", var.c_str(), fb_get_error().c_str());
+        die("requirements not met!");
+    }
+
+    bool match = false;
+    for (const auto& option : options) {
+        if (option == var_value || (option.back() == '*' &&
+                                    !var_value.compare(0, option.length() - 1, option, 0,
+                                                       option.length() - 1))) {
+            match = true;
+            break;
+        }
+    }
+
+    if (invert) {
+        match = !match;
+    }
+
+    if (match) {
+        double split = now();
+        fprintf(stderr, "OKAY [%7.3fs]\n", (split - start));
+        return;
+    }
+
+    fprintf(stderr, "FAILED\n\n");
+    fprintf(stderr, "Device %s is '%s'.\n", var.c_str(), var_value.c_str());
+    fprintf(stderr, "Update %s '%s'", invert ? "rejects" : "requires", options[0].c_str());
+    for (auto it = std::next(options.begin()); it != options.end(); ++it) {
+        fprintf(stderr, " or '%s'", it->c_str());
+    }
+    fprintf(stderr, ".\n\n");
+    die("requirements not met!");
 }
 
-#define MAX_OPTIONS 32
-static void check_requirement(char* line) {
-    char *val[MAX_OPTIONS];
-    unsigned count;
-    char *x;
-    int invert = 0;
-
+bool ParseRequirementLine(const std::string& line, std::string* name, std::string* product,
+                          bool* invert, std::vector<std::string>* options) {
     // "require product=alpha|beta|gamma"
     // "require version-bootloader=1234"
     // "require-for-product:gamma version-bootloader=istanbul|constantinople"
     // "require partition-exists=vendor"
+    *product = "";
+    *invert = false;
 
-    char* name = line;
-    const char* product = "";
-    if (!strncmp(name, "reject ", 7)) {
-        name += 7;
-        invert = 1;
-    } else if (!strncmp(name, "require ", 8)) {
-        name += 8;
-        invert = 0;
-    } else if (!strncmp(name, "require-for-product:", 20)) {
-        // Get the product and point name past it
-        product = name + 20;
-        name = strchr(name, ' ');
-        if (!name) die("android-info.txt syntax error: %s", line);
-        *name = 0;
-        name += 1;
-        invert = 0;
+    auto require_reject_regex = std::regex{"(require\\s+|reject\\s+)?\\s*(\\S+)\\s*=\\s*(.*)"};
+    auto require_product_regex =
+            std::regex{"require-for-product:\\s*(\\S+)\\s+(\\S+)\\s*=\\s*(.*)"};
+    std::smatch match_results;
+
+    if (std::regex_match(line, match_results, require_reject_regex)) {
+        *invert = Trim(match_results[1]) == "reject";
+    } else if (std::regex_match(line, match_results, require_product_regex)) {
+        *product = match_results[1];
+    } else {
+        return false;
     }
 
-    x = strchr(name, '=');
-    if (x == 0) return;
-    *x = 0;
-    val[0] = x + 1;
-
-    name = strip(name);
-
-    // "require partition-exists=x" is a special case, added because of the trouble we had when
-    // Pixel 2 shipped with new partitions and users used old versions of fastboot to flash them,
-    // missing out new partitions. A device with new partitions can use "partition-exists" to
-    // override the fields `optional_if_no_image` in the `images` array.
-    if (!strcmp(name, "partition-exists")) {
-        const char* partition_name = val[0];
-        std::string has_slot;
-        if (!fb_getvar(std::string("has-slot:") + partition_name, &has_slot) ||
-            (has_slot != "yes" && has_slot != "no")) {
-            die("device doesn't have required partition %s!", partition_name);
-        }
-        bool known_partition = false;
-        for (size_t i = 0; i < arraysize(images); ++i) {
-            if (images[i].nickname && !strcmp(images[i].nickname, partition_name)) {
-                images[i].optional_if_no_image = false;
-                known_partition = true;
-            }
-        }
-        if (!known_partition) {
-            die("device requires partition %s which is not known to this version of fastboot",
-                partition_name);
-        }
-        return;
-    }
-
-    for(count = 1; count < MAX_OPTIONS; count++) {
-        x = strchr(val[count - 1],'|');
-        if (x == 0) break;
-        *x = 0;
-        val[count] = x + 1;
-    }
-
+    *name = match_results[2];
     // Work around an unfortunate name mismatch.
-    const char* var = name;
-    if (!strcmp(name, "board")) var = "product";
-
-    const char** out = reinterpret_cast<const char**>(malloc(sizeof(char*) * count));
-    if (out == nullptr) die("out of memory");
-
-    for (size_t i = 0; i < count; ++i) {
-        out[i] = xstrdup(strip(val[i]));
+    if (*name == "board") {
+        *name = "product";
     }
 
-    fb_require(product, var, invert, count, out);
+    auto raw_options = Split(match_results[3], "|");
+    for (const auto& option : raw_options) {
+        auto trimmed_option = Trim(option);
+        options->emplace_back(trimmed_option);
+    }
+
+    return true;
 }
 
-static void check_requirements(char* data, int64_t sz) {
-    char* s = data;
-    while (sz-- > 0) {
-        if (*s == '\n') {
-            *s++ = 0;
-            check_requirement(data);
-            data = s;
+// "require partition-exists=x" is a special case, added because of the trouble we had when
+// Pixel 2 shipped with new partitions and users used old versions of fastboot to flash them,
+// missing out new partitions. A device with new partitions can use "partition-exists" to
+// override the fields `optional_if_no_image` in the `images` array.
+static void HandlePartitionExists(const std::vector<std::string>& options) {
+    const std::string& partition_name = options[0];
+    std::string has_slot;
+    if (!fb_getvar("has-slot:" + partition_name, &has_slot) ||
+        (has_slot != "yes" && has_slot != "no")) {
+        die("device doesn't have required partition %s!", partition_name.c_str());
+    }
+    bool known_partition = false;
+    for (size_t i = 0; i < arraysize(images); ++i) {
+        if (images[i].nickname && images[i].nickname == partition_name) {
+            images[i].optional_if_no_image = false;
+            known_partition = true;
+        }
+    }
+    if (!known_partition) {
+        die("device requires partition %s which is not known to this version of fastboot",
+            partition_name.c_str());
+    }
+}
+
+static void CheckRequirements(const std::string& data) {
+    std::string cur_product;
+    if (!fb_getvar("product", &cur_product)) {
+        fprintf(stderr, "getvar:product FAILED (%s)\n", fb_get_error().c_str());
+    }
+
+    auto lines = Split(data, "\n");
+    for (const auto& line : lines) {
+        if (line.empty()) {
+            continue;
+        }
+
+        std::string name;
+        std::string product;
+        bool invert;
+        std::vector<std::string> options;
+
+        if (!ParseRequirementLine(line, &name, &product, &invert, &options)) {
+            fprintf(stderr, "android-info.txt syntax error: %s\n", line.c_str());
+            continue;
+        }
+        if (name == "partition-exists") {
+            HandlePartitionExists(options);
         } else {
-            s++;
+            CheckRequirement(cur_product, name, product, invert, options);
         }
     }
 }
@@ -1156,7 +1193,7 @@
     if (!source_.ReadFile("android-info.txt", &contents)) {
         die("could not read android-info.txt");
     }
-    check_requirements(reinterpret_cast<char*>(contents.data()), contents.size());
+    ::CheckRequirements({contents.data(), contents.size()});
 }
 
 void FlashAllTool::DetermineSecondarySlot() {
@@ -1265,8 +1302,6 @@
 static void do_update(const char* filename, const std::string& slot_override, bool skip_secondary) {
     dump_info();
 
-    fb_query_save("product", cur_product, sizeof(cur_product));
-
     ZipArchiveHandle zip;
     int error = OpenArchive(filename, &zip);
     if (error != 0) {
@@ -1302,8 +1337,6 @@
     std::string fname;
     dump_info();
 
-    fb_query_save("product", cur_product, sizeof(cur_product));
-
     FlashAllTool tool(LocalImageSource(), slot_override, skip_secondary, wipe);
     tool.Flash();
 }
diff --git a/fastboot/fastboot_driver.cpp b/fastboot/fastboot_driver.cpp
index 97857d9..72ba619 100644
--- a/fastboot/fastboot_driver.cpp
+++ b/fastboot/fastboot_driver.cpp
@@ -147,28 +147,6 @@
     return SUCCESS;
 }
 
-RetCode FastBootDriver::Require(const std::string& var, const std::vector<std::string>& allowed,
-                                bool* reqmet, bool invert) {
-    *reqmet = invert;
-    RetCode ret;
-    std::string response;
-    if ((ret = GetVar(var, &response))) {
-        return ret;
-    }
-
-    // Now check if we have a match
-    for (const auto s : allowed) {
-        // If it ends in *, and starting substring match
-        if (response == s || (s.length() && s.back() == '*' &&
-                              !response.compare(0, s.length() - 1, s, 0, s.length() - 1))) {
-            *reqmet = !invert;
-            break;
-        }
-    }
-
-    return SUCCESS;
-}
-
 RetCode FastBootDriver::Download(int fd, size_t size, std::string* response,
                                  std::vector<std::string>* info) {
     RetCode ret;
diff --git a/fastboot/fastboot_test.cpp b/fastboot/fastboot_test.cpp
index 43201fa..e0bbd56 100644
--- a/fastboot/fastboot_test.cpp
+++ b/fastboot/fastboot_test.cpp
@@ -59,3 +59,145 @@
     EXPECT_DEATH(fb.ParseOsVersion(&hdr, "1.128.3"), "bad OS version");
     EXPECT_DEATH(fb.ParseOsVersion(&hdr, "1.2.128"), "bad OS version");
 }
+
+extern bool ParseRequirementLine(const std::string& line, std::string* name, std::string* product,
+                                 bool* invert, std::vector<std::string>* options);
+
+static void ParseRequirementLineTest(const std::string& line, const std::string& expected_name,
+                                     const std::string& expected_product, bool expected_invert,
+                                     const std::vector<std::string>& expected_options) {
+    std::string name;
+    std::string product;
+    bool invert;
+    std::vector<std::string> options;
+
+    EXPECT_TRUE(ParseRequirementLine(line, &name, &product, &invert, &options)) << line;
+
+    EXPECT_EQ(expected_name, name) << line;
+    EXPECT_EQ(expected_product, product) << line;
+    EXPECT_EQ(expected_invert, invert) << line;
+    EXPECT_EQ(expected_options, options) << line;
+}
+
+TEST(FastBoot, ParseRequirementLineSuccesses) {
+    // Examples provided in the code + slight variations.
+    ParseRequirementLineTest("require product=alpha", "product", "", false, {"alpha"});
+    ParseRequirementLineTest("require product=alpha|beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require version-bootloader=1234", "version-bootloader", "", false,
+                             {"1234"});
+    ParseRequirementLineTest("require-for-product:gamma version-bootloader=istanbul",
+                             "version-bootloader", "gamma", false, {"istanbul"});
+    ParseRequirementLineTest("require-for-product:gamma version-bootloader=istanbul|constantinople",
+                             "version-bootloader", "gamma", false, {"istanbul", "constantinople"});
+    ParseRequirementLineTest("require partition-exists=vendor", "partition-exists", "", false,
+                             {"vendor"});
+    ParseRequirementLineTest("reject product=alpha", "product", "", true, {"alpha"});
+    ParseRequirementLineTest("reject product=alpha|beta|gamma", "product", "", true,
+                             {"alpha", "beta", "gamma"});
+
+    // Without any prefix, assume 'require'
+    ParseRequirementLineTest("product=alpha|beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    // Including if the variable name is otherwise a prefix keyword
+    ParseRequirementLineTest("require = alpha", "require", "", false, {"alpha"});
+    ParseRequirementLineTest("reject = alpha", "reject", "", false, {"alpha"});
+    ParseRequirementLineTest("require-for-product:gamma = alpha", "require-for-product:gamma", "",
+                             false, {"alpha"});
+
+    // Extra spaces are allowed.
+    ParseRequirementLineTest("require    product=alpha|beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product    =alpha|beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product=   alpha|beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product   =   alpha|beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product=alpha  |beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product=alpha|  beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product=alpha  |  beta|gamma", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require product=alpha|beta|gamma   ", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("product  =  alpha  |  beta  |  gamma   ", "product", "", false,
+                             {"alpha", "beta", "gamma"});
+    ParseRequirementLineTest("require-for-product:  gamma version-bootloader=istanbul",
+                             "version-bootloader", "gamma", false, {"istanbul"});
+
+    // Extraneous ending | is okay, implies accepting an empty string.
+    ParseRequirementLineTest("require product=alpha|", "product", "", false, {"alpha", ""});
+    ParseRequirementLineTest("require product=alpha|beta|gamma|", "product", "", false,
+                             {"alpha", "beta", "gamma", ""});
+
+    // Accept empty options, double ||, etc, implies accepting an empty string.
+    ParseRequirementLineTest("require product=alpha||beta|   |gamma", "product", "", false,
+                             {"alpha", "", "beta", "", "gamma"});
+    ParseRequirementLineTest("require product=alpha||beta|gamma", "product", "", false,
+                             {"alpha", "", "beta", "gamma"});
+    ParseRequirementLineTest("require product=alpha|beta|   |gamma", "product", "", false,
+                             {"alpha", "beta", "", "gamma"});
+    ParseRequirementLineTest("require product=alpha||", "product", "", false, {"alpha", "", ""});
+    ParseRequirementLineTest("require product=alpha|| ", "product", "", false, {"alpha", "", ""});
+    ParseRequirementLineTest("require product=alpha| ", "product", "", false, {"alpha", ""});
+    ParseRequirementLineTest("require product=alpha|beta| ", "product", "", false,
+                             {"alpha", "beta", ""});
+
+    // No option string is also treating as accepting an empty string.
+    ParseRequirementLineTest("require =", "require", "", false, {""});
+    ParseRequirementLineTest("require = |", "require", "", false, {"", ""});
+    ParseRequirementLineTest("reject =", "reject", "", false, {""});
+    ParseRequirementLineTest("reject = |", "reject", "", false, {"", ""});
+    ParseRequirementLineTest("require-for-product: =", "require-for-product:", "", false, {""});
+    ParseRequirementLineTest("require-for-product: = | ", "require-for-product:", "", false,
+                             {"", ""});
+    ParseRequirementLineTest("require product=", "product", "", false, {""});
+    ParseRequirementLineTest("require product = ", "product", "", false, {""});
+    ParseRequirementLineTest("require product = | ", "product", "", false, {"", ""});
+    ParseRequirementLineTest("reject product=", "product", "", true, {""});
+    ParseRequirementLineTest("reject product = ", "product", "", true, {""});
+    ParseRequirementLineTest("reject product = | ", "product", "", true, {"", ""});
+    ParseRequirementLineTest("require-for-product:gamma product=", "product", "gamma", false, {""});
+    ParseRequirementLineTest("require-for-product:gamma product = ", "product", "gamma", false,
+                             {""});
+    ParseRequirementLineTest("require-for-product:gamma product = |", "product", "gamma", false,
+                             {"", ""});
+
+    // Check for board -> product substitution.
+    ParseRequirementLineTest("require board=alpha", "product", "", false, {"alpha"});
+    ParseRequirementLineTest("board=alpha", "product", "", false, {"alpha"});
+}
+
+static void ParseRequirementLineTestMalformed(const std::string& line) {
+    std::string name;
+    std::string product;
+    bool invert;
+    std::vector<std::string> options;
+
+    EXPECT_FALSE(ParseRequirementLine(line, &name, &product, &invert, &options)) << line;
+}
+
+TEST(FastBoot, ParseRequirementLineMalformed) {
+    ParseRequirementLineTestMalformed("nothing");
+    ParseRequirementLineTestMalformed("");
+    ParseRequirementLineTestMalformed("=");
+    ParseRequirementLineTestMalformed("|");
+
+    ParseRequirementLineTestMalformed("require");
+    ParseRequirementLineTestMalformed("require ");
+    ParseRequirementLineTestMalformed("reject");
+    ParseRequirementLineTestMalformed("reject ");
+    ParseRequirementLineTestMalformed("require-for-product:");
+    ParseRequirementLineTestMalformed("require-for-product: ");
+
+    ParseRequirementLineTestMalformed("require product");
+    ParseRequirementLineTestMalformed("reject product");
+
+    ParseRequirementLineTestMalformed("require-for-product:gamma");
+    ParseRequirementLineTestMalformed("require-for-product:gamma product");
+
+    // No spaces allowed before between require-for-product and :.
+    ParseRequirementLineTestMalformed("require-for-product :");
+}
diff --git a/fastboot/util.cpp b/fastboot/util.cpp
index 125182d..7d15047 100644
--- a/fastboot/util.cpp
+++ b/fastboot/util.cpp
@@ -74,9 +74,3 @@
     static constexpr char kStatusFormat[] = "%-50s ";
     fprintf(stderr, kStatusFormat, message.c_str());
 }
-
-char* xstrdup(const char* s) {
-    char* result = strdup(s);
-    if (!result) die("out of memory");
-    return result;
-}
diff --git a/fastboot/util.h b/fastboot/util.h
index 20be461..533d2c7 100644
--- a/fastboot/util.h
+++ b/fastboot/util.h
@@ -9,7 +9,6 @@
 
 /* util stuff */
 double now();
-char* xstrdup(const char*);
 void set_verbose();
 
 void Status(const std::string& message);